diff --git a/mk/source.mk b/mk/source.mk
index 8d9a0186b2..7f6ecb3643 100644
--- a/mk/source.mk
+++ b/mk/source.mk
@@ -109,9 +109,11 @@ COMMON_SRC = \
             drivers/pin_pull_up_down.c \
             drivers/resource.c \
             drivers/serial.c \
+            drivers/serial_impl.c \
             drivers/serial_pinconfig.c \
             drivers/serial_uart.c \
             drivers/serial_uart_pinconfig.c \
+            drivers/serial_uart_hw.c \
             drivers/sound_beeper.c \
             drivers/stack_check.c \
             drivers/system.c \
@@ -128,6 +130,7 @@ COMMON_SRC = \
             io/beeper.c \
             io/piniobox.c \
             io/serial.c \
+            io/serial_resource.c \
             io/smartaudio_protocol.c \
             io/statusindicator.c \
             io/tramp_protocol.c \
diff --git a/src/main/cli/cli.c b/src/main/cli/cli.c
index 2f23d9ea3f..96951fff95 100644
--- a/src/main/cli/cli.c
+++ b/src/main/cli/cli.c
@@ -328,9 +328,10 @@ typedef enum {
 } rebootTarget_e;
 
 typedef struct serialPassthroughPort_s {
-    int id;
+    serialPortIdentifier_e id;
     uint32_t baud;
-    unsigned mode;
+    portMode_e mode;
+    portOptions_e options;
     serialPort_t *port;
 } serialPassthroughPort_t;
 
@@ -993,7 +994,7 @@ static void cliShowParseError(const char *cmdName)
 
 static void cliShowInvalidArgumentCountError(const char *cmdName)
 {
-    cliPrintErrorLinef(cmdName, "INVALID ARGUMENT COUNT", cmdName);
+    cliPrintErrorLinef(cmdName, "INVALID ARGUMENT COUNT");
 }
 
 static void cliShowArgumentRangeError(const char *cmdName, char *name, int min, int max)
@@ -1278,7 +1279,7 @@ static void printSerial(dumpFlags_t dumpMask, const serialConfig_t *serialConfig
 {
     const char *format = "serial %d %d %ld %ld %ld %ld";
     headingStr = cliPrintSectionHeading(dumpMask, false, headingStr);
-    for (uint32_t i = 0; i < SERIAL_PORT_COUNT; i++) {
+    for (unsigned i = 0; i < ARRAYLEN(serialConfig->portConfigs); i++) {
         if (!serialIsPortAvailable(serialConfig->portConfigs[i].identifier)) {
             continue;
         };
@@ -1398,24 +1399,24 @@ static void cliSerial(const char *cmdName, char *cmdline)
 }
 
 #if defined(USE_SERIAL_PASSTHROUGH)
-static void cbCtrlLine(void *context, uint16_t ctrl)
+static void cbCtrlLine_reset(void *context, uint16_t ctrl)
 {
-#ifdef USE_PINIO
-    int contextValue = (int)(long)context;
-    if (contextValue) {
-        pinioSet(contextValue - 1, !(ctrl & CTRL_LINE_STATE_DTR));
-    } else
-#endif /* USE_PINIO */
     UNUSED(context);
-
     if (!(ctrl & CTRL_LINE_STATE_DTR)) {
         systemReset();
     }
 }
 
-static int cliParseSerialMode(const char *tok)
+#ifdef USE_PINIO
+static void cbCtrlLine_pinIO(void *context, uint16_t ctrl)
 {
-    int mode = 0;
+    pinioSet((intptr_t)context, !(ctrl & CTRL_LINE_STATE_DTR));
+}
+#endif
+
+static portMode_e cliParseSerialMode(const char *tok)
+{
+    portMode_e mode = 0;
 
     if (strcasestr(tok, "rx")) {
         mode |= MODE_RX;
@@ -1427,6 +1428,29 @@ static int cliParseSerialMode(const char *tok)
     return mode;
 }
 
+static portOptions_e cliParseSerialOptions(const char *tok)
+{
+    struct {
+        const char* tag;
+        portOptions_e val;
+    } map[] = {
+        {"Invert", SERIAL_INVERTED},
+        {"Stop2", SERIAL_STOPBITS_2},
+        {"Even", SERIAL_PARITY_EVEN},
+        {"Bidir", SERIAL_BIDIR},
+        {"Pushpull", SERIAL_BIDIR_PP},
+        {"Saudio", SERIAL_PULL_SMARTAUDIO},
+        {"Check", SERIAL_CHECK_TX},
+    };
+    portOptions_e options = 0;
+    for (unsigned i = 0; i < ARRAYLEN(map); i++) {
+        if (strstr(tok, map[i].tag) != 0) {
+            options |= map[i].val;
+        }
+    }
+    return options;
+}
+
 static void cliSerialPassthrough(const char *cmdName, char *cmdline)
 {
     if (isEmpty(cmdline)) {
@@ -1434,64 +1458,90 @@ static void cliSerialPassthrough(const char *cmdName, char *cmdline)
         return;
     }
 
-    serialPassthroughPort_t ports[2] = { {SERIAL_PORT_NONE, 0, 0, NULL}, {cliPort->identifier, 0, 0, cliPort} };
+    serialPassthroughPort_t ports[2] = { {SERIAL_PORT_NONE, 0, 0, 0, NULL}, {cliPort->identifier, 0, 0, 0, cliPort} };
     bool enableBaudCb = false;
-    int port1PinioDtr = 0;
-    bool port1ResetOnDtr = false;
-#ifdef USE_PWM_OUTPUT
-    bool escSensorPassthrough = false;
-#endif
-    char *saveptr;
-    char* tok = strtok_r(cmdline, " ", &saveptr);
-    int index = 0;
-
-    while (tok != NULL) {
-        switch (index) {
-        case 0:
-            if (strcasestr(tok, "esc_sensor")) {
-#ifdef USE_PWM_OUTPUT
-                escSensorPassthrough = true;
-#endif
-                const serialPortConfig_t *portConfig = findSerialPortConfig(FUNCTION_ESC_SENSOR);
-                ports[0].id = portConfig->identifier;
-            } else {
-                ports[0].id = atoi(tok);
-            }
-            break;
-        case 1:
-            ports[0].baud = atoi(tok);
-            break;
-        case 2:
-            ports[0].mode = cliParseSerialMode(tok);
-            break;
-        case 3:
-            if (strncasecmp(tok, "reset", strlen(tok)) == 0) {
-                port1ResetOnDtr = true;
 #ifdef USE_PINIO
-            } else if (strncasecmp(tok, "none", strlen(tok)) == 0) {
-                port1PinioDtr = 0;
+    int port1PinioDtr = -1;          // route port2 USB DTR to pinio
+#endif
+    bool port1ResetOnDtr = false;    // reset board with DTR
+    bool escSensorPassthrough = false;
+
+    char* nexttok = cmdline;
+    char* tok;
+    int index = 0;
+    while ((tok = strsep(&nexttok, " ")) != NULL) {
+        if (*tok == '\0') { // skip adjacent delimiters
+            continue;
+        }
+        unsigned portN = (index < 4) ? 0 : 1;  // port1 / port2
+        switch (index) {
+        case 0: // port1 to open: esc_sensor, portName, port ID port1
+        case 4: // port2 to use (defaults to CLI serial if no more arguments)
+        {
+            serialPortIdentifier_e portId;
+            char* endptr;
+            if (portN == 0 && strcasestr(tok, "esc_sensor") != NULL) {
+                escSensorPassthrough = true;
+                const serialPortConfig_t *portConfig = findSerialPortConfig(FUNCTION_ESC_SENSOR);
+                portId = portConfig ? portConfig->identifier : SERIAL_PORT_NONE;
+            } else if (strcasecmp(tok, "cli") == 0) {
+                portId = cliPort->identifier;
+            } else if ((portId = findSerialPortByName(tok, strcasecmp)) >= 0) {
+                // empty
+            } else if ((portId = strtol(tok, &endptr, 10)) >= 0 && *endptr == '\0') {
+                // empty
             } else {
-                port1PinioDtr = atoi(tok);
-                if (port1PinioDtr < 0 || port1PinioDtr > PINIO_COUNT) {
-                    cliPrintLinef("Invalid PinIO number %d", port1PinioDtr);
-                    return ;
-                }
-#endif /* USE_PINIO */
+                cliPrintLinef("Failed parsing port%d (%s)", portN + 1, tok);
+                return;
             }
-            break;
-        case 4:
-            ports[1].id = atoi(tok);
-            ports[1].port = NULL;
-            break;
-        case 5:
-            ports[1].baud = atoi(tok);
-            break;
-        case 6:
-            ports[1].mode = cliParseSerialMode(tok);
+            if (portN == 1) { // port1 is specified, don't use CLI port
+                ports[portN].port = NULL;
+            }
+            ports[portN].id = portId;
             break;
         }
+        case 1: // baudrate
+        case 5: {
+            int baud = atoi(tok);
+            ports[portN].baud = baud;
+            break;
+        }
+        case 2: // port1 mode (rx/tx/rxtx) + options
+        case 6: // port2 mode + options
+            ports[portN].mode = cliParseSerialMode(tok);
+            ports[portN].options = cliParseSerialOptions(tok);
+            break;
+        case 3: // DTR action
+            if (strcasecmp(tok, "reset") == 0) {
+                port1ResetOnDtr = true;
+                break;
+            }
+            if (strcasecmp(tok, "none") == 0) {
+                break;
+            }
+#ifdef USE_PINIO
+            port1PinioDtr = atoi(tok);
+            if (port1PinioDtr < 0 || port1PinioDtr >= PINIO_COUNT) {
+                cliPrintLinef("Invalid PinIO number %d", port1PinioDtr);
+                return;
+            }
+#endif /* USE_PINIO */
+            break;
+        default:
+            cliPrintLinef("Unexpected argument %d (%s)", index + 1, tok);
+            return;
+        }
         index++;
-        tok = strtok_r(NULL, " ", &saveptr);
+    }
+
+
+    for (unsigned i = 0; i < ARRAYLEN(ports); i++) {
+        if (findSerialPortIndexByIdentifier(ports[i].id) < 0) {
+            cliPrintLinef("Invalid port%d %d", i + 1, ports[i].id);
+            return;
+        } else {
+            cliPrintLinef("Port%d: %s", i + 1, serialName(ports[i].id, "<invalid>"));
+        }
     }
 
     // Port checks
@@ -1500,74 +1550,70 @@ static void cliSerialPassthrough(const char *cmdName, char *cmdline)
         return ;
     }
 
-    for (int i = 0; i < 2; i++) {
-        if (findSerialPortIndexByIdentifier(ports[i].id) == -1) {
-            cliPrintLinef("Invalid port%d %d", i + 1, ports[i].id);
-            return ;
-        } else {
-            cliPrintLinef("Port%d: %d ", i + 1, ports[i].id);
-        }
-    }
-
     if (ports[0].baud == 0 && ports[1].id == SERIAL_PORT_USB_VCP) {
         enableBaudCb = true;
     }
 
     for (int i = 0; i < 2; i++) {
-        serialPort_t **port = &(ports[i].port);
-        if (*port != NULL) {
+        serialPassthroughPort_t* cfg = &ports[i];
+        if (cfg->port != NULL) {  // port already selected, don't touch it (used when port2 defaults to cli)
             continue;
         }
 
         int portIndex = i + 1;
-        serialPortUsage_t *portUsage = findSerialPortUsageByIdentifier(ports[i].id);
+        serialPortUsage_t *portUsage = findSerialPortUsageByIdentifier(cfg->id);
         if (!portUsage || portUsage->serialPort == NULL) {
-            bool isUseDefaultBaud = false;
-            if (ports[i].baud == 0) {
+            // serial port is not open yet
+            const bool isUseDefaultBaud = cfg->baud == 0;
+            if (isUseDefaultBaud) {
                 // Set default baud
-                ports[i].baud = 57600;
-                isUseDefaultBaud = true;
+                cfg->baud = 57600;
             }
 
-            if (!ports[i].mode) {
-                ports[i].mode = MODE_RXTX;
+            if (!cfg->mode) {
+                cliPrintLinef("Using RXTX mode as default");
+                cfg->mode = MODE_RXTX;
             }
 
-            *port = openSerialPort(ports[i].id, FUNCTION_NONE, NULL, NULL,
-                                            ports[i].baud, ports[i].mode,
-                                            SERIAL_NOT_INVERTED);
-            if (!*port) {
+            if (cfg->options) {
+                cliPrintLinef("Port%d: using options 0x%x",
+                              portIndex, cfg->options);
+            }
+            cfg->port = openSerialPort(cfg->id, FUNCTION_NONE,
+                                       NULL, NULL,   // rxCallback
+                                       cfg->baud, cfg->mode, cfg->options);
+            if (!cfg->port) {
                 cliPrintLinef("Port%d could not be opened.", portIndex);
                 return;
             }
 
-            if (isUseDefaultBaud) {
-                cliPrintf("Port%d opened, default baud = %d.\r\n", portIndex, ports[i].baud);
-            } else {
-                cliPrintf("Port%d opened, baud = %d.\r\n", portIndex, ports[i].baud);
-            }
+            cliPrintf("Port%d opened, %sbaud = %d.\r\n", portIndex, isUseDefaultBaud ? "default ":"", cfg->baud);
         } else {
-            *port = portUsage->serialPort;
+            cfg->port = portUsage->serialPort;
             // If the user supplied a mode, override the port's mode, otherwise
             // leave the mode unchanged. serialPassthrough() handles one-way ports.
             // Set the baud rate if specified
-            if (ports[i].baud) {
-                cliPrintf("Port%d is already open, setting baud = %d.\r\n", portIndex, ports[i].baud);
-                serialSetBaudRate(*port, ports[i].baud);
-            } else {
-                cliPrintf("Port%d is already open, baud = %d.\r\n", portIndex, (*port)->baudRate);
+            if (cfg->baud) {
+                serialSetBaudRate(cfg->port, cfg->baud);
+            }
+            cliPrintLinef("Port%d is already open, %sbaud = %d.", portIndex, cfg->baud ? "new " : "", cfg->port->baudRate);
+
+            if (cfg->mode && cfg->port->mode != cfg->mode) {
+                cliPrintLinef("Port%d mode changed from %d to %d.",
+                          portIndex, cfg->port->mode, cfg->mode);
+                serialSetMode(cfg->port, cfg->mode);
             }
 
-            if (ports[i].mode && (*port)->mode != ports[i].mode) {
-                cliPrintf("Port%d mode changed from %d to %d.\r\n",
-                    portIndex, (*port)->mode, ports[i].mode);
-                serialSetMode(*port, ports[i].mode);
+            if (cfg->options) {
+                cliPrintLinef("Port%d is open, can't change options from 0x%x to 0x%x",
+                              portIndex, cfg->port->options, cfg->options);
             }
 
             // If this port has a rx callback associated we need to remove it now.
             // Otherwise no data will be pushed in the serial port buffer!
-            if ((*port)->rxCallback) {
-                (*port)->rxCallback = NULL;
+            if (cfg->port->rxCallback) {
+                cliPrintLinef("Port%d: Callback removed", portIndex);
+                cfg->port->rxCallback = NULL;
             }
         }
     }
@@ -1580,20 +1626,26 @@ static void cliSerialPassthrough(const char *cmdName, char *cmdline)
         serialSetBaudRateCb(ports[1].port, serialSetBaudRate, ports[0].port);
     }
 
-    char *resetMessage = "";
+    const char *resetMessage = "";
     if (port1ResetOnDtr && ports[1].id == SERIAL_PORT_USB_VCP) {
         resetMessage = "or drop DTR ";
     }
 
     cliPrintLinef("Forwarding, power cycle %sto exit.", resetMessage);
 
-    if ((ports[1].id == SERIAL_PORT_USB_VCP) && (port1ResetOnDtr
+    if ((ports[1].id == SERIAL_PORT_USB_VCP)) {
+        do {
+            if (port1ResetOnDtr) {
+                serialSetCtrlLineStateCb(ports[1].port, cbCtrlLine_reset, NULL);
+                break;
+            }
 #ifdef USE_PINIO
-        || port1PinioDtr
+            if (port1PinioDtr >= 0) {
+                serialSetCtrlLineStateCb(ports[1].port, cbCtrlLine_pinIO, (void *)(intptr_t)(port1PinioDtr));
+                break;
+            }
 #endif /* USE_PINIO */
-        )) {
-        // Register control line state callback
-        serialSetCtrlLineStateCb(ports[0].port, cbCtrlLine, (void *)(intptr_t)(port1PinioDtr));
+        } while (0);
     }
 
 // XXX Review ESC pass through under refactored motor handling
@@ -1608,7 +1660,7 @@ static void cliSerialPassthrough(const char *cmdName, char *cmdline)
                 const timerHardware_t *timerHardware = timerGetConfiguredByTag(tag);
                 if (timerHardware) {
                     IO_t io = IOGetByTag(tag);
-                    IOInit(io, OWNER_MOTOR, 0);
+                    IOInit(io, OWNER_MOTOR, i);
                     IOConfigGPIO(io, IOCFG_OUT_PP);
                     if (timerHardware->output & TIMER_OUTPUT_INVERTED) {
                         IOLo(io);
@@ -5022,7 +5074,7 @@ typedef struct {
 
 const cliResourceValue_t resourceTable[] = {
 #if defined(USE_BEEPER)
-    DEFS( OWNER_BEEPER,        PG_BEEPER_DEV_CONFIG, beeperDevConfig_t, ioTag) ,
+    DEFS( OWNER_BEEPER,        PG_BEEPER_DEV_CONFIG, beeperDevConfig_t, ioTag ),
 #endif
     DEFA( OWNER_MOTOR,         PG_MOTOR_CONFIG, motorConfig_t, dev.ioTags[0], MAX_SUPPORTED_MOTORS ),
 #if defined(USE_SERVOS)
@@ -5041,20 +5093,21 @@ const cliResourceValue_t resourceTable[] = {
 #if defined(USE_LED_STRIP)
     DEFS( OWNER_LED_STRIP,     PG_LED_STRIP_CONFIG, ledStripConfig_t, ioTag ),
 #endif
-#ifdef USE_UART
-    DEFA( OWNER_SERIAL_TX,     PG_SERIAL_PIN_CONFIG, serialPinConfig_t, ioTagTx[0], SERIAL_UART_COUNT ),
-    DEFA( OWNER_SERIAL_RX,     PG_SERIAL_PIN_CONFIG, serialPinConfig_t, ioTagRx[0], SERIAL_UART_COUNT ),
+#if defined(USE_UART)
+    DEFA( OWNER_SERIAL_TX,     PG_SERIAL_PIN_CONFIG, serialPinConfig_t, ioTagTx[RESOURCE_UART_OFFSET], RESOURCE_UART_COUNT ),
+    DEFA( OWNER_SERIAL_RX,     PG_SERIAL_PIN_CONFIG, serialPinConfig_t, ioTagRx[RESOURCE_UART_OFFSET], RESOURCE_UART_COUNT ),
 #endif
-#ifdef USE_INVERTER
-    DEFA( OWNER_INVERTER,      PG_SERIAL_PIN_CONFIG, serialPinConfig_t, ioTagInverter[0], SERIAL_PORT_MAX_INDEX ),
+#if defined(USE_INVERTER)
+    DEFA( OWNER_INVERTER,      PG_SERIAL_PIN_CONFIG, serialPinConfig_t, ioTagInverter[RESOURCE_UART_OFFSET], RESOURCE_UART_COUNT ),
+    // LPUART and SOFTSERIAL don't need external inversion
 #endif
 #if defined(USE_SOFTSERIAL)
-    DEFA( OWNER_SOFTSERIAL_TX, PG_SOFTSERIAL_PIN_CONFIG, softSerialPinConfig_t, ioTagTx[0], SOFTSERIAL_COUNT ),
-    DEFA( OWNER_SOFTSERIAL_RX, PG_SOFTSERIAL_PIN_CONFIG, softSerialPinConfig_t, ioTagRx[0], SOFTSERIAL_COUNT ),
+    DEFA( OWNER_SOFTSERIAL_TX, PG_SERIAL_PIN_CONFIG, serialPinConfig_t, ioTagTx[RESOURCE_SOFTSERIAL_OFFSET], RESOURCE_SOFTSERIAL_COUNT ),
+    DEFA( OWNER_SOFTSERIAL_RX, PG_SERIAL_PIN_CONFIG, serialPinConfig_t, ioTagRx[RESOURCE_SOFTSERIAL_OFFSET], RESOURCE_SOFTSERIAL_COUNT ),
 #endif
-#ifdef USE_LPUART1
-    DEFA( OWNER_LPUART_TX,     PG_SERIAL_PIN_CONFIG, serialPinConfig_t, ioTagTx[SERIAL_UART_COUNT], SERIAL_LPUART_COUNT ),
-    DEFA( OWNER_LPUART_RX,     PG_SERIAL_PIN_CONFIG, serialPinConfig_t, ioTagRx[SERIAL_UART_COUNT], SERIAL_LPUART_COUNT ),
+#if defined(USE_LPUART)
+    DEFA( OWNER_LPUART_TX,     PG_SERIAL_PIN_CONFIG, serialPinConfig_t, ioTagTx[RESOURCE_LPUART_OFFSET], RESOURCE_LPUART_COUNT ),
+    DEFA( OWNER_LPUART_RX,     PG_SERIAL_PIN_CONFIG, serialPinConfig_t, ioTagRx[RESOURCE_LPUART_OFFSET], RESOURCE_LPUART_COUNT ),
 #endif
 #ifdef USE_I2C
     DEFW( OWNER_I2C_SCL,       PG_I2C_CONFIG, i2cConfig_t, ioTagScl, I2CDEV_COUNT ),
@@ -5163,10 +5216,10 @@ const cliResourceValue_t resourceTable[] = {
 #undef DEFA
 #undef DEFW
 
-static ioTag_t *getIoTag(const cliResourceValue_t value, uint8_t index)
+static ioTag_t* getIoTag(const cliResourceValue_t value, uint8_t index)
 {
     const pgRegistry_t* rec = pgFind(value.pgn);
-    return CONST_CAST(ioTag_t *, rec->address + value.stride * index + value.offset);
+    return (ioTag_t *)(rec->address + value.stride * index + value.offset);
 }
 
 static void printResource(dumpFlags_t dumpMask, const char *headingStr)
@@ -5321,6 +5374,7 @@ typedef struct dmaoptEntry_s {
 // DEFS : Single entry
 // DEFA : Array of uint8_t (stride = 1)
 // DEFW : Wider stride case; array of structs.
+// DEFW_OFS: array of structs, starting at offset ofs
 
 #define DEFS(device, peripheral, pgn, type, member) \
     { device, peripheral, pgn, 0,               offsetof(type, member), 0, MASK_IGNORED }
@@ -5329,7 +5383,10 @@ typedef struct dmaoptEntry_s {
     { device, peripheral, pgn, sizeof(uint8_t), offsetof(type, member), max, mask }
 
 #define DEFW(device, peripheral, pgn, type, member, max, mask) \
-    { device, peripheral, pgn, sizeof(type), offsetof(type, member), max, mask }
+    DEFW_OFS(device, peripheral, pgn, type, member, 0, max, mask)
+
+#define DEFW_OFS(device, peripheral, pgn, type, member, ofs, max, mask)  \
+    { device, peripheral, pgn, sizeof(type), offsetof(type, member) + (ofs) * sizeof(type), max, mask }
 
 dmaoptEntry_t dmaoptEntryTable[] = {
     DEFW("SPI_SDO", DMA_PERIPH_SPI_SDO, PG_SPI_PIN_CONFIG,     spiPinConfig_t,     txDmaopt, SPIDEV_COUNT,                    MASK_IGNORED),
@@ -5339,8 +5396,14 @@ dmaoptEntry_t dmaoptEntryTable[] = {
     DEFW("SPI_RX",   DMA_PERIPH_SPI_SDI, PG_SPI_PIN_CONFIG,     spiPinConfig_t,     rxDmaopt, SPIDEV_COUNT,                    MASK_IGNORED),
     DEFA("ADC",      DMA_PERIPH_ADC,      PG_ADC_CONFIG,         adcConfig_t,        dmaopt,   ADCDEV_COUNT,                    MASK_IGNORED),
     DEFS("SDIO",     DMA_PERIPH_SDIO,     PG_SDIO_CONFIG,        sdioConfig_t,       dmaopt),
-    DEFW("UART_TX",  DMA_PERIPH_UART_TX,  PG_SERIAL_UART_CONFIG, serialUartConfig_t, txDmaopt, UARTDEV_CONFIG_MAX,              MASK_IGNORED),
-    DEFW("UART_RX",  DMA_PERIPH_UART_RX,  PG_SERIAL_UART_CONFIG, serialUartConfig_t, rxDmaopt, UARTDEV_CONFIG_MAX,              MASK_IGNORED),
+#ifdef USE_UART
+    DEFW_OFS("UART_TX",  DMA_PERIPH_UART_TX,  PG_SERIAL_UART_CONFIG, serialUartConfig_t, txDmaopt, RESOURCE_UART_OFFSET, RESOURCE_UART_COUNT, MASK_IGNORED),
+    DEFW_OFS("UART_RX",  DMA_PERIPH_UART_RX,  PG_SERIAL_UART_CONFIG, serialUartConfig_t, rxDmaopt, RESOURCE_UART_OFFSET, RESOURCE_UART_COUNT, MASK_IGNORED),
+#endif
+#ifdef USE_LPUART
+    DEFW_OFS("LPUART_TX",  DMA_PERIPH_UART_TX,  PG_SERIAL_UART_CONFIG, serialUartConfig_t, txDmaopt, RESOURCE_LPUART_OFFSET, RESOURCE_LPUART_COUNT, MASK_IGNORED),
+    DEFW_OFS("LPUART_RX",  DMA_PERIPH_UART_RX,  PG_SERIAL_UART_CONFIG, serialUartConfig_t, rxDmaopt, RESOURCE_LPUART_OFFSET, RESOURCE_LPUART_COUNT, MASK_IGNORED),
+#endif
 #if defined(STM32H7) || defined(STM32G4)
     DEFW("TIMUP",    DMA_PERIPH_TIMUP,    PG_TIMER_UP_CONFIG,    timerUpConfig_t,    dmaopt,   HARDWARE_TIMER_DEFINITION_COUNT, TIMUP_TIMERS),
 #endif
@@ -6071,7 +6134,7 @@ static void cliResource(const char *cmdName, char *cmdline)
     }
 
     pch = strtok_r(NULL, " ", &saveptr);
-    int index = atoi(pch);
+    int index = pch ? atoi(pch) : 0;
 
     if (resourceTable[resourceIndex].maxIndex > 0 || index > 0) {
         if (index <= 0 || index > RESOURCE_VALUE_MAX_INDEX(resourceTable[resourceIndex].maxIndex)) {
@@ -6083,11 +6146,13 @@ static void cliResource(const char *cmdName, char *cmdline)
         pch = strtok_r(NULL, " ", &saveptr);
     }
 
-    ioTag_t *tag = getIoTag(resourceTable[resourceIndex], index);
+    ioTag_t *resourceTag = getIoTag(resourceTable[resourceIndex], index);
 
-    if (strlen(pch) > 0) {
-        if (strToPin(pch, tag)) {
-            if (*tag == IO_TAG_NONE) {
+    if (pch && strlen(pch) > 0) {
+        ioTag_t tag;
+        if (strToPin(pch, &tag)) {
+            if (!tag) {
+                *resourceTag = tag;
 #ifdef MINIMAL_CLI
                 cliPrintLine("Freed");
 #else
@@ -6095,9 +6160,10 @@ static void cliResource(const char *cmdName, char *cmdline)
 #endif
                 return;
             } else {
-                ioRec_t *rec = IO_Rec(IOGetByTag(*tag));
+                ioRec_t *rec = IO_Rec(IOGetByTag(tag));
                 if (rec) {
-                    resourceCheck(resourceIndex, index, *tag);
+                    *resourceTag = tag;
+                    resourceCheck(resourceIndex, index, tag);
 #ifdef MINIMAL_CLI
                     cliPrintLinef(" %c%02d set", IO_GPIOPortIdx(rec) + 'A', IO_GPIOPinIdx(rec));
 #else
@@ -6106,12 +6172,18 @@ static void cliResource(const char *cmdName, char *cmdline)
                 } else {
                     cliShowParseError(cmdName);
                 }
-                return;
             }
+        } else {
+            cliPrintErrorLinef(cmdName, "Failed to parse '%s' as pin", pch);
         }
+    } else {
+        ioTag_t tag = *resourceTag;
+        char ioName[5];
+        if (tag) {
+            tfp_sprintf(ioName, "%c%02d", IO_GPIOPortIdxByTag(tag) + 'A', IO_GPIOPinIdxByTag(tag));
+        }
+        cliPrintLinef("# resource %s %d %s", ownerNames[resourceTable[resourceIndex].owner], RESOURCE_INDEX(index), tag ? ioName : "NONE");
     }
-
-    cliShowParseError(cmdName);
 }
 #endif
 
diff --git a/src/main/common/printf_serial.c b/src/main/common/printf_serial.c
index 4e29b993ce..6be8bc2044 100644
--- a/src/main/common/printf_serial.c
+++ b/src/main/common/printf_serial.c
@@ -33,7 +33,7 @@
 
 #include "printf_serial.h"
 
-#ifdef SERIAL_PORT_COUNT
+#if SERIAL_PORT_COUNT > 0
 
 static serialPort_t *printfSerialPort;
 
diff --git a/src/main/common/utils.h b/src/main/common/utils.h
index 981f9da986..726640b9f2 100644
--- a/src/main/common/utils.h
+++ b/src/main/common/utils.h
@@ -75,6 +75,11 @@ http://resnet.uoregon.edu/~gurney_j/jmpc/bitwise.html
 #define BITCOUNT(x) (((BX_(x)+(BX_(x)>>4)) & 0x0F0F0F0F) % 255)
 #define BX_(x) ((x) - (((x)>>1)&0x77777777) - (((x)>>2)&0x33333333) - (((x)>>3)&0x11111111))
 
+static inline int popcount(unsigned x) { return __builtin_popcount(x); }
+static inline int popcount32(uint32_t x) { return __builtin_popcount(x); }
+static inline int popcount64(uint64_t x) { return __builtin_popcountll(x); }
+
+
 
 /*
  * https://groups.google.com/forum/?hl=en#!msg/comp.lang.c/attFnqwhvGk/sGBKXvIkY3AJ
diff --git a/src/main/config/config.c b/src/main/config/config.c
index ae2630a94e..240f1e4b7a 100644
--- a/src/main/config/config.c
+++ b/src/main/config/config.c
@@ -416,11 +416,16 @@ static void validateAndFixConfig(void)
     if (systemConfig()->configurationState == CONFIGURATION_STATE_UNCONFIGURED) {
         // enable some compiled-in features by default
         uint32_t autoFeatures =
-            FEATURE_OSD | FEATURE_LED_STRIP
-#if defined(SOFTSERIAL1_RX_PIN) || defined(SOFTSERIAL2_RX_PIN) || defined(SOFTSERIAL1_TX_PIN) || defined(SOFTSERIAL2_TX_PIN)
-            | FEATURE_SOFTSERIAL
+            FEATURE_OSD | FEATURE_LED_STRIP;
+#if defined(USE_SOFTSERIAL)
+        // enable softserial if at least one pin is configured
+        for (unsigned i = RESOURCE_SOFTSERIAL_OFFSET; i < RESOURCE_SOFTSERIAL_OFFSET + RESOURCE_SOFTSERIAL_COUNT; i++) {
+            if (serialPinConfig()->ioTagTx[i] || serialPinConfig()->ioTagRx[i]) {
+                autoFeatures |= FEATURE_SOFTSERIAL;
+                break;
+            }
+        }
 #endif
-            ;
         featureEnableImmediate(autoFeatures & featuresSupportedByBuild);
     }
 
@@ -530,12 +535,11 @@ static void validateAndFixConfig(void)
     // Find the first serial port on which MSP Displayport is enabled
     displayPortMspSetSerial(SERIAL_PORT_NONE);
 
-    for (uint8_t serialPort  = 0; serialPort < SERIAL_PORT_COUNT; serialPort++) {
-        const serialPortConfig_t *portConfig = &serialConfig()->portConfigs[serialPort];
-
-        if (portConfig &&
-            (portConfig->identifier != SERIAL_PORT_USB_VCP) &&
-            ((portConfig->functionMask & (FUNCTION_VTX_MSP | FUNCTION_MSP)) == (FUNCTION_VTX_MSP | FUNCTION_MSP))) {
+    for (const serialPortConfig_t *portConfig = serialConfig()->portConfigs;
+         portConfig < ARRAYEND(serialConfig()->portConfigs);
+         portConfig++) {
+        if ((portConfig->identifier != SERIAL_PORT_USB_VCP)
+            && ((portConfig->functionMask & (FUNCTION_VTX_MSP | FUNCTION_MSP)) == (FUNCTION_VTX_MSP | FUNCTION_MSP))) {
             displayPortMspSetSerial(portConfig->identifier);
             break;
         }
diff --git a/src/main/drivers/dma_reqmap.h b/src/main/drivers/dma_reqmap.h
index 3bef748731..c8bb516f68 100644
--- a/src/main/drivers/dma_reqmap.h
+++ b/src/main/drivers/dma_reqmap.h
@@ -50,7 +50,7 @@ typedef enum {
     DMA_PERIPH_SPI_SDI,
     DMA_PERIPH_ADC,
     DMA_PERIPH_SDIO,
-    DMA_PERIPH_UART_TX,
+    DMA_PERIPH_UART_TX,   // LPUART is handled as UART
     DMA_PERIPH_UART_RX,
     DMA_PERIPH_TIMUP,
 } dmaPeripheral_e;
diff --git a/src/main/drivers/inverter.c b/src/main/drivers/inverter.c
index 847b9b01b4..77796b0c76 100644
--- a/src/main/drivers/inverter.c
+++ b/src/main/drivers/inverter.c
@@ -25,33 +25,40 @@
 
 #ifdef USE_INVERTER
 
-#include "io/serial.h" // For SERIAL_PORT_IDENTIFIER_TO_INDEX
+#include "io/serial.h"
 #include "drivers/io.h"
 #include "drivers/serial.h"
+#include "drivers/serial_impl.h"
+
 
 #include "inverter.h"
 
 static const serialPinConfig_t *pSerialPinConfig;
 
-static void inverterSet(int identifier, bool on)
+static IO_t findInverterPin(serialPortIdentifier_e identifier)
 {
-    IO_t pin = IOGetByTag(pSerialPinConfig->ioTagInverter[SERIAL_PORT_IDENTIFIER_TO_INDEX(identifier)]);
-
-    if (pin) {
-        IOWrite(pin, on);
+    const int resourceIndex = serialResourceIndex(identifier);
+    if (resourceIndex >= 0 && resourceIndex < (int)ARRAYLEN(pSerialPinConfig->ioTagInverter)) {
+        return IOGetByTag(pSerialPinConfig->ioTagInverter[resourceIndex]);
+    } else {
+        return NULL;
     }
 }
 
-static void initInverter(int identifier)
+static void inverterSet(IO_t pin,  bool on)
 {
-    int uartIndex = SERIAL_PORT_IDENTIFIER_TO_INDEX(identifier);
-    IO_t pin = IOGetByTag(pSerialPinConfig->ioTagInverter[uartIndex]);
+    IOWrite(pin, on);
+}
 
+static void initInverter(serialPortIdentifier_e identifier)
+{
+    IO_t pin = findInverterPin(identifier);
     if (pin) {
-        IOInit(pin, OWNER_INVERTER, RESOURCE_INDEX(uartIndex));
+        const int ownerIndex = serialOwnerIndex(identifier);
+        // only UART supports inverter, so OWNER_INVERTER+ownerIndex does work
+        IOInit(pin, OWNER_INVERTER, ownerIndex);
         IOConfigGPIO(pin, IOCFG_OUT_PP);
-
-        inverterSet(identifier, false);
+        inverterSet(pin, false);
     }
 }
 
@@ -59,73 +66,18 @@ void initInverters(const serialPinConfig_t *serialPinConfigToUse)
 {
     pSerialPinConfig = serialPinConfigToUse;
 
-#ifdef USE_UART1
-    initInverter(SERIAL_PORT_USART1);
-#endif
-
-#ifdef USE_UART2
-    initInverter(SERIAL_PORT_USART2);
-#endif
-
-#ifdef USE_UART3
-    initInverter(SERIAL_PORT_USART3);
-#endif
-
-#ifdef USE_UART4
-    initInverter(SERIAL_PORT_UART4);
-#endif
-
-#ifdef USE_UART5
-    initInverter(SERIAL_PORT_UART5);
-#endif
-
-#ifdef USE_UART6
-    initInverter(SERIAL_PORT_USART6);
-#endif
+    for (unsigned i = 0; i < ARRAYLEN(serialPortIdentifiers); i++) {
+        // it is safe to pass port without inverter
+        initInverter(serialPortIdentifiers[i]);
+    }
 }
 
-void enableInverter(USART_TypeDef *USARTx, bool on)
+void enableInverter(serialPortIdentifier_e identifier, bool on)
 {
-    int identifier = SERIAL_PORT_NONE;
-
-#ifdef USE_UART1
-    if (USARTx == USART1) {
-        identifier = SERIAL_PORT_USART1;
-    }
-#endif
-
-#ifdef USE_UART2
-    if (USARTx == USART2) {
-        identifier = SERIAL_PORT_USART2;
-    }
-#endif
-
-#ifdef USE_UART3
-    if (USARTx == USART3) {
-        identifier = SERIAL_PORT_USART3;
-    }
-#endif
-
-#ifdef USE_UART4
-    if (USARTx == UART4) {
-        identifier = SERIAL_PORT_UART4;
-    }
-#endif
-
-#ifdef USE_UART5
-    if (USARTx == UART5) {
-        identifier = SERIAL_PORT_UART5;
-    }
-#endif
-
-#ifdef USE_UART6
-    if (USARTx == USART6) {
-        identifier = SERIAL_PORT_USART6;
-    }
-#endif
-
-    if (identifier != SERIAL_PORT_NONE) {
-        inverterSet(identifier, on);
+    const IO_t pin = findInverterPin(identifier);
+    if (pin) {
+        inverterSet(pin, on);
     }
 }
+
 #endif // USE_INVERTER
diff --git a/src/main/drivers/inverter.h b/src/main/drivers/inverter.h
index 97d2708def..f04021beb4 100644
--- a/src/main/drivers/inverter.h
+++ b/src/main/drivers/inverter.h
@@ -21,7 +21,7 @@
 #pragma once
 
 #include "drivers/serial.h"
+#include "io/serial.h"
 
 void initInverters(const serialPinConfig_t *serialPinConfigToUse);
-
-void enableInverter(USART_TypeDef *USARTx, bool on);
+void enableInverter(serialPortIdentifier_e portId, bool on);
diff --git a/src/main/drivers/io.c b/src/main/drivers/io.c
index 68ddd85346..bd11be4de1 100644
--- a/src/main/drivers/io.c
+++ b/src/main/drivers/io.c
@@ -174,7 +174,7 @@ IO_t IOGetByTag(ioTag_t tag)
         return NULL;
     }
     // count bits before this pin on single port
-    int offset = __builtin_popcount(((1 << pinIdx) - 1) & ioDefUsedMask[portIdx]);
+    int offset = popcount(((1 << pinIdx) - 1) & ioDefUsedMask[portIdx]);
     // and add port offset
     offset += ioDefUsedOffset[portIdx];
     return ioRecs + offset;
diff --git a/src/main/drivers/io.h b/src/main/drivers/io.h
index ba4a5f6f1e..e3369670d4 100644
--- a/src/main/drivers/io.h
+++ b/src/main/drivers/io.h
@@ -38,7 +38,10 @@
 
 #if defined(STM32F7) || defined(STM32H7) || defined(STM32G4)
 
-//speed is packed inside modebits 5 and 2,
+// speed is packed between modebits 4 and 1,
+// 7       6        5        4         3         2        1        0
+// 0 <pupd-1> <pupd-0> <mode-4> <speed-1> <speed-0> <mode-1> <mode-0>
+// mode-4 is equivalent to STM32F4 otype (pushpull/od)
 #define IO_CONFIG(mode, speed, pupd) ((mode) | ((speed) << 2) | ((pupd) << 5))
 
 #define IOCFG_OUT_PP         IO_CONFIG(GPIO_MODE_OUTPUT_PP, GPIO_SPEED_FREQ_LOW,  GPIO_NOPULL)
@@ -86,7 +89,7 @@
 #define IOCFG_IPD            IO_CONFIG(GPIO_MODE_INPUT  , GPIO_DRIVE_STRENGTH_MODERATE, 0,             GPIO_PULL_DOWN)
 #define IOCFG_IPU            IO_CONFIG(GPIO_MODE_INPUT  , GPIO_DRIVE_STRENGTH_MODERATE, 0,             GPIO_PULL_UP)
 #define IOCFG_IN_FLOATING    IO_CONFIG(GPIO_MODE_INPUT  , GPIO_DRIVE_STRENGTH_MODERATE, 0,             GPIO_PULL_NONE)
-#define IOCFG_IPU_25         IO_CONFIG(GPIO_MODE_INPUT  , GPIO_DRIVE_STRENGTH_MODERATE , 0, GPIO_PULL_UP)
+#define IOCFG_IPU_25         IO_CONFIG(GPIO_MODE_INPUT  , GPIO_DRIVE_STRENGTH_MODERATE, 0, GPIO_PULL_UP)
 
 #elif defined(APM32F4)
 
diff --git a/src/main/drivers/nvic.h b/src/main/drivers/nvic.h
index e1c270213f..e6db969c8a 100644
--- a/src/main/drivers/nvic.h
+++ b/src/main/drivers/nvic.h
@@ -77,19 +77,23 @@
 #define NVIC_PRIO_SPI_DMA                  NVIC_BUILD_PRIORITY(0, 0)
 #define NVIC_PRIO_SDIO_DMA                 NVIC_BUILD_PRIORITY(0, 0)
 
-#ifdef USE_HAL_DRIVER
 // utility macros to join/split priority
+#ifdef USE_HAL_DRIVER
+
 #define NVIC_PRIORITY_GROUPING NVIC_PRIORITYGROUP_2
 #define NVIC_BUILD_PRIORITY(base,sub) (((((base)<<(4-(7-(NVIC_PRIORITY_GROUPING))))|((sub)&(0x0f>>(7-(NVIC_PRIORITY_GROUPING)))))<<4)&0xf0)
 #define NVIC_PRIORITY_BASE(prio) (((prio)>>(4-(7-(NVIC_PRIORITY_GROUPING))))>>4)
 #define NVIC_PRIORITY_SUB(prio) (((prio)&(0x0f>>(7-(NVIC_PRIORITY_GROUPING))))>>4)
+
 #elif defined(USE_ATBSP_DRIVER)
+
 #define NVIC_PRIORITY_GROUPING NVIC_PRIORITY_GROUP_2
 #define NVIC_BUILD_PRIORITY(base,sub) (((((base)<<(4-(7-(NVIC_PRIORITY_GROUPING))))|((sub)&(0x0f>>(7-(NVIC_PRIORITY_GROUPING)))))<<4)&0xf0)
 #define NVIC_PRIORITY_BASE(prio) (((prio)>>(4-(7-(NVIC_PRIORITY_GROUPING))))>>4)
 #define NVIC_PRIORITY_SUB(prio) (((prio)&((0x0f>>(7-(NVIC_PRIORITY_GROUPING)))<<4))>>4)
+
 #else
-// utility macros to join/split priority
+
 #define NVIC_PRIORITY_GROUPING NVIC_PriorityGroup_2
 #define NVIC_BUILD_PRIORITY(base,sub) (((((base)<<(4-(7-(NVIC_PRIORITY_GROUPING>>8))))|((sub)&(0x0f>>(7-(NVIC_PRIORITY_GROUPING>>8)))))<<4)&0xf0)
 #define NVIC_PRIORITY_BASE(prio) (((prio)>>(4-(7-(NVIC_PRIORITY_GROUPING>>8))))>>4)
diff --git a/src/main/drivers/pinio.c b/src/main/drivers/pinio.c
index 0f5d096097..f93e590656 100644
--- a/src/main/drivers/pinio.c
+++ b/src/main/drivers/pinio.c
@@ -60,8 +60,7 @@ void pinioInit(const pinioConfig_t *pinioConfig)
             break;
         }
 
-        if (pinioConfig->config[i] & PINIO_CONFIG_OUT_INVERTED)
-        {
+        if (pinioConfig->config[i] & PINIO_CONFIG_OUT_INVERTED) {
             pinioRuntime[i].inverted = true;
             IOHi(io);
             pinioRuntime[i].state = true;
@@ -76,7 +75,10 @@ void pinioInit(const pinioConfig_t *pinioConfig)
 
 void pinioSet(int index, bool on)
 {
-    bool newState = on ^ pinioRuntime[index].inverted;
+    if (index < 0 || index >= PINIO_COUNT) {
+        return;
+    }
+    const bool newState = on ^ pinioRuntime[index].inverted;
     if (newState != pinioRuntime[index].state) {
         IOWrite(pinioRuntime[index].io, newState);
         pinioRuntime[index].state = newState;
diff --git a/src/main/drivers/resource.c b/src/main/drivers/resource.c
index 24882a3065..38cb50b899 100644
--- a/src/main/drivers/resource.c
+++ b/src/main/drivers/resource.c
@@ -34,8 +34,8 @@ const char * const ownerNames[OWNER_TOTAL_COUNT] = {
     "ADC_CURR",
     "ADC_EXT",
     "ADC_RSSI",
-    "SERIAL_TX",
-    "SERIAL_RX",
+    [OWNER_SERIAL_TX] = "SERIAL_TX",
+    [OWNER_SERIAL_RX] = "SERIAL_RX",
     "DEBUG",
     "TIMER",
     "SONAR_TRIGGER",
@@ -111,9 +111,9 @@ const char * const ownerNames[OWNER_TOTAL_COUNT] = {
     "SWD",
     "RX_SPI_EXPRESSLRS_RESET",
     "RX_SPI_EXPRESSLRS_BUSY",
-    "SOFTSERIAL_TX",
-    "SOFTSERIAL_RX",
-    "LPUART_TX",
-    "LPUART_RX",
+    [OWNER_SOFTSERIAL_TX] = "SOFTSERIAL_TX",
+    [OWNER_SOFTSERIAL_RX] = "SOFTSERIAL_RX",
+    [OWNER_LPUART_TX] = "LPUART_TX",
+    [OWNER_LPUART_RX] = "LPUART_RX",
     "GYRO_CLKIN",
 };
diff --git a/src/main/drivers/resource.h b/src/main/drivers/resource.h
index ddb9720be6..2d924a6f78 100644
--- a/src/main/drivers/resource.h
+++ b/src/main/drivers/resource.h
@@ -32,7 +32,7 @@ typedef enum {
     OWNER_ADC_CURR,
     OWNER_ADC_EXT,
     OWNER_ADC_RSSI,
-    OWNER_SERIAL_TX,
+    OWNER_SERIAL_TX,   // TX must be just before RX
     OWNER_SERIAL_RX,
     OWNER_PINDEBUG,
     OWNER_TIMER,
@@ -109,9 +109,9 @@ typedef enum {
     OWNER_SWD,
     OWNER_RX_SPI_EXPRESSLRS_RESET,
     OWNER_RX_SPI_EXPRESSLRS_BUSY,
-    OWNER_SOFTSERIAL_TX,
+    OWNER_SOFTSERIAL_TX,         // TX must be just before RX
     OWNER_SOFTSERIAL_RX,
-    OWNER_LPUART_TX,
+    OWNER_LPUART_TX,             // TX must be just before RX
     OWNER_LPUART_RX,
     OWNER_GYRO_CLKIN,
     OWNER_TOTAL_COUNT
diff --git a/src/main/drivers/serial.c b/src/main/drivers/serial.c
index 3ec8f0fc1b..d93bddb77d 100644
--- a/src/main/drivers/serial.c
+++ b/src/main/drivers/serial.c
@@ -23,6 +23,7 @@
 
 #include "platform.h"
 
+#include "io/serial.h"
 #include "serial.h"
 
 void serialPrint(serialPort_t *instance, const char *str)
@@ -130,3 +131,4 @@ void serialWriteBufShim(void *instance, const uint8_t *data, int count)
 {
     serialWriteBuf((serialPort_t *)instance, data, count);
 }
+
diff --git a/src/main/drivers/serial.h b/src/main/drivers/serial.h
index da41245166..49f647225f 100644
--- a/src/main/drivers/serial.h
+++ b/src/main/drivers/serial.h
@@ -23,8 +23,7 @@
 #include "drivers/io.h"
 #include "drivers/io_types.h"
 #include "drivers/resource.h"
-// TODO(hertz@): uncomment and use UARTDevice_e::MAX_UARTDEV
-// #include "drivers/serial_uart.h"
+#include "drivers/serial_resource.h"
 
 #include "pg/pg.h"
 
@@ -45,18 +44,27 @@ typedef enum {
     SERIAL_BIDIR         = 1 << 3,
 
     /*
-     * Note on SERIAL_BIDIR_PP
+     * Note on SERIAL_BIDIR_PP *on some MCU families*
      * With SERIAL_BIDIR_PP, the very first start bit of back-to-back bytes
      * is lost and the first data byte will be lost by a framing error.
      * To ensure the first start bit to be sent, prepend a zero byte (0x00)
      * to actual data bytes.
      */
-    SERIAL_BIDIR_OD        = 0 << 4,
-    SERIAL_BIDIR_PP        = 1 << 4,
-    SERIAL_BIDIR_NOPULL    = 1 << 5, // disable pulls in BIDIR RX mode
-    SERIAL_BIDIR_PP_PD     = 1 << 6, // PP mode, normall inverted, but with PullDowns, to fix SA after bidir issue fixed (#10220)
+    // output configuration in BIDIR non-inverted mode
+    // pushpull is used in UNIDIR or inverted mode by default
+    // SERIAL_BIDIR must be specified explicitly
+    SERIAL_BIDIR_OD        = 0 << 4, // default in BIDIR non-inverted mode
+    SERIAL_BIDIR_PP        = 1 << 4, // force pushpull
+
+    SERIAL_PULL_DEFAULT    = 0 << 5, // pulldown in inverted mode, pullup otherwise
+    SERIAL_PULL_NONE       = 1 << 5, // disable pulls in RX or opendrain TX mode
+    // option for Smartaudio serial port - line is in MARK state when idle - break condition.
+    // DO NOT USE unless absolutely necessary
+    // SERIAL_PULL_NONE has precedence
+    SERIAL_PULL_SMARTAUDIO = 1 << 6, // set PULLDOWN on RX, even when not inverted.
 
     // If this option is set then switch the TX line to input when not in use to detect it being pulled low
+    // (and prevent powering external device by TX pin)
     SERIAL_CHECK_TX        = 1 << 7,
 } portOptions_e;
 
@@ -90,32 +98,19 @@ typedef struct serialPort_s {
 
     serialIdleCallbackPtr idleCallback;
 
-    uint8_t identifier;
+    uint8_t identifier;  // actually serialPortIdentifier_e; avoid circular header dependency
 } serialPort_t;
 
-#define SERIAL_PORT_MAX_INDEX 11
-#define SERIAL_UART_COUNT 10
-#define SERIAL_LPUART_COUNT 1
-
 typedef struct serialPinConfig_s {
-    ioTag_t ioTagTx[SERIAL_PORT_MAX_INDEX];
-    ioTag_t ioTagRx[SERIAL_PORT_MAX_INDEX];
-    ioTag_t ioTagInverter[SERIAL_PORT_MAX_INDEX];
+    ioTag_t ioTagTx[RESOURCE_SERIAL_COUNT];
+    ioTag_t ioTagRx[RESOURCE_SERIAL_COUNT];
+#ifdef USE_INVERTER
+    ioTag_t ioTagInverter[RESOURCE_UART_COUNT]; // this array is only for UARTs.
+#endif
 } serialPinConfig_t;
 
 PG_DECLARE(serialPinConfig_t, serialPinConfig);
 
-#if defined(USE_SOFTSERIAL)
-#define SOFTSERIAL_COUNT 2
-
-typedef struct softSerialPinConfig_s {
-    ioTag_t ioTagTx[SOFTSERIAL_COUNT];
-    ioTag_t ioTagRx[SOFTSERIAL_COUNT];
-} softSerialPinConfig_t;
-
-PG_DECLARE(softSerialPinConfig_t, softSerialPinConfig);
-#endif
-
 struct serialPortVTable {
     void (*serialWrite)(serialPort_t *instance, uint8_t ch);
 
diff --git a/src/main/drivers/serial_impl.c b/src/main/drivers/serial_impl.c
new file mode 100644
index 0000000000..fbca450441
--- /dev/null
+++ b/src/main/drivers/serial_impl.c
@@ -0,0 +1,39 @@
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "platform.h"
+
+
+#include "io/serial.h"
+
+#include "serial.h"
+#include "serial_impl.h"
+
+// convert options into pin pull mode (up/down/none)
+serialPullMode_t serialOptions_pull(portOptions_e options)
+{
+    // handle SmartAudio first - different SA versions need different values
+    // add more cases here if necessary
+    if (options & SERIAL_PULL_SMARTAUDIO) {
+#ifdef USE_SMARTAUDIO_NOPULLDOWN
+        return serialPullNone;
+#else
+        return serialPullDown;
+#endif
+    }
+    if (options & SERIAL_PULL_NONE) {
+        return serialPullNone;                            // explicit nopull
+    } else if (options & SERIAL_INVERTED) {
+        return serialPullDown;
+    } else {
+        return serialPullUp;
+    }
+}
+
+// is pushPull mode necessary
+bool serialOptions_pushPull(portOptions_e options)
+{
+    return options & (SERIAL_INVERTED | SERIAL_BIDIR_PP);
+}
+
+
diff --git a/src/main/drivers/serial_impl.h b/src/main/drivers/serial_impl.h
new file mode 100644
index 0000000000..7f2e0068a8
--- /dev/null
+++ b/src/main/drivers/serial_impl.h
@@ -0,0 +1,39 @@
+/*
+ * This file is part of Betaflight.
+ *
+ * Betaflight is free software. You can redistribute this software
+ * and/or modify this software under the terms of the GNU General
+ * Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * Betaflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this software.
+ *
+ * If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <stdbool.h>
+
+/*
+ * common functions related to serial port implementation
+ */
+
+// owner of Tx pin (+1 for Rx)
+resourceOwner_e serialOwnerTxRx(serialPortIdentifier_e identifier);
+// index for given owner
+int serialOwnerIndex(serialPortIdentifier_e identifier);
+
+typedef enum { serialPullNone = 0, serialPullDown = 1, serialPullUp = 2 } serialPullMode_t;
+serialPullMode_t serialOptions_pull(portOptions_e options);
+bool serialOptions_pushPull(portOptions_e options);
+
+
diff --git a/src/main/drivers/serial_pinconfig.c b/src/main/drivers/serial_pinconfig.c
index f2e902e30a..9b80d0f92d 100644
--- a/src/main/drivers/serial_pinconfig.c
+++ b/src/main/drivers/serial_pinconfig.c
@@ -34,159 +34,7 @@
 
 #include "pg/pg_ids.h"
 
-// Backward compatibility for existing targets
-
-// Default pin (NONE).
-
-#ifdef USE_UART1
-# if !defined(UART1_RX_PIN)
-#  define UART1_RX_PIN NONE
-# endif
-# if !defined(UART1_TX_PIN)
-#  define UART1_TX_PIN NONE
-# endif
-# if !defined(INVERTER_PIN_UART1)
-#  define INVERTER_PIN_UART1 NONE
-# endif
-#endif
-
-#ifdef USE_UART2
-# if !defined(UART2_RX_PIN)
-#  define UART2_RX_PIN NONE
-# endif
-# if !defined(UART2_TX_PIN)
-#  define UART2_TX_PIN NONE
-# endif
-# if !defined(INVERTER_PIN_UART2)
-#  define INVERTER_PIN_UART2 NONE
-# endif
-#endif
-
-#ifdef USE_UART3
-# if !defined(UART3_RX_PIN)
-#  define UART3_RX_PIN NONE
-# endif
-# if !defined(UART3_TX_PIN)
-#  define UART3_TX_PIN NONE
-# endif
-# if !defined(INVERTER_PIN_UART3)
-#  define INVERTER_PIN_UART3 NONE
-# endif
-#endif
-
-#ifdef USE_UART4
-# if !defined(UART4_RX_PIN)
-#  define UART4_RX_PIN NONE
-# endif
-# if !defined(UART4_TX_PIN)
-#  define UART4_TX_PIN NONE
-# endif
-# if !defined(INVERTER_PIN_UART4)
-#  define INVERTER_PIN_UART4 NONE
-# endif
-#endif
-
-#ifdef USE_UART5
-# if !defined(UART5_RX_PIN)
-#  define UART5_RX_PIN NONE
-# endif
-# if !defined(UART5_TX_PIN)
-#  define UART5_TX_PIN NONE
-# endif
-# if !defined(INVERTER_PIN_UART5)
-#  define INVERTER_PIN_UART5 NONE
-# endif
-#endif
-
-#ifdef USE_UART6
-# if !defined(UART6_RX_PIN)
-#  define UART6_RX_PIN NONE
-# endif
-# if !defined(UART6_TX_PIN)
-#  define UART6_TX_PIN NONE
-# endif
-# if !defined(INVERTER_PIN_UART6)
-#  define INVERTER_PIN_UART6 NONE
-# endif
-#endif
-
-#ifdef USE_UART7
-# if !defined(UART7_RX_PIN)
-#  define UART7_RX_PIN NONE
-# endif
-# if !defined(UART7_TX_PIN)
-#  define UART7_TX_PIN NONE
-# endif
-# if !defined(INVERTER_PIN_UART7)
-#  define INVERTER_PIN_UART7 NONE
-# endif
-#endif
-
-#ifdef USE_UART8
-# if !defined(UART8_RX_PIN)
-#  define UART8_RX_PIN NONE
-# endif
-# if !defined(UART8_TX_PIN)
-#  define UART8_TX_PIN NONE
-# endif
-# if !defined(INVERTER_PIN_UART8)
-#  define INVERTER_PIN_UART8 NONE
-# endif
-#endif
-
-#ifdef USE_UART9
-# if !defined(UART9_RX_PIN)
-#  define UART9_RX_PIN NONE
-# endif
-# if !defined(UART9_TX_PIN)
-#  define UART9_TX_PIN NONE
-# endif
-# if !defined(INVERTER_PIN_UART9)
-#  define INVERTER_PIN_UART9 NONE
-# endif
-#endif
-
-#ifdef USE_UART10
-# if !defined(UART10_RX_PIN)
-#  define UART10_RX_PIN NONE
-# endif
-# if !defined(UART10_TX_PIN)
-#  define UART10_TX_PIN NONE
-# endif
-# if !defined(INVERTER_PIN_UART10)
-#  define INVERTER_PIN_UART10 NONE
-# endif
-#endif
-
-#ifdef USE_LPUART1
-# if !defined(LPUART1_RX_PIN)
-#  define LPUART1_RX_PIN NONE
-# endif
-# if !defined(LPUART1_TX_PIN)
-#  define LPUART1_TX_PIN NONE
-# endif
-# if !defined(INVERTER_PIN_LPUART1)
-#  define INVERTER_PIN_LPUART1 NONE
-# endif
-#endif
-
-#ifdef USE_SOFTSERIAL
-# if !defined(SOFTSERIAL1_RX_PIN)
-#  define SOFTSERIAL1_RX_PIN NONE
-# endif
-# if !defined(SOFTSERIAL1_TX_PIN)
-#  define SOFTSERIAL1_TX_PIN NONE
-# endif
-
-# if !defined(SOFTSERIAL2_RX_PIN)
-#  define SOFTSERIAL2_RX_PIN NONE
-# endif
-# if !defined(SOFTSERIAL2_TX_PIN)
-#  define SOFTSERIAL2_TX_PIN NONE
-# endif
-#endif
-
-#if defined(USE_UART) || defined(USE_SOFTSERIAL)
+#if defined(USE_UART) || defined(USE_LPUART) || defined(USE_SOFTSERIAL)
 typedef struct serialDefaultPin_s {
     serialPortIdentifier_e ident;
     ioTag_t rxIO, txIO, inverterIO;
@@ -224,7 +72,13 @@ static const serialDefaultPin_t serialDefaultPin[] = {
     { SERIAL_PORT_USART10, IO_TAG(UART10_RX_PIN), IO_TAG(UART10_TX_PIN), IO_TAG(INVERTER_PIN_UART10) },
 #endif
 #ifdef USE_LPUART1
-    { SERIAL_PORT_LPUART1, IO_TAG(LPUART1_RX_PIN), IO_TAG(LPUART1_TX_PIN), IO_TAG(INVERTER_PIN_LPUART1) },
+    { SERIAL_PORT_LPUART1, IO_TAG(LPUART1_RX_PIN), IO_TAG(LPUART1_TX_PIN), IO_TAG(NONE) },
+#endif
+#ifdef USE_SOFTSERIAL1
+    { SERIAL_PORT_SOFTSERIAL1, IO_TAG(SOFTSERIAL1_RX_PIN), IO_TAG(SOFTSERIAL1_TX_PIN), IO_TAG(NONE) },
+#endif
+#ifdef USE_SOFTSERIAL2
+    { SERIAL_PORT_SOFTSERIAL2, IO_TAG(SOFTSERIAL2_RX_PIN), IO_TAG(SOFTSERIAL2_TX_PIN), IO_TAG(NONE) },
 #endif
 };
 
@@ -232,38 +86,21 @@ PG_REGISTER_WITH_RESET_FN(serialPinConfig_t, serialPinConfig, PG_SERIAL_PIN_CONF
 
 void pgResetFn_serialPinConfig(serialPinConfig_t *serialPinConfig)
 {
-    for (size_t index = 0 ; index < ARRAYLEN(serialDefaultPin) ; index++) {
-        const serialDefaultPin_t *defpin = &serialDefaultPin[index];
-        serialPinConfig->ioTagRx[SERIAL_PORT_IDENTIFIER_TO_INDEX(defpin->ident)] = defpin->rxIO;
-        serialPinConfig->ioTagTx[SERIAL_PORT_IDENTIFIER_TO_INDEX(defpin->ident)] = defpin->txIO;
-        serialPinConfig->ioTagInverter[SERIAL_PORT_IDENTIFIER_TO_INDEX(defpin->ident)] = defpin->inverterIO;
+    for (const serialDefaultPin_t *defpin = serialDefaultPin; defpin < ARRAYEND(serialDefaultPin); defpin++) {
+        const int resourceIndex = serialResourceIndex(defpin->ident);
+        if (resourceIndex >= 0) {
+            serialPinConfig->ioTagRx[resourceIndex] = defpin->rxIO;
+            serialPinConfig->ioTagTx[resourceIndex] = defpin->txIO;
+#if defined(USE_INVERTER)
+            // LPUART/SOFTSERIAL do not need/support inverter
+            if (resourceIndex < (int)ARRAYLEN(serialPinConfig->ioTagInverter)) {
+                serialPinConfig->ioTagInverter[resourceIndex] = defpin->inverterIO;
+            }
+#endif
+        }
     }
 }
 
-#if defined(USE_SOFTSERIAL)
-typedef struct softSerialDefaultPin_s {
-    serialPortIdentifier_e ident;
-    ioTag_t rxIO, txIO;
-} softSerialDefaultPin_t;
-
-static const softSerialDefaultPin_t softSerialDefaultPin[SOFTSERIAL_COUNT] = {
-#ifdef USE_SOFTSERIAL
-    { SERIAL_PORT_SOFTSERIAL1, IO_TAG(SOFTSERIAL1_RX_PIN), IO_TAG(SOFTSERIAL1_TX_PIN) },
-    { SERIAL_PORT_SOFTSERIAL2, IO_TAG(SOFTSERIAL2_RX_PIN), IO_TAG(SOFTSERIAL2_TX_PIN) },
-#endif
-};
-
-PG_REGISTER_WITH_RESET_FN(softSerialPinConfig_t, softSerialPinConfig, PG_SOFTSERIAL_PIN_CONFIG, 0);
-
-void pgResetFn_softSerialPinConfig(softSerialPinConfig_t *softSerialPinConfig)
-{
-    for (size_t index = 0 ; index < ARRAYLEN(softSerialDefaultPin) ; index++) {
-        const softSerialDefaultPin_t *defpin = &softSerialDefaultPin[index];
-        softSerialPinConfig->ioTagRx[SOFTSERIAL_PORT_IDENTIFIER_TO_INDEX(defpin->ident)] = defpin->rxIO;
-        softSerialPinConfig->ioTagTx[SOFTSERIAL_PORT_IDENTIFIER_TO_INDEX(defpin->ident)] = defpin->txIO;
-    }
-}
-#endif
 
 #endif
 #endif
diff --git a/src/main/drivers/serial_resource.h b/src/main/drivers/serial_resource.h
new file mode 100644
index 0000000000..e301fe5644
--- /dev/null
+++ b/src/main/drivers/serial_resource.h
@@ -0,0 +1,40 @@
+/*
+ * This file is part of Betaflight.
+ *
+ * Betaflight is free software. You can redistribute this software
+ * and/or modify this software under the terms of the GNU General
+ * Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * Betaflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this software.
+ *
+ * If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+/*
+  #defines used for serial port resource access (pin/dma/inversion)
+  target/serial_post.h normalizes enabled port definitions (and port counts),
+  values are just renamed here
+ */
+
+// use _MAX value here, resource command needs linear mapping
+//  (UART8 is always at index RESOURCE_UART_OFFSET + 7, no matter which other ports are enabled)
+#define RESOURCE_UART_COUNT SERIAL_UART_MAX
+#define RESOURCE_LPUART_COUNT SERIAL_LPUART_MAX
+#define RESOURCE_SOFTSERIAL_COUNT SERIAL_SOFTSERIAL_MAX
+#define RESOURCE_SERIAL_COUNT (RESOURCE_UART_COUNT + RESOURCE_LPUART_COUNT + RESOURCE_SOFTSERIAL_COUNT)
+// resources are stored in one array, in UART, LPUART, SOFTSERIAL order. Code does assume this ordering,
+//  do not change it without adapting relevant code.
+#define RESOURCE_UART_OFFSET 0
+#define RESOURCE_LPUART_OFFSET RESOURCE_UART_COUNT
+#define RESOURCE_SOFTSERIAL_OFFSET (RESOURCE_UART_COUNT + RESOURCE_LPUART_COUNT)
diff --git a/src/main/drivers/serial_softserial.c b/src/main/drivers/serial_softserial.c
index 47a4f7b97e..f3fd39c97e 100644
--- a/src/main/drivers/serial_softserial.c
+++ b/src/main/drivers/serial_softserial.c
@@ -37,9 +37,12 @@
 
 #include "common/utils.h"
 
+#include "io/serial.h"
+
 #include "drivers/nvic.h"
 #include "drivers/io.h"
 #include "drivers/serial.h"
+#include "drivers/serial_impl.h"
 #include "drivers/timer.h"
 
 #include "serial_softserial.h"
@@ -47,8 +50,6 @@
 #define RX_TOTAL_BITS 10
 #define TX_TOTAL_BITS 10
 
-#define MAX_SOFTSERIAL_PORTS 2
-
 typedef enum {
     TIMER_MODE_SINGLE,
     TIMER_MODE_DUAL,
@@ -87,7 +88,6 @@ typedef struct softSerial_s {
     uint16_t         transmissionErrors;
     uint16_t         receiveErrors;
 
-    uint8_t          softSerialPortIndex;
     timerMode_e      timerMode;
 
     timerOvrHandlerRec_t overCb;
@@ -95,23 +95,16 @@ typedef struct softSerial_s {
 } softSerial_t;
 
 static const struct serialPortVTable softSerialVTable; // Forward
-
-static softSerial_t softSerialPorts[MAX_SOFTSERIAL_PORTS];
+// SERIAL_SOFTSERIAL_COUNT is fine, softserial ports must start from 1 and be continuous
+static softSerial_t softSerialPorts[SERIAL_SOFTSERIAL_COUNT];
 
 void onSerialTimerOverflow(timerOvrHandlerRec_t *cbRec, captureCompare_t capture);
 void onSerialRxPinChange(timerCCHandlerRec_t *cbRec, captureCompare_t capture);
 
-static void setTxSignal(softSerial_t *softSerial, uint8_t state)
+typedef enum { IDLE = ENABLE, MARK = DISABLE } SerialTxState_e;
+static void setTxSignal(softSerial_t *softSerial, SerialTxState_e state)
 {
-    if (softSerial->port.options & SERIAL_INVERTED) {
-        state = !state;
-    }
-
-    if (state) {
-        IOHi(softSerial->txIO);
-    } else {
-        IOLo(softSerial->txIO);
-    }
+    IOWrite(softSerial->txIO, (softSerial->port.options & SERIAL_INVERTED) ? !state : state);
 }
 
 static void serialEnableCC(softSerial_t *softSerial)
@@ -123,15 +116,13 @@ static void serialEnableCC(softSerial_t *softSerial)
 #endif
 }
 
+// switch to receive mode
 static void serialInputPortActivate(softSerial_t *softSerial)
 {
-    if (softSerial->port.options & SERIAL_INVERTED) {
-        const uint8_t pinConfig = (softSerial->port.options & SERIAL_BIDIR_NOPULL) ? IOCFG_AF_PP : IOCFG_AF_PP_PD;
-        IOConfigGPIOAF(softSerial->rxIO, pinConfig, softSerial->timerHardware->alternateFunction);
-    } else {
-        const uint8_t pinConfig = (softSerial->port.options & SERIAL_BIDIR_NOPULL) ? IOCFG_AF_PP : IOCFG_AF_PP_UP;
-        IOConfigGPIOAF(softSerial->rxIO, pinConfig, softSerial->timerHardware->alternateFunction);
-    }
+    const serialPullMode_t pull = serialOptions_pull(softSerial->port.options);
+    const uint8_t pinConfig = ((const uint8_t[]){IOCFG_AF_PP, IOCFG_AF_PP_PD, IOCFG_AF_PP_UP})[pull];
+    // softserial can easily support opendrain mode, but it is not implemented
+    IOConfigGPIOAF(softSerial->rxIO, pinConfig, softSerial->timerHardware->alternateFunction);
 
     softSerial->rxActive = true;
     softSerial->isSearchingForStartBit = true;
@@ -151,25 +142,27 @@ static void serialInputPortDeActivate(softSerial_t *softSerial)
 #else
     TIM_CCxCmd(softSerial->timerHardware->tim, softSerial->timerHardware->channel, TIM_CCx_Disable);
 #endif
-
-    IOConfigGPIO(softSerial->rxIO, IOCFG_IN_FLOATING);
+    IOConfigGPIO(softSerial->rxIO, IOCFG_IN_FLOATING); // leave AF mode; serialOutputPortActivate will follow immediately
     softSerial->rxActive = false;
 }
 
 static void serialOutputPortActivate(softSerial_t *softSerial)
 {
-    if (softSerial->exTimerHardware)
+    if (softSerial->exTimerHardware) {
         IOConfigGPIOAF(softSerial->txIO, IOCFG_OUT_PP, softSerial->exTimerHardware->alternateFunction);
-    else
+    } else {
         IOConfigGPIO(softSerial->txIO, IOCFG_OUT_PP);
+    }
 }
 
 static void serialOutputPortDeActivate(softSerial_t *softSerial)
 {
-    if (softSerial->exTimerHardware)
+    if (softSerial->exTimerHardware) {
+        // TODO: there in no AF associated with input port
         IOConfigGPIOAF(softSerial->txIO, IOCFG_IN_FLOATING, softSerial->exTimerHardware->alternateFunction);
-    else
+    } else {
         IOConfigGPIO(softSerial->txIO, IOCFG_IN_FLOATING);
+    }
 }
 
 static bool isTimerPeriodTooLarge(uint32_t timerPeriod)
@@ -183,19 +176,10 @@ static void serialTimerConfigureTimebase(const timerHardware_t *timerHardwarePtr
     uint32_t clock = baseClock;
     uint32_t timerPeriod;
 
-    do {
-        timerPeriod = clock / baud;
-        if (isTimerPeriodTooLarge(timerPeriod)) {
-            if (clock > 1) {
-                clock = clock / 2;   // this is wrong - mhz stays the same ... This will double baudrate until ok (but minimum baudrate is < 1200)
-            } else {
-                // TODO unable to continue, unable to determine clock and timerPeriods for the given baud
-            }
-
-        }
-    } while (isTimerPeriodTooLarge(timerPeriod));
-
-    timerConfigure(timerHardwarePtr, timerPeriod, baseClock);
+    while (timerPeriod = clock / baud, isTimerPeriodTooLarge(timerPeriod) && clock > 1) {
+        clock = clock / 2;   // minimum baudrate is < 1200
+    }
+    timerConfigure(timerHardwarePtr, timerPeriod, clock);
 }
 
 static void resetBuffers(softSerial_t *softSerial)
@@ -211,15 +195,32 @@ static void resetBuffers(softSerial_t *softSerial)
     softSerial->port.txBufferHead = 0;
 }
 
-serialPort_t *openSoftSerial(softSerialPortIndex_e portIndex, serialReceiveCallbackPtr rxCallback, void *rxCallbackData, uint32_t baud, portMode_e mode, portOptions_e options)
+softSerial_t* softSerialFromIdentifier(serialPortIdentifier_e identifier)
 {
-    softSerial_t *softSerial = &(softSerialPorts[portIndex]);
+    if (identifier >= SERIAL_PORT_SOFTSERIAL1 && identifier < SERIAL_PORT_SOFTSERIAL1 + SERIAL_SOFTSERIAL_COUNT) {
+        return &softSerialPorts[identifier - SERIAL_PORT_SOFTSERIAL1];
+    }
+    return NULL;
+}
 
-    ioTag_t tagRx = softSerialPinConfig()->ioTagRx[portIndex];
-    ioTag_t tagTx = softSerialPinConfig()->ioTagTx[portIndex];
+serialPort_t *softSerialOpen(serialPortIdentifier_e identifier, serialReceiveCallbackPtr rxCallback, void *rxCallbackData, uint32_t baud, portMode_e mode, portOptions_e options)
+{
+    softSerial_t *softSerial = softSerialFromIdentifier(identifier);
+    if (!softSerial) {
+        return NULL;
+    }
+    // fill identifier early, so initialization code can use it
+    softSerial->port.identifier = identifier;
 
-    const timerHardware_t *timerTx = timerAllocate(tagTx, OWNER_SOFTSERIAL_TX, RESOURCE_INDEX(portIndex));
-    const timerHardware_t *timerRx = (tagTx == tagRx) ? timerTx : timerAllocate(tagRx, OWNER_SOFTSERIAL_RX, RESOURCE_INDEX(portIndex));
+    const int resourceIndex = serialResourceIndex(identifier);
+    const resourceOwner_e ownerTxRx = serialOwnerTxRx(identifier); // rx is always +1
+    const int ownerIndex = serialOwnerIndex(identifier);
+
+    const ioTag_t tagRx = serialPinConfig()->ioTagRx[resourceIndex];
+    const ioTag_t tagTx = serialPinConfig()->ioTagTx[resourceIndex];
+
+    const timerHardware_t *timerTx = timerAllocate(tagTx, ownerTxRx, ownerIndex);
+    const timerHardware_t *timerRx = (tagTx == tagRx) ? timerTx : timerAllocate(tagRx, ownerTxRx + 1, ownerIndex);
 
     IO_t rxIO = IOGetByTag(tagRx);
     IO_t txIO = IOGetByTag(tagTx);
@@ -227,7 +228,7 @@ serialPort_t *openSoftSerial(softSerialPortIndex_e portIndex, serialReceiveCallb
     if (options & SERIAL_BIDIR) {
         // If RX and TX pins are both assigned, we CAN use either with a timer.
         // However, for consistency with hardware UARTs, we only use TX pin,
-        // and this pin must have a timer, and it should not be N-Channel.
+        // and this pin must have a timer, and it must not be N-Channel.
         if (!timerTx || (timerTx->output & TIMER_OUTPUT_N_CHANNEL)) {
             return NULL;
         }
@@ -235,10 +236,10 @@ serialPort_t *openSoftSerial(softSerialPortIndex_e portIndex, serialReceiveCallb
         softSerial->timerHardware = timerTx;
         softSerial->txIO = txIO;
         softSerial->rxIO = txIO;
-        IOInit(txIO, OWNER_SOFTSERIAL_TX, RESOURCE_INDEX(portIndex));
+        IOInit(txIO, ownerTxRx, ownerIndex);
     } else {
         if (mode & MODE_RX) {
-            // Need a pin & a timer on RX. Channel should not be N-Channel.
+            // Need a pin & a timer on RX. Channel must not be N-Channel.
             if (!timerRx || (timerRx->output & TIMER_OUTPUT_N_CHANNEL)) {
                 return NULL;
             }
@@ -246,27 +247,29 @@ serialPort_t *openSoftSerial(softSerialPortIndex_e portIndex, serialReceiveCallb
             softSerial->rxIO = rxIO;
             softSerial->timerHardware = timerRx;
             if (!((mode & MODE_TX) && rxIO == txIO)) {
-                IOInit(rxIO, OWNER_SOFTSERIAL_RX, RESOURCE_INDEX(portIndex));
+                // RX only on pin
+                IOInit(rxIO, ownerTxRx + 1, ownerIndex);
             }
         }
 
         if (mode & MODE_TX) {
             // Need a pin on TX
-            if (!tagTx)
+            if (!txIO)
                 return NULL;
 
             softSerial->txIO = txIO;
 
             if (!(mode & MODE_RX)) {
                 // TX Simplex, must have a timer
-                if (!timerTx)
+                if (!timerTx) {
                     return NULL;
+                }
                 softSerial->timerHardware = timerTx;
             } else {
-                // Duplex
+                // Duplex, use timerTx if available
                 softSerial->exTimerHardware = timerTx;
             }
-            IOInit(txIO, OWNER_SOFTSERIAL_TX, RESOURCE_INDEX(portIndex));
+            IOInit(txIO, ownerTxRx, ownerIndex);
         }
     }
 
@@ -279,8 +282,6 @@ serialPort_t *openSoftSerial(softSerialPortIndex_e portIndex, serialReceiveCallb
 
     resetBuffers(softSerial);
 
-    softSerial->softSerialPortIndex = portIndex;
-
     softSerial->transmissionErrors = 0;
     softSerial->receiveErrors = 0;
 
@@ -317,7 +318,7 @@ serialPort_t *openSoftSerial(softSerialPortIndex_e portIndex, serialReceiveCallb
 
     if (!(options & SERIAL_BIDIR)) {
         serialOutputPortActivate(softSerial);
-        setTxSignal(softSerial, ENABLE);
+        setTxSignal(softSerial, IDLE);
     }
 
     serialInputPortActivate(softSerial);
@@ -332,14 +333,12 @@ serialPort_t *openSoftSerial(softSerialPortIndex_e portIndex, serialReceiveCallb
 
 void processTxState(softSerial_t *softSerial)
 {
-    uint8_t mask;
-
     if (!softSerial->isTransmittingData) {
         if (isSoftSerialTransmitBufferEmpty((serialPort_t *)softSerial)) {
             // Transmit buffer empty.
-            // Start listening if not already in if half-duplex
+            // Switch to RX mode if not already listening and running in half-duplex mode
             if (!softSerial->rxActive && softSerial->port.options & SERIAL_BIDIR) {
-                serialOutputPortDeActivate(softSerial);
+                serialOutputPortDeActivate(softSerial); // TODO: not necessary
                 serialInputPortActivate(softSerial);
             }
             return;
@@ -352,7 +351,7 @@ void processTxState(softSerial_t *softSerial)
         }
 
         // build internal buffer, MSB = Stop Bit (1) + data bits (MSB to LSB) + start bit(0) LSB
-        softSerial->internalTxBuffer = (1 << (TX_TOTAL_BITS - 1)) | (byteToSend << 1);
+        softSerial->internalTxBuffer = (1 << (TX_TOTAL_BITS - 1)) | (byteToSend << 1) | 0;
         softSerial->bitsLeftToTransmit = TX_TOTAL_BITS;
         softSerial->isTransmittingData = true;
 
@@ -365,16 +364,18 @@ void processTxState(softSerial_t *softSerial)
             // and continuing here may cause bit period to decrease causing sampling errors
             // at the receiver under high rates.
             // Note that there will be (little less than) 1-bit delay; take it as "turn around time".
-            // XXX We may be able to reload counter and continue. (Future work.)
+            // This time is important in noninverted pulldown bidir mode (SmartAudio).
+            //   During this period, TX pin is in IDLE state so next startbit (MARK) can be detected
+            // XXX Otherwise, we may be able to reload counter and continue. (Future work.)
             return;
         }
     }
 
     if (softSerial->bitsLeftToTransmit) {
-        mask = softSerial->internalTxBuffer & 1;
+        const bool bit = softSerial->internalTxBuffer & 1;
         softSerial->internalTxBuffer >>= 1;
 
-        setTxSignal(softSerial, mask);
+        setTxSignal(softSerial, bit);
         softSerial->bitsLeftToTransmit--;
         return;
     }
@@ -390,8 +391,7 @@ enum {
 void applyChangedBits(softSerial_t *softSerial)
 {
     if (softSerial->rxEdge == TRAILING) {
-        uint8_t bitToSet;
-        for (bitToSet = softSerial->rxLastLeadingEdgeAtBitIndex; bitToSet < softSerial->rxBitIndex; bitToSet++) {
+        for (unsigned bitToSet = softSerial->rxLastLeadingEdgeAtBitIndex; bitToSet < softSerial->rxBitIndex; bitToSet++) {
             softSerial->internalRxBuffer |= 1 << bitToSet;
         }
     }
@@ -477,12 +477,13 @@ void onSerialRxPinChange(timerCCHandlerRec_t *cbRec, captureCompare_t capture)
     UNUSED(capture);
 
     softSerial_t *self = container_of(cbRec, softSerial_t, edgeCb);
-    bool inverted = self->port.options & SERIAL_INVERTED;
 
     if ((self->port.mode & MODE_RX) == 0) {
         return;
     }
 
+    const bool inverted = self->port.options & SERIAL_INVERTED;
+
     if (self->isSearchingForStartBit) {
         // Synchronize the bit timing so that it will interrupt at the center
         // of the bit period.
diff --git a/src/main/drivers/serial_softserial.h b/src/main/drivers/serial_softserial.h
index 5ef163f775..d3f81a683e 100644
--- a/src/main/drivers/serial_softserial.h
+++ b/src/main/drivers/serial_softserial.h
@@ -22,12 +22,9 @@
 
 #define SOFTSERIAL_BUFFER_SIZE 256
 
-typedef enum {
-    SOFTSERIAL1 = 0,
-    SOFTSERIAL2
-} softSerialPortIndex_e;
+#include "io/serial.h"
 
-serialPort_t *openSoftSerial(softSerialPortIndex_e portIndex, serialReceiveCallbackPtr rxCallback, void *rxCallbackData, uint32_t baud, portMode_e mode, portOptions_e options);
+serialPort_t *softSerialOpen(serialPortIdentifier_e identifier, serialReceiveCallbackPtr rxCallback, void *rxCallbackData, uint32_t baud, portMode_e mode, portOptions_e options);
 
 // serialPort API
 void softSerialWriteByte(serialPort_t *instance, uint8_t ch);
diff --git a/src/main/drivers/serial_uart.c b/src/main/drivers/serial_uart.c
index 8a12b6186d..c278613856 100644
--- a/src/main/drivers/serial_uart.c
+++ b/src/main/drivers/serial_uart.c
@@ -38,10 +38,13 @@
 #include <common/maths.h>
 #include "common/utils.h"
 
+#include "io/serial.h"
+
 #include "drivers/dma.h"
 #include "drivers/dma_reqmap.h"
 #include "drivers/rcc.h"
 #include "drivers/serial.h"
+#include "drivers/serial_impl.h"
 #include "drivers/serial_uart.h"
 #include "drivers/serial_uart_impl.h"
 
@@ -63,13 +66,10 @@
 #error Undefined UART_{TX,RX}_BUFFER_ATTRIBUTE for this MCU
 #endif
 
-#define UART_BUFFERS(n) \
-    UART_BUFFER(UART_TX_BUFFER_ATTRIBUTE, n, T); \
-    UART_BUFFER(UART_RX_BUFFER_ATTRIBUTE, n, R); struct dummy_s
-
-#define LPUART_BUFFERS(n) \
-    LPUART_BUFFER(UART_TX_BUFFER_ATTRIBUTE, n, T); \
-    LPUART_BUFFER(UART_RX_BUFFER_ATTRIBUTE, n, R); struct dummy_s
+#define UART_BUFFERS(n)                                         \
+    UART_BUFFER(UART_TX_BUFFER_ATTRIBUTE, n, T);                \
+    UART_BUFFER(UART_RX_BUFFER_ATTRIBUTE, n, R); struct dummy_s \
+/**/
 
 #ifdef USE_UART1
 UART_BUFFERS(1);
@@ -112,22 +112,103 @@ UART_BUFFERS(10);
 #endif
 
 #ifdef USE_LPUART1
-LPUART_BUFFERS(1);
+UART_BUFFERS(Lp1);  // TODO - maybe some other naming scheme ?
 #endif
 
 #undef UART_BUFFERS
 
-serialPort_t *uartOpen(UARTDevice_e device, serialReceiveCallbackPtr rxCallback, void *rxCallbackData, uint32_t baudRate, portMode_e mode, portOptions_e options)
+// store only devices configured for target (USE_UARTx)
+// some entries may be unused, for example because of pin configuration
+// uartDeviceIdx_e is direct index into this table
+FAST_DATA_ZERO_INIT uartDevice_t uartDevice[UARTDEV_COUNT];
+
+// map serialPortIdentifier_e to uartDeviceIdx_e
+uartDeviceIdx_e uartDeviceIdxFromIdentifier(serialPortIdentifier_e identifier)
 {
-    uartPort_t *uartPort = serialUART(device, baudRate, mode, options);
-
-    if (!uartPort)
-        return (serialPort_t *)uartPort;
-
-#ifdef USE_DMA
-    uartPort->txDMAEmpty = true;
+#ifdef USE_LPUART1
+    if (identifier == SERIAL_PORT_LPUART1) {
+        return UARTDEV_LP1;
+    }
 #endif
 
+#if 1 // TODO ...
+    // store +1 in table - unset values default to 0
+    // table is for UART only to save space (LPUART is handled separately)
+#define _R(id, dev) [id] = (dev) + 1
+    static const uartDeviceIdx_e uartMap[] = {
+#ifdef USE_UART1
+        _R(SERIAL_PORT_USART1, UARTDEV_1),
+#endif
+#ifdef USE_UART2
+        _R(SERIAL_PORT_USART2, UARTDEV_2),
+#endif
+#ifdef USE_UART3
+        _R(SERIAL_PORT_USART3, UARTDEV_3),
+#endif
+#ifdef USE_UART4
+        _R(SERIAL_PORT_UART4, UARTDEV_4),
+#endif
+#ifdef USE_UART5
+        _R(SERIAL_PORT_UART5, UARTDEV_5),
+#endif
+#ifdef USE_UART6
+        _R(SERIAL_PORT_USART6, UARTDEV_6),
+#endif
+#ifdef USE_UART7
+        _R(SERIAL_PORT_USART7, UARTDEV_7),
+#endif
+#ifdef USE_UART8
+        _R(SERIAL_PORT_USART8, UARTDEV_8),
+#endif
+#ifdef USE_UART9
+        _R(SERIAL_PORT_UART9, UARTDEV_9),
+#endif
+#ifdef USE_UART10
+        _R(SERIAL_PORT_USART10, UARTDEV_10),
+#endif
+    };
+#undef _R
+    if (identifier >= 0 && identifier < (int)ARRAYLEN(uartMap)) {
+        // UART case, but given USE_UARTx may not be defined
+        return uartMap[identifier] ? uartMap[identifier] - 1 : UARTDEV_INVALID;
+    }
+#else
+    {
+        const int idx = identifier - SERIAL_PORT_USART1;
+        if (idx >= 0 && idx < SERIAL_UART_MAX) {
+            if (BIT(idx) & SERIAL_UART_MASK) {
+                // return number of enabled UART ports smaller than idx
+                return popcount((BIT(idx) - 1) & SERIAL_UART_MASK);
+            } else {
+                return UARTDEV_INVALID;
+            }
+        }
+    }
+#endif
+    // neither LPUART nor UART
+    return UARTDEV_INVALID;
+}
+
+uartDevice_t *uartDeviceFromIdentifier(serialPortIdentifier_e identifier)
+{
+    const uartDeviceIdx_e deviceIdx = uartDeviceIdxFromIdentifier(identifier);
+    return deviceIdx != UARTDEV_INVALID ? &uartDevice[deviceIdx] : NULL;
+}
+
+serialPort_t *uartOpen(serialPortIdentifier_e identifier, serialReceiveCallbackPtr rxCallback, void *rxCallbackData, uint32_t baudRate, portMode_e mode, portOptions_e options)
+{
+    uartDevice_t *uartDevice = uartDeviceFromIdentifier(identifier);
+    if (!uartDevice) {
+        return NULL;
+    }
+    // fill identifier early, so initialization code can use it
+    uartDevice->port.port.identifier = identifier;
+
+    uartPort_t *uartPort = serialUART(uartDevice, baudRate, mode, options);
+    if (!uartPort) {
+        return NULL;
+    }
+
     // common serial initialisation code should move to serialPort::init()
     uartPort->port.rxBufferHead = uartPort->port.rxBufferTail = 0;
     uartPort->port.txBufferHead = uartPort->port.txBufferTail = 0;
@@ -381,6 +462,7 @@ const struct serialPortVTable uartVTable[] = {
     }
 };
 
+// TODO - move to serial_uart_hw.c
 #ifdef USE_DMA
 void uartConfigureDma(uartDevice_t *uartdev)
 {
@@ -388,11 +470,22 @@ void uartConfigureDma(uartDevice_t *uartdev)
     const uartHardware_t *hardware = uartdev->hardware;
 
 #ifdef USE_DMA_SPEC
-    UARTDevice_e device = hardware->device;
-    const dmaChannelSpec_t *dmaChannelSpec;
+    const serialPortIdentifier_e uartPortIdentifier = hardware->identifier;
+    const uartDeviceIdx_e uartDeviceIdx = uartDeviceIdxFromIdentifier(uartPortIdentifier);
+    if (uartDeviceIdx == UARTDEV_INVALID) {
+        return;
+    }
+    const int resourceIdx = serialResourceIndex(uartPortIdentifier);
+    const int ownerIndex = serialOwnerIndex(uartPortIdentifier);
+    const resourceOwner_e ownerTxRx = serialOwnerTxRx(uartPortIdentifier); // rx is always +1
 
-    if (serialUartConfig(device)->txDmaopt != DMA_OPT_UNUSED) {
-        dmaChannelSpec = dmaGetChannelSpecByPeripheral(DMA_PERIPH_UART_TX, device, serialUartConfig(device)->txDmaopt);
+    const dmaChannelSpec_t *dmaChannelSpec;
+    const serialUartConfig_t *cfg = serialUartConfig(resourceIdx);
+    if (!cfg) {
+        return;
+    }
+    if (cfg->txDmaopt != DMA_OPT_UNUSED) {
+        dmaChannelSpec = dmaGetChannelSpecByPeripheral(DMA_PERIPH_UART_TX, uartDeviceIdx, cfg->txDmaopt);
         if (dmaChannelSpec) {
             uartPort->txDMAResource = dmaChannelSpec->ref;
 #if defined(STM32F4) || defined(STM32F7) || defined(STM32H7) || defined(STM32G4) || defined(APM32F4)
@@ -403,8 +496,8 @@ void uartConfigureDma(uartDevice_t *uartdev)
         }
     }
 
-    if (serialUartConfig(device)->rxDmaopt != DMA_OPT_UNUSED) {
-        dmaChannelSpec = dmaGetChannelSpecByPeripheral(DMA_PERIPH_UART_RX, device, serialUartConfig(device)->txDmaopt);
+    if (cfg->rxDmaopt != DMA_OPT_UNUSED) {
+        dmaChannelSpec = dmaGetChannelSpecByPeripheral(DMA_PERIPH_UART_RX, uartDeviceIdx, cfg->txDmaopt);
         if (dmaChannelSpec) {
             uartPort->rxDMAResource = dmaChannelSpec->ref;
 #if defined(STM32F4) || defined(STM32F7) || defined(STM32H7) || defined(STM32G4) || defined(APM32F4)
@@ -414,7 +507,7 @@ void uartConfigureDma(uartDevice_t *uartdev)
 #endif
         }
     }
-#else
+#else /* USE_DMA_SPEC */
     // Non USE_DMA_SPEC does not support configurable ON/OFF of UART DMA
 
     if (hardware->rxDMAResource) {
@@ -434,11 +527,11 @@ void uartConfigureDma(uartDevice_t *uartdev)
         uartPort->txDMAMuxId = hardware->txDMAMuxId;
 #endif
     }
-#endif
+#endif /* USE_DMA_SPEC */
 
     if (uartPort->txDMAResource) {
-        dmaIdentifier_e identifier = dmaGetIdentifier(uartPort->txDMAResource);
-        if (dmaAllocate(identifier, OWNER_SERIAL_TX, RESOURCE_INDEX(hardware->device))) {
+        const dmaIdentifier_e identifier = dmaGetIdentifier(uartPort->txDMAResource);
+        if (dmaAllocate(identifier, ownerTxRx, ownerIndex)) {
             dmaEnable(identifier);
 #if defined(AT32F4)
             dmaMuxEnable(identifier, uartPort->txDMAMuxId);
@@ -449,8 +542,8 @@ void uartConfigureDma(uartDevice_t *uartdev)
     }
 
     if (uartPort->rxDMAResource) {
-        dmaIdentifier_e identifier = dmaGetIdentifier(uartPort->rxDMAResource);
-        if (dmaAllocate(identifier, OWNER_SERIAL_RX, RESOURCE_INDEX(hardware->device))) {
+        const dmaIdentifier_e identifier = dmaGetIdentifier(uartPort->rxDMAResource);
+        if (dmaAllocate(identifier, ownerTxRx + 1, ownerIndex)) {
             dmaEnable(identifier);
 #if defined(AT32F4)
             dmaMuxEnable(identifier, uartPort->rxDMAMuxId);
@@ -461,12 +554,13 @@ void uartConfigureDma(uartDevice_t *uartdev)
 }
 #endif
 
-#define UART_IRQHandler(type, number, dev) \
-    FAST_IRQ_HANDLER void type ## number ## _IRQHandler(void) \
-    { \
-        uartPort_t *uartPort = &(uartDevmap[dev]->port); \
-        uartIrqHandler(uartPort); \
-    }
+#define UART_IRQHandler(type, number, dev)                      \
+    FAST_IRQ_HANDLER void type ## number ## _IRQHandler(void)   \
+    {                                                           \
+        uartPort_t *uartPort = &(uartDevice[(dev)].port);       \
+        uartIrqHandler(uartPort);                               \
+    }                                                           \
+/**/
 
 #ifdef USE_UART1
 UART_IRQHandler(USART, 1, UARTDEV_1) // USART1 Rx/Tx IRQ Handler
@@ -509,7 +603,7 @@ UART_IRQHandler(UART, 10, UARTDEV_10) // UART10 Rx/Tx IRQ Handler
 #endif
 
 #ifdef USE_LPUART1
-UART_IRQHandler(LPUART, 1, LPUARTDEV_1) // LPUART1 Rx/Tx IRQ Handler
+UART_IRQHandler(LPUART, 1, UARTDEV_LP1) // LPUART1 Rx/Tx IRQ Handler
 #endif
 
 
diff --git a/src/main/drivers/serial_uart.h b/src/main/drivers/serial_uart.h
index 1213d64a51..3c0296b3da 100644
--- a/src/main/drivers/serial_uart.h
+++ b/src/main/drivers/serial_uart.h
@@ -21,30 +21,7 @@
 #pragma once
 
 #include "drivers/dma.h" // For dmaResource_t
-
-// Since serial ports can be used for any function these buffer sizes should be equal
-// The two largest things that need to be sent are: 1, MSP responses, 2, UBLOX SVINFO packet.
-
-// Size must be a power of two due to various optimizations which use 'and' instead of 'mod'
-// Various serial routines return the buffer occupied size as uint8_t which would need to be extended in order to
-// increase size further.
-
-typedef enum {
-    UARTDEV_1 = 0,
-    UARTDEV_2 = 1,
-    UARTDEV_3 = 2,
-    UARTDEV_4 = 3,
-    UARTDEV_5 = 4,
-    UARTDEV_6 = 5,
-    UARTDEV_7 = 6,
-    UARTDEV_8 = 7,
-    UARTDEV_9 = 8,
-    UARTDEV_10 = 9,
-    LPUARTDEV_1 = 10,
-    UARTDEV_COUNT
-} UARTDevice_e;
-
-STATIC_ASSERT(UARTDEV_COUNT == SERIAL_PORT_MAX_INDEX, serial_pinconfig_does_not_match_uartdevs);
+#include "io/serial.h"   // TODO: maybe move serialPortIdentifier_e into separate header
 
 typedef struct uartPort_s {
     serialPort_t port;
@@ -84,4 +61,4 @@ typedef struct uartPort_s {
 } uartPort_t;
 
 void uartPinConfigure(const serialPinConfig_t *pSerialPinConfig);
-serialPort_t *uartOpen(UARTDevice_e device, serialReceiveCallbackPtr rxCallback, void *rxCallbackData, uint32_t baudRate, portMode_e mode, portOptions_e options);
+serialPort_t *uartOpen(serialPortIdentifier_e identifier, serialReceiveCallbackPtr rxCallback, void *rxCallbackData, uint32_t baudRate, portMode_e mode, portOptions_e options);
diff --git a/src/main/drivers/serial_uart_hw.c b/src/main/drivers/serial_uart_hw.c
new file mode 100644
index 0000000000..91e42c005f
--- /dev/null
+++ b/src/main/drivers/serial_uart_hw.c
@@ -0,0 +1,210 @@
+/*
+ * This file is part of Betaflight.
+ *
+ * Betaflight is free software. You can redistribute this software
+ * and/or modify this software under the terms of the GNU General
+ * Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * Betaflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this software.
+ *
+ * If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * Common  UART hardware functions
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "platform.h"
+
+#if defined(USE_UART) && !defined(SIMULATOR_BUILD)
+
+#include "build/build_config.h"
+
+#include "drivers/nvic.h"
+#include "drivers/rcc.h"
+#include "drivers/inverter.h"
+#include "drivers/serial.h"
+#include "drivers/serial_impl.h"
+#include "drivers/serial_uart.h"
+#include "drivers/serial_uart_impl.h"
+
+// TODO: split this function into mcu-specific UART files ?
+static void enableRxIrq(const uartHardware_t *hardware)
+{
+#if defined(USE_HAL_DRIVER)
+        HAL_NVIC_SetPriority(hardware->irqn, NVIC_PRIORITY_BASE(hardware->rxPriority), NVIC_PRIORITY_SUB(hardware->rxPriority));
+        HAL_NVIC_EnableIRQ(hardware->irqn);
+#elif defined(STM32F4)
+        NVIC_InitTypeDef NVIC_InitStructure;
+        NVIC_InitStructure.NVIC_IRQChannel = hardware->irqn;
+        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = NVIC_PRIORITY_BASE(hardware->rxPriority);
+        NVIC_InitStructure.NVIC_IRQChannelSubPriority = NVIC_PRIORITY_SUB(hardware->rxPriority);
+        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
+        NVIC_Init(&NVIC_InitStructure);
+#elif defined(AT32F4)
+        nvic_irq_enable(hardware->irqn, NVIC_PRIORITY_BASE(hardware->rxPriority), NVIC_PRIORITY_SUB(hardware->rxPriority));
+#elif defined(APM32F4)
+        DAL_NVIC_SetPriority(hardware->irqn, NVIC_PRIORITY_BASE(hardware->rxPriority), NVIC_PRIORITY_SUB(hardware->rxPriority));
+        DAL_NVIC_EnableIRQ(hardware->irqn);
+#else
+# error "Unhandled MCU type"
+#endif
+}
+
+uartPort_t *serialUART(uartDevice_t *uartdev, uint32_t baudRate, portMode_e mode, portOptions_e options)
+{
+    uartPort_t *s = &uartdev->port;
+
+    const uartHardware_t *hardware = uartdev->hardware;
+
+    s->port.vTable = uartVTable;
+
+    s->port.baudRate = baudRate;
+
+    s->port.rxBuffer = hardware->rxBuffer;
+    s->port.txBuffer = hardware->txBuffer;
+    s->port.rxBufferSize = hardware->rxBufferSize;
+    s->port.txBufferSize = hardware->txBufferSize;
+
+    s->USARTx = hardware->reg;
+
+#ifdef USE_HAL_DRIVER
+    s->Handle.Instance = hardware->reg;
+#endif
+
+    s->checkUsartTxOutput = checkUsartTxOutput;
+
+    if (hardware->rcc) {
+        RCC_ClockCmd(hardware->rcc, ENABLE);
+    }
+
+#ifdef USE_DMA
+    uartConfigureDma(uartdev);
+    s->txDMAEmpty = true;
+#endif
+
+    IO_t txIO = IOGetByTag(uartdev->tx.pin);
+    IO_t rxIO = IOGetByTag(uartdev->rx.pin);
+
+    uartdev->txPinState = TX_PIN_IGNORE;
+
+    const serialPortIdentifier_e identifier = s->port.identifier;
+
+    const int ownerIndex = serialOwnerIndex(identifier);
+    const resourceOwner_e ownerTxRx = serialOwnerTxRx(identifier); // rx is always +1
+
+    // prepare AF modes
+#if UART_TRAIT_AF_PORT
+    uint8_t rxAf = hardware->af;
+    uint8_t txAf = hardware->af;
+#elif UART_TRAIT_AF_PIN
+    uint8_t rxAf = uartdev->rx.af;
+    uint8_t txAf = uartdev->tx.af;
+#endif
+
+// Note: F4 did not check txIO before refactoring
+    if ((options & SERIAL_BIDIR) && txIO) {
+        // pushPull / openDrain
+        const bool pushPull = serialOptions_pushPull(options);
+        // pull direction
+        const serialPullMode_t pull = serialOptions_pull(options);
+#if defined(STM32F7) || defined(STM32H7) || defined(STM32G4) || defined(APM32F4)
+        // Note: APM32F4 is different from STM32F4 here
+        const ioConfig_t ioCfg = IO_CONFIG(
+            pushPull ? GPIO_MODE_AF_PP : GPIO_MODE_AF_OD,
+            GPIO_SPEED_FREQ_HIGH,
+            ((const unsigned[]){GPIO_NOPULL, GPIO_PULLDOWN, GPIO_PULLUP})[pull]
+        );
+#elif defined(AT32F4)
+        const ioConfig_t ioCfg = IO_CONFIG(
+            GPIO_MODE_MUX,
+            GPIO_DRIVE_STRENGTH_STRONGER,
+            pushPull ? GPIO_OUTPUT_PUSH_PULL : GPIO_OUTPUT_OPEN_DRAIN,
+            ((const gpio_pull_type[]){GPIO_PULL_NONE, GPIO_PULL_DOWN, GPIO_PULL_UP})[pull]
+        );
+#elif defined(STM32F4)
+        // UART inverter is not supproted on F4, but keep it in line with other CPUs
+        // External inverter in bidir mode would be quite problematic anyway
+        const ioConfig_t ioCfg = IO_CONFIG(
+            GPIO_Mode_AF,
+            GPIO_Low_Speed,  // TODO: should use stronger drive
+            pushPull ? GPIO_OType_PP : GPIO_OType_OD,
+            ((const unsigned[]){GPIO_PuPd_NOPULL, GPIO_PuPd_DOWN, GPIO_PuPd_UP})[pull]
+        );
+#endif
+        IOInit(txIO, ownerTxRx, ownerIndex);
+        IOConfigGPIOAF(txIO, ioCfg, txAf);
+    } else {
+        if ((mode & MODE_TX) && txIO) {
+            IOInit(txIO, ownerTxRx, ownerIndex);
+
+            if (options & SERIAL_CHECK_TX) {
+#if defined(STM32F7)
+                // see https://github.com/betaflight/betaflight/pull/13021
+                // Allow for F7 UART idle preamble to be sent on startup
+                uartdev->txPinState = TX_PIN_MONITOR;
+                // Switch TX to UART output whilst UART sends idle preamble
+                checkUsartTxOutput(s);
+#else
+                uartdev->txPinState = TX_PIN_ACTIVE;
+                // Switch TX to an input with pullup so it's state can be monitored
+                uartTxMonitor(s);
+#endif
+            } else {
+#if defined(STM32F4) || defined(APM32F4)
+                // TODO: no need for pullup on TX only pin
+                const ioConfig_t ioCfg = IOCFG_AF_PP_UP;
+#else
+                const ioConfig_t ioCfg = IOCFG_AF_PP;
+#endif
+                IOConfigGPIOAF(txIO, ioCfg, txAf);
+            }
+        }
+
+        if ((mode & MODE_RX) && rxIO) {
+#if defined(STM32F4) || defined(APM32F4)
+            // no inversion possible on F4, always use pullup
+            const ioConfig_t ioCfg = IOCFG_AF_PP_UP;
+#else
+            // TODO: pullup/pulldown should be enabled for RX (based on inversion)
+            const ioConfig_t ioCfg = IOCFG_AF_PP;
+#endif
+            IOInit(rxIO, ownerTxRx + 1, ownerIndex);
+            IOConfigGPIOAF(rxIO, ioCfg, rxAf);
+        }
+    }
+
+    if (true
+#ifdef USE_DMA
+        && !s->rxDMAResource  // do not enable IRW if using rxDMA
+#endif
+        ) {
+        enableRxIrq(hardware);
+    }
+    return s;
+}
+
+// called from platform-specific uartReconfigure
+void uartConfigureExternalPinInversion(uartPort_t *uartPort)
+{
+#if !defined(USE_INVERTER)
+    UNUSED(uartPort);
+#else
+    const bool inverted = uartPort->port.options & SERIAL_INVERTED;
+    enableInverter(uartPort->port.identifier, inverted);
+#endif
+}
+
+#endif /* USE_UART */
diff --git a/src/main/drivers/serial_uart_impl.h b/src/main/drivers/serial_uart_impl.h
index 48e72e6216..e6b15d27a3 100644
--- a/src/main/drivers/serial_uart_impl.h
+++ b/src/main/drivers/serial_uart_impl.h
@@ -22,8 +22,28 @@
 
 // Configuration constants
 
+// TODO: this comment is obsolete
+
+// Since serial ports can be used for any function these buffer sizes should be equal
+// The two largest things that need to be sent are: 1, MSP responses, 2, UBLOX SVINFO packet.
+
+// Size must be a power of two due to various optimizations which use 'and' instead of 'mod'
+// Various serial routines return the buffer occupied size as uint8_t which would need to be extended in order to
+// increase size further.
+
+// define some common UART features
+#if defined(STM32F7) || defined(STM32H7) || defined(STM32G4) || defined(AT32F43x)
+#define UART_TRAIT_AF_PIN 1        // pin AF mode is configured for each pin individually
+#else
+#define UART_TRAIT_AF_PORT 1       // all pins on given uart use same AF
+#endif
+
+#if !defined(STM32F4) || !defined(APM32F4) // all others support pinswap
+#define UART_TRAIT_PINSWAP 1
+#endif
+
 #if defined(STM32F4)
-#define UARTDEV_COUNT_MAX 6
+
 #define UARTHARDWARE_MAX_PINS 4
 #ifndef UART_RX_BUFFER_SIZE
 #define UART_RX_BUFFER_SIZE     256
@@ -35,8 +55,9 @@
 #define UART_TX_BUFFER_SIZE     256
 #endif
 #endif
+
 #elif defined(STM32F7)
-#define UARTDEV_COUNT_MAX 8
+
 #define UARTHARDWARE_MAX_PINS 4
 #ifndef UART_RX_BUFFER_SIZE
 #define UART_RX_BUFFER_SIZE     256
@@ -48,8 +69,9 @@
 #define UART_TX_BUFFER_SIZE     256
 #endif
 #endif
+
 #elif defined(STM32H7)
-#define UARTDEV_COUNT_MAX 11 // UARTs 1 to 10 + LPUART1
+
 #define UARTHARDWARE_MAX_PINS 5
 #ifndef UART_RX_BUFFER_SIZE
 #define UART_RX_BUFFER_SIZE     256
@@ -61,8 +83,9 @@
 #define UART_TX_BUFFER_SIZE     256
 #endif
 #endif
+
 #elif defined(STM32G4)
-#define UARTDEV_COUNT_MAX 11  // UARTs 1 to 5 + LPUART1 (index 10)
+
 #define UARTHARDWARE_MAX_PINS 3
 #ifndef UART_RX_BUFFER_SIZE
 #define UART_RX_BUFFER_SIZE     256
@@ -74,8 +97,9 @@
 #define UART_TX_BUFFER_SIZE     256
 #endif
 #endif
+
 #elif defined(AT32F4)
-#define UARTDEV_COUNT_MAX 8  // UARTs 1 to 5 + LPUART1 (index 9)
+
 #define UARTHARDWARE_MAX_PINS 5
 #ifndef UART_RX_BUFFER_SIZE
 #define UART_RX_BUFFER_SIZE     256
@@ -88,7 +112,7 @@
 #endif
 #endif
 #elif defined(APM32F4)
-#define UARTDEV_COUNT_MAX 6
+
 #define UARTHARDWARE_MAX_PINS 4
 #ifndef UART_RX_BUFFER_SIZE
 #define UART_RX_BUFFER_SIZE     256
@@ -100,89 +124,59 @@
 #define UART_TX_BUFFER_SIZE     256
 #endif
 #endif
+
 #else
 #error unknown MCU family
 #endif
 
-// Count number of configured UARTs
-
+// compressed index of UART/LPUART. Direct index into uartDevice[]
+typedef enum {
+    UARTDEV_INVALID = -1,
 #ifdef USE_UART1
-#define UARTDEV_COUNT_1 1
-#else
-#define UARTDEV_COUNT_1 0
+    UARTDEV_1,
 #endif
-
 #ifdef USE_UART2
-#define UARTDEV_COUNT_2 1
-#else
-#define UARTDEV_COUNT_2 0
+    UARTDEV_2,
 #endif
-
 #ifdef USE_UART3
-#define UARTDEV_COUNT_3 1
-#else
-#define UARTDEV_COUNT_3 0
+    UARTDEV_3,
 #endif
-
 #ifdef USE_UART4
-#define UARTDEV_COUNT_4 1
-#else
-#define UARTDEV_COUNT_4 0
+    UARTDEV_4,
 #endif
-
 #ifdef USE_UART5
-#define UARTDEV_COUNT_5 1
-#else
-#define UARTDEV_COUNT_5 0
+    UARTDEV_5,
 #endif
-
 #ifdef USE_UART6
-#define UARTDEV_COUNT_6 1
-#else
-#define UARTDEV_COUNT_6 0
+    UARTDEV_6,
 #endif
-
 #ifdef USE_UART7
-#define UARTDEV_COUNT_7 1
-#else
-#define UARTDEV_COUNT_7 0
+    UARTDEV_7,
 #endif
-
 #ifdef USE_UART8
-#define UARTDEV_COUNT_8 1
-#else
-#define UARTDEV_COUNT_8 0
+    UARTDEV_8,
 #endif
-
 #ifdef USE_UART9
-#define UARTDEV_COUNT_9 1
-#else
-#define UARTDEV_COUNT_9 0
+    UARTDEV_9,
 #endif
-
 #ifdef USE_UART10
-#define UARTDEV_COUNT_10 1
-#else
-#define UARTDEV_COUNT_10 0
+    UARTDEV_10,
 #endif
-
 #ifdef USE_LPUART1
-#define LPUARTDEV_COUNT_1 1
-#else
-#define LPUARTDEV_COUNT_1 0
+    UARTDEV_LP1,
 #endif
-
-#define UARTDEV_COUNT (UARTDEV_COUNT_1 + UARTDEV_COUNT_2 + UARTDEV_COUNT_3 + UARTDEV_COUNT_4 + UARTDEV_COUNT_5 + UARTDEV_COUNT_6 + UARTDEV_COUNT_7 + UARTDEV_COUNT_8 + UARTDEV_COUNT_9 + UARTDEV_COUNT_10 + LPUARTDEV_COUNT_1)
+    UARTDEV_COUNT
+} uartDeviceIdx_e;
 
 typedef struct uartPinDef_s {
     ioTag_t pin;
-#if defined(STM32F7) || defined(STM32H7) || defined(STM32G4) || defined(AT32F43x) || defined(APM32F4)
+#if UART_TRAIT_AF_PIN
     uint8_t af;
 #endif
 } uartPinDef_t;
 
 typedef struct uartHardware_s {
-    UARTDevice_e device;    // XXX Not required for full allocation
+    serialPortIdentifier_e identifier;
     USART_TypeDef* reg;
 
 #ifdef USE_DMA
@@ -190,14 +184,14 @@ typedef struct uartHardware_s {
     dmaResource_t *rxDMAResource;
     // For H7 and G4  , {tx|rx}DMAChannel are DMAMUX input index for  peripherals (DMA_REQUEST_xxx); H7:RM0433 Table 110, G4:RM0440 Table 80.
     // For F4 and F7, these are 32-bit channel identifiers (DMA_CHANNEL_x)
-    // For at32f435/7 DmaChannel is the dmamux ,need to call dmamuxenable using dmamuxid
+    // For at32f435/7 DmaChannel is the dmamux, need to call dmamuxenable using dmamuxid
 #if defined(STM32F4) || defined(STM32F7) || defined(STM32H7) || defined(STM32G4) || defined(APM32F4)
     uint32_t txDMAChannel;
     uint32_t rxDMAChannel;
 #elif defined(AT32F4)
     uint32_t txDMAMuxId;//for dmaspec->dmamux  and using dmaMuxEnable(dmax,muxid)
     uint32_t rxDMAMuxId;
-#endif 
+#endif
 
 #endif // USE_DMA
 
@@ -206,16 +200,12 @@ typedef struct uartHardware_s {
 
     rccPeriphTag_t rcc;
 
-#if !defined(STM32F7)
+#if UART_TRAIT_AF_PORT
     uint8_t af;
 #endif
 
-#if defined(STM32F7) || defined(STM32H7) || defined(STM32G4)
-    uint8_t txIrq;
-    uint8_t rxIrq;
-#else
-    uint8_t irqn;
-#endif
+    uint8_t irqn;                  // uart IRQ. One shared IRQ per uart
+
     uint8_t txPriority;
     uint8_t rxPriority;
 
@@ -225,7 +215,7 @@ typedef struct uartHardware_s {
     uint16_t rxBufferSize;
 } uartHardware_t;
 
-extern const uartHardware_t uartHardware[];
+extern const uartHardware_t uartHardware[UARTDEV_COUNT];
 
 // uartDevice_t is an actual device instance.
 // XXX Instances are allocated for uarts defined by USE_UARTx atm.
@@ -236,6 +226,7 @@ typedef enum {
     TX_PIN_IGNORE
 } txPinState_t;
 
+// TODO: merge uartPort_t and uartDevice_t
 typedef struct uartDevice_s {
     uartPort_t port;
     const uartHardware_t *hardware;
@@ -243,19 +234,24 @@ typedef struct uartDevice_s {
     uartPinDef_t tx;
     volatile uint8_t *rxBuffer;
     volatile uint8_t *txBuffer;
-#if !defined(STM32F4) || !defined(APM32F4) // Don't support pin swap.
+#if UART_TRAIT_PINSWAP
     bool pinSwap;
 #endif
     txPinState_t txPinState;
 } uartDevice_t;
 
-extern uartDevice_t *uartDevmap[];
+extern uartDevice_t uartDevice[UARTDEV_COUNT];  // indexed by uartDeviceIdx_e;
+
+uartDeviceIdx_e uartDeviceIdxFromIdentifier(serialPortIdentifier_e identifier);
+uartDevice_t* uartDeviceFromIdentifier(serialPortIdentifier_e identifier);
 
 extern const struct serialPortVTable uartVTable[];
 
 void uartTryStartTxDMA(uartPort_t *s);
 
-uartPort_t *serialUART(UARTDevice_e device, uint32_t baudRate, portMode_e mode, portOptions_e options);
+uartPort_t *serialUART(uartDevice_t *uart, uint32_t baudRate, portMode_e mode, portOptions_e options);
+
+void uartConfigureExternalPinInversion(uartPort_t *uartPort);
 
 void uartIrqHandler(uartPort_t *s);
 
@@ -284,15 +280,10 @@ void uartTxMonitor(uartPort_t *s);
 
 #define UART_BUFFER(type, n, rxtx) type volatile uint8_t uart ## n ## rxtx ## xBuffer[UART_ ## rxtx ## X_BUFFER_SIZE]
 
-#define UART_BUFFERS_EXTERN(n) \
-    UART_BUFFER(extern, n, R); \
-    UART_BUFFER(extern, n, T); struct dummy_s
-
-#define LPUART_BUFFER(type, n, rxtx) type volatile uint8_t lpuart ## n ## rxtx ## xBuffer[UART_ ## rxtx ## X_BUFFER_SIZE]
-
-#define LPUART_BUFFERS_EXTERN(n) \
-    LPUART_BUFFER(extern, n, R); \
-    LPUART_BUFFER(extern, n, T); struct dummy_s
+#define UART_BUFFERS_EXTERN(n)                \
+    UART_BUFFER(extern, n, R);                \
+    UART_BUFFER(extern, n, T); struct dummy_s \
+/**/
 
 #ifdef USE_UART1
 UART_BUFFERS_EXTERN(1);
@@ -335,7 +326,7 @@ UART_BUFFERS_EXTERN(10);
 #endif
 
 #ifdef USE_LPUART1
-LPUART_BUFFERS_EXTERN(1);
+UART_BUFFERS_EXTERN(Lp1);
 #endif
 
 #undef UART_BUFFERS_EXTERN
diff --git a/src/main/drivers/serial_uart_pinconfig.c b/src/main/drivers/serial_uart_pinconfig.c
index 49ef1226ad..502744a6fb 100644
--- a/src/main/drivers/serial_uart_pinconfig.c
+++ b/src/main/drivers/serial_uart_pinconfig.c
@@ -41,48 +41,47 @@
 #include "drivers/serial_uart.h"
 #include "drivers/serial_uart_impl.h"
 
-static FAST_DATA_ZERO_INIT uartDevice_t uartDevice[UARTDEV_COUNT];      // Only those configured in target.h
-FAST_DATA_ZERO_INIT uartDevice_t *uartDevmap[UARTDEV_COUNT_MAX]; // Full array
-
 void uartPinConfigure(const serialPinConfig_t *pSerialPinConfig)
 {
-    uartDevice_t *uartdev = uartDevice;
-
-    for (size_t hindex = 0; hindex < UARTDEV_COUNT; hindex++) {
-
-        const uartHardware_t *hardware = &uartHardware[hindex];
-        const UARTDevice_e device = hardware->device;
-
-#if !defined(STM32F4) || !defined(APM32F4) // Don't support pin swap.
-        uartdev->pinSwap = false;
+    for (const uartHardware_t* hardware = uartHardware; hardware < ARRAYEND(uartHardware); hardware++) {
+        const serialPortIdentifier_e identifier = hardware->identifier;
+        uartDevice_t* uartdev = uartDeviceFromIdentifier(identifier);
+        const int resourceIndex = serialResourceIndex(identifier);
+        if (uartdev == NULL || resourceIndex < 0) {
+            // malformed uartHardware
+            continue;
+        }
+        const ioTag_t cfgRx = pSerialPinConfig->ioTagRx[resourceIndex];
+        const ioTag_t cfgTx = pSerialPinConfig->ioTagTx[resourceIndex];
+#if UART_TRAIT_PINSWAP
+        bool swap = false;
 #endif
-        for (int pindex = 0 ; pindex < UARTHARDWARE_MAX_PINS ; pindex++) {
-            if (pSerialPinConfig->ioTagRx[device] && (pSerialPinConfig->ioTagRx[device] == hardware->rxPins[pindex].pin)) {
+        for (unsigned pindex = 0 ; pindex < UARTHARDWARE_MAX_PINS ; pindex++) {
+            if (cfgRx && cfgRx == hardware->rxPins[pindex].pin) {
                 uartdev->rx = hardware->rxPins[pindex];
             }
 
-            if (pSerialPinConfig->ioTagTx[device] && (pSerialPinConfig->ioTagTx[device] == hardware->txPins[pindex].pin)) {
+            if (cfgTx && cfgTx == hardware->txPins[pindex].pin) {
                 uartdev->tx = hardware->txPins[pindex];
             }
-
-
-#if !defined(STM32F4) || !defined(APM32F4)
+#if UART_TRAIT_PINSWAP
             // Check for swapped pins
-            if (pSerialPinConfig->ioTagTx[device] && (pSerialPinConfig->ioTagTx[device] == hardware->rxPins[pindex].pin)) {
+            if (cfgTx && cfgTx == hardware->rxPins[pindex].pin) {
                 uartdev->tx = hardware->rxPins[pindex];
-                uartdev->pinSwap = true;
+                swap = true;
             }
 
-            if (pSerialPinConfig->ioTagRx[device] && (pSerialPinConfig->ioTagRx[device] == hardware->txPins[pindex].pin)) {
+            if (cfgRx && cfgRx == hardware->txPins[pindex].pin) {
                 uartdev->rx = hardware->txPins[pindex];
-                uartdev->pinSwap = true;
+                swap = true;
             }
 #endif
         }
-
-        if (uartdev->rx.pin || uartdev->tx.pin) {
+        if (uartdev->rx.pin || uartdev->tx.pin ) {
             uartdev->hardware = hardware;
-            uartDevmap[device] = uartdev++;
+#if UART_TRAIT_PINSWAP
+            uartdev->pinSwap = swap;
+#endif
         }
     }
 }
diff --git a/src/main/fc/init.c b/src/main/fc/init.c
index f833f9df4b..b2ba5330ab 100644
--- a/src/main/fc/init.c
+++ b/src/main/fc/init.c
@@ -260,7 +260,7 @@ static void sdCardAndFSInit(void)
 
 void init(void)
 {
-#ifdef SERIAL_PORT_COUNT
+#if SERIAL_PORT_COUNT > 0
     printfSerialInit();
 #endif
 
@@ -519,17 +519,21 @@ void init(void)
 #endif
 
 #if defined(AVOID_UART1_FOR_PWM_PPM)
-    serialInit(featureIsEnabled(FEATURE_SOFTSERIAL),
-            featureIsEnabled(FEATURE_RX_PPM) || featureIsEnabled(FEATURE_RX_PARALLEL_PWM) ? SERIAL_PORT_USART1 : SERIAL_PORT_NONE);
+# define SERIALPORT_TO_AVOID SERIAL_PORT_USART1
 #elif defined(AVOID_UART2_FOR_PWM_PPM)
-    serialInit(featureIsEnabled(FEATURE_SOFTSERIAL),
-            featureIsEnabled(FEATURE_RX_PPM) || featureIsEnabled(FEATURE_RX_PARALLEL_PWM) ? SERIAL_PORT_USART2 : SERIAL_PORT_NONE);
+# define SERIALPORT_TO_AVOID SERIAL_PORT_USART2
 #elif defined(AVOID_UART3_FOR_PWM_PPM)
-    serialInit(featureIsEnabled(FEATURE_SOFTSERIAL),
-            featureIsEnabled(FEATURE_RX_PPM) || featureIsEnabled(FEATURE_RX_PARALLEL_PWM) ? SERIAL_PORT_USART3 : SERIAL_PORT_NONE);
-#else
-    serialInit(featureIsEnabled(FEATURE_SOFTSERIAL), SERIAL_PORT_NONE);
+# define SERIALPORT_TO_AVOID SERIAL_PORT_USART3
 #endif
+    {
+        serialPortIdentifier_e serialPortToAvoid = SERIAL_PORT_NONE;
+#if defined(SERIALPORT_TO_AVOID)
+        if (featureIsEnabled(FEATURE_RX_PPM) || featureIsEnabled(FEATURE_RX_PARALLEL_PWM)) {
+            serialPortToAvoid = SERIALPORT_TO_AVOID;
+        }
+#endif
+        serialInit(featureIsEnabled(FEATURE_SOFTSERIAL), serialPortToAvoid);
+    }
 
     mixerInit(mixerConfig()->mixerMode);
 
diff --git a/src/main/io/gps.c b/src/main/io/gps.c
index 8360af4ce6..acb85ac1de 100644
--- a/src/main/io/gps.c
+++ b/src/main/io/gps.c
@@ -435,8 +435,8 @@ void gpsInit(void)
         mode &= ~MODE_TX;
     }
 #endif
-
-    if ((gpsPortConfig->identifier >= SERIAL_PORT_USART1) && (gpsPortConfig->identifier <= SERIAL_PORT_USART_MAX)){
+    if (serialType(gpsPortConfig->identifier) == SERIALTYPE_UART
+        || serialType(gpsPortConfig->identifier) == SERIALTYPE_LPUART){
         options |= SERIAL_CHECK_TX;
     }
 
diff --git a/src/main/io/serial.c b/src/main/io/serial.c
index 3266da2165..9816ce4624 100644
--- a/src/main/io/serial.c
+++ b/src/main/io/serial.c
@@ -100,8 +100,10 @@ const serialPortIdentifier_e serialPortIdentifiers[SERIAL_PORT_COUNT] = {
 #ifdef USE_UART10
     SERIAL_PORT_USART10,
 #endif
-#ifdef USE_SOFTSERIAL
+#ifdef USE_SOFTSERIAL1
     SERIAL_PORT_SOFTSERIAL1,
+#endif
+#ifdef USE_SOFTSERIAL2
     SERIAL_PORT_SOFTSERIAL2,
 #endif
 #ifdef USE_LPUART1
@@ -109,24 +111,77 @@ const serialPortIdentifier_e serialPortIdentifiers[SERIAL_PORT_COUNT] = {
 #endif
 };
 
+const char* serialPortNames[SERIAL_PORT_COUNT] = {
+#ifdef USE_VCP
+    "VCP",
+#endif
+#ifdef USE_UART1
+    "UART1",
+#endif
+#ifdef USE_UART2
+    "UART2",
+#endif
+#ifdef USE_UART3
+    "UART3",
+#endif
+#ifdef USE_UART4
+    "UART4",
+#endif
+#ifdef USE_UART5
+    "UART5",
+#endif
+#ifdef USE_UART6
+    "UART6",
+#endif
+#ifdef USE_UART7
+    "UART7",
+#endif
+#ifdef USE_UART8
+    "UART8",
+#endif
+#ifdef USE_UART9
+    "UART9",
+#endif
+#ifdef USE_UART10
+    "UART10",
+#endif
+#ifdef USE_SOFTSERIAL1
+    "SOFT1",
+#endif
+#ifdef USE_SOFTSERIAL2
+    "SOFT2",
+#endif
+#ifdef USE_LPUART1
+    "LPUART1",
+#endif
+};
+
 static uint8_t serialPortCount;
 
 const uint32_t baudRates[] = {0, 9600, 19200, 38400, 57600, 115200, 230400, 250000,
         400000, 460800, 500000, 921600, 1000000, 1500000, 2000000, 2470000}; // see baudRate_e
 
-#define BAUD_RATE_COUNT ARRAYLEN(baudRates) 
-
-serialPortConfig_t *serialFindPortConfigurationMutable(serialPortIdentifier_e identifier)
+static serialPortConfig_t* findInPortConfigs_identifier(const serialPortConfig_t cfgs[], size_t count, serialPortIdentifier_e identifier)
 {
-    for (int index = 0; index < SERIAL_PORT_COUNT; index++) {
-        serialPortConfig_t *candidate = &serialConfigMutable()->portConfigs[index];
-        if (candidate->identifier == identifier) {
-            return candidate;
+    for (unsigned i = 0; i < count; i++) {
+        if (cfgs[i].identifier == identifier) {
+            // drop const on return - wrapper function will add it back if necessary
+            return (serialPortConfig_t*)&cfgs[i];
         }
     }
     return NULL;
 }
 
+serialPortConfig_t* serialFindPortConfigurationMutable(serialPortIdentifier_e identifier)
+{
+    return findInPortConfigs_identifier(serialConfigMutable()->portConfigs, ARRAYLEN(serialConfigMutable()->portConfigs), identifier);
+}
+
+const serialPortConfig_t* serialFindPortConfiguration(serialPortIdentifier_e identifier)
+{
+    return findInPortConfigs_identifier(serialConfigMutable()->portConfigs, ARRAYLEN(serialConfig()->portConfigs), identifier);
+}
+
 PG_REGISTER_WITH_RESET_FN(serialConfig_t, serialConfig, PG_SERIAL_CONFIG, 1);
 
 void pgResetFn_serialConfig(serialConfig_t *serialConfig)
@@ -134,11 +189,12 @@ void pgResetFn_serialConfig(serialConfig_t *serialConfig)
     memset(serialConfig, 0, sizeof(serialConfig_t));
 
     for (int i = 0; i < SERIAL_PORT_COUNT; i++) {
-        serialConfig->portConfigs[i].identifier = serialPortIdentifiers[i];
-        serialConfig->portConfigs[i].msp_baudrateIndex = BAUD_115200;
-        serialConfig->portConfigs[i].gps_baudrateIndex = BAUD_57600;
-        serialConfig->portConfigs[i].telemetry_baudrateIndex = BAUD_AUTO;
-        serialConfig->portConfigs[i].blackbox_baudrateIndex = BAUD_115200;
+        serialPortConfig_t* pCfg = &serialConfig->portConfigs[i];
+        pCfg->identifier = serialPortIdentifiers[i];
+        pCfg->msp_baudrateIndex = BAUD_115200;
+        pCfg->gps_baudrateIndex = BAUD_57600;
+        pCfg->telemetry_baudrateIndex = BAUD_AUTO;
+        pCfg->blackbox_baudrateIndex = BAUD_115200;
     }
 
     serialConfig->portConfigs[0].functionMask = FUNCTION_MSP;
@@ -221,9 +277,7 @@ void pgResetFn_serialConfig(serialConfig_t *serialConfig)
 
 baudRate_e lookupBaudRateIndex(uint32_t baudRate)
 {
-    uint8_t index;
-
-    for (index = 0; index < BAUD_RATE_COUNT; index++) {
+    for (unsigned index = 0; index < ARRAYLEN(baudRates); index++) {
         if (baudRates[index] == baudRate) {
             return index;
         }
@@ -233,7 +287,7 @@ baudRate_e lookupBaudRateIndex(uint32_t baudRate)
 
 int findSerialPortIndexByIdentifier(serialPortIdentifier_e identifier)
 {
-    for (int index = 0; index < SERIAL_PORT_COUNT; index++) {
+    for (unsigned index = 0; index < ARRAYLEN(serialPortIdentifiers); index++) {
         if (serialPortIdentifiers[index] == identifier) {
             return index;
         }
@@ -241,13 +295,35 @@ int findSerialPortIndexByIdentifier(serialPortIdentifier_e identifier)
     return -1;
 }
 
+// find serial port by name.
+// when cmp is NULL, case-insensitive compare is used
+// cmp is strcmp-like function
+serialPortIdentifier_e findSerialPortByName(const char* portName, int (*cmp)(const char *portName, const char *candidate))
+{
+    if (!cmp) { // use strcasecmp by default
+        cmp = strcasecmp;
+    }
+    for (unsigned i = 0; i < ARRAYLEN(serialPortNames); i++) {
+        if (cmp(portName, serialPortNames[i]) == 0) {
+            return serialPortIdentifiers[i];  // 1:1 map between names and identifiers
+        }
+    }
+    return SERIAL_PORT_NONE;
+}
+
+
+const char* serialName(serialPortIdentifier_e identifier, const char* notFound)
+{
+    const int idx = findSerialPortIndexByIdentifier(identifier);
+    return idx >= 0 ? serialPortNames[idx] : notFound;
+}
+
+
 serialPortUsage_t *findSerialPortUsageByIdentifier(serialPortIdentifier_e identifier)
 {
-    uint8_t index;
-    for (index = 0; index < SERIAL_PORT_COUNT; index++) {
-        serialPortUsage_t *candidate = &serialPortUsageList[index];
-        if (candidate->identifier == identifier) {
-            return candidate;
+    for (serialPortUsage_t* usage = serialPortUsageList; usage < ARRAYEND(serialPortUsageList); usage++) {
+        if (usage->identifier == identifier) {
+            return usage;
         }
     }
     return NULL;
@@ -255,11 +331,9 @@ serialPortUsage_t *findSerialPortUsageByIdentifier(serialPortIdentifier_e identi
 
 serialPortUsage_t *findSerialPortUsageByPort(const serialPort_t *serialPort)
 {
-    uint8_t index;
-    for (index = 0; index < SERIAL_PORT_COUNT; index++) {
-        serialPortUsage_t *candidate = &serialPortUsageList[index];
-        if (candidate->serialPort == serialPort) {
-            return candidate;
+    for (serialPortUsage_t* usage = serialPortUsageList; usage < ARRAYEND(serialPortUsageList); usage++) {
+        if (usage->serialPort == serialPort) {
+            return usage;
         }
     }
     return NULL;
@@ -280,7 +354,7 @@ const serialPortConfig_t *findSerialPortConfig(serialPortFunction_e function)
 
 const serialPortConfig_t *findNextSerialPortConfig(serialPortFunction_e function)
 {
-    while (findSerialPortConfigState.lastIndex < SERIAL_PORT_COUNT) {
+    while (findSerialPortConfigState.lastIndex < ARRAYLEN(serialConfig()->portConfigs)) {
         const serialPortConfig_t *candidate = &serialConfig()->portConfigs[findSerialPortConfigState.lastIndex++];
 
         if (candidate->functionMask & function) {
@@ -305,7 +379,7 @@ bool isSerialPortShared(const serialPortConfig_t *portConfig, uint16_t functionM
 
 serialPort_t *findSharedSerialPort(uint16_t functionMask, serialPortFunction_e sharedWithFunction)
 {
-    for (unsigned i = 0; i < SERIAL_PORT_COUNT; i++) {
+    for (unsigned i = 0; i < ARRAYLEN(serialConfig()->portConfigs); i++) {
         const serialPortConfig_t *candidate = &serialConfig()->portConfigs[i];
 
         if (isSerialPortShared(candidate, functionMask, sharedWithFunction)) {
@@ -338,12 +412,11 @@ bool isSerialConfigValid(serialConfig_t *serialConfigToCheck)
      */
     uint8_t mspPortCount = 0;
 
-    for (int index = 0; index < SERIAL_PORT_COUNT; index++) {
+    for (unsigned index = 0; index < ARRAYLEN(serialConfigToCheck->portConfigs); index++) {
         const serialPortConfig_t *portConfig = &serialConfigToCheck->portConfigs[index];
 
 #ifdef USE_SOFTSERIAL
-        if ((portConfig->identifier == SERIAL_PORT_SOFTSERIAL1) ||
-            (portConfig->identifier == SERIAL_PORT_SOFTSERIAL2)) {
+        if (serialType(portConfig->identifier) == SERIALTYPE_SOFTSERIAL) {
             // Ensure MSP or serial RX is not enabled on soft serial ports
             serialConfigToCheck->portConfigs[index].functionMask &= ~(FUNCTION_MSP | FUNCTION_RX_SERIAL);
             // Ensure that the baud rate on soft serial ports is limited to 19200
@@ -357,12 +430,14 @@ bool isSerialConfigValid(serialConfig_t *serialConfigToCheck)
 
         if (portConfig->functionMask & FUNCTION_MSP) {
             mspPortCount++;
-        } else if (portConfig->identifier == SERIAL_PORT_USB_VCP) {
+        }
+        if (portConfig->identifier == SERIAL_PORT_USB_VCP
+            && (portConfig->functionMask & FUNCTION_MSP) == 0) {
             // Require MSP to be enabled for the VCP port
             return false;
         }
 
-        uint8_t bitCount = BITCOUNT(portConfig->functionMask);
+        uint8_t bitCount = popcount(portConfig->functionMask);
 
 #ifdef USE_VTX_MSP
         if ((portConfig->functionMask & FUNCTION_VTX_MSP) && bitCount == 1) { // VTX MSP has to be shared with RX or MSP serial
@@ -395,17 +470,6 @@ bool isSerialConfigValid(serialConfig_t *serialConfigToCheck)
     return true;
 }
 
-const serialPortConfig_t *serialFindPortConfiguration(serialPortIdentifier_e identifier)
-{
-    for (int index = 0; index < SERIAL_PORT_COUNT; index++) {
-        const serialPortConfig_t *candidate = &serialConfig()->portConfigs[index];
-        if (candidate->identifier == identifier) {
-            return candidate;
-        }
-    }
-    return NULL;
-}
-
 bool doesConfigurationUsePort(serialPortIdentifier_e identifier)
 {
     const serialPortConfig_t *candidate = serialFindPortConfiguration(identifier);
@@ -421,7 +485,7 @@ serialPort_t *openSerialPort(
     portMode_e mode,
     portOptions_e options)
 {
-#if !(defined(USE_UART) || defined(USE_SOFTSERIAL))
+#if !(defined(USE_UART) || defined(USE_SOFTSERIAL) || defined(USE_LPUART))
     UNUSED(rxCallback);
     UNUSED(rxCallbackData);
     UNUSED(baudRate);
@@ -437,71 +501,34 @@ serialPort_t *openSerialPort(
 
     serialPort_t *serialPort = NULL;
 
-#if defined(USE_SOFTSERIAL) && !defined(USE_OVERRIDE_SOFTSERIAL_BAUDRATE)
-    if (((identifier == SERIAL_PORT_SOFTSERIAL1) || (identifier == SERIAL_PORT_SOFTSERIAL2)) && (baudRate > 19200)) {
-        // Don't continue if baud rate requested is higher then the limit set on soft serial ports
-        return NULL;
-    }
+    switch (serialType(identifier)) {
+#if defined(USE_VCP)
+    case SERIALTYPE_USB_VCP:
+        serialPort = usbVcpOpen();
+        break;
 #endif
-
-    switch (identifier) {
-#ifdef USE_VCP
-        case SERIAL_PORT_USB_VCP:
-            serialPort = usbVcpOpen();
-            break;
-#endif
-
 #if defined(USE_UART)
-#ifdef USE_UART1
-        case SERIAL_PORT_USART1:
-#endif
-#ifdef USE_UART2
-        case SERIAL_PORT_USART2:
-#endif
-#ifdef USE_UART3
-        case SERIAL_PORT_USART3:
-#endif
-#ifdef USE_UART4
-        case SERIAL_PORT_UART4:
-#endif
-#ifdef USE_UART5
-        case SERIAL_PORT_UART5:
-#endif
-#ifdef USE_UART6
-        case SERIAL_PORT_USART6:
-#endif
-#ifdef USE_UART7
-        case SERIAL_PORT_USART7:
-#endif
-#ifdef USE_UART8
-        case SERIAL_PORT_USART8:
-#endif
-#ifdef USE_UART9
-        case SERIAL_PORT_UART9:
-#endif
-#ifdef USE_UART10
-        case SERIAL_PORT_USART10:
-#endif
-#ifdef USE_LPUART1
-        case SERIAL_PORT_LPUART1:
-#endif
+    case SERIALTYPE_UART:
+    case SERIALTYPE_LPUART:
 #if defined(SIMULATOR_BUILD)
-            // emulate serial ports over TCP
-            serialPort = serTcpOpen(SERIAL_PORT_IDENTIFIER_TO_UARTDEV(identifier), rxCallback, rxCallbackData, baudRate, mode, options);
+        // emulate serial ports over TCP
+        serialPort = serTcpOpen(identifier, rxCallback, rxCallbackData, baudRate, mode, options);
 #else
-            serialPort = uartOpen(SERIAL_PORT_IDENTIFIER_TO_UARTDEV(identifier), rxCallback, rxCallbackData, baudRate, mode, options);
+        serialPort = uartOpen(identifier, rxCallback, rxCallbackData, baudRate, mode, options);
 #endif
-            break;
 #endif
-
+        break;
 #ifdef USE_SOFTSERIAL
-        case SERIAL_PORT_SOFTSERIAL1:
-            serialPort = openSoftSerial(SOFTSERIAL1, rxCallback, rxCallbackData, baudRate, mode, options);
-            break;
-        case SERIAL_PORT_SOFTSERIAL2:
-            serialPort = openSoftSerial(SOFTSERIAL2, rxCallback, rxCallbackData, baudRate, mode, options);
-            break;
-#endif
+    case SERIALTYPE_SOFTSERIAL:
+# if !defined(USE_OVERRIDE_SOFTSERIAL_BAUDRATE)
+        if (baudRate > 19200) {
+            // Don't continue if baud rate requested is higher then the limit set on soft serial ports
+            return NULL;
+        }
+# endif // !USE_OVERRIDE_SOFTSERIAL_BAUDRATE
+        serialPort = softSerialOpen(identifier, rxCallback, rxCallbackData, baudRate, mode, options);
+        break;
+#endif // USE_SOFTSERIAL
         default:
             break;
     }
@@ -510,7 +537,7 @@ serialPort_t *openSerialPort(
         return NULL;
     }
 
-    serialPort->identifier = identifier;
+    serialPort->identifier = identifier; // Some versions of *Open() set this member sooner
 
     serialPortUsage->function = function;
     serialPortUsage->serialPort = serialPort;
@@ -545,50 +572,43 @@ void serialInit(bool softserialEnabled, serialPortIdentifier_e serialPortToDisab
     for (int index = 0; index < SERIAL_PORT_COUNT; index++) {
         serialPortUsageList[index].identifier = serialPortIdentifiers[index];
 
-        if (serialPortToDisable != SERIAL_PORT_NONE) {
-            if (serialPortUsageList[index].identifier == serialPortToDisable) {
+        if (serialPortToDisable != SERIAL_PORT_NONE
+            && serialPortUsageList[index].identifier == serialPortToDisable) {
                 serialPortUsageList[index].identifier = SERIAL_PORT_NONE;
                 serialPortCount--;
-            }
+                continue;  // this index is deleted
         }
-#if !defined(SIMULATOR_BUILD)
-        else if (serialPortUsageList[index].identifier <= SERIAL_PORT_USART10
-#ifdef USE_LPUART1
-            || serialPortUsageList[index].identifier == SERIAL_PORT_LPUART1
-#endif
-        ) {
-            int resourceIndex = SERIAL_PORT_IDENTIFIER_TO_INDEX(serialPortUsageList[index].identifier);
-            if (!(serialPinConfig()->ioTagTx[resourceIndex] || serialPinConfig()->ioTagRx[resourceIndex])) {
-                serialPortUsageList[index].identifier = SERIAL_PORT_NONE;
-                serialPortCount--;
-            }
-        }
-#endif
-#ifdef USE_SOFTSERIAL
-        else if (((serialPortUsageList[index].identifier == SERIAL_PORT_SOFTSERIAL1) &&
-                   (!softserialEnabled || !(softSerialPinConfig()->ioTagRx[SOFTSERIAL1] || softSerialPinConfig()->ioTagTx[SOFTSERIAL1]))) ||
-                  ((serialPortUsageList[index].identifier == SERIAL_PORT_SOFTSERIAL2) &&
-                   (!softserialEnabled || !(softSerialPinConfig()->ioTagRx[SOFTSERIAL2] || softSerialPinConfig()->ioTagTx[SOFTSERIAL2]))))
-#else
-        else if (
-            (serialPortUsageList[index].identifier == SERIAL_PORT_SOFTSERIAL1) ||
-            (serialPortUsageList[index].identifier == SERIAL_PORT_SOFTSERIAL2)
-        )
-#endif
         {
-            serialPortUsageList[index].identifier = SERIAL_PORT_NONE;
-            serialPortCount--;
+#if !defined(SIMULATOR_BUILD)  // no serialPinConfig on SITL
+            const int resourceIndex = serialResourceIndex(serialPortUsageList[index].identifier);
+            if (resourceIndex >= 0   // resource exists
+                && !(serialPinConfig()->ioTagTx[resourceIndex] || serialPinConfig()->ioTagRx[resourceIndex])) {
+                serialPortUsageList[index].identifier = SERIAL_PORT_NONE;
+                serialPortCount--;
+                continue;
+            }
+#endif
+        }
+        if (serialType(serialPortUsageList[index].identifier) == SERIALTYPE_SOFTSERIAL) {
+            if (true
+#ifdef USE_SOFTSERIAL
+                && !softserialEnabled
+#endif
+                ) {
+                serialPortUsageList[index].identifier = SERIAL_PORT_NONE;
+                serialPortCount--;
+                continue;
+            }
         }
     }
 }
 
 void serialRemovePort(serialPortIdentifier_e identifier)
 {
-    for (uint8_t index = 0; index < SERIAL_PORT_COUNT; index++) {
-        if (serialPortUsageList[index].identifier == identifier) {
-            serialPortUsageList[index].identifier = SERIAL_PORT_NONE;
-            serialPortCount--;
-        }
+    serialPortUsage_t* usage;
+    while ((usage = findSerialPortUsageByIdentifier(identifier)) != NULL) {
+        usage->identifier = SERIAL_PORT_NONE;
+        serialPortCount--;
     }
 }
 
@@ -599,12 +619,7 @@ uint8_t serialGetAvailablePortCount(void)
 
 bool serialIsPortAvailable(serialPortIdentifier_e identifier)
 {
-    for (uint8_t index = 0; index < SERIAL_PORT_COUNT; index++) {
-        if (serialPortUsageList[index].identifier == identifier) {
-            return true;
-        }
-    }
-    return false;
+    return findSerialPortUsageByIdentifier(identifier) != NULL;
 }
 
 void waitForSerialPortToFinishTransmitting(serialPort_t *serialPort)
diff --git a/src/main/io/serial.h b/src/main/io/serial.h
index 9db0c91ee6..3c3bad3ffa 100644
--- a/src/main/io/serial.h
+++ b/src/main/io/serial.h
@@ -83,40 +83,46 @@ typedef enum {
     SERIAL_PORT_ALL = -2,
     SERIAL_PORT_NONE = -1,
     SERIAL_PORT_USART1 = 0,
+    SERIAL_PORT_UART1 = SERIAL_PORT_USART1,
     SERIAL_PORT_USART2,
+    SERIAL_PORT_UART2 = SERIAL_PORT_USART2,
     SERIAL_PORT_USART3,
+    SERIAL_PORT_UART3 = SERIAL_PORT_USART3,
     SERIAL_PORT_UART4,
     SERIAL_PORT_UART5,
     SERIAL_PORT_USART6,
+    SERIAL_PORT_UART6 = SERIAL_PORT_USART6,
     SERIAL_PORT_USART7,
+    SERIAL_PORT_UART7 = SERIAL_PORT_USART7,
     SERIAL_PORT_USART8,
+    SERIAL_PORT_UART8 = SERIAL_PORT_USART8,
     SERIAL_PORT_UART9,
     SERIAL_PORT_USART10,
+    SERIAL_PORT_UART10 = SERIAL_PORT_USART10,
     SERIAL_PORT_USART_MAX = SERIAL_PORT_USART10,
+
     SERIAL_PORT_USB_VCP = 20,
+
     SERIAL_PORT_SOFTSERIAL1 = 30,
     SERIAL_PORT_SOFTSERIAL2,
+
     SERIAL_PORT_LPUART1 = 40,
-    SERIAL_PORT_IDENTIFIER_MAX = SERIAL_PORT_LPUART1,
 } serialPortIdentifier_e;
 
+// use value from target serial port normalization
+#define SERIAL_PORT_COUNT (SERIAL_UART_COUNT + SERIAL_LPUART_COUNT + SERIAL_SOFTSERIAL_COUNT + SERIAL_VCP_COUNT)
+
 extern const serialPortIdentifier_e serialPortIdentifiers[SERIAL_PORT_COUNT];
 
-#define SOFTSERIAL_PORT_IDENTIFIER_TO_INDEX(x) ((x) - SERIAL_PORT_SOFTSERIAL1)
+typedef enum {
+    SERIALTYPE_INVALID = -1,
+    SERIALTYPE_USB_VCP = 0,
+    SERIALTYPE_UART,
+    SERIALTYPE_LPUART,
+    SERIALTYPE_SOFTSERIAL,
+    SERIALTYPE_COUNT
+} serialType_e;
 
-#if defined(USE_LPUART1)
-
-#define SERIAL_PORT_IDENTIFIER_TO_INDEX(x) \
-    (((x) <= SERIAL_PORT_USART_MAX) ? ((x) - SERIAL_PORT_USART1) : ((x) - SERIAL_PORT_LPUART1) + LPUARTDEV_1)
-#define SERIAL_PORT_IDENTIFIER_TO_UARTDEV(x) \
-    (((x) <= SERIAL_PORT_USART_MAX) ? ((x) - SERIAL_PORT_USART1 + UARTDEV_1) : ((x) - SERIAL_PORT_LPUART1) + LPUARTDEV_1)
-
-#else
-
-#define SERIAL_PORT_IDENTIFIER_TO_INDEX(x) ((x) - SERIAL_PORT_USART1)
-#define SERIAL_PORT_IDENTIFIER_TO_UARTDEV(x) ((x) - SERIAL_PORT_USART1 + UARTDEV_1)
-
-#endif
 //
 // runtime
 //
@@ -170,6 +176,9 @@ bool isSerialPortShared(const serialPortConfig_t *portConfig, uint16_t functionM
 void pgResetFn_serialConfig(serialConfig_t *serialConfig); //!!TODO remove need for this
 serialPortUsage_t *findSerialPortUsageByIdentifier(serialPortIdentifier_e identifier);
 int findSerialPortIndexByIdentifier(serialPortIdentifier_e identifier);
+serialPortIdentifier_e findSerialPortByName(const char* portName, int (*cmp)(const char *portName, const char *candidate));
+const char* serialName(serialPortIdentifier_e identifier, const char* notFound);
+
 //
 // runtime
 //
@@ -188,6 +197,10 @@ void waitForSerialPortToFinishTransmitting(serialPort_t *serialPort);
 
 baudRate_e lookupBaudRateIndex(uint32_t baudRate);
 
+serialType_e serialType(serialPortIdentifier_e identifier);
+
+// resource index of given identifier, or -1 if not available
+int serialResourceIndex(serialPortIdentifier_e identifier);
 
 //
 // msp/cli/bootloader
diff --git a/src/main/io/serial_resource.c b/src/main/io/serial_resource.c
new file mode 100644
index 0000000000..571cb92b80
--- /dev/null
+++ b/src/main/io/serial_resource.c
@@ -0,0 +1,128 @@
+/*
+ * This file is part of Betaflight.
+ *
+ * Betaflight is free software. You can redistribute this software
+ * and/or modify this software under the terms of the GNU General
+ * Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * Betaflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this software.
+ *
+ * If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <limits.h>
+
+#include "platform.h"
+
+#include "io/serial.h"
+
+// convert identifier into port type
+serialType_e serialType(serialPortIdentifier_e identifier)
+{
+#ifdef USE_VCP
+    if (identifier == SERIAL_PORT_USB_VCP) {
+        return SERIALTYPE_USB_VCP;
+    }
+#endif
+#ifdef USE_UART
+    if (identifier >= SERIAL_PORT_USART1 && identifier < SERIAL_PORT_USART1 + SERIAL_UART_MAX) {
+        const unsigned idx = identifier - SERIAL_PORT_USART1;
+        if (BIT(idx) & SERIAL_UART_MASK) {
+            return SERIALTYPE_UART;
+        } else {
+            // no other type in this range
+            return SERIALTYPE_INVALID;
+        }
+    }
+#endif
+#ifdef USE_LPUART
+    if (identifier >= SERIAL_PORT_LPUART1 && identifier < SERIAL_PORT_LPUART1 + SERIAL_LPUART_MAX) {
+        const unsigned idx = identifier - SERIAL_PORT_LPUART1;
+        if (BIT(idx) & SERIAL_LPUART_MASK) {
+            return SERIALTYPE_LPUART;
+        } else {
+            // no other type in this range
+            return SERIALTYPE_INVALID;
+        }
+    }
+#endif
+#ifdef USE_SOFTSERIAL
+    if (identifier >= SERIAL_PORT_SOFTSERIAL1 && identifier < SERIAL_PORT_SOFTSERIAL1 + SERIAL_SOFTSERIAL_MAX) {
+        // sotserials always start from 1, without holes
+        return SERIALTYPE_SOFTSERIAL;
+    }
+#endif
+    return SERIALTYPE_INVALID;
+}
+
+
+static const struct SerialTypeInfo {
+    resourceOwner_e owner;
+    serialPortIdentifier_e firstId;
+    int8_t resourceOffset;
+} serialTypeMap[] = {
+    [SERIALTYPE_USB_VCP] = { OWNER_FREE /* no owner*/, SERIAL_PORT_USB_VCP, -1 },
+    [SERIALTYPE_UART] = { OWNER_SERIAL_TX, SERIAL_PORT_USART1, RESOURCE_UART_OFFSET },
+    [SERIALTYPE_LPUART] = { OWNER_LPUART_TX, SERIAL_PORT_LPUART1, RESOURCE_LPUART_OFFSET },
+    [SERIALTYPE_SOFTSERIAL] = { OWNER_SOFTSERIAL_TX, SERIAL_PORT_SOFTSERIAL1, RESOURCE_SOFTSERIAL_OFFSET },
+};
+
+STATIC_ASSERT(ARRAYLEN(serialTypeMap) == SERIALTYPE_COUNT, "type table mismatch");
+
+static const struct SerialTypeInfo* serialTypeInfo(serialPortIdentifier_e identifier)
+{
+    const serialType_e type = serialType(identifier);
+    if (type == SERIALTYPE_INVALID) {
+        return NULL;
+    }
+    return serialTypeMap + type;
+}
+
+// resourceOwner_e for this serial (UART/LPUART/SOFTSERIAL/..)
+// Used together with serialOwnerIndex to identify claimed resources
+// Tx member is returned, Rx is always Tx + 1
+// OWNER_FREE is returned for serials without owner (VCP)
+resourceOwner_e serialOwnerTxRx(serialPortIdentifier_e identifier)
+{
+    const struct SerialTypeInfo* inf = serialTypeInfo(identifier);
+    return inf ? inf->owner : OWNER_FREE;
+}
+
+
+// return index used to claim given resource. Returned value is 1 based, for IOInit and similar
+// 0 is returned when given port is not defined or if it is singleton port (USB)
+int serialOwnerIndex(serialPortIdentifier_e identifier)
+{
+    const struct SerialTypeInfo* inf = serialTypeInfo(identifier);
+    if (!inf || inf->owner == OWNER_FREE) {
+        return 0;
+    }
+    return RESOURCE_INDEX(identifier - inf->firstId);
+}
+
+// map identifier into index used to store port resources:
+//   pins(RX,TX), external inversion, port DMA configuration
+// order is UART, LPUART, SOFTSERIAL, with each group using index
+//  coresponding to port name (UART1 -> 0, UART5 -> 4, but LPUART -> 5 if
+//  there is no UART6 and higher on given target.
+// -1 is returned if given port is not defined or is not using resources
+// some code uses this ordering for optimizations, be carefull if reordering is necessary
+int serialResourceIndex(serialPortIdentifier_e identifier)
+{
+    const struct SerialTypeInfo* inf = serialTypeInfo(identifier);
+    if (!inf || inf->resourceOffset < 0) {
+        return -1;
+    }
+    return identifier - inf->firstId + inf->resourceOffset;
+}
diff --git a/src/main/io/smartaudio_protocol.h b/src/main/io/smartaudio_protocol.h
index ccdc974feb..5db92f39c6 100644
--- a/src/main/io/smartaudio_protocol.h
+++ b/src/main/io/smartaudio_protocol.h
@@ -22,7 +22,6 @@
 
 #include "drivers/serial.h"
 
-#define SMARTAUDIO_SERIAL_OPTIONS   SERIAL_NOT_INVERTED | SERIAL_BIDIR_NOPULL | SERIAL_STOPBITS_2
 #define SMARTAUDIO_DEFAULT_BAUD     4900
 #define SMARTAUDIO_MIN_BAUD         4800
 #define SMARTAUDIO_MAX_BAUD         4950
diff --git a/src/main/io/vtx.h b/src/main/io/vtx.h
index d2a36034c0..2ccde3c86a 100644
--- a/src/main/io/vtx.h
+++ b/src/main/io/vtx.h
@@ -39,7 +39,7 @@ typedef struct vtxSettingsConfig_s {
     uint16_t freq;          // sets freq in MHz if band=0
     uint16_t pitModeFreq;   // sets out-of-range pitmode frequency
     uint8_t lowPowerDisarm; // min power while disarmed, from vtxLowerPowerDisarm_e
-    uint8_t softserialAlt;  // pull line low before sending frame even with SOFTSERIAL
+    uint8_t softserialAlt;  // prepend 0xff before sending frame even with SOFTSERIAL
 } vtxSettingsConfig_t;
 
 PG_DECLARE(vtxSettingsConfig_t, vtxSettingsConfig);
diff --git a/src/main/io/vtx_msp.c b/src/main/io/vtx_msp.c
index 96d5be031c..557a8d3a6f 100644
--- a/src/main/io/vtx_msp.c
+++ b/src/main/io/vtx_msp.c
@@ -199,7 +199,7 @@ static void vtxMspProcess(vtxDevice_t *vtxDevice, timeUs_t currentTimeUs)
             if (isCrsfPortConfig(portConfig)) {
                 mspCrsfPush(MSP_VTX_CONFIG, frame, sizeof(frame));
             } else {
-                mspSerialPush((serialPortIdentifier_e) portConfig->identifier, MSP_VTX_CONFIG, frame, sizeof(frame), MSP_DIRECTION_REPLY, MSP_V2_NATIVE);
+                mspSerialPush(portConfig->identifier, MSP_VTX_CONFIG, frame, sizeof(frame), MSP_DIRECTION_REPLY, MSP_V2_NATIVE);
             }
             packetCounter++;
             mspVtxLastTimeUs = currentTimeUs;
diff --git a/src/main/io/vtx_smartaudio.c b/src/main/io/vtx_smartaudio.c
index 757772b49b..77594de30e 100644
--- a/src/main/io/vtx_smartaudio.c
+++ b/src/main/io/vtx_smartaudio.c
@@ -497,26 +497,34 @@ static void saReceiveFrame(uint8_t c)
 static void saSendFrame(uint8_t *buf, int len)
 {
     if (!IS_RC_MODE_ACTIVE(BOXVTXCONTROLDISABLE)) {
-#ifndef AT32F4
-        switch (smartAudioSerialPort->identifier) {
-        case SERIAL_PORT_SOFTSERIAL1:
-        case SERIAL_PORT_SOFTSERIAL2:
-            if (vtxSettingsConfig()->softserialAlt) {
-                serialWrite(smartAudioSerialPort, 0x00); // Generate 1st start byte
-            }
+        bool prepend00;
+        switch (serialType(smartAudioSerialPort->identifier)) {
+        case SERIALTYPE_SOFTSERIAL:
+            prepend00 = vtxSettingsConfig()->softserialAlt;
+            break;
+        case SERIALTYPE_UART:
+        case SERIALTYPE_LPUART: // decide HW uarts by MCU type
+#ifdef AT32F4
+            prepend00 = false;
+#else
+            prepend00 = true;
+#endif
             break;
         default:
-            serialWrite(smartAudioSerialPort, 0x00); // Generate 1st start byte
-            break;
+            prepend00 = false;
+        }
+        if (prepend00) {
+            // line is in MARK/BREAK, so only 2 stopbits will be visible (startbit and zeroes are not visible)
+            // startbit of next byte (0xaa) can be recognized
+            serialWrite(smartAudioSerialPort, 0x00);
         }
-#endif //AT32F4
 
         for (int i = 0 ; i < len ; i++) {
             serialWrite(smartAudioSerialPort, buf[i]);
         }
-        #ifdef USE_AKK_SMARTAUDIO
+#ifdef USE_AKK_SMARTAUDIO
         serialWrite(smartAudioSerialPort, 0x00); // AKK/RDQ SmartAudio devices can expect an extra byte due to manufacturing errors.
-        #endif // USE_AKK_SMARTAUDIO
+#endif
 
         saStat.pktsent++;
     } else {
@@ -705,20 +713,15 @@ bool vtxSmartAudioInit(void)
     dprintf(("smartAudioInit: OK\r\n"));
 #endif
 
-    // Note, for SA, which uses bidirectional mode, would normally require pullups. 
-    // the SA protocol instead requires pulldowns, and therefore uses SERIAL_BIDIR_PP_PD instead of SERIAL_BIDIR_PP
     const serialPortConfig_t *portConfig = findSerialPortConfig(FUNCTION_VTX_SMARTAUDIO);
-    if (portConfig) {
-        portOptions_e portOptions = SERIAL_STOPBITS_2 | SERIAL_BIDIR | SERIAL_BIDIR_PP_PD | SERIAL_BIDIR_NOPULL;
-#ifdef USE_SMARTAUDIO_NOPULLDOWN
-        // softserial hack (#13797)
-        if (smartAudioSerialPort->identifier == SERIAL_PORT_SOFTSERIAL1 || smartAudioSerialPort->identifier == SERIAL_PORT_SOFTSERIAL2) {
-            portOptions &= ~SERIAL_BIDIR_PP_PD;
-            portOptions |= SERIAL_BIDIR_PP;
-        }
-#endif
-        smartAudioSerialPort = openSerialPort(portConfig->identifier, FUNCTION_VTX_SMARTAUDIO, NULL, NULL, 4800, MODE_RXTX, portOptions);
+    if (!portConfig) {
+        return false;
     }
+    // Note, for SA, which uses bidirectional mode, would normally require pullups.
+    // the SA protocol usually requires pulldowns, and therefore uses SERIAL_PULL_SMARTAUDIO together with SERIAL_BIDIR_PP
+    // serial driver handles different pullup/pulldown/nopull quirks when SERIAL_PULL_SMARTAUDIO is used
+    const portOptions_e portOptions = SERIAL_NOT_INVERTED | SERIAL_STOPBITS_2 | SERIAL_BIDIR | SERIAL_BIDIR_PP | SERIAL_PULL_SMARTAUDIO;
+    smartAudioSerialPort = openSerialPort(portConfig->identifier, FUNCTION_VTX_SMARTAUDIO, NULL, NULL, 4800, MODE_RXTX, portOptions);
 
     if (!smartAudioSerialPort) {
         return false;
diff --git a/src/main/io/vtx_tramp.c b/src/main/io/vtx_tramp.c
index 3fa87c7e9b..e62ea32390 100644
--- a/src/main/io/vtx_tramp.c
+++ b/src/main/io/vtx_tramp.c
@@ -654,9 +654,9 @@ bool vtxTrampInit(void)
     if (portConfig) {
         portOptions_e portOptions = 0;
 #if defined(USE_VTX_COMMON)
-        portOptions = portOptions | (vtxConfig()->halfDuplex ? SERIAL_BIDIR : SERIAL_UNIDIR);
+        portOptions |= vtxConfig()->halfDuplex ? SERIAL_BIDIR : 0;
 #else
-        portOptions = SERIAL_BIDIR;
+        portOptions |= SERIAL_BIDIR;
 #endif
 
         trampSerialPort = openSerialPort(portConfig->identifier, FUNCTION_VTX_TRAMP, NULL, NULL, 9600, MODE_RXTX, portOptions);
diff --git a/src/main/msp/msp_serial.c b/src/main/msp/msp_serial.c
index d497141cbc..f0ba78feb6 100644
--- a/src/main/msp/msp_serial.c
+++ b/src/main/msp/msp_serial.c
@@ -57,7 +57,7 @@ void mspSerialAllocatePorts(void)
 {
     uint8_t portIndex = 0;
     const serialPortConfig_t *portConfig = findSerialPortConfig(FUNCTION_MSP);
-    while (portConfig && portIndex < MAX_MSP_PORT_COUNT) {
+    while (portConfig && portIndex < ARRAYLEN(mspPorts)) {
         mspPort_t *mspPort = &mspPorts[portIndex];
 
         if (mspPort->port) {
@@ -69,7 +69,8 @@ void mspSerialAllocatePorts(void)
 
         if (mspConfig()->halfDuplex) {
             options |= SERIAL_BIDIR;
-        } else if ((portConfig->identifier >= SERIAL_PORT_USART1) && (portConfig->identifier <= SERIAL_PORT_USART_MAX)){
+        } else if (serialType(portConfig->identifier) == SERIALTYPE_UART
+                   || serialType(portConfig->identifier) == SERIALTYPE_LPUART) {
             options |= SERIAL_CHECK_TX;
         }
 
@@ -87,7 +88,7 @@ void mspSerialAllocatePorts(void)
 
 void mspSerialReleasePortIfAllocated(serialPort_t *serialPort)
 {
-    for (uint8_t portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
+    for (unsigned portIndex = 0; portIndex < ARRAYLEN(mspPorts); portIndex++) {
         mspPort_t *candidateMspPort = &mspPorts[portIndex];
         if (candidateMspPort->port == serialPort) {
             closeSerialPort(serialPort);
@@ -96,11 +97,11 @@ void mspSerialReleasePortIfAllocated(serialPort_t *serialPort)
     }
 }
 
-mspDescriptor_t getMspSerialPortDescriptor(const uint8_t portIdentifier)
+mspDescriptor_t getMspSerialPortDescriptor(const serialPortIdentifier_e portIdentifier)
 {
-    for (uint8_t portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
+    for (unsigned portIndex = 0; portIndex < ARRAYLEN(mspPorts); portIndex++) {
         mspPort_t *candidateMspPort = &mspPorts[portIndex];
-        if (candidateMspPort->port->identifier == portIdentifier) {
+        if (candidateMspPort->port && candidateMspPort->port->identifier == portIdentifier) {
             return candidateMspPort->descriptor;
         }
     }
@@ -110,7 +111,7 @@ mspDescriptor_t getMspSerialPortDescriptor(const uint8_t portIdentifier)
 #if defined(USE_TELEMETRY)
 void mspSerialReleaseSharedTelemetryPorts(void)
 {
-    for (uint8_t portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
+    for (unsigned portIndex = 0; portIndex < ARRAYLEN(mspPorts); portIndex++) {
         mspPort_t *candidateMspPort = &mspPorts[portIndex];
         if (candidateMspPort->sharedWithTelemetry) {
             closeSerialPort(candidateMspPort->port);
@@ -520,7 +521,7 @@ void mspProcessPacket(mspPort_t *mspPort, mspProcessCommandFnPtr mspProcessComma
  */
 void mspSerialProcess(mspEvaluateNonMspData_e evaluateNonMspData, mspProcessCommandFnPtr mspProcessCommandFn, mspProcessReplyFnPtr mspProcessReplyFn)
 {
-    for (uint8_t portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
+    for (unsigned portIndex = 0; portIndex < ARRAYLEN(mspPorts); portIndex++) {
         mspPort_t * const mspPort = &mspPorts[portIndex];
         if (!mspPort->port) {
             continue;
@@ -576,7 +577,7 @@ void mspSerialProcess(mspEvaluateNonMspData_e evaluateNonMspData, mspProcessComm
 
 bool mspSerialWaiting(void)
 {
-    for (uint8_t portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
+    for (unsigned portIndex = 0; portIndex < ARRAYLEN(mspPorts); portIndex++) {
         mspPort_t * const mspPort = &mspPorts[portIndex];
         if (!mspPort->port) {
             continue;
@@ -599,7 +600,7 @@ int mspSerialPush(serialPortIdentifier_e port, uint8_t cmd, uint8_t *data, int d
 {
     int ret = 0;
 
-    for (int portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
+    for (unsigned portIndex = 0; ARRAYLEN(mspPorts); portIndex++) {
         mspPort_t * const mspPort = &mspPorts[portIndex];
 
         // XXX Kludge!!! Avoid zombie VCP port (avoid VCP entirely for now)
@@ -628,7 +629,7 @@ uint32_t mspSerialTxBytesFree(void)
 {
     uint32_t ret = UINT32_MAX;
 
-    for (int portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
+    for (unsigned portIndex = 0; portIndex < ARRAYLEN(mspPorts); portIndex++) {
         mspPort_t * const mspPort = &mspPorts[portIndex];
         if (!mspPort->port) {
             continue;
diff --git a/src/main/msp/msp_serial.h b/src/main/msp/msp_serial.h
index af447a5422..a080408fc7 100644
--- a/src/main/msp/msp_serial.h
+++ b/src/main/msp/msp_serial.h
@@ -128,6 +128,6 @@ void mspSerialProcess(mspEvaluateNonMspData_e evaluateNonMspData, mspProcessComm
 void mspSerialAllocatePorts(void);
 void mspSerialReleasePortIfAllocated(struct serialPort_s *serialPort);
 void mspSerialReleaseSharedTelemetryPorts(void);
-mspDescriptor_t getMspSerialPortDescriptor(const uint8_t portIdentifier);
+mspDescriptor_t getMspSerialPortDescriptor(const serialPortIdentifier_e portIdentifier);
 int mspSerialPush(serialPortIdentifier_e port, uint8_t cmd, uint8_t *data, int datalen, mspDirection_e direction, mspVersion_e mspVersion);
 uint32_t mspSerialTxBytesFree(void);
diff --git a/src/main/pg/pg_ids.h b/src/main/pg/pg_ids.h
index 7c2c853f52..6342fc8cc4 100644
--- a/src/main/pg/pg_ids.h
+++ b/src/main/pg/pg_ids.h
@@ -157,8 +157,8 @@
 #define PG_RX_EXPRESSLRS_SPI_CONFIG 555
 #define PG_SCHEDULER_CONFIG         556
 #define PG_MSP_CONFIG               557
-#define PG_SOFTSERIAL_PIN_CONFIG    558
-#define PG_BETAFLIGHT_END           558
+//#define PG_SOFTSERIAL_PIN_CONFIG    558  // removed, merged into SERIAL_PIN_CONFIG
+#define PG_BETAFLIGHT_END           557
 
 
 // OSD configuration (subject to change)
diff --git a/src/main/pg/serial_uart.c b/src/main/pg/serial_uart.c
index bd10b4d484..355d28170a 100644
--- a/src/main/pg/serial_uart.c
+++ b/src/main/pg/serial_uart.c
@@ -34,49 +34,50 @@
 #include "drivers/io_types.h"
 #include "drivers/serial.h"
 #include "drivers/serial_uart.h"
+#include "drivers/dma_reqmap.h"
 
 // TODO(hertz@): UARTDEV_CONFIG_MAX is measured to be exactly 8, which cannot accomodate even all the UARTs below
 PG_REGISTER_ARRAY_WITH_RESET_FN(serialUartConfig_t, UARTDEV_CONFIG_MAX, serialUartConfig, PG_SERIAL_UART_CONFIG, 0);
 
 typedef struct uartDmaopt_s {
-    UARTDevice_e device;
+    serialPortIdentifier_e identifier;
     int8_t txDmaopt;
     int8_t rxDmaopt;
 } uartDmaopt_t;
 
-static uartDmaopt_t uartDmaopt[] = {
+static const uartDmaopt_t uartDmaopt[] = {
 #ifdef USE_UART1
-    { UARTDEV_1, UART1_TX_DMA_OPT, UART1_RX_DMA_OPT },
+    { SERIAL_PORT_USART1, UART1_TX_DMA_OPT, UART1_RX_DMA_OPT },
 #endif
 #ifdef USE_UART2
-    { UARTDEV_2, UART2_TX_DMA_OPT, UART2_RX_DMA_OPT },
+    { SERIAL_PORT_USART2, UART2_TX_DMA_OPT, UART2_RX_DMA_OPT },
 #endif
 #ifdef USE_UART3
-    { UARTDEV_3, UART3_TX_DMA_OPT, UART3_RX_DMA_OPT },
+    { SERIAL_PORT_USART3, UART3_TX_DMA_OPT, UART3_RX_DMA_OPT },
 #endif
 #ifdef USE_UART4
-    { UARTDEV_4, UART4_TX_DMA_OPT, UART4_RX_DMA_OPT },
+    { SERIAL_PORT_UART4, UART4_TX_DMA_OPT, UART4_RX_DMA_OPT },
 #endif
 #ifdef USE_UART5
-    { UARTDEV_5, UART5_TX_DMA_OPT, UART5_RX_DMA_OPT },
+    { SERIAL_PORT_UART5, UART5_TX_DMA_OPT, UART5_RX_DMA_OPT },
 #endif
-#ifdef USE_UART6
-    { UARTDEV_6, UART6_TX_DMA_OPT, UART6_RX_DMA_OPT },
+#ifdef USE_USART6
+    { SERIAL_PORT_UART6, UART6_TX_DMA_OPT, UART6_RX_DMA_OPT },
 #endif
-#ifdef USE_UART7
-    { UARTDEV_7, UART7_TX_DMA_OPT, UART7_RX_DMA_OPT },
+#ifdef USE_USART7
+    { SERIAL_PORT_UART7, UART7_TX_DMA_OPT, UART7_RX_DMA_OPT },
 #endif
-#ifdef USE_UART8
-    { UARTDEV_8, UART8_TX_DMA_OPT, UART8_RX_DMA_OPT },
+#ifdef USE_USART8
+    { SERIAL_PORT_UART8, UART8_TX_DMA_OPT, UART8_RX_DMA_OPT },
 #endif
 #ifdef USE_UART9
-    { UARTDEV_9, UART9_TX_DMA_OPT, UART9_RX_DMA_OPT },
+    { SERIAL_PORT_UART9, UART9_TX_DMA_OPT, UART9_RX_DMA_OPT },
 #endif
 #ifdef USE_UART10
-    { UARTDEV_10, UART10_TX_DMA_OPT, UART10_RX_DMA_OPT },
+    { SERIAL_PORT_UART10, UART10_TX_DMA_OPT, UART10_RX_DMA_OPT },
 #endif
 #ifdef USE_LPUART1
-    { LPUARTDEV_1, DMA_OPT_UNUSED, DMA_OPT_UNUSED },
+    { SERIAL_PORT_LPUART1, DMA_OPT_UNUSED, DMA_OPT_UNUSED },
 #endif
 };
 
@@ -88,9 +89,11 @@ void pgResetFn_serialUartConfig(serialUartConfig_t *config)
     }
 
     for (unsigned i = 0; i < ARRAYLEN(uartDmaopt); i++) {
-        UARTDevice_e device = uartDmaopt[i].device;
-        config[device].txDmaopt = uartDmaopt[i].txDmaopt;
-        config[device].rxDmaopt = uartDmaopt[i].rxDmaopt;
+        const int resourceIndex = serialResourceIndex(uartDmaopt[i].identifier);
+        if (resourceIndex >= 0 && resourceIndex < UARTDEV_CONFIG_MAX) {  // hadle corrupted config gracefuly
+            config[resourceIndex].txDmaopt = uartDmaopt[i].txDmaopt;
+            config[resourceIndex].rxDmaopt = uartDmaopt[i].rxDmaopt;
+        }
     }
 }
 #endif
diff --git a/src/main/pg/serial_uart.h b/src/main/pg/serial_uart.h
index 17bac8e465..26d625f18b 100644
--- a/src/main/pg/serial_uart.h
+++ b/src/main/pg/serial_uart.h
@@ -24,12 +24,9 @@
 #include <stdbool.h>
 
 #include "pg/pg.h"
-#include "drivers/io_types.h"
-#include "drivers/dma_reqmap.h"
+#include "drivers/serial_resource.h"
 
-
-// TODO(hertz@): this alternative got out of sync
-#define UARTDEV_CONFIG_MAX 11 // Alternative to UARTDEV_COUNT_MAX, which requires serial_uart_imp.h
+#define UARTDEV_CONFIG_MAX (RESOURCE_UART_COUNT + RESOURCE_LPUART_COUNT)
 
 typedef struct serialUartConfig_s {
     int8_t txDmaopt;
diff --git a/src/main/rx/ibus.c b/src/main/rx/ibus.c
index c39355bb9a..18e56d768a 100644
--- a/src/main/rx/ibus.c
+++ b/src/main/rx/ibus.c
@@ -231,7 +231,7 @@ bool ibusInit(const rxConfig_t *rxConfig, rxRuntimeState_t *rxRuntimeState)
         NULL,
         IBUS_BAUDRATE,
         portShared ? MODE_RXTX : MODE_RX,
-        (rxConfig->serialrx_inverted ? SERIAL_INVERTED : 0) | (rxConfig->halfDuplex || portShared ? SERIAL_BIDIR : 0)
+        (rxConfig->serialrx_inverted ? SERIAL_INVERTED : SERIAL_NOT_INVERTED) | ((rxConfig->halfDuplex || portShared) ? SERIAL_BIDIR : 0)
         );
 
 #if defined(USE_TELEMETRY) && defined(USE_TELEMETRY_IBUS)
diff --git a/src/main/rx/sbus.c b/src/main/rx/sbus.c
index 9c1be0c0c7..626c6586b4 100644
--- a/src/main/rx/sbus.c
+++ b/src/main/rx/sbus.c
@@ -189,13 +189,17 @@ bool sbusInit(const rxConfig_t *rxConfig, rxRuntimeState_t *rxRuntimeState)
     bool portShared = false;
 #endif
 
+    // On SBUS, SERIAL_INVERTED is default
+    const portOptions_e portOptions = SBUS_PORT_OPTIONS
+        | (rxConfig->serialrx_inverted ? SERIAL_NOT_INVERTED : SERIAL_INVERTED)
+        | (rxConfig->halfDuplex ? SERIAL_BIDIR : 0);
     serialPort_t *sBusPort = openSerialPort(portConfig->identifier,
         FUNCTION_RX_SERIAL,
         sbusDataReceive,
         &sbusFrameData,
         sbusBaudRate,
         portShared ? MODE_RXTX : MODE_RX,
-        SBUS_PORT_OPTIONS | (rxConfig->serialrx_inverted ? 0 : SERIAL_INVERTED) | (rxConfig->halfDuplex ? SERIAL_BIDIR : 0)
+        portOptions
         );
 
     if (rxConfig->rssi_src_frame_errors) {
diff --git a/src/main/rx/spektrum.c b/src/main/rx/spektrum.c
index 0f12fda67d..1a55375693 100644
--- a/src/main/rx/spektrum.c
+++ b/src/main/rx/spektrum.c
@@ -238,9 +238,9 @@ void spektrumBind(rxConfig_t *rxConfig)
             return;
         }
 
-        int index = SERIAL_PORT_IDENTIFIER_TO_INDEX(portConfig->identifier);
-        ioTag_t txPin = serialPinConfig()->ioTagTx[index];
-        ioTag_t rxPin = serialPinConfig()->ioTagRx[index];
+        const int resourceIndex = serialResourceIndex(portConfig->identifier);
+        const ioTag_t txPin = serialPinConfig()->ioTagTx[resourceIndex];
+        const ioTag_t rxPin = serialPinConfig()->ioTagRx[resourceIndex];
 
         // Take care half-duplex case
         switch (rxRuntimeState.serialrxProvider) {
diff --git a/src/main/sensors/voltage.c b/src/main/sensors/voltage.c
index 12102103dd..ada22bb28f 100644
--- a/src/main/sensors/voltage.c
+++ b/src/main/sensors/voltage.c
@@ -386,5 +386,5 @@ void voltageStableUpdate(voltageMeter_t* vm)
 // voltage is stable when it was within VOLTAGE_STABLE_MAX_DELTA for 10 update periods
 bool voltageIsStable(voltageMeter_t* vm)
 {
-    return __builtin_popcount(vm->voltageStableBits & (BIT(VOLTAGE_STABLE_BITS_TOTAL + 1) - 1)) >= VOLTAGE_STABLE_BITS_THRESHOLD;
+    return popcount(vm->voltageStableBits & (BIT(VOLTAGE_STABLE_BITS_TOTAL + 1) - 1)) >= VOLTAGE_STABLE_BITS_THRESHOLD;
 }
diff --git a/src/main/target/common_defaults_post.h b/src/main/target/common_defaults_post.h
index 9f4fe582df..18ac19fd59 100644
--- a/src/main/target/common_defaults_post.h
+++ b/src/main/target/common_defaults_post.h
@@ -94,16 +94,6 @@
 #endif
 #endif
 
-#if defined(USE_UART1) || defined(USE_UART2) || defined(USE_UART3) || defined(USE_UART4) || defined(USE_UART5) || defined(USE_UART6) || defined(USE_UART7) || defined(USE_UART8)
-#define USE_UART
-#endif
-
-#ifdef USE_UART
-#if defined(INVERTER_PIN_UART1) || defined(INVERTER_PIN_UART2) || defined(INVERTER_PIN_UART3) || defined(INVERTER_PIN_UART4) || defined(INVERTER_PIN_UART5) || defined(INVERTER_PIN_UART6)
-#define USE_INVERTER
-#endif
-#endif
-
 #ifndef DEFAULT_MIXER
 #define DEFAULT_MIXER    MIXER_QUADX
 #endif
diff --git a/src/main/target/common_post.h b/src/main/target/common_post.h
index 0cba847123..a143df0415 100644
--- a/src/main/target/common_post.h
+++ b/src/main/target/common_post.h
@@ -85,6 +85,10 @@
     In the future we can move to specific drivers being added only - to save flash space.
 */
 
+
+// normalize serial ports definitions
+#include "serial_post.h"
+
 #if defined(USE_MAG) && !defined(USE_VIRTUAL_MAG)
 
 #ifndef USE_MAG_DATA_READY_SIGNAL
diff --git a/src/main/target/serial_post.h b/src/main/target/serial_post.h
new file mode 100644
index 0000000000..b7af5b4649
--- /dev/null
+++ b/src/main/target/serial_post.h
@@ -0,0 +1,523 @@
+/*
+ * This file is part of Betaflight.
+ *
+ * Betaflight is free software. You can redistribute this software
+ * and/or modify this software under the terms of the GNU General
+ * Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * Betaflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this software.
+ *
+ * If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+/*
+This file is automatically generated by src/utils/gen-serial.py script from src/utils/templates/serial_post.h jinja2 template.
+Do not modify this file directly, your changes will be eventually lost.
+See template file for aditional documentation.
+
+To generate this file again, run
+> python ./src/utils/gen-serial-j2.py > ./src/main/target/serial_post.h
+in Betaflight topmost directory.
+
+This include will provide following defines:
+SERIAL_<type><n>_USED 0/1 - always defined, value depends on target configuration
+SERIAL_<type>_MASK        - bitmask of used ports or given type. <port>1 is BIT(0)
+SERIAL_<type>_COUNT       - number of enabled ports of given type
+SERIAL_<type>_MAX         - <index of highest used port> + 1, 0 when no port is enabled
+
+All <type><n>_(RX|TX)_PINS are normalized too:
+ - if port is enabled, both will be defined (possibly as NONE)
+ - if port is not enable, both will be undefined, possibly with warning
+  - pass -DWARN_UNUSED_SERIAL_PORT to compiler to check pin defined without corresponding port being enabled.
+
+Generated on 2024-11-04
+
+Configuration used:
+{   'LPUART': {'depends': {'UART'}, 'ids': [1]},
+    'SOFTSERIAL': {   'force_continuous': True,
+                      'ids': [1, 2],
+                      'use_enables_all': True},
+    'UART': {'ids': [1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 'inverter': True},
+    'VCP': {'no_pins': True, 'singleton': True}}
+
+*/
+
+#include "common/utils.h" // BIT, LOG2
+
+/****                                UART                                 *****/
+
+#if defined(USE_UART1)
+# define SERIAL_UART1_USED 1
+#else
+# define SERIAL_UART1_USED 0
+#endif
+#if defined(USE_UART2)
+# define SERIAL_UART2_USED 1
+#else
+# define SERIAL_UART2_USED 0
+#endif
+#if defined(USE_UART3)
+# define SERIAL_UART3_USED 1
+#else
+# define SERIAL_UART3_USED 0
+#endif
+#if defined(USE_UART4)
+# define SERIAL_UART4_USED 1
+#else
+# define SERIAL_UART4_USED 0
+#endif
+#if defined(USE_UART5)
+# define SERIAL_UART5_USED 1
+#else
+# define SERIAL_UART5_USED 0
+#endif
+#if defined(USE_UART6)
+# define SERIAL_UART6_USED 1
+#else
+# define SERIAL_UART6_USED 0
+#endif
+#if defined(USE_UART7)
+# define SERIAL_UART7_USED 1
+#else
+# define SERIAL_UART7_USED 0
+#endif
+#if defined(USE_UART8)
+# define SERIAL_UART8_USED 1
+#else
+# define SERIAL_UART8_USED 0
+#endif
+#if defined(USE_UART9)
+# define SERIAL_UART9_USED 1
+#else
+# define SERIAL_UART9_USED 0
+#endif
+#if defined(USE_UART10)
+# define SERIAL_UART10_USED 1
+#else
+# define SERIAL_UART10_USED 0
+#endif
+
+#define SERIAL_UART_MASK ((SERIAL_UART1_USED * BIT(1 - 1)) | (SERIAL_UART2_USED * BIT(2 - 1)) | (SERIAL_UART3_USED * BIT(3 - 1)) | (SERIAL_UART4_USED * BIT(4 - 1)) | (SERIAL_UART5_USED * BIT(5 - 1)) | (SERIAL_UART6_USED * BIT(6 - 1)) | (SERIAL_UART7_USED * BIT(7 - 1)) | (SERIAL_UART8_USED * BIT(8 - 1)) | (SERIAL_UART9_USED * BIT(9 - 1)) | (SERIAL_UART10_USED * BIT(10 - 1)))
+#define SERIAL_UART_COUNT (SERIAL_UART1_USED + SERIAL_UART2_USED + SERIAL_UART3_USED + SERIAL_UART4_USED + SERIAL_UART5_USED + SERIAL_UART6_USED + SERIAL_UART7_USED + SERIAL_UART8_USED + SERIAL_UART9_USED + SERIAL_UART10_USED)
+// 0 if no port is defined
+#define SERIAL_UART_MAX (SERIAL_UART_MASK ? LOG2(SERIAL_UART_MASK) + 1 : 0)
+
+
+// enable USE_INVERTED first, before normalization
+#if !defined(USE_INVERTER) && (INVERTER_PIN_UART1 || INVERTER_PIN_UART2 || INVERTER_PIN_UART3 || INVERTER_PIN_UART4 || INVERTER_PIN_UART5 || INVERTER_PIN_UART6 || INVERTER_PIN_UART7 || INVERTER_PIN_UART8 || INVERTER_PIN_UART9 || INVERTER_PIN_UART10)
+# define USE_INVERTER
+#endif
+// Normalize UART TX/RX/INVERTER
+#if SERIAL_UART1_USED && !defined(UART1_RX_PIN)
+# define UART1_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART1_USED && defined(UART1_RX_PIN)
+# warning "UART1_RX_PIN is defined but UART1 is not enabled"
+#endif
+#if !SERIAL_UART1_USED &&  defined(UART1_RX_PIN)
+# undef UART1_RX_PIN
+#endif
+#if SERIAL_UART1_USED && !defined(UART1_TX_PIN)
+# define UART1_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART1_USED && defined(UART1_TX_PIN)
+# warning "UART1_TX_PIN is defined but UART1 is not enabled"
+#endif
+#if !SERIAL_UART1_USED &&  defined(UART1_TX_PIN)
+# undef UART1_TX_PIN
+#endif
+#if SERIAL_UART1_USED && !defined(INVERTER_PIN_UART1)
+# define INVERTER_PIN_UART1 NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART1_USED && defined(INVERTER_PIN_UART1)
+# warning "INVERTER_PIN_UART1 is defined but UART1 is not enabled"
+#endif
+#if !SERIAL_UART1_USED &&  defined(INVERTER_PIN_UART1)
+# undef INVERTER_PIN_UART1
+#endif
+#if SERIAL_UART2_USED && !defined(UART2_RX_PIN)
+# define UART2_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART2_USED && defined(UART2_RX_PIN)
+# warning "UART2_RX_PIN is defined but UART2 is not enabled"
+#endif
+#if !SERIAL_UART2_USED &&  defined(UART2_RX_PIN)
+# undef UART2_RX_PIN
+#endif
+#if SERIAL_UART2_USED && !defined(UART2_TX_PIN)
+# define UART2_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART2_USED && defined(UART2_TX_PIN)
+# warning "UART2_TX_PIN is defined but UART2 is not enabled"
+#endif
+#if !SERIAL_UART2_USED &&  defined(UART2_TX_PIN)
+# undef UART2_TX_PIN
+#endif
+#if SERIAL_UART2_USED && !defined(INVERTER_PIN_UART2)
+# define INVERTER_PIN_UART2 NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART2_USED && defined(INVERTER_PIN_UART2)
+# warning "INVERTER_PIN_UART2 is defined but UART2 is not enabled"
+#endif
+#if !SERIAL_UART2_USED &&  defined(INVERTER_PIN_UART2)
+# undef INVERTER_PIN_UART2
+#endif
+#if SERIAL_UART3_USED && !defined(UART3_RX_PIN)
+# define UART3_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART3_USED && defined(UART3_RX_PIN)
+# warning "UART3_RX_PIN is defined but UART3 is not enabled"
+#endif
+#if !SERIAL_UART3_USED &&  defined(UART3_RX_PIN)
+# undef UART3_RX_PIN
+#endif
+#if SERIAL_UART3_USED && !defined(UART3_TX_PIN)
+# define UART3_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART3_USED && defined(UART3_TX_PIN)
+# warning "UART3_TX_PIN is defined but UART3 is not enabled"
+#endif
+#if !SERIAL_UART3_USED &&  defined(UART3_TX_PIN)
+# undef UART3_TX_PIN
+#endif
+#if SERIAL_UART3_USED && !defined(INVERTER_PIN_UART3)
+# define INVERTER_PIN_UART3 NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART3_USED && defined(INVERTER_PIN_UART3)
+# warning "INVERTER_PIN_UART3 is defined but UART3 is not enabled"
+#endif
+#if !SERIAL_UART3_USED &&  defined(INVERTER_PIN_UART3)
+# undef INVERTER_PIN_UART3
+#endif
+#if SERIAL_UART4_USED && !defined(UART4_RX_PIN)
+# define UART4_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART4_USED && defined(UART4_RX_PIN)
+# warning "UART4_RX_PIN is defined but UART4 is not enabled"
+#endif
+#if !SERIAL_UART4_USED &&  defined(UART4_RX_PIN)
+# undef UART4_RX_PIN
+#endif
+#if SERIAL_UART4_USED && !defined(UART4_TX_PIN)
+# define UART4_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART4_USED && defined(UART4_TX_PIN)
+# warning "UART4_TX_PIN is defined but UART4 is not enabled"
+#endif
+#if !SERIAL_UART4_USED &&  defined(UART4_TX_PIN)
+# undef UART4_TX_PIN
+#endif
+#if SERIAL_UART4_USED && !defined(INVERTER_PIN_UART4)
+# define INVERTER_PIN_UART4 NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART4_USED && defined(INVERTER_PIN_UART4)
+# warning "INVERTER_PIN_UART4 is defined but UART4 is not enabled"
+#endif
+#if !SERIAL_UART4_USED &&  defined(INVERTER_PIN_UART4)
+# undef INVERTER_PIN_UART4
+#endif
+#if SERIAL_UART5_USED && !defined(UART5_RX_PIN)
+# define UART5_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART5_USED && defined(UART5_RX_PIN)
+# warning "UART5_RX_PIN is defined but UART5 is not enabled"
+#endif
+#if !SERIAL_UART5_USED &&  defined(UART5_RX_PIN)
+# undef UART5_RX_PIN
+#endif
+#if SERIAL_UART5_USED && !defined(UART5_TX_PIN)
+# define UART5_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART5_USED && defined(UART5_TX_PIN)
+# warning "UART5_TX_PIN is defined but UART5 is not enabled"
+#endif
+#if !SERIAL_UART5_USED &&  defined(UART5_TX_PIN)
+# undef UART5_TX_PIN
+#endif
+#if SERIAL_UART5_USED && !defined(INVERTER_PIN_UART5)
+# define INVERTER_PIN_UART5 NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART5_USED && defined(INVERTER_PIN_UART5)
+# warning "INVERTER_PIN_UART5 is defined but UART5 is not enabled"
+#endif
+#if !SERIAL_UART5_USED &&  defined(INVERTER_PIN_UART5)
+# undef INVERTER_PIN_UART5
+#endif
+#if SERIAL_UART6_USED && !defined(UART6_RX_PIN)
+# define UART6_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART6_USED && defined(UART6_RX_PIN)
+# warning "UART6_RX_PIN is defined but UART6 is not enabled"
+#endif
+#if !SERIAL_UART6_USED &&  defined(UART6_RX_PIN)
+# undef UART6_RX_PIN
+#endif
+#if SERIAL_UART6_USED && !defined(UART6_TX_PIN)
+# define UART6_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART6_USED && defined(UART6_TX_PIN)
+# warning "UART6_TX_PIN is defined but UART6 is not enabled"
+#endif
+#if !SERIAL_UART6_USED &&  defined(UART6_TX_PIN)
+# undef UART6_TX_PIN
+#endif
+#if SERIAL_UART6_USED && !defined(INVERTER_PIN_UART6)
+# define INVERTER_PIN_UART6 NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART6_USED && defined(INVERTER_PIN_UART6)
+# warning "INVERTER_PIN_UART6 is defined but UART6 is not enabled"
+#endif
+#if !SERIAL_UART6_USED &&  defined(INVERTER_PIN_UART6)
+# undef INVERTER_PIN_UART6
+#endif
+#if SERIAL_UART7_USED && !defined(UART7_RX_PIN)
+# define UART7_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART7_USED && defined(UART7_RX_PIN)
+# warning "UART7_RX_PIN is defined but UART7 is not enabled"
+#endif
+#if !SERIAL_UART7_USED &&  defined(UART7_RX_PIN)
+# undef UART7_RX_PIN
+#endif
+#if SERIAL_UART7_USED && !defined(UART7_TX_PIN)
+# define UART7_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART7_USED && defined(UART7_TX_PIN)
+# warning "UART7_TX_PIN is defined but UART7 is not enabled"
+#endif
+#if !SERIAL_UART7_USED &&  defined(UART7_TX_PIN)
+# undef UART7_TX_PIN
+#endif
+#if SERIAL_UART7_USED && !defined(INVERTER_PIN_UART7)
+# define INVERTER_PIN_UART7 NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART7_USED && defined(INVERTER_PIN_UART7)
+# warning "INVERTER_PIN_UART7 is defined but UART7 is not enabled"
+#endif
+#if !SERIAL_UART7_USED &&  defined(INVERTER_PIN_UART7)
+# undef INVERTER_PIN_UART7
+#endif
+#if SERIAL_UART8_USED && !defined(UART8_RX_PIN)
+# define UART8_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART8_USED && defined(UART8_RX_PIN)
+# warning "UART8_RX_PIN is defined but UART8 is not enabled"
+#endif
+#if !SERIAL_UART8_USED &&  defined(UART8_RX_PIN)
+# undef UART8_RX_PIN
+#endif
+#if SERIAL_UART8_USED && !defined(UART8_TX_PIN)
+# define UART8_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART8_USED && defined(UART8_TX_PIN)
+# warning "UART8_TX_PIN is defined but UART8 is not enabled"
+#endif
+#if !SERIAL_UART8_USED &&  defined(UART8_TX_PIN)
+# undef UART8_TX_PIN
+#endif
+#if SERIAL_UART8_USED && !defined(INVERTER_PIN_UART8)
+# define INVERTER_PIN_UART8 NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART8_USED && defined(INVERTER_PIN_UART8)
+# warning "INVERTER_PIN_UART8 is defined but UART8 is not enabled"
+#endif
+#if !SERIAL_UART8_USED &&  defined(INVERTER_PIN_UART8)
+# undef INVERTER_PIN_UART8
+#endif
+#if SERIAL_UART9_USED && !defined(UART9_RX_PIN)
+# define UART9_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART9_USED && defined(UART9_RX_PIN)
+# warning "UART9_RX_PIN is defined but UART9 is not enabled"
+#endif
+#if !SERIAL_UART9_USED &&  defined(UART9_RX_PIN)
+# undef UART9_RX_PIN
+#endif
+#if SERIAL_UART9_USED && !defined(UART9_TX_PIN)
+# define UART9_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART9_USED && defined(UART9_TX_PIN)
+# warning "UART9_TX_PIN is defined but UART9 is not enabled"
+#endif
+#if !SERIAL_UART9_USED &&  defined(UART9_TX_PIN)
+# undef UART9_TX_PIN
+#endif
+#if SERIAL_UART9_USED && !defined(INVERTER_PIN_UART9)
+# define INVERTER_PIN_UART9 NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART9_USED && defined(INVERTER_PIN_UART9)
+# warning "INVERTER_PIN_UART9 is defined but UART9 is not enabled"
+#endif
+#if !SERIAL_UART9_USED &&  defined(INVERTER_PIN_UART9)
+# undef INVERTER_PIN_UART9
+#endif
+#if SERIAL_UART10_USED && !defined(UART10_RX_PIN)
+# define UART10_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART10_USED && defined(UART10_RX_PIN)
+# warning "UART10_RX_PIN is defined but UART10 is not enabled"
+#endif
+#if !SERIAL_UART10_USED &&  defined(UART10_RX_PIN)
+# undef UART10_RX_PIN
+#endif
+#if SERIAL_UART10_USED && !defined(UART10_TX_PIN)
+# define UART10_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART10_USED && defined(UART10_TX_PIN)
+# warning "UART10_TX_PIN is defined but UART10 is not enabled"
+#endif
+#if !SERIAL_UART10_USED &&  defined(UART10_TX_PIN)
+# undef UART10_TX_PIN
+#endif
+#if SERIAL_UART10_USED && !defined(INVERTER_PIN_UART10)
+# define INVERTER_PIN_UART10 NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_UART10_USED && defined(INVERTER_PIN_UART10)
+# warning "INVERTER_PIN_UART10 is defined but UART10 is not enabled"
+#endif
+#if !SERIAL_UART10_USED &&  defined(INVERTER_PIN_UART10)
+# undef INVERTER_PIN_UART10
+#endif
+
+/****                                LPUART                                 *****/
+
+#if defined(USE_LPUART1)
+# define SERIAL_LPUART1_USED 1
+#else
+# define SERIAL_LPUART1_USED 0
+#endif
+
+#define SERIAL_LPUART_MASK ((SERIAL_LPUART1_USED * BIT(1 - 1)))
+#define SERIAL_LPUART_COUNT (SERIAL_LPUART1_USED)
+// 0 if no port is defined
+#define SERIAL_LPUART_MAX (SERIAL_LPUART_MASK ? LOG2(SERIAL_LPUART_MASK) + 1 : 0)
+
+
+// Normalize LPUART TX/RX
+#if SERIAL_LPUART1_USED && !defined(LPUART1_RX_PIN)
+# define LPUART1_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_LPUART1_USED && defined(LPUART1_RX_PIN)
+# warning "LPUART1_RX_PIN is defined but LPUART1 is not enabled"
+#endif
+#if !SERIAL_LPUART1_USED &&  defined(LPUART1_RX_PIN)
+# undef LPUART1_RX_PIN
+#endif
+#if SERIAL_LPUART1_USED && !defined(LPUART1_TX_PIN)
+# define LPUART1_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_LPUART1_USED && defined(LPUART1_TX_PIN)
+# warning "LPUART1_TX_PIN is defined but LPUART1 is not enabled"
+#endif
+#if !SERIAL_LPUART1_USED &&  defined(LPUART1_TX_PIN)
+# undef LPUART1_TX_PIN
+#endif
+
+/****                                SOFTSERIAL                                 *****/
+#if defined(USE_SOFTSERIAL)
+# if !defined(USE_SOFTSERIAL1)
+#  define USE_SOFTSERIAL1
+# endif
+# if !defined(USE_SOFTSERIAL2)
+#  define USE_SOFTSERIAL2
+# endif
+#endif
+
+#if defined(USE_SOFTSERIAL1)
+# define SERIAL_SOFTSERIAL1_USED 1
+#else
+# define SERIAL_SOFTSERIAL1_USED 0
+#endif
+#if defined(USE_SOFTSERIAL2)
+# define SERIAL_SOFTSERIAL2_USED 1
+#else
+# define SERIAL_SOFTSERIAL2_USED 0
+#endif
+
+#define SERIAL_SOFTSERIAL_MASK ((SERIAL_SOFTSERIAL1_USED * BIT(1 - 1)) | (SERIAL_SOFTSERIAL2_USED * BIT(2 - 1)))
+#define SERIAL_SOFTSERIAL_COUNT (SERIAL_SOFTSERIAL1_USED + SERIAL_SOFTSERIAL2_USED)
+// 0 if no port is defined
+#define SERIAL_SOFTSERIAL_MAX (SERIAL_SOFTSERIAL_MASK ? LOG2(SERIAL_SOFTSERIAL_MASK) + 1 : 0)
+
+#if SERIAL_SOFTSERIAL_COUNT != SERIAL_SOFTSERIAL_MAX
+# error SOFTSERIAL ports must start with SOFTSERIAL1 and be continuous
+#endif
+
+// Normalize SOFTSERIAL TX/RX
+#if SERIAL_SOFTSERIAL1_USED && !defined(SOFTSERIAL1_RX_PIN)
+# define SOFTSERIAL1_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_SOFTSERIAL1_USED && defined(SOFTSERIAL1_RX_PIN)
+# warning "SOFTSERIAL1_RX_PIN is defined but SOFTSERIAL1 is not enabled"
+#endif
+#if !SERIAL_SOFTSERIAL1_USED &&  defined(SOFTSERIAL1_RX_PIN)
+# undef SOFTSERIAL1_RX_PIN
+#endif
+#if SERIAL_SOFTSERIAL1_USED && !defined(SOFTSERIAL1_TX_PIN)
+# define SOFTSERIAL1_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_SOFTSERIAL1_USED && defined(SOFTSERIAL1_TX_PIN)
+# warning "SOFTSERIAL1_TX_PIN is defined but SOFTSERIAL1 is not enabled"
+#endif
+#if !SERIAL_SOFTSERIAL1_USED &&  defined(SOFTSERIAL1_TX_PIN)
+# undef SOFTSERIAL1_TX_PIN
+#endif
+#if SERIAL_SOFTSERIAL2_USED && !defined(SOFTSERIAL2_RX_PIN)
+# define SOFTSERIAL2_RX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_SOFTSERIAL2_USED && defined(SOFTSERIAL2_RX_PIN)
+# warning "SOFTSERIAL2_RX_PIN is defined but SOFTSERIAL2 is not enabled"
+#endif
+#if !SERIAL_SOFTSERIAL2_USED &&  defined(SOFTSERIAL2_RX_PIN)
+# undef SOFTSERIAL2_RX_PIN
+#endif
+#if SERIAL_SOFTSERIAL2_USED && !defined(SOFTSERIAL2_TX_PIN)
+# define SOFTSERIAL2_TX_PIN NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_SOFTSERIAL2_USED && defined(SOFTSERIAL2_TX_PIN)
+# warning "SOFTSERIAL2_TX_PIN is defined but SOFTSERIAL2 is not enabled"
+#endif
+#if !SERIAL_SOFTSERIAL2_USED &&  defined(SOFTSERIAL2_TX_PIN)
+# undef SOFTSERIAL2_TX_PIN
+#endif
+
+/****                                VCP                                 *****/
+
+#if defined(USE_VCP)
+# define SERIAL_VCP_USED 1
+#else
+# define SERIAL_VCP_USED 0
+#endif
+
+// set one bit if port is enabled for consistency
+#define SERIAL_VCP_MASK (SERIAL_VCP_USED * BIT(0))
+#define SERIAL_VCP_COUNT (SERIAL_VCP_USED)
+// 0 if no port is defined
+#define SERIAL_VCP_MAX (SERIAL_VCP_MASK ? LOG2(SERIAL_VCP_MASK) + 1 : 0)
+
+
+
+// normalize USE_x after all ports are enumerated (x_COUNT of dependencies must be available)
+#if !defined(USE_UART) && (SERIAL_UART_COUNT || SERIAL_LPUART_COUNT)
+# define USE_UART
+#endif
+#if !defined(USE_LPUART) && (SERIAL_LPUART_COUNT)
+# define USE_LPUART
+#endif
+#if !defined(USE_SOFTSERIAL) && (SERIAL_SOFTSERIAL_COUNT)
+# define USE_SOFTSERIAL
+#endif
+#if !defined(USE_VCP) && (SERIAL_VCP_COUNT)
+# define USE_VCP
+#endif
+
diff --git a/src/main/telemetry/hott.c b/src/main/telemetry/hott.c
index 512f9783c2..54445b635e 100644
--- a/src/main/telemetry/hott.c
+++ b/src/main/telemetry/hott.c
@@ -372,13 +372,13 @@ static void workAroundForHottTelemetryOnUsart(serialPort_t *instance, portMode_e
     if (telemetryConfig()->halfDuplex) {
         portOptions |= SERIAL_BIDIR;
     }
-
+    // TODO - identifier is set only after opening port
     hottPort = openSerialPort(instance->identifier, FUNCTION_TELEMETRY_HOTT, NULL, NULL, HOTT_BAUDRATE, mode, portOptions);
 }
 
 static bool hottIsUsingHardwareUART(void)
 {
-    return !(portConfig->identifier == SERIAL_PORT_SOFTSERIAL1 || portConfig->identifier == SERIAL_PORT_SOFTSERIAL2);
+    return serialType(portConfig->identifier) != SERIALTYPE_SOFTSERIAL;
 }
 
 static void hottConfigurePortForTX(void)
diff --git a/src/main/telemetry/smartport.c b/src/main/telemetry/smartport.c
index 0459418c1f..b2de692a05 100644
--- a/src/main/telemetry/smartport.c
+++ b/src/main/telemetry/smartport.c
@@ -487,7 +487,9 @@ static void freeSmartPortTelemetryPort(void)
 static void configureSmartPortTelemetryPort(void)
 {
     if (portConfig) {
-        portOptions_e portOptions = (telemetryConfig()->halfDuplex ? SERIAL_BIDIR : SERIAL_UNIDIR) | (telemetryConfig()->telemetry_inverted ? SERIAL_NOT_INVERTED : SERIAL_INVERTED);
+        // On SmartPort, SERIAL_INVERTED is default
+        const portOptions_e portOptions = (telemetryConfig()->halfDuplex ? SERIAL_BIDIR : 0)
+            | (telemetryConfig()->telemetry_inverted ? SERIAL_NOT_INVERTED : SERIAL_INVERTED);
 
         smartPortSerialPort = openSerialPort(portConfig->identifier, FUNCTION_TELEMETRY_SMARTPORT, NULL, NULL, SMARTPORT_BAUD, SMARTPORT_UART_MODE, portOptions);
     }
diff --git a/src/platform/APM32/dma_reqmap_mcu.c b/src/platform/APM32/dma_reqmap_mcu.c
index 57b0132fda..892341af71 100644
--- a/src/platform/APM32/dma_reqmap_mcu.c
+++ b/src/platform/APM32/dma_reqmap_mcu.c
@@ -30,6 +30,7 @@
 #include "drivers/dma_reqmap.h"
 #include "drivers/serial.h"
 #include "drivers/serial_uart.h"
+#include "drivers/serial_uart_impl.h"
 
 #include "pg/timerio.h"
 
@@ -69,20 +70,30 @@ static const dmaPeripheralMapping_t dmaPeripheralMapping[] = {
     { DMA_PERIPH_SDIO,    0,         { DMA(2, 3, 4), DMA(2, 6, 4) } },
 #endif // USE_SDCARD_SDIO
 
-#ifdef USE_UART
+#ifdef USE_UART1
     { DMA_PERIPH_UART_TX, UARTDEV_1, { DMA(2, 7, 4) } },
     { DMA_PERIPH_UART_RX, UARTDEV_1, { DMA(2, 5, 4), DMA(2, 2, 4) } },
+#endif
+#ifdef USE_UART2
     { DMA_PERIPH_UART_TX, UARTDEV_2, { DMA(1, 6, 4) } },
     { DMA_PERIPH_UART_RX, UARTDEV_2, { DMA(1, 5, 4) } },
+#endif
+#ifdef USE_UART3
     { DMA_PERIPH_UART_TX, UARTDEV_3, { DMA(1, 3, 4) } },
     { DMA_PERIPH_UART_RX, UARTDEV_3, { DMA(1, 1, 4) } },
+#endif
+#ifdef USE_UART4
     { DMA_PERIPH_UART_TX, UARTDEV_4, { DMA(1, 4, 4) } },
     { DMA_PERIPH_UART_RX, UARTDEV_4, { DMA(1, 2, 4) } },
+#endif
+#ifdef USE_UART5
     { DMA_PERIPH_UART_TX, UARTDEV_5, { DMA(1, 7, 4) } },
     { DMA_PERIPH_UART_RX, UARTDEV_5, { DMA(1, 0, 4) } },
+#endif
+#ifdef USE_UART6
     { DMA_PERIPH_UART_TX, UARTDEV_6, { DMA(2, 6, 5), DMA(2, 7, 5) } },
     { DMA_PERIPH_UART_RX, UARTDEV_6, { DMA(2, 1, 5), DMA(2, 2, 5) } },
-#endif // USE_UART
+#endif
 };
 
 #define TC(chan) DEF_TIM_CHANNEL(CH_ ## chan)
diff --git a/src/platform/APM32/serial_uart_apm32.c b/src/platform/APM32/serial_uart_apm32.c
index a04b5de27a..399ff85324 100644
--- a/src/platform/APM32/serial_uart_apm32.c
+++ b/src/platform/APM32/serial_uart_apm32.c
@@ -24,46 +24,26 @@
  * Dominic Clifton - Serial port abstraction, Separation of common STM32 code for cleanflight, various cleanups.
  * Hamasaki/Timecop - Initial baseflight code
 */
+
 #include <stdbool.h>
 #include <stdint.h>
-#include <stdlib.h>
 
 #include "platform.h"
 
-#include "build/debug.h"
-
 #ifdef USE_UART
 
 #include "build/build_config.h"
 #include "build/atomic.h"
 
 #include "common/utils.h"
-#include "drivers/io.h"
-#include "drivers/nvic.h"
 #include "drivers/inverter.h"
-#include "drivers/dma.h"
+#include "drivers/nvic.h"
 #include "drivers/rcc.h"
 
 #include "drivers/serial.h"
 #include "drivers/serial_uart.h"
 #include "drivers/serial_uart_impl.h"
 
-static void usartConfigurePinInversion(uartPort_t *uartPort)
-{
-#if !defined(USE_INVERTER)
-    UNUSED(uartPort);
-#else
-    bool inverted = uartPort->port.options & SERIAL_INVERTED;
-
-#ifdef USE_INVERTER
-    if (inverted) {
-        // Enable hardware inverter if available.
-        enableInverter(uartPort->USARTx, true);
-    }
-#endif
-#endif
-}
-
 // XXX uartReconfigure does not handle resource management properly.
 
 void uartReconfigure(uartPort_t *uartPort)
@@ -84,29 +64,25 @@ void uartReconfigure(uartPort_t *uartPort)
     if (uartPort->port.mode & MODE_TX)
         uartPort->Handle.Init.Mode |= UART_MODE_TX;
 
-
-    usartConfigurePinInversion(uartPort);
+    // config external pin inverter (no internal pin inversion available)
+    uartConfigureExternalPinInversion(uartPort);
 
 #ifdef TARGET_USART_CONFIG
+    // TODO: move declaration into header file
     void usartTargetConfigure(uartPort_t *);
     usartTargetConfigure(uartPort);
 #endif
 
-    if (uartPort->port.options & SERIAL_BIDIR)
-    {
+    if (uartPort->port.options & SERIAL_BIDIR) {
         DAL_HalfDuplex_Init(&uartPort->Handle);
-    }
-    else
-    {
+    } else {
         DAL_UART_Init(&uartPort->Handle);
     }
 
     // Receive DMA or IRQ
-    if (uartPort->port.mode & MODE_RX)
-    {
+    if (uartPort->port.mode & MODE_RX) {
 #ifdef USE_DMA
-        if (uartPort->rxDMAResource)
-        {
+        if (uartPort->rxDMAResource) {
             uartPort->rxDMAHandle.Instance = (DMA_ARCH_TYPE *)uartPort->rxDMAResource;
             uartPort->txDMAHandle.Init.Channel = uartPort->rxDMAChannel;
             uartPort->rxDMAHandle.Init.Direction = DMA_PERIPH_TO_MEMORY;
@@ -170,8 +146,7 @@ void uartReconfigure(uartPort_t *uartPort)
 
             DAL_DMA_DeInit(&uartPort->txDMAHandle);
             DAL_StatusTypeDef status = DAL_DMA_Init(&uartPort->txDMAHandle);
-            if (status != DAL_OK)
-            {
+            if (status != DAL_OK) {
                 while (1);
             }
             /* Associate the initialized DMA handle to the UART handle */
@@ -187,55 +162,14 @@ void uartReconfigure(uartPort_t *uartPort)
             SET_BIT(uartPort->USARTx->CTRL1, USART_CTRL1_TXCIEN);
         }
     }
-    return;
-}
-
-bool checkUsartTxOutput(uartPort_t *s)
-{
-    uartDevice_t *uart = container_of(s, uartDevice_t, port);
-    IO_t txIO = IOGetByTag(uart->tx.pin);
-
-    if ((uart->txPinState == TX_PIN_MONITOR) && txIO) {
-        if (IORead(txIO)) {
-            // TX is high so we're good to transmit
-
-            // Enable USART TX output
-            uart->txPinState = TX_PIN_ACTIVE;
-            IOConfigGPIOAF(txIO, IOCFG_AF_PP, uart->tx.af);
-
-            // Enable the UART transmitter
-            SET_BIT(s->Handle.Instance->CTRL1, USART_CTRL1_TXEN);
-
-            return true;
-        } else {
-            // TX line is pulled low so don't enable USART TX
-            return false;
-        }
-    }
-
-    return true;
-}
-
-void uartTxMonitor(uartPort_t *s)
-{
-    uartDevice_t *uart = container_of(s, uartDevice_t, port);
-
-    if (uart->txPinState == TX_PIN_ACTIVE) {
-        IO_t txIO = IOGetByTag(uart->tx.pin);
-
-        // Disable the UART transmitter
-        CLEAR_BIT(s->Handle.Instance->CTRL1, USART_CTRL1_TXEN);
-
-        // Switch TX to an input with pullup so it's state can be monitored
-        uart->txPinState = TX_PIN_MONITOR;
-        IOConfigGPIO(txIO, IOCFG_IPU);
-    }
 }
 
 #ifdef USE_DMA
-
 void uartTryStartTxDMA(uartPort_t *s)
 {
+    // uartTryStartTxDMA must be protected, since it is called from
+    // uartWrite and handleUsartTxDma (an ISR).
+
     ATOMIC_BLOCK(NVIC_PRIO_SERIALUART_TXDMA) {
         if (IS_DMA_ENABLED(s->txDMAResource)) {
             // DMA is already in progress
@@ -254,106 +188,19 @@ void uartTryStartTxDMA(uartPort_t *s)
             return;
         }
 
-        uint16_t size;
+        unsigned chunk;
         uint32_t fromwhere = s->port.txBufferTail;
 
         if (s->port.txBufferHead > s->port.txBufferTail) {
-            size = s->port.txBufferHead - s->port.txBufferTail;
+            chunk = s->port.txBufferHead - s->port.txBufferTail;
             s->port.txBufferTail = s->port.txBufferHead;
         } else {
-            size = s->port.txBufferSize - s->port.txBufferTail;
+            chunk = s->port.txBufferSize - s->port.txBufferTail;
             s->port.txBufferTail = 0;
         }
         s->txDMAEmpty = false;
-
-        DAL_UART_Transmit_DMA(&s->Handle, (uint8_t *)&s->port.txBuffer[fromwhere], size);
+        DAL_UART_Transmit_DMA(&s->Handle, (uint8_t*)s->port.txBuffer + fromwhere, chunk);
     }
 }
-
-static void handleUsartTxDma(uartPort_t *s)
-{
-    uartDevice_t *uart = container_of(s, uartDevice_t, port);
-
-    uartTryStartTxDMA(s);
-
-    if (s->txDMAEmpty && (uart->txPinState != TX_PIN_IGNORE)) {
-        // Switch TX to an input with pullup so it's state can be monitored
-        uartTxMonitor(s);
-    }
-}
-
-void uartDmaIrqHandler(dmaChannelDescriptor_t* descriptor)
-{
-    UNUSED(descriptor);
-    uartPort_t *s = &(((uartDevice_t*)(descriptor->userParam))->port);
-    if (DMA_GET_FLAG_STATUS(descriptor, DMA_IT_TCIF))
-    {
-        DMA_CLEAR_FLAG(descriptor, DMA_IT_TCIF);
-        DMA_CLEAR_FLAG(descriptor, DMA_IT_HTIF);
-        if (DMA_GET_FLAG_STATUS(descriptor, DMA_IT_FEIF))
-        {
-            DMA_CLEAR_FLAG(descriptor, DMA_IT_FEIF);
-        }
-        handleUsartTxDma(s);
-    }
-    if (DMA_GET_FLAG_STATUS(descriptor, DMA_IT_TEIF))
-    {
-        DMA_CLEAR_FLAG(descriptor, DMA_IT_TEIF);
-    }
-    if (DMA_GET_FLAG_STATUS(descriptor, DMA_IT_DMEIF))
-    {
-        DMA_CLEAR_FLAG(descriptor, DMA_IT_DMEIF);
-    }
-}
-#endif // USE_DMA
-
-FAST_IRQ_HANDLER void uartIrqHandler(uartPort_t *s)
-{
-    UART_HandleTypeDef *huart = &s->Handle;
-    uint32_t isrflags = READ_REG(huart->Instance->STS);
-    uint32_t cr1its = READ_REG(huart->Instance->CTRL1);
-    uint32_t cr3its = READ_REG(huart->Instance->CTRL3);
-    /* UART in mode Receiver ---------------------------------------------------*/
-    if (!s->rxDMAResource && (((isrflags & USART_STS_RXBNEFLG) != RESET) && ((cr1its & USART_CTRL1_RXBNEIEN) != RESET))) {
-        if (s->port.rxCallback) {
-            s->port.rxCallback(huart->Instance->DATA, s->port.rxCallbackData);
-        } else {
-            s->port.rxBuffer[s->port.rxBufferHead] = huart->Instance->DATA;
-            s->port.rxBufferHead = (s->port.rxBufferHead + 1) % s->port.rxBufferSize;
-        }
-    }
-
-    // Detect completion of transmission
-    if (((isrflags & USART_STS_TXCFLG) != RESET) && ((cr1its & USART_CTRL1_TXCIEN) != RESET)) {
-        // Switch TX to an input with pullup so it's state can be monitored
-        uartTxMonitor(s);
-
-        __DAL_UART_CLEAR_FLAG(huart, UART_IT_TC);
-    }
-
-    if (!s->txDMAResource && (((isrflags & USART_STS_TXBEFLG) != RESET) && ((cr1its & USART_CTRL1_TXBEIEN) != RESET))) {
-        if (s->port.txBufferTail != s->port.txBufferHead) {
-            huart->Instance->DATA = (((uint16_t) s->port.txBuffer[s->port.txBufferTail]) & (uint16_t) 0x01FFU);
-            s->port.txBufferTail = (s->port.txBufferTail + 1) % s->port.txBufferSize;
-        } else {
-            __DAL_UART_DISABLE_IT(huart, UART_IT_TXE);
-        }
-    }
-
-    if (((isrflags & USART_STS_OVREFLG) != RESET) && (((cr1its & USART_CTRL1_RXBNEIEN) != RESET)
-                                                 || ((cr3its & USART_CTRL3_ERRIEN) != RESET))) {
-        __DAL_UART_CLEAR_OREFLAG(huart);
-    }
-
-    if (((isrflags & USART_STS_IDLEFLG) != RESET) && ((cr1its & USART_STS_IDLEFLG) != RESET)) {
-        if (s->port.idleCallback) {
-            s->port.idleCallback();
-        }
-
-        // clear
-        (void) huart->Instance->STS;
-        (void) huart->Instance->DATA;
-    }
-}
-
+#endif
 #endif // USE_UART
diff --git a/src/platform/APM32/serial_uart_apm32f4xx.c b/src/platform/APM32/serial_uart_apm32f4xx.c
index 7e9153fc03..1dde4d9682 100644
--- a/src/platform/APM32/serial_uart_apm32f4xx.c
+++ b/src/platform/APM32/serial_uart_apm32f4xx.c
@@ -26,7 +26,6 @@
 #include <stdint.h>
 
 #include "platform.h"
-#include "build/debug.h"
 
 #ifdef USE_UART
 
@@ -45,7 +44,7 @@
 const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #ifdef USE_UART1
     {
-        .device = UARTDEV_1,
+        .identifier = SERIAL_PORT_USART1,
         .reg = USART1,
         .rxDMAChannel = DMA_CHANNEL_4,
         .txDMAChannel = DMA_CHANNEL_4,
@@ -55,13 +54,9 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #ifdef USE_UART1_TX_DMA
         .txDMAResource = (dmaResource_t *)DMA2_Stream7,
 #endif
-        .rxPins = { 
-            { DEFIO_TAG_E(PA10), GPIO_AF7_USART1 },
-            { DEFIO_TAG_E(PB7), GPIO_AF7_USART1 },
+        .rxPins = { { DEFIO_TAG_E(PA10) }, { DEFIO_TAG_E(PB7) },
             },
-        .txPins = {
-            { DEFIO_TAG_E(PA9), GPIO_AF7_USART1 }, 
-            { DEFIO_TAG_E(PB6), GPIO_AF7_USART1 },
+        .txPins = { { DEFIO_TAG_E(PA9) }, { DEFIO_TAG_E(PB6) },
             },
         .af = GPIO_AF7_USART1,
         .rcc = RCC_APB2(USART1),
@@ -77,7 +72,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART2
     {
-        .device = UARTDEV_2,
+        .identifier = SERIAL_PORT_USART2,
         .reg = USART2,
         .rxDMAChannel = DMA_CHANNEL_4,
         .txDMAChannel = DMA_CHANNEL_4,
@@ -87,14 +82,8 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #ifdef USE_UART2_TX_DMA
         .txDMAResource = (dmaResource_t *)DMA1_Stream6,
 #endif
-        .rxPins = { 
-            { DEFIO_TAG_E(PA3), GPIO_AF7_USART2 }, 
-            { DEFIO_TAG_E(PD6), GPIO_AF7_USART2 } 
-            },
-        .txPins = { 
-            { DEFIO_TAG_E(PA2), GPIO_AF7_USART2 }, 
-            { DEFIO_TAG_E(PD5), GPIO_AF7_USART2 } 
-            },
+        .rxPins = { { DEFIO_TAG_E(PA3) }, { DEFIO_TAG_E(PD6) } },
+        .txPins = { { DEFIO_TAG_E(PA2) }, { DEFIO_TAG_E(PD5) } },
         .af = GPIO_AF7_USART2,
         .rcc = RCC_APB1(USART2),
         .irqn = USART2_IRQn,
@@ -109,7 +98,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART3
     {
-        .device = UARTDEV_3,
+        .identifier = SERIAL_PORT_USART3,
         .reg = USART3,
         .rxDMAChannel = DMA_CHANNEL_4,
         .txDMAChannel = DMA_CHANNEL_4,
@@ -119,16 +108,8 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #ifdef USE_UART3_TX_DMA
         .txDMAResource = (dmaResource_t *)DMA1_Stream3,
 #endif
-        .rxPins = {
-            { DEFIO_TAG_E(PB11), GPIO_AF7_USART3 }, 
-            { DEFIO_TAG_E(PC11), GPIO_AF7_USART3 }, 
-            { DEFIO_TAG_E(PD9), GPIO_AF7_USART3 } 
-            },
-        .txPins = { 
-            { DEFIO_TAG_E(PB10), GPIO_AF7_USART3 }, 
-            { DEFIO_TAG_E(PC10), GPIO_AF7_USART3 }, 
-            { DEFIO_TAG_E(PD8), GPIO_AF7_USART3 } 
-            },
+        .rxPins = { { DEFIO_TAG_E(PB11) }, { DEFIO_TAG_E(PC11) }, { DEFIO_TAG_E(PD9) } },
+        .txPins = { { DEFIO_TAG_E(PB10) }, { DEFIO_TAG_E(PC10) }, { DEFIO_TAG_E(PD8) } },
         .af = GPIO_AF7_USART3,
         .rcc = RCC_APB1(USART3),
         .irqn = USART3_IRQn,
@@ -143,7 +124,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART4
     {
-        .device = UARTDEV_4,
+        .identifier = SERIAL_PORT_UART4,
         .reg = UART4,
         .rxDMAChannel = DMA_CHANNEL_4,
         .txDMAChannel = DMA_CHANNEL_4,
@@ -153,14 +134,8 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #ifdef USE_UART4_TX_DMA
         .txDMAResource = (dmaResource_t *)DMA1_Stream4,
 #endif
-        .rxPins = { 
-            { DEFIO_TAG_E(PA1), GPIO_AF8_UART4 }, 
-            { DEFIO_TAG_E(PC11), GPIO_AF8_UART4 } 
-            },
-        .txPins = { 
-            { DEFIO_TAG_E(PA0), GPIO_AF8_UART4 }, 
-            { DEFIO_TAG_E(PC10), GPIO_AF8_UART4 } 
-            },
+        .rxPins = { { DEFIO_TAG_E(PA1) }, { DEFIO_TAG_E(PC11) } },
+        .txPins = { { DEFIO_TAG_E(PA0) }, { DEFIO_TAG_E(PC10) } },
         .af = GPIO_AF8_UART4,
         .rcc = RCC_APB1(UART4),
         .irqn = UART4_IRQn,
@@ -175,7 +150,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART5
     {
-        .device = UARTDEV_5,
+        .identifier = SERIAL_PORT_UART5,
         .reg = UART5,
         .rxDMAChannel = DMA_CHANNEL_4,
         .txDMAChannel = DMA_CHANNEL_4,
@@ -185,12 +160,8 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #ifdef USE_UART5_TX_DMA
         .txDMAResource = (dmaResource_t *)DMA1_Stream7,
 #endif
-        .rxPins = { 
-            { DEFIO_TAG_E(PD2), GPIO_AF8_UART5 } 
-            },
-        .txPins = { 
-            { DEFIO_TAG_E(PC12), GPIO_AF8_UART5 } 
-            },
+        .rxPins = { { DEFIO_TAG_E(PD2) } },
+        .txPins = { { DEFIO_TAG_E(PC12) } },
         .af = GPIO_AF8_UART5,
         .rcc = RCC_APB1(UART5),
         .irqn = UART5_IRQn,
@@ -205,7 +176,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART6
     {
-        .device = UARTDEV_6,
+        .identifier = SERIAL_PORT_USART6,
         .reg = USART6,
         .rxDMAChannel = DMA_CHANNEL_5,
         .txDMAChannel = DMA_CHANNEL_5,
@@ -215,14 +186,8 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #ifdef USE_UART6_TX_DMA
         .txDMAResource = (dmaResource_t *)DMA2_Stream6,
 #endif
-        .rxPins = { 
-            { DEFIO_TAG_E(PC7), GPIO_AF8_USART6 }, 
-            { DEFIO_TAG_E(PG9), GPIO_AF8_USART6 } 
-            },
-        .txPins = { 
-            { DEFIO_TAG_E(PC6), GPIO_AF8_USART6 }, 
-            { DEFIO_TAG_E(PG14), GPIO_AF8_USART6 } 
-            },
+        .rxPins = { { DEFIO_TAG_E(PC7) }, { DEFIO_TAG_E(PG9) } },
+        .txPins = { { DEFIO_TAG_E(PC6) }, { DEFIO_TAG_E(PG14) } },
         .af = GPIO_AF8_USART6,
         .rcc = RCC_APB2(USART6),
         .irqn = USART6_IRQn,
@@ -236,83 +201,130 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #endif
 };
 
-// XXX Should serialUART be consolidated?
-
-uartPort_t *serialUART(UARTDevice_e device, uint32_t baudRate, portMode_e mode, portOptions_e options)
+bool checkUsartTxOutput(uartPort_t *s)
 {
-    uartDevice_t *uartdev = uartDevmap[device];
-    if (!uartdev) {
-        return NULL;
-    }
+    uartDevice_t *uart = container_of(s, uartDevice_t, port);
+    IO_t txIO = IOGetByTag(uart->tx.pin);
 
-    uartPort_t *s = &(uartdev->port);
+    if ((uart->txPinState == TX_PIN_MONITOR) && txIO) {
+        if (IORead(txIO)) {
+            // TX is high so we're good to transmit
 
-    s->port.vTable = uartVTable;
+            // Enable USART TX output
+            uart->txPinState = TX_PIN_ACTIVE;
+            IOConfigGPIOAF(txIO, IOCFG_AF_PP, uart->hardware->af);
 
-    s->port.baudRate = baudRate;
+            // Enable the UART transmitter
+            SET_BIT(s->Handle.Instance->CTRL1, USART_CTRL1_TXEN);
 
-    const uartHardware_t *hardware = uartdev->hardware;
-
-    s->USARTx = hardware->reg;
-
-    s->port.rxBuffer = hardware->rxBuffer;
-    s->port.txBuffer = hardware->txBuffer;
-    s->port.rxBufferSize = hardware->rxBufferSize;
-    s->port.txBufferSize = hardware->txBufferSize;
-
-    s->checkUsartTxOutput = checkUsartTxOutput;
-
-#ifdef USE_DMA
-    uartConfigureDma(uartdev);
-#endif
-
-    s->Handle.Instance = hardware->reg;
-
-    if (hardware->rcc) {
-        RCC_ClockCmd(hardware->rcc, ENABLE);
-    }
-
-    IO_t txIO = IOGetByTag(uartdev->tx.pin);
-    IO_t rxIO = IOGetByTag(uartdev->rx.pin);
-
-    uartdev->txPinState = TX_PIN_IGNORE;
-
-    if ((options & SERIAL_BIDIR) && txIO) {
-        ioConfig_t ioCfg = IO_CONFIG(
-            ((options & SERIAL_INVERTED) || (options & SERIAL_BIDIR_PP) || (options & SERIAL_BIDIR_PP_PD)) ? GPIO_MODE_AF_PP : GPIO_MODE_AF_OD,
-            GPIO_SPEED_FREQ_HIGH,
-            ((options & SERIAL_INVERTED) || (options & SERIAL_BIDIR_PP_PD)) ? GPIO_PULLDOWN : GPIO_PULLUP
-        );
-
-        IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
-        IOConfigGPIOAF(txIO, ioCfg, uartdev->tx.af);
-    }
-    else {
-        if ((mode & MODE_TX) && txIO) {
-            IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
-
-            if (options & SERIAL_CHECK_TX) {
-                uartdev->txPinState = TX_PIN_MONITOR;
-                // Switch TX to UART output whilst UART sends idle preamble
-                checkUsartTxOutput(s);
-            } else {
-                IOConfigGPIOAF(txIO, IOCFG_AF_PP, uartdev->tx.af);
-            }
-        }
-
-        if ((mode & MODE_RX) && rxIO) {
-            IOInit(rxIO, OWNER_SERIAL_RX, RESOURCE_INDEX(device));
-            IOConfigGPIOAF(rxIO, IOCFG_AF_PP, uartdev->rx.af);
+            return true;
+        } else {
+            // TX line is pulled low so don't enable USART TX
+            return false;
         }
     }
 
-#ifdef USE_DMA
-    if (!s->rxDMAResource) {
-        DAL_NVIC_SetPriority(hardware->irqn, NVIC_PRIORITY_BASE(hardware->rxPriority), NVIC_PRIORITY_SUB(hardware->rxPriority));
-        DAL_NVIC_EnableIRQ(hardware->irqn);
-    }
-#endif
-
-    return s;
+    return true;
 }
+
+void uartTxMonitor(uartPort_t *s)
+{
+    uartDevice_t *uart = container_of(s, uartDevice_t, port);
+
+    if (uart->txPinState == TX_PIN_ACTIVE) {
+        IO_t txIO = IOGetByTag(uart->tx.pin);
+
+        // Disable the UART transmitter
+        CLEAR_BIT(s->Handle.Instance->CTRL1, USART_CTRL1_TXEN);
+
+        // Switch TX to an input with pullup so it's state can be monitored
+        uart->txPinState = TX_PIN_MONITOR;
+        IOConfigGPIO(txIO, IOCFG_IPU);
+    }
+}
+
+static void handleUsartTxDma(uartPort_t *s)
+{
+    uartDevice_t *uart = container_of(s, uartDevice_t, port);
+
+    uartTryStartTxDMA(s);
+
+    if (s->txDMAEmpty && (uart->txPinState != TX_PIN_IGNORE)) {
+        // Switch TX to an input with pullup so it's state can be monitored
+        uartTxMonitor(s);
+    }
+}
+
+void uartDmaIrqHandler(dmaChannelDescriptor_t* descriptor)
+{
+    uartPort_t *s = &(((uartDevice_t*)(descriptor->userParam))->port);
+    if (DMA_GET_FLAG_STATUS(descriptor, DMA_IT_TCIF))
+    {
+        DMA_CLEAR_FLAG(descriptor, DMA_IT_TCIF);
+        DMA_CLEAR_FLAG(descriptor, DMA_IT_HTIF);
+        if (DMA_GET_FLAG_STATUS(descriptor, DMA_IT_FEIF))
+        {
+            DMA_CLEAR_FLAG(descriptor, DMA_IT_FEIF);
+        }
+        handleUsartTxDma(s);
+    }
+    if (DMA_GET_FLAG_STATUS(descriptor, DMA_IT_TEIF))
+    {
+        DMA_CLEAR_FLAG(descriptor, DMA_IT_TEIF);
+    }
+    if (DMA_GET_FLAG_STATUS(descriptor, DMA_IT_DMEIF))
+    {
+        DMA_CLEAR_FLAG(descriptor, DMA_IT_DMEIF);
+    }
+}
+
+FAST_IRQ_HANDLER void uartIrqHandler(uartPort_t *s)
+{
+    UART_HandleTypeDef *huart = &s->Handle;
+    uint32_t isrflags = READ_REG(huart->Instance->STS);
+    uint32_t cr1its = READ_REG(huart->Instance->CTRL1);
+    uint32_t cr3its = READ_REG(huart->Instance->CTRL3);
+    /* UART in mode Receiver ---------------------------------------------------*/
+    if (!s->rxDMAResource && (((isrflags & USART_STS_RXBNEFLG) != RESET) && ((cr1its & USART_CTRL1_RXBNEIEN) != RESET))) {
+        if (s->port.rxCallback) {
+            s->port.rxCallback(huart->Instance->DATA, s->port.rxCallbackData);
+        } else {
+            s->port.rxBuffer[s->port.rxBufferHead] = huart->Instance->DATA;
+            s->port.rxBufferHead = (s->port.rxBufferHead + 1) % s->port.rxBufferSize;
+        }
+    }
+
+    // Detect completion of transmission
+    if (((isrflags & USART_STS_TXCFLG) != RESET) && ((cr1its & USART_CTRL1_TXCIEN) != RESET)) {
+        // Switch TX to an input with pullup so it's state can be monitored
+        uartTxMonitor(s);
+
+        __DAL_UART_CLEAR_FLAG(huart, UART_IT_TC);
+    }
+
+    if (!s->txDMAResource && (((isrflags & USART_STS_TXBEFLG) != RESET) && ((cr1its & USART_CTRL1_TXBEIEN) != RESET))) {
+        if (s->port.txBufferTail != s->port.txBufferHead) {
+            huart->Instance->DATA = (((uint16_t) s->port.txBuffer[s->port.txBufferTail]) & (uint16_t) 0x01FFU);
+            s->port.txBufferTail = (s->port.txBufferTail + 1) % s->port.txBufferSize;
+        } else {
+            __DAL_UART_DISABLE_IT(huart, UART_IT_TXE);
+        }
+    }
+
+    if (((isrflags & USART_STS_OVREFLG) != RESET) && (((cr1its & USART_CTRL1_RXBNEIEN) != RESET)
+                                                 || ((cr3its & USART_CTRL3_ERRIEN) != RESET))) {
+        __DAL_UART_CLEAR_OREFLAG(huart);
+    }
+
+    if (((isrflags & USART_STS_IDLEFLG) != RESET) && ((cr1its & USART_STS_IDLEFLG) != RESET)) {
+        if (s->port.idleCallback) {
+            s->port.idleCallback();
+        }
+
+        // clear
+        (void) huart->Instance->STS;
+        (void) huart->Instance->DATA;
+    }
+}
+
 #endif // USE_UART
diff --git a/src/platform/APM32/target/APM32F405/target.h b/src/platform/APM32/target/APM32F405/target.h
index f823194180..367ab649ad 100644
--- a/src/platform/APM32/target/APM32F405/target.h
+++ b/src/platform/APM32/target/APM32F405/target.h
@@ -49,8 +49,6 @@
 #define USE_UART5
 #define USE_UART6
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 6)
-
 #define USE_INVERTER
 
 #define USE_SPI_DEVICE_1
diff --git a/src/platform/APM32/target/APM32F407/target.h b/src/platform/APM32/target/APM32F407/target.h
index 93e5a64920..a88cea7e6e 100644
--- a/src/platform/APM32/target/APM32F407/target.h
+++ b/src/platform/APM32/target/APM32F407/target.h
@@ -49,8 +49,6 @@
 #define USE_UART5
 #define USE_UART6
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 6)
-
 #define USE_INVERTER
 
 #define USE_SPI_DEVICE_1
diff --git a/src/platform/AT32/dma_reqmap_mcu.c b/src/platform/AT32/dma_reqmap_mcu.c
index b6323f9e1d..653efd3c3f 100644
--- a/src/platform/AT32/dma_reqmap_mcu.c
+++ b/src/platform/AT32/dma_reqmap_mcu.c
@@ -31,7 +31,7 @@
 #include "drivers/dma_reqmap.h"
 #include "drivers/serial.h"
 #include "drivers/serial_uart.h"
-
+#include "drivers/serial_uart_impl.h"
 #include "pg/timerio.h"
 
 typedef struct dmaPeripheralMapping_s {
@@ -97,17 +97,28 @@ static const dmaPeripheralMapping_t dmaPeripheralMapping[] = {
     REQMAP(ADC, 3),
 #endif
 
-#ifdef USE_UART
+    // UARTDEV_x enum value exists only when coresponding UART is enabled
+#ifdef USE_UART1
     REQMAP_DIR(UART, 1, TX),
     REQMAP_DIR(UART, 1, RX),
+#endif
+#ifdef USE_UART2
     REQMAP_DIR(UART, 2, TX),
     REQMAP_DIR(UART, 2, RX),
+#endif
+#ifdef USE_UART3
     REQMAP_DIR(UART, 3, TX),
     REQMAP_DIR(UART, 3, RX),
+#endif
+#ifdef USE_UART4
     REQMAP_DIR(UART, 4, TX),
     REQMAP_DIR(UART, 4, RX),
+#endif
+#ifdef USE_UART5
     REQMAP_DIR(UART, 5, TX),
     REQMAP_DIR(UART, 5, RX),
+#endif
+#ifdef USE_UART6
     REQMAP_DIR(UART, 6, TX),
     REQMAP_DIR(UART, 6, RX),
 #endif
diff --git a/src/platform/AT32/serial_uart_at32bsp.c b/src/platform/AT32/serial_uart_at32bsp.c
index 2ba9a09573..0ba46faf5c 100644
--- a/src/platform/AT32/serial_uart_at32bsp.c
+++ b/src/platform/AT32/serial_uart_at32bsp.c
@@ -48,40 +48,9 @@
 #include "drivers/serial_uart.h"
 #include "drivers/serial_uart_impl.h"
 
-static void usartConfigurePinInversion(uartPort_t *uartPort) {
-#if !defined(USE_INVERTER) && !defined(STM32F303xC)
-    UNUSED(uartPort);
-#else
-    bool inverted = uartPort->port.options & SERIAL_INVERTED;
-
-#ifdef USE_INVERTER
-    if (inverted) {
-        // Enable hardware inverter if available.
-        enableInverter(uartPort->USARTx, TRUE);
-    }
-#endif
-#endif
-}
-
-static uartDevice_t *uartFindDevice(uartPort_t *uartPort)
-{
-    for (uint32_t i = 0; i < UARTDEV_COUNT_MAX; i++) {
-        uartDevice_t *candidate = uartDevmap[i];
-
-        if (&candidate->port == uartPort) {
-            return candidate;
-        }
-    }
-    return NULL;
-}
-
 static void uartConfigurePinSwap(uartPort_t *uartPort)
 {
-    uartDevice_t *uartDevice = uartFindDevice(uartPort);
-    if (!uartDevice) {
-        return;
-    }
-
+    uartDevice_t *uartDevice = container_of(uartPort, uartDevice_t, port);
     if (uartDevice->pinSwap) {
         usart_transmit_receive_pin_swap(uartDevice->port.USARTx, TRUE);
     }
@@ -107,15 +76,15 @@ void uartReconfigure(uartPort_t *uartPort)
     if (uartPort->port.mode & MODE_RX) {
         usart_receiver_enable(uartPort->USARTx, TRUE);
     }
-    
+
     if (uartPort->port.mode & MODE_TX) {
         usart_transmitter_enable(uartPort->USARTx, TRUE);
     }
 
-    //config pin inverter
-    usartConfigurePinInversion(uartPort);
+    // config external pin inverter (no internal pin inversion available)
+    uartConfigureExternalPinInversion(uartPort);
 
-    //config pin swap
+    // config pin swap
     uartConfigurePinSwap(uartPort);
 
     if (uartPort->port.options & SERIAL_BIDIR) {
@@ -132,16 +101,16 @@ void uartReconfigure(uartPort_t *uartPort)
         if (uartPort->rxDMAResource) {
 
             dma_default_para_init(&DMA_InitStructure);
-            DMA_InitStructure.loop_mode_enable=TRUE;
-            DMA_InitStructure.peripheral_base_addr=uartPort->rxDMAPeripheralBaseAddr;
+            DMA_InitStructure.loop_mode_enable = TRUE;
+            DMA_InitStructure.peripheral_base_addr = uartPort->rxDMAPeripheralBaseAddr;
             DMA_InitStructure.priority  = DMA_PRIORITY_MEDIUM;
-            DMA_InitStructure.peripheral_inc_enable =FALSE;
-            DMA_InitStructure.peripheral_data_width =DMA_PERIPHERAL_DATA_WIDTH_BYTE;
-            DMA_InitStructure.memory_inc_enable =TRUE;
+            DMA_InitStructure.peripheral_inc_enable = FALSE;
+            DMA_InitStructure.peripheral_data_width = DMA_PERIPHERAL_DATA_WIDTH_BYTE;
+            DMA_InitStructure.memory_inc_enable = TRUE;
             DMA_InitStructure.memory_data_width = DMA_MEMORY_DATA_WIDTH_BYTE;
-            DMA_InitStructure.memory_base_addr=(uint32_t)uartPort->port.rxBuffer;
+            DMA_InitStructure.memory_base_addr = (uint32_t)uartPort->port.rxBuffer;
             DMA_InitStructure.buffer_size = uartPort->port.rxBufferSize;
-            DMA_InitStructure.direction= DMA_DIR_PERIPHERAL_TO_MEMORY;
+            DMA_InitStructure.direction = DMA_DIR_PERIPHERAL_TO_MEMORY;
 
             xDMA_DeInit(uartPort->rxDMAResource);
             xDMA_Init(uartPort->rxDMAResource, &DMA_InitStructure);
@@ -159,16 +128,16 @@ void uartReconfigure(uartPort_t *uartPort)
     if (uartPort->port.mode & MODE_TX) {
         if (uartPort->txDMAResource) {
             dma_default_para_init(&DMA_InitStructure);
-            DMA_InitStructure.loop_mode_enable=FALSE;
-            DMA_InitStructure.peripheral_base_addr=uartPort->txDMAPeripheralBaseAddr;
-            DMA_InitStructure.priority  = DMA_PRIORITY_MEDIUM;
-            DMA_InitStructure.peripheral_inc_enable =FALSE;
-            DMA_InitStructure.peripheral_data_width =DMA_PERIPHERAL_DATA_WIDTH_BYTE;
-            DMA_InitStructure.memory_inc_enable =TRUE;
+            DMA_InitStructure.loop_mode_enable = FALSE;
+            DMA_InitStructure.peripheral_base_addr = uartPort->txDMAPeripheralBaseAddr;
+            DMA_InitStructure.priority = DMA_PRIORITY_MEDIUM;
+            DMA_InitStructure.peripheral_inc_enable = FALSE;
+            DMA_InitStructure.peripheral_data_width = DMA_PERIPHERAL_DATA_WIDTH_BYTE;
+            DMA_InitStructure.memory_inc_enable = TRUE;
             DMA_InitStructure.memory_data_width = DMA_MEMORY_DATA_WIDTH_BYTE;
-            DMA_InitStructure.memory_base_addr=(uint32_t)uartPort->port.txBuffer;
+            DMA_InitStructure.memory_base_addr = (uint32_t)uartPort->port.txBuffer;
             DMA_InitStructure.buffer_size = uartPort->port.txBufferSize;
-            DMA_InitStructure.direction= DMA_DIR_MEMORY_TO_PERIPHERAL;
+            DMA_InitStructure.direction = DMA_DIR_MEMORY_TO_PERIPHERAL;
 
             xDMA_DeInit(uartPort->txDMAResource);
             xDMA_Init(uartPort->txDMAResource, &DMA_InitStructure);
@@ -181,7 +150,7 @@ void uartReconfigure(uartPort_t *uartPort)
         }
         usart_interrupt_enable(uartPort->USARTx, USART_TDC_INT, TRUE);
     }
-
+    // TODO: usart_enable is called twice
     usart_enable(uartPort->USARTx,TRUE);
 }
 
@@ -328,7 +297,7 @@ void uartIrqHandler(uartPort_t *s)
     if (usart_flag_get(s->USARTx, USART_ROERR_FLAG) == SET) {
         usart_flag_clear(s->USARTx, USART_ROERR_FLAG);
     }
-    
+
     if (usart_flag_get(s->USARTx, USART_IDLEF_FLAG) == SET) {
         if (s->port.idleCallback) {
             s->port.idleCallback();
diff --git a/src/platform/AT32/serial_uart_at32f43x.c b/src/platform/AT32/serial_uart_at32f43x.c
index eb06a663d5..86a786ee77 100644
--- a/src/platform/AT32/serial_uart_at32f43x.c
+++ b/src/platform/AT32/serial_uart_at32f43x.c
@@ -89,7 +89,7 @@
 const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #ifdef USE_UART1
     {
-        .device = UARTDEV_1,
+        .identifier = SERIAL_PORT_USART1,
         .reg = USART1,
 #ifdef USE_DMA
         .rxDMAMuxId = DMAMUX_DMAREQ_ID_USART1_RX,
@@ -120,7 +120,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART2
     {
-        .device = UARTDEV_2,
+        .identifier = SERIAL_PORT_USART2,
         .reg = USART2,
 #ifdef USE_DMA
         .rxDMAMuxId = DMAMUX_DMAREQ_ID_USART2_RX,
@@ -151,7 +151,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART3
     {
-        .device = UARTDEV_3,
+        .identifier = SERIAL_PORT_USART3,
         .reg = USART3,
 #ifdef USE_DMA
         .rxDMAMuxId = DMAMUX_DMAREQ_ID_USART3_RX,
@@ -182,7 +182,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART4
     {
-        .device = UARTDEV_4,
+        .identifier = SERIAL_PORT_UART4,
         .reg = UART4,
 #ifdef USE_DMA
         .rxDMAMuxId = DMAMUX_DMAREQ_ID_UART4_RX,
@@ -213,7 +213,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART5
     {
-        .device = UARTDEV_5,
+        .identifier = SERIAL_PORT_UART5,
         .reg = UART5,
 #ifdef USE_DMA
         .rxDMAMuxId = DMAMUX_DMAREQ_ID_UART5_RX,
@@ -246,7 +246,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART6
     {
-        .device = UARTDEV_6,
+        .identifier = SERIAL_PORT_USART6,
         .reg = USART6,
 #ifdef USE_DMA
         .rxDMAMuxId = DMAMUX_DMAREQ_ID_USART6_RX,
@@ -279,7 +279,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART7
     {
-        .device = UARTDEV_7,
+        .identifier = SERIAL_PORT_UART7,
         .reg = UART7,
 #ifdef USE_DMA
         .rxDMAMuxId = DMAMUX_DMAREQ_ID_UART7_RX,
@@ -313,7 +313,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART8
     {
-        .device = UARTDEV_8,
+        .identifier = SERIAL_PORT_UART8,
         .reg = UART8, //USE UART8 FOR PIN CONFIG
 #ifdef USE_DMA
         .rxDMAMuxId = DMAMUX_DMAREQ_ID_UART8_RX,
@@ -348,79 +348,4 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 };
 
-uartPort_t *serialUART(UARTDevice_e device, uint32_t baudRate, portMode_e mode, portOptions_e options)
-{
-    uartDevice_t *uartdev = uartDevmap[device];
-    if (!uartdev) {
-        return NULL;
-    }
-
-    uartPort_t *s = &(uartdev->port);
-
-    s->port.vTable = uartVTable;
-
-    s->port.baudRate = baudRate;
-
-    const uartHardware_t *hardware = uartdev->hardware;
-
-    s->USARTx = hardware->reg;
-
-    s->port.rxBuffer = hardware->rxBuffer;
-    s->port.txBuffer = hardware->txBuffer;
-    s->port.rxBufferSize = hardware->rxBufferSize;
-    s->port.txBufferSize = hardware->txBufferSize;
-
-    s->checkUsartTxOutput = checkUsartTxOutput;
-
-#ifdef USE_DMA
-    uartConfigureDma(uartdev);
-#endif
-
-    if (hardware->rcc) {
-        RCC_ClockCmd(hardware->rcc, ENABLE);
-    }
-
-    IO_t txIO = IOGetByTag(uartdev->tx.pin);
-    IO_t rxIO = IOGetByTag(uartdev->rx.pin);
-
-    uartdev->txPinState = TX_PIN_IGNORE;
-
-    if ((options & SERIAL_BIDIR) && txIO) {
-        //mode,speed,otype,pupd
-        ioConfig_t ioCfg = IO_CONFIG(
-            GPIO_MODE_MUX,
-            GPIO_DRIVE_STRENGTH_STRONGER,
-            ((options & SERIAL_INVERTED) || (options & SERIAL_BIDIR_PP) || (options & SERIAL_BIDIR_PP_PD)) ? GPIO_OUTPUT_PUSH_PULL : GPIO_OUTPUT_OPEN_DRAIN,
-            ((options & SERIAL_INVERTED) || (options & SERIAL_BIDIR_PP_PD)) ? GPIO_PULL_DOWN : GPIO_PULL_UP
-        );
-        IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
-        IOConfigGPIOAF(txIO, ioCfg, uartdev->tx.af);
-    } else {
-        if ((mode & MODE_TX) && txIO) {
-            IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
-
-            if (((options & SERIAL_INVERTED) == SERIAL_NOT_INVERTED) && !(options & SERIAL_BIDIR_PP_PD)) {
-                uartdev->txPinState = TX_PIN_ACTIVE;
-                // Switch TX to an input with pullup so it's state can be monitored
-                uartTxMonitor(s);
-            } else {
-                IOConfigGPIOAF(txIO, IOCFG_AF_PP, uartdev->tx.af);
-            }
-        }
-
-        if ((mode & MODE_RX) && rxIO) {
-            IOInit(rxIO, OWNER_SERIAL_RX, RESOURCE_INDEX(device));
-            IOConfigGPIOAF(rxIO, IOCFG_AF_PP, uartdev->rx.af);
-        }
-    }
-
-#ifdef USE_DMA
-    if (!s->rxDMAResource)
-#endif
-    {
-        nvic_irq_enable(hardware->irqn,NVIC_PRIORITY_BASE(hardware->rxPriority), NVIC_PRIORITY_SUB(hardware->rxPriority));
-    }
-
-    return s;
-}
 #endif // USE_UART
diff --git a/src/platform/AT32/target/AT32F435G/target.h b/src/platform/AT32/target/AT32F435G/target.h
index 2fb17f97cc..9e23368a48 100644
--- a/src/platform/AT32/target/AT32F435G/target.h
+++ b/src/platform/AT32/target/AT32F435G/target.h
@@ -40,8 +40,6 @@
 
 #define USE_VCP
 
-#define UNIFIED_SERIAL_PORT_COUNT       1
-
 #define USE_UART1
 #define USE_UART2
 #define USE_UART3
@@ -51,8 +49,6 @@
 #define USE_UART7
 #define USE_UART8
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 8)
-
 #define TARGET_IO_PORTA         0xffff
 #define TARGET_IO_PORTB         0xffff
 #define TARGET_IO_PORTC         0xffff
diff --git a/src/platform/AT32/target/AT32F435M/target.h b/src/platform/AT32/target/AT32F435M/target.h
index 94fabbfc07..b446ca4123 100644
--- a/src/platform/AT32/target/AT32F435M/target.h
+++ b/src/platform/AT32/target/AT32F435M/target.h
@@ -40,8 +40,6 @@
 
 #define USE_VCP
 
-#define UNIFIED_SERIAL_PORT_COUNT       1
-
 #define USE_UART1
 #define USE_UART2
 #define USE_UART3
@@ -51,8 +49,6 @@
 #define USE_UART7
 #define USE_UART8
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 8)
-
 #define TARGET_IO_PORTA         0xffff
 #define TARGET_IO_PORTB         0xffff
 #define TARGET_IO_PORTC         0xffff
diff --git a/src/platform/SITL/target/SITL/target.h b/src/platform/SITL/target/SITL/target.h
index 5dea7eb975..68124c0450 100644
--- a/src/platform/SITL/target/SITL/target.h
+++ b/src/platform/SITL/target/SITL/target.h
@@ -92,8 +92,6 @@
 #define USE_UART7
 #define USE_UART8
 
-#define SERIAL_PORT_COUNT 8
-
 #define DEFAULT_RX_FEATURE      FEATURE_RX_MSP
 #define DEFAULT_FEATURES        (FEATURE_GPS | FEATURE_TELEMETRY)
 
diff --git a/src/platform/STM32/adc_stm32g4xx.c b/src/platform/STM32/adc_stm32g4xx.c
index e3780b5fc7..7febda692e 100644
--- a/src/platform/STM32/adc_stm32g4xx.c
+++ b/src/platform/STM32/adc_stm32g4xx.c
@@ -372,7 +372,7 @@ void adcInit(const adcConfig_t *config)
 
         RCC_ClockCmd(adc->rccADC, ENABLE);
 
-        int configuredAdcChannels = BITCOUNT(adc->channelBits);
+        int configuredAdcChannels = popcount(adc->channelBits);
 
         adcInitDevice(adc, configuredAdcChannels);
 
@@ -472,11 +472,11 @@ void adcInit(const adcConfig_t *config)
 
         // Start conversion in DMA mode
 
-        if (HAL_ADC_Start_DMA(&adc->ADCHandle, (uint32_t *)&adcConversionBuffer[dmaBufferIndex], BITCOUNT(adc->channelBits)) != HAL_OK) {
+        if (HAL_ADC_Start_DMA(&adc->ADCHandle, (uint32_t *)&adcConversionBuffer[dmaBufferIndex], popcount(adc->channelBits)) != HAL_OK) {
             handleError();
         }
 
-        dmaBufferIndex += BITCOUNT(adc->channelBits);
+        dmaBufferIndex += popcount(adc->channelBits);
     }
 }
 
diff --git a/src/platform/STM32/adc_stm32h7xx.c b/src/platform/STM32/adc_stm32h7xx.c
index d4ade965d9..f12b6b0360 100644
--- a/src/platform/STM32/adc_stm32h7xx.c
+++ b/src/platform/STM32/adc_stm32h7xx.c
@@ -424,7 +424,7 @@ void adcInit(const adcConfig_t *config)
         __HAL_RCC_ADC_CONFIG(RCC_ADCCLKSOURCE_CLKP);
 #endif
 
-        int configuredAdcChannels = BITCOUNT(adc->channelBits);
+        int configuredAdcChannels = popcount(adc->channelBits);
 
         adcInitDevice(adc, configuredAdcChannels);
 
@@ -529,11 +529,11 @@ void adcInit(const adcConfig_t *config)
 
         // Start conversion in DMA mode
 
-        if (HAL_ADC_Start_DMA(&adc->ADCHandle, (uint32_t *)&adcConversionBuffer[dmaBufferIndex], BITCOUNT(adc->channelBits)) != HAL_OK) {
+        if (HAL_ADC_Start_DMA(&adc->ADCHandle, (uint32_t *)&adcConversionBuffer[dmaBufferIndex], popcount(adc->channelBits)) != HAL_OK) {
             errorHandler();
         }
 
-        dmaBufferIndex += BITCOUNT(adc->channelBits);
+        dmaBufferIndex += popcount(adc->channelBits);
     }
 }
 
diff --git a/src/platform/STM32/bus_quadspi_hal.c b/src/platform/STM32/bus_quadspi_hal.c
index fae4fb009b..f3d91a42ff 100644
--- a/src/platform/STM32/bus_quadspi_hal.c
+++ b/src/platform/STM32/bus_quadspi_hal.c
@@ -127,6 +127,7 @@ static const uint32_t quadSpi_addressSizeMap[] = {
 
 static uint32_t quadSpi_addressSizeFromValue(uint8_t addressSize)
 {
+    // TODO addressSize + 7) / 8)
     return quadSpi_addressSizeMap[((addressSize + 1) / 8) - 1]; // rounds to nearest QSPI_ADDRESS_* value that will hold the address.
 }
 
diff --git a/src/platform/STM32/dma_reqmap_mcu.c b/src/platform/STM32/dma_reqmap_mcu.c
index f3633517dc..57001a1919 100644
--- a/src/platform/STM32/dma_reqmap_mcu.c
+++ b/src/platform/STM32/dma_reqmap_mcu.c
@@ -30,6 +30,7 @@
 #include "drivers/dma_reqmap.h"
 #include "drivers/serial.h"
 #include "drivers/serial_uart.h"
+#include "drivers/serial_uart_impl.h"
 
 #include "pg/timerio.h"
 
@@ -98,21 +99,29 @@ static const dmaPeripheralMapping_t dmaPeripheralMapping[] = {
     REQMAP(ADC, 5),
 #endif
 
-#ifdef USE_UART
+#ifdef USE_UART1
     REQMAP_DIR(UART, 1, TX),
     REQMAP_DIR(UART, 1, RX),
+#endif
+#ifdef USE_UART2
     REQMAP_DIR(UART, 2, TX),
     REQMAP_DIR(UART, 2, RX),
+#endif
+#ifdef USE_UART3
     REQMAP_DIR(UART, 3, TX),
     REQMAP_DIR(UART, 3, RX),
+#endif
+#ifdef USE_UART4
     REQMAP_DIR(UART, 4, TX),
     REQMAP_DIR(UART, 4, RX),
+#endif
+#ifdef USE_UART5
     REQMAP_DIR(UART, 5, TX),
     REQMAP_DIR(UART, 5, RX),
-#ifdef USE_LPUART1
-    { DMA_PERIPH_UART_TX, LPUARTDEV_1, DMA_REQUEST_LPUART1_TX },
-    { DMA_PERIPH_UART_RX, LPUARTDEV_1, DMA_REQUEST_LPUART1_RX },
 #endif
+#ifdef USE_LPUART1
+    { DMA_PERIPH_UART_TX, UARTDEV_LP1, DMA_REQUEST_LPUART1_TX },
+    { DMA_PERIPH_UART_RX, UARTDEV_LP1, DMA_REQUEST_LPUART1_RX },
 #endif
 
 #ifdef USE_TIMER
@@ -256,33 +265,49 @@ static const dmaPeripheralMapping_t dmaPeripheralMapping[] = {
 #endif
 #endif
 
-#ifdef USE_UART
+#ifdef USE_UART1
     REQMAP_DIR(UART, 1, TX),
     REQMAP_DIR(UART, 1, RX),
+#endif
+#ifdef USE_UART2
     REQMAP_DIR(UART, 2, TX),
     REQMAP_DIR(UART, 2, RX),
+#endif
+#ifdef USE_UART3
     REQMAP_DIR(UART, 3, TX),
     REQMAP_DIR(UART, 3, RX),
+#endif
+#ifdef USE_UART4
     REQMAP_DIR(UART, 4, TX),
     REQMAP_DIR(UART, 4, RX),
+#endif
+#ifdef USE_UART5
     REQMAP_DIR(UART, 5, TX),
     REQMAP_DIR(UART, 5, RX),
+#endif
+#ifdef USE_UART6
     REQMAP_DIR(UART, 6, TX),
     REQMAP_DIR(UART, 6, RX),
+#endif
+#ifdef USE_UART7
     REQMAP_DIR(UART, 7, TX),
     REQMAP_DIR(UART, 7, RX),
+#endif
+#ifdef USE_UART8
     REQMAP_DIR(UART, 8, TX),
     REQMAP_DIR(UART, 8, RX),
-#if defined(STM32H7A3xxQ)
+#endif
+#ifdef USE_UART9
     REQMAP_DIR(UART, 9, TX),
     REQMAP_DIR(UART, 9, RX),
+#endif
+#ifdef USE_UART10
     REQMAP_DIR(UART, 10, TX),
     REQMAP_DIR(UART, 10, RX),
 #endif
 #ifdef USE_LPUART1
-    { DMA_PERIPH_UART_TX, LPUARTDEV_1, BDMA_REQUEST_LPUART1_TX },
-    { DMA_PERIPH_UART_RX, LPUARTDEV_1, BDMA_REQUEST_LPUART1_RX },
-#endif
+    { DMA_PERIPH_UART_TX, UARTDEV_LP1, BDMA_REQUEST_LPUART1_TX },
+    { DMA_PERIPH_UART_RX, UARTDEV_LP1, BDMA_REQUEST_LPUART1_RX },
 #endif
 
 #ifdef USE_TIMER
@@ -414,17 +439,27 @@ static const dmaPeripheralMapping_t dmaPeripheralMapping[] = {
     { DMA_PERIPH_SDIO,    0,         { DMA(2, 3, 4), DMA(2, 6, 4) } },
 #endif
 
-#ifdef USE_UART
+#ifdef USE_UART1
     { DMA_PERIPH_UART_TX, UARTDEV_1, { DMA(2, 7, 4) } },
     { DMA_PERIPH_UART_RX, UARTDEV_1, { DMA(2, 5, 4), DMA(2, 2, 4) } },
+#endif
+#ifdef USE_UART2
     { DMA_PERIPH_UART_TX, UARTDEV_2, { DMA(1, 6, 4) } },
     { DMA_PERIPH_UART_RX, UARTDEV_2, { DMA(1, 5, 4) } },
+#endif
+#ifdef USE_UART3
     { DMA_PERIPH_UART_TX, UARTDEV_3, { DMA(1, 3, 4) } },
     { DMA_PERIPH_UART_RX, UARTDEV_3, { DMA(1, 1, 4) } },
+#endif
+#ifdef USE_UART4
     { DMA_PERIPH_UART_TX, UARTDEV_4, { DMA(1, 4, 4) } },
     { DMA_PERIPH_UART_RX, UARTDEV_4, { DMA(1, 2, 4) } },
+#endif
+#ifdef USE_UART5
     { DMA_PERIPH_UART_TX, UARTDEV_5, { DMA(1, 7, 4) } },
     { DMA_PERIPH_UART_RX, UARTDEV_5, { DMA(1, 0, 4) } },
+#endif
+#ifdef USE_UART6
     { DMA_PERIPH_UART_TX, UARTDEV_6, { DMA(2, 6, 5), DMA(2, 7, 5) } },
     { DMA_PERIPH_UART_RX, UARTDEV_6, { DMA(2, 1, 5), DMA(2, 2, 5) } },
 #endif
@@ -485,8 +520,7 @@ const dmaChannelSpec_t *dmaGetChannelSpecByPeripheral(dmaPeripheral_e device, ui
         return NULL;
     }
 
-    for (unsigned i = 0 ; i < ARRAYLEN(dmaPeripheralMapping) ; i++) {
-        const dmaPeripheralMapping_t *periph = &dmaPeripheralMapping[i];
+    for (const dmaPeripheralMapping_t *periph =  dmaPeripheralMapping; periph < ARRAYEND(dmaPeripheralMapping) ; periph++) {
 #if defined(STM32H7) || defined(STM32G4)
         if (periph->device == device && periph->index == index) {
             dmaChannelSpec_t *dmaSpec = &dmaChannelSpec[opt];
diff --git a/src/platform/STM32/dma_reqmap_mcu.h b/src/platform/STM32/dma_reqmap_mcu.h
index 1d45e56f6b..810202ca86 100644
--- a/src/platform/STM32/dma_reqmap_mcu.h
+++ b/src/platform/STM32/dma_reqmap_mcu.h
@@ -22,6 +22,7 @@
 #pragma once
 
 #if defined(STM32H7) || defined(STM32G4)
+
 #define MAX_PERIPHERAL_DMA_OPTIONS 16
 #define MAX_TIMER_DMA_OPTIONS 16
 #else
diff --git a/src/platform/STM32/serial_uart_hal.c b/src/platform/STM32/serial_uart_hal.c
index 5fed1aa031..3b0bf22673 100644
--- a/src/platform/STM32/serial_uart_hal.c
+++ b/src/platform/STM32/serial_uart_hal.c
@@ -67,26 +67,10 @@ static void usartConfigurePinInversion(uartPort_t *uartPort)
     }
 }
 
-static uartDevice_t *uartFindDevice(const uartPort_t *uartPort)
-{
-    for (uint32_t i = 0; i < UARTDEV_COUNT_MAX; i++) {
-        uartDevice_t *candidate = uartDevmap[i];
-
-        if (&candidate->port == uartPort) {
-            return candidate;
-        }
-    }
-    return NULL;
-}
-
-#if !(defined(STM32F4))
+#if UART_TRAIT_PINSWAP
 static void uartConfigurePinSwap(uartPort_t *uartPort)
 {
-    uartDevice_t *uartDevice = uartFindDevice(uartPort);
-    if (!uartDevice) {
-        return;
-    }
-
+    uartDevice_t *uartDevice = container_of(uartPort, uartDevice_t, port);
     if (uartDevice->pinSwap) {
         uartDevice->port.Handle.AdvancedInit.AdvFeatureInit |= UART_ADVFEATURE_SWAP_INIT;
         uartDevice->port.Handle.AdvancedInit.Swap = UART_ADVFEATURE_SWAP_ENABLE;
@@ -130,12 +114,9 @@ void uartReconfigure(uartPort_t *uartPort)
     usartTargetConfigure(uartPort);
 #endif
 
-    if (uartPort->port.options & SERIAL_BIDIR)
-    {
+    if (uartPort->port.options & SERIAL_BIDIR) {
         HAL_HalfDuplex_Init(&uartPort->Handle);
-    }
-    else
-    {
+    } else {
         HAL_UART_Init(&uartPort->Handle);
     }
 
diff --git a/src/platform/STM32/serial_uart_stdperiph.c b/src/platform/STM32/serial_uart_stdperiph.c
index 2d3255e0f3..b65275c427 100644
--- a/src/platform/STM32/serial_uart_stdperiph.c
+++ b/src/platform/STM32/serial_uart_stdperiph.c
@@ -48,22 +48,6 @@
 #include "drivers/serial_uart.h"
 #include "drivers/serial_uart_impl.h"
 
-static void usartConfigurePinInversion(uartPort_t *uartPort)
-{
-#if !defined(USE_INVERTER)
-    UNUSED(uartPort);
-#else
-    bool inverted = uartPort->port.options & SERIAL_INVERTED;
-
-#ifdef USE_INVERTER
-    if (inverted) {
-        // Enable hardware inverter if available.
-        enableInverter(uartPort->USARTx, true);
-    }
-#endif
-#endif
-}
-
 void uartReconfigure(uartPort_t *uartPort)
 {
     USART_InitTypeDef USART_InitStructure;
@@ -91,7 +75,8 @@ void uartReconfigure(uartPort_t *uartPort)
 
     USART_Init(uartPort->USARTx, &USART_InitStructure);
 
-    usartConfigurePinInversion(uartPort);
+    // config external pin inverter (no internal pin inversion available)
+    uartConfigureExternalPinInversion(uartPort);
 
     if (uartPort->port.options & SERIAL_BIDIR)
         USART_HalfDuplexCmd(uartPort->USARTx, ENABLE);
@@ -103,6 +88,7 @@ void uartReconfigure(uartPort_t *uartPort)
     // Receive DMA or IRQ
     DMA_InitTypeDef DMA_InitStructure;
     if (uartPort->port.mode & MODE_RX) {
+ #ifdef USE_DMA
         if (uartPort->rxDMAResource) {
             DMA_StructInit(&DMA_InitStructure);
             DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
@@ -133,7 +119,9 @@ void uartReconfigure(uartPort_t *uartPort)
             xDMA_Cmd(uartPort->rxDMAResource, ENABLE);
             USART_DMACmd(uartPort->USARTx, USART_DMAReq_Rx, ENABLE);
             uartPort->rxDMAPos = xDMA_GetCurrDataCounter(uartPort->rxDMAResource);
-        } else {
+        } else
+#endif
+        {
             USART_ClearITPendingBit(uartPort->USARTx, USART_IT_RXNE);
             USART_ITConfig(uartPort->USARTx, USART_IT_RXNE, ENABLE);
             USART_ITConfig(uartPort->USARTx, USART_IT_IDLE, ENABLE);
@@ -142,6 +130,7 @@ void uartReconfigure(uartPort_t *uartPort)
 
     // Transmit DMA or IRQ
     if (uartPort->port.mode & MODE_TX) {
+#ifdef USE_DMA
         if (uartPort->txDMAResource) {
             DMA_StructInit(&DMA_InitStructure);
             DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
@@ -177,14 +166,16 @@ void uartReconfigure(uartPort_t *uartPort)
 
             xDMA_SetCurrDataCounter(uartPort->txDMAResource, 0);
             USART_DMACmd(uartPort->USARTx, USART_DMAReq_Tx, ENABLE);
-        } else {
+        } else
+#endif
+        {
             USART_ITConfig(uartPort->USARTx, USART_IT_TXE, ENABLE);
         }
         // Enable the interrupt so completion of the transmission will be signalled
         USART_ITConfig(uartPort->USARTx, USART_IT_TC, ENABLE);
     }
 
-    USART_Cmd(uartPort->USARTx, ENABLE);
+    USART_Cmd(uartPort->USARTx, ENABLE); // TODO : enabling twice?
 }
 
 #ifdef USE_DMA
@@ -209,7 +200,7 @@ void uartTryStartTxDMA(uartPort_t *s)
         }
 
         if (s->port.txBufferHead == s->port.txBufferTail) {
-            // No more data to transmit.
+            // No more data to transmit
             s->txDMAEmpty = true;
             return;
         }
@@ -222,15 +213,16 @@ void uartTryStartTxDMA(uartPort_t *s)
         DMAx_SetMemoryAddress(s->txDMAResource, (uint32_t)&s->port.txBuffer[s->port.txBufferTail]);
 #endif
 
+        unsigned chunk;
         if (s->port.txBufferHead > s->port.txBufferTail) {
-            xDMA_SetCurrDataCounter(s->txDMAResource, s->port.txBufferHead - s->port.txBufferTail);
+            chunk = s->port.txBufferHead - s->port.txBufferTail;
             s->port.txBufferTail = s->port.txBufferHead;
         } else {
-            xDMA_SetCurrDataCounter(s->txDMAResource, s->port.txBufferSize - s->port.txBufferTail);
+            chunk = s->port.txBufferSize - s->port.txBufferTail;
             s->port.txBufferTail = 0;
         }
         s->txDMAEmpty = false;
-
+        xDMA_SetCurrDataCounter(s->txDMAResource, chunk);
     reenable:
         xDMA_Cmd(s->txDMAResource, ENABLE);
     }
diff --git a/src/platform/STM32/serial_uart_stm32f4xx.c b/src/platform/STM32/serial_uart_stm32f4xx.c
index b2790df6a1..d289a1e671 100644
--- a/src/platform/STM32/serial_uart_stm32f4xx.c
+++ b/src/platform/STM32/serial_uart_stm32f4xx.c
@@ -26,7 +26,6 @@
 #include <stdint.h>
 
 #include "platform.h"
-#include "build/debug.h"
 
 #ifdef USE_UART
 
@@ -45,7 +44,7 @@
 const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #ifdef USE_UART1
     {
-        .device = UARTDEV_1,
+        .identifier = SERIAL_PORT_USART1,
         .reg = USART1,
         .rxDMAChannel = DMA_Channel_4,
         .txDMAChannel = DMA_Channel_4,
@@ -79,7 +78,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART2
     {
-        .device = UARTDEV_2,
+        .identifier = SERIAL_PORT_USART2,
         .reg = USART2,
         .rxDMAChannel = DMA_Channel_4,
         .txDMAChannel = DMA_Channel_4,
@@ -105,7 +104,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART3
     {
-        .device = UARTDEV_3,
+        .identifier = SERIAL_PORT_USART3,
         .reg = USART3,
         .rxDMAChannel = DMA_Channel_4,
         .txDMAChannel = DMA_Channel_4,
@@ -131,7 +130,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART4
     {
-        .device = UARTDEV_4,
+        .identifier = SERIAL_PORT_UART4,
         .reg = UART4,
         .rxDMAChannel = DMA_Channel_4,
         .txDMAChannel = DMA_Channel_4,
@@ -157,7 +156,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART5
     {
-        .device = UARTDEV_5,
+        .identifier = SERIAL_PORT_UART5,
         .reg = UART5,
         .rxDMAChannel = DMA_Channel_4,
         .txDMAChannel = DMA_Channel_4,
@@ -183,7 +182,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART6
     {
-        .device = UARTDEV_6,
+        .identifier = SERIAL_PORT_USART6,
         .reg = USART6,
         .rxDMAChannel = DMA_Channel_5,
         .txDMAChannel = DMA_Channel_5,
@@ -297,83 +296,6 @@ void uartDmaIrqHandler(dmaChannelDescriptor_t* descriptor)
     }
 }
 
-// XXX Should serialUART be consolidated?
-
-uartPort_t *serialUART(UARTDevice_e device, uint32_t baudRate, portMode_e mode, portOptions_e options)
-{
-    uartDevice_t *uart = uartDevmap[device];
-    if (!uart) return NULL;
-
-    const uartHardware_t *hardware = uart->hardware;
-
-    if (!hardware) return NULL; // XXX Can't happen !?
-
-    uartPort_t *s = &(uart->port);
-    s->port.vTable = uartVTable;
-
-    s->port.baudRate = baudRate;
-
-    s->port.rxBuffer = hardware->rxBuffer;
-    s->port.txBuffer = hardware->txBuffer;
-    s->port.rxBufferSize = hardware->rxBufferSize;
-    s->port.txBufferSize = hardware->txBufferSize;
-
-    s->USARTx = hardware->reg;
-
-    s->checkUsartTxOutput = checkUsartTxOutput;
-
-#ifdef USE_DMA
-    uartConfigureDma(uart);
-#endif
-
-    IO_t txIO = IOGetByTag(uart->tx.pin);
-    IO_t rxIO = IOGetByTag(uart->rx.pin);
-
-    if (hardware->rcc) {
-        RCC_ClockCmd(hardware->rcc, ENABLE);
-    }
-
-    uart->txPinState = TX_PIN_IGNORE;
-
-    if (options & SERIAL_BIDIR) {
-        IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
-        IOConfigGPIOAF(txIO, (options & SERIAL_BIDIR_PP_PD) ? IOCFG_AF_PP_PD 
-                             : (options & SERIAL_BIDIR_PP) ? IOCFG_AF_PP
-                             : IOCFG_AF_OD, hardware->af);
-    } else {
-        if ((mode & MODE_TX) && txIO) {
-            IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
-
-            if (options & SERIAL_CHECK_TX) {
-                uart->txPinState = TX_PIN_ACTIVE;
-                // Switch TX to an input with pullup so it's state can be monitored
-                uartTxMonitor(s);
-            } else {
-                IOConfigGPIOAF(txIO, IOCFG_AF_PP_UP, hardware->af);
-            }
-        }
-
-        if ((mode & MODE_RX) && rxIO) {
-            IOInit(rxIO, OWNER_SERIAL_RX, RESOURCE_INDEX(device));
-            IOConfigGPIOAF(rxIO, IOCFG_AF_PP_UP, hardware->af);
-        }
-    }
-
-#ifdef USE_DMA
-    if (!(s->rxDMAResource)) {
-        NVIC_InitTypeDef NVIC_InitStructure;
-
-        NVIC_InitStructure.NVIC_IRQChannel = hardware->irqn;
-        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = NVIC_PRIORITY_BASE(hardware->rxPriority);
-        NVIC_InitStructure.NVIC_IRQChannelSubPriority = NVIC_PRIORITY_SUB(hardware->rxPriority);
-        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
-        NVIC_Init(&NVIC_InitStructure);
-    }
-#endif
-
-    return s;
-}
-
 void uartIrqHandler(uartPort_t *s)
 {
     if (!s->rxDMAResource && (USART_GetITStatus(s->USARTx, USART_IT_RXNE) == SET)) {
@@ -416,4 +338,4 @@ void uartIrqHandler(uartPort_t *s)
         (void) s->USARTx->DR;
     }
 }
-#endif
+#endif // USE_UART
diff --git a/src/platform/STM32/serial_uart_stm32f7xx.c b/src/platform/STM32/serial_uart_stm32f7xx.c
index a63ff201d2..3205cf8620 100644
--- a/src/platform/STM32/serial_uart_stm32f7xx.c
+++ b/src/platform/STM32/serial_uart_stm32f7xx.c
@@ -44,7 +44,7 @@
 const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #ifdef USE_UART1
     {
-        .device = UARTDEV_1,
+        .identifier = SERIAL_PORT_USART1,
         .reg = USART1,
         .rxDMAChannel = DMA_CHANNEL_4,
         .txDMAChannel = DMA_CHANNEL_4,
@@ -69,7 +69,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #endif
         },
         .rcc = RCC_APB2(USART1),
-        .rxIrq = USART1_IRQn,
+        .irqn = USART1_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART1_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART1,
         .txBuffer = uart1TxBuffer,
@@ -81,7 +81,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART2
     {
-        .device = UARTDEV_2,
+        .identifier = SERIAL_PORT_USART2,
         .reg = USART2,
         .rxDMAChannel = DMA_CHANNEL_4,
         .txDMAChannel = DMA_CHANNEL_4,
@@ -100,7 +100,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PD5), GPIO_AF7_USART2 }
         },
         .rcc = RCC_APB1(USART2),
-        .rxIrq = USART2_IRQn,
+        .irqn = USART2_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART2_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART2,
         .txBuffer = uart2TxBuffer,
@@ -112,7 +112,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART3
     {
-        .device = UARTDEV_3,
+        .identifier = SERIAL_PORT_USART3,
         .reg = USART3,
         .rxDMAChannel = DMA_CHANNEL_4,
         .txDMAChannel = DMA_CHANNEL_4,
@@ -133,7 +133,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PD8), GPIO_AF7_USART3 }
         },
         .rcc = RCC_APB1(USART3),
-        .rxIrq = USART3_IRQn,
+        .irqn = USART3_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART3_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART3,
         .txBuffer = uart3TxBuffer,
@@ -145,7 +145,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART4
     {
-        .device = UARTDEV_4,
+        .identifier = SERIAL_PORT_UART4,
         .reg = UART4,
         .rxDMAChannel = DMA_CHANNEL_4,
         .txDMAChannel = DMA_CHANNEL_4,
@@ -172,7 +172,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #endif
         },
         .rcc = RCC_APB1(UART4),
-        .rxIrq = UART4_IRQn,
+        .irqn = UART4_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART4_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART4,
         .txBuffer = uart4TxBuffer,
@@ -184,7 +184,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART5
     {
-        .device = UARTDEV_5,
+        .identifier = SERIAL_PORT_UART5,
         .reg = UART5,
         .rxDMAChannel = DMA_CHANNEL_4,
         .txDMAChannel = DMA_CHANNEL_4,
@@ -211,7 +211,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #endif
         },
         .rcc = RCC_APB1(UART5),
-        .rxIrq = UART5_IRQn,
+        .irqn = UART5_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART5_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART5,
         .txBuffer = uart5TxBuffer,
@@ -223,7 +223,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART6
     {
-        .device = UARTDEV_6,
+        .identifier = SERIAL_PORT_USART6,
         .reg = USART6,
         .rxDMAChannel = DMA_CHANNEL_5,
         .txDMAChannel = DMA_CHANNEL_5,
@@ -242,7 +242,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PG14), GPIO_AF8_USART6 }
         },
         .rcc = RCC_APB2(USART6),
-        .rxIrq = USART6_IRQn,
+        .irqn = USART6_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART6_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART6,
         .txBuffer = uart6TxBuffer,
@@ -254,7 +254,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART7
     {
-        .device = UARTDEV_7,
+        .identifier = SERIAL_PORT_UART7,
         .reg = UART7,
         .rxDMAChannel = DMA_CHANNEL_5,
         .txDMAChannel = DMA_CHANNEL_5,
@@ -281,7 +281,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #endif
         },
         .rcc = RCC_APB1(UART7),
-        .rxIrq = UART7_IRQn,
+        .irqn = UART7_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART7_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART7,
         .txBuffer = uart7TxBuffer,
@@ -293,7 +293,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART8
     {
-        .device = UARTDEV_8,
+        .identifier = SERIAL_PORT_UART8,
         .reg = UART8,
         .rxDMAChannel = DMA_CHANNEL_5,
         .txDMAChannel = DMA_CHANNEL_5,
@@ -310,7 +310,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PE1), GPIO_AF8_UART8 }
         },
         .rcc = RCC_APB1(UART8),
-        .rxIrq = UART8_IRQn,
+        .irqn = UART8_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART8_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART8,
         .txBuffer = uart8TxBuffer,
@@ -321,83 +321,4 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #endif
 };
 
-// XXX Should serialUART be consolidated?
-
-uartPort_t *serialUART(UARTDevice_e device, uint32_t baudRate, portMode_e mode, portOptions_e options)
-{
-    uartDevice_t *uartdev = uartDevmap[device];
-    if (!uartdev) {
-        return NULL;
-    }
-
-    uartPort_t *s = &(uartdev->port);
-
-    s->port.vTable = uartVTable;
-
-    s->port.baudRate = baudRate;
-
-    const uartHardware_t *hardware = uartdev->hardware;
-
-    s->USARTx = hardware->reg;
-
-    s->port.rxBuffer = hardware->rxBuffer;
-    s->port.txBuffer = hardware->txBuffer;
-    s->port.rxBufferSize = hardware->rxBufferSize;
-    s->port.txBufferSize = hardware->txBufferSize;
-
-    s->checkUsartTxOutput = checkUsartTxOutput;
-
-#ifdef USE_DMA
-    uartConfigureDma(uartdev);
-#endif
-
-    s->Handle.Instance = hardware->reg;
-
-    if (hardware->rcc) {
-        RCC_ClockCmd(hardware->rcc, ENABLE);
-    }
-
-    IO_t txIO = IOGetByTag(uartdev->tx.pin);
-    IO_t rxIO = IOGetByTag(uartdev->rx.pin);
-
-    uartdev->txPinState = TX_PIN_IGNORE;
-
-    if ((options & SERIAL_BIDIR) && txIO) {
-        ioConfig_t ioCfg = IO_CONFIG(
-            ((options & SERIAL_INVERTED) || (options & SERIAL_BIDIR_PP) || (options & SERIAL_BIDIR_PP_PD)) ? GPIO_MODE_AF_PP : GPIO_MODE_AF_OD,
-            GPIO_SPEED_FREQ_HIGH,
-            ((options & SERIAL_INVERTED) || (options & SERIAL_BIDIR_PP_PD)) ? GPIO_PULLDOWN : GPIO_PULLUP
-        );
-
-        IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
-        IOConfigGPIOAF(txIO, ioCfg, uartdev->tx.af);
-    }
-    else {
-        if ((mode & MODE_TX) && txIO) {
-            IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
-
-            if (options & SERIAL_CHECK_TX) {
-                uartdev->txPinState = TX_PIN_MONITOR;
-                // Switch TX to UART output whilst UART sends idle preamble
-                checkUsartTxOutput(s);
-            } else {
-                IOConfigGPIOAF(txIO, IOCFG_AF_PP, uartdev->tx.af);
-            }
-        }
-
-        if ((mode & MODE_RX) && rxIO) {
-            IOInit(rxIO, OWNER_SERIAL_RX, RESOURCE_INDEX(device));
-            IOConfigGPIOAF(rxIO, IOCFG_AF_PP, uartdev->rx.af);
-        }
-    }
-
-#ifdef USE_DMA
-    if (!s->rxDMAResource) {
-        HAL_NVIC_SetPriority(hardware->rxIrq, NVIC_PRIORITY_BASE(hardware->rxPriority), NVIC_PRIORITY_SUB(hardware->rxPriority));
-        HAL_NVIC_EnableIRQ(hardware->rxIrq);
-    }
-#endif
-
-    return s;
-}
 #endif // USE_UART
diff --git a/src/platform/STM32/serial_uart_stm32g4xx.c b/src/platform/STM32/serial_uart_stm32g4xx.c
index 295fa23b96..211e6f41fa 100644
--- a/src/platform/STM32/serial_uart_stm32g4xx.c
+++ b/src/platform/STM32/serial_uart_stm32g4xx.c
@@ -77,7 +77,7 @@
 const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #ifdef USE_UART1
     {
-        .device = UARTDEV_1,
+        .identifier = SERIAL_PORT_USART1,
         .reg = USART1,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_USART1_RX,
@@ -96,7 +96,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PC4),  GPIO_AF7_USART1 },
         },
         .rcc = RCC_APB2(USART1),
-        .rxIrq = USART1_IRQn,
+        .irqn = USART1_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART1_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART1,
         .txBuffer = uart1TxBuffer,
@@ -108,7 +108,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART2
     {
-        .device = UARTDEV_2,
+        .identifier = SERIAL_PORT_USART2,
         .reg = USART2,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_USART2_RX,
@@ -127,7 +127,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PB3),  GPIO_AF7_USART2 },
         },
         .rcc = RCC_APB11(USART2),
-        .rxIrq = USART2_IRQn,
+        .irqn = USART2_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART2_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART2,
         .txBuffer = uart2TxBuffer,
@@ -139,7 +139,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART3
     {
-        .device = UARTDEV_3,
+        .identifier = SERIAL_PORT_USART3,
         .reg = USART3,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_USART3_RX,
@@ -158,7 +158,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PC10), GPIO_AF7_USART3 },
         },
         .rcc = RCC_APB11(USART3),
-        .rxIrq = USART3_IRQn,
+        .irqn = USART3_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART3_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART3,
         .txBuffer = uart3TxBuffer,
@@ -170,7 +170,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART4
     {
-        .device = UARTDEV_4,
+        .identifier = SERIAL_PORT_UART4,
         .reg = UART4,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_UART4_RX,
@@ -185,7 +185,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PC10), GPIO_AF5_UART4 },
         },
         .rcc = RCC_APB11(UART4),
-        .rxIrq = UART4_IRQn,
+        .irqn = UART4_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART4_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART4,
         .txBuffer = uart4TxBuffer,
@@ -197,7 +197,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART5
     {
-        .device = UARTDEV_5,
+        .identifier = SERIAL_PORT_UART5,
         .reg = UART5,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_UART5_RX,
@@ -212,7 +212,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PC12), GPIO_AF5_UART5 },
         },
         .rcc = RCC_APB11(UART5),
-        .rxIrq = UART5_IRQn,
+        .irqn = UART5_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART5_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART5,
         .txBuffer = uart5TxBuffer,
@@ -224,7 +224,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_LPUART1
     {
-        .device = LPUARTDEV_1,
+        .identifier = SERIAL_PORT_LPUART1,
         .reg = LPUART1,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_LPUART1_RX,
@@ -243,95 +243,15 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PC1),  GPIO_AF8_LPUART1 },
         },
         .rcc = RCC_APB12(LPUART1),
-        .rxIrq = LPUART1_IRQn,
+        .irqn = LPUART1_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART6_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART6,
-        .txBuffer = lpuart1TxBuffer,
-        .rxBuffer = lpuart1RxBuffer,
-        .txBufferSize = sizeof(lpuart1TxBuffer),
-        .rxBufferSize = sizeof(lpuart1RxBuffer),
+        .txBuffer = uartLp1TxBuffer,
+        .rxBuffer = uartLp1RxBuffer,
+        .txBufferSize = sizeof(uartLp1TxBuffer),
+        .rxBufferSize = sizeof(uartLp1RxBuffer),
     },
 #endif
 };
 
-
-// XXX Should serialUART be consolidated?
-
-uartPort_t *serialUART(UARTDevice_e device, uint32_t baudRate, portMode_e mode, portOptions_e options)
-{
-    uartDevice_t *uartdev = uartDevmap[device];
-    if (!uartdev) {
-        return NULL;
-    }
-
-    uartPort_t *s = &(uartdev->port);
-
-    s->port.vTable = uartVTable;
-
-    s->port.baudRate = baudRate;
-
-    const uartHardware_t *hardware = uartdev->hardware;
-
-    s->USARTx = hardware->reg;
-
-    s->port.rxBuffer = hardware->rxBuffer;
-    s->port.txBuffer = hardware->txBuffer;
-    s->port.rxBufferSize = hardware->rxBufferSize;
-    s->port.txBufferSize = hardware->txBufferSize;
-
-    s->checkUsartTxOutput = checkUsartTxOutput;
-
-#ifdef USE_DMA
-    uartConfigureDma(uartdev);
-#endif
-
-    s->Handle.Instance = hardware->reg;
-
-    if (hardware->rcc) {
-        RCC_ClockCmd(hardware->rcc, ENABLE);
-    }
-
-    IO_t txIO = IOGetByTag(uartdev->tx.pin);
-    IO_t rxIO = IOGetByTag(uartdev->rx.pin);
-
-    uartdev->txPinState = TX_PIN_IGNORE;
-
-    if ((options & SERIAL_BIDIR) && txIO) {
-        ioConfig_t ioCfg = IO_CONFIG(
-            ((options & SERIAL_INVERTED) || (options & SERIAL_BIDIR_PP) || (options & SERIAL_BIDIR_PP_PD)) ? GPIO_MODE_AF_PP : GPIO_MODE_AF_OD,
-            GPIO_SPEED_FREQ_HIGH,
-            ((options & SERIAL_INVERTED) || (options & SERIAL_BIDIR_PP_PD)) ? GPIO_PULLDOWN : GPIO_PULLUP
-        );
-
-        IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
-        IOConfigGPIOAF(txIO, ioCfg, uartdev->tx.af);
-    } else {
-        if ((mode & MODE_TX) && txIO) {
-            IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
-
-            if (options & SERIAL_CHECK_TX) {
-                uartdev->txPinState = TX_PIN_ACTIVE;
-                // Switch TX to an input with pullup so it's state can be monitored
-                uartTxMonitor(s);
-            } else {
-                IOConfigGPIOAF(txIO, IOCFG_AF_PP, uartdev->tx.af);
-            }
-        }
-
-        if ((mode & MODE_RX) && rxIO) {
-            IOInit(rxIO, OWNER_SERIAL_RX, RESOURCE_INDEX(device));
-            IOConfigGPIOAF(rxIO, IOCFG_AF_PP, uartdev->rx.af);
-        }
-    }
-
-#ifdef USE_DMA
-    if (!s->rxDMAResource)
-#endif
-    {
-        HAL_NVIC_SetPriority(hardware->rxIrq, NVIC_PRIORITY_BASE(hardware->rxPriority), NVIC_PRIORITY_SUB(hardware->rxPriority));
-        HAL_NVIC_EnableIRQ(hardware->rxIrq);
-    }
-
-    return s;
-}
 #endif // USE_UART
diff --git a/src/platform/STM32/serial_uart_stm32h7xx.c b/src/platform/STM32/serial_uart_stm32h7xx.c
index c21a908d4d..c892077b85 100644
--- a/src/platform/STM32/serial_uart_stm32h7xx.c
+++ b/src/platform/STM32/serial_uart_stm32h7xx.c
@@ -103,7 +103,7 @@
 const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 #ifdef USE_UART1
     {
-        .device = UARTDEV_1,
+        .identifier = SERIAL_PORT_USART1,
         .reg = USART1,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_USART1_RX,
@@ -122,7 +122,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PB14), GPIO_AF4_USART1 },
         },
         .rcc = RCC_APB2(USART1),
-        .rxIrq = USART1_IRQn,
+        .irqn = USART1_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART1_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART1,
         .txBuffer = uart1TxBuffer,
@@ -134,7 +134,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART2
     {
-        .device = UARTDEV_2,
+        .identifier = SERIAL_PORT_USART2,
         .reg = USART2,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_USART2_RX,
@@ -151,7 +151,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PD5), GPIO_AF7_USART2 }
         },
         .rcc = RCC_APB1L(USART2),
-        .rxIrq = USART2_IRQn,
+        .irqn = USART2_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART2_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART2,
         .txBuffer = uart2TxBuffer,
@@ -163,7 +163,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART3
     {
-        .device = UARTDEV_3,
+        .identifier = SERIAL_PORT_USART3,
         .reg = USART3,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_USART3_RX,
@@ -182,7 +182,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PD8), GPIO_AF7_USART3 }
         },
         .rcc = RCC_APB1L(USART3),
-        .rxIrq = USART3_IRQn,
+        .irqn = USART3_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART3_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART3,
         .txBuffer = uart3TxBuffer,
@@ -194,7 +194,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART4
     {
-        .device = UARTDEV_4,
+        .identifier = SERIAL_PORT_UART4,
         .reg = UART4,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_UART4_RX,
@@ -217,7 +217,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PD1),  GPIO_AF8_UART4 }
         },
         .rcc = RCC_APB1L(UART4),
-        .rxIrq = UART4_IRQn,
+        .irqn = UART4_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART4_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART4,
         .txBuffer = uart4TxBuffer,
@@ -229,7 +229,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART5
     {
-        .device = UARTDEV_5,
+        .identifier = SERIAL_PORT_UART5,
         .reg = UART5,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_UART5_RX,
@@ -248,7 +248,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PC12), GPIO_AF8_UART5 },
         },
         .rcc = RCC_APB1L(UART5),
-        .rxIrq = UART5_IRQn,
+        .irqn = UART5_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART5_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART5,
         .txBuffer = uart5TxBuffer,
@@ -260,7 +260,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART6
     {
-        .device = UARTDEV_6,
+        .identifier = SERIAL_PORT_USART6,
         .reg = USART6,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_USART6_RX,
@@ -277,7 +277,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PG14), GPIO_AF7_USART6 }
         },
         .rcc = RCC_APB2(USART6),
-        .rxIrq = USART6_IRQn,
+        .irqn = USART6_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART6_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART6,
         .txBuffer = uart6TxBuffer,
@@ -289,7 +289,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART7
     {
-        .device = UARTDEV_7,
+        .identifier = SERIAL_PORT_USART7,
         .reg = UART7,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_UART7_RX,
@@ -310,7 +310,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PF7),  GPIO_AF7_UART7 },
         },
         .rcc = RCC_APB1L(UART7),
-        .rxIrq = UART7_IRQn,
+        .irqn = UART7_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART7_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART7,
         .txBuffer = uart7TxBuffer,
@@ -322,7 +322,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART8
     {
-        .device = UARTDEV_8,
+        .identifier = SERIAL_PORT_USART8,
         .reg = UART8,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_UART8_RX,
@@ -337,7 +337,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PE1), GPIO_AF8_UART8 }
         },
         .rcc = RCC_APB1L(UART8),
-        .rxIrq = UART8_IRQn,
+        .irqn = UART8_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART8_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART8,
         .txBuffer = uart8TxBuffer,
@@ -349,7 +349,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART9
     {
-        .device = UARTDEV_9,
+        .identifier = SERIAL_PORT_UART9,
         .reg = UART9,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_UART9_RX,
@@ -364,7 +364,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PD15), GPIO_AF11_UART9 }
         },
         .rcc = RCC_APB2(UART9),
-        .rxIrq = UART9_IRQn,
+        .irqn = UART9_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART9_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART9,
         .txBuffer = uart9TxBuffer,
@@ -376,7 +376,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_UART10
     {
-        .device = UARTDEV_10,
+        .identifier = SERIAL_PORT_USART10,
         .reg = USART10,
 #ifdef USE_DMA
         .rxDMAChannel = DMA_REQUEST_USART10_RX,
@@ -391,7 +391,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PE3), GPIO_AF11_USART10 }
         },
         .rcc = RCC_APB2(USART10),
-        .rxIrq = USART10_IRQn,
+        .irqn = USART10_IRQn,
         .txPriority = NVIC_PRIO_SERIALUART10_TXDMA,
         .rxPriority = NVIC_PRIO_SERIALUART10,
         .txBuffer = uart10TxBuffer,
@@ -403,7 +403,7 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
 
 #ifdef USE_LPUART1
     {
-        .device = LPUARTDEV_1,
+        .identifier = SERIAL_PORT_LPUART1,
         .reg = LPUART1,
 #ifdef USE_DMA
         .rxDMAChannel = BDMA_REQUEST_LPUART1_RX,
@@ -420,95 +420,16 @@ const uartHardware_t uartHardware[UARTDEV_COUNT] = {
             { DEFIO_TAG_E(PB6),  GPIO_AF8_LPUART }
         },
         .rcc = RCC_APB4(LPUART1),
-        .rxIrq = LPUART1_IRQn,
+        .irqn = LPUART1_IRQn,
         .txPriority = NVIC_PRIO_SERIALLPUART1_TXDMA, // Not used until DMA is supported
         .rxPriority = NVIC_PRIO_SERIALLPUART1,       // Not used until DMA is supported
-        .txBuffer = lpuart1TxBuffer,
-        .rxBuffer = lpuart1RxBuffer,
-        .txBufferSize = sizeof(lpuart1TxBuffer),
-        .rxBufferSize = sizeof(lpuart1RxBuffer),
+        .txBuffer = uartLp1TxBuffer,
+        .rxBuffer = uartLp1RxBuffer,
+        .txBufferSize = sizeof(uartLp1TxBuffer),
+        .rxBufferSize = sizeof(uartLp1RxBuffer),
     },
 #endif
 
 };
 
-// XXX Should serialUART be consolidated?
-
-uartPort_t *serialUART(UARTDevice_e device, uint32_t baudRate, portMode_e mode, portOptions_e options)
-{
-    uartDevice_t *uartdev = uartDevmap[device];
-    if (!uartdev) {
-        return NULL;
-    }
-
-    uartPort_t *s = &(uartdev->port);
-
-    s->port.vTable = uartVTable;
-
-    s->port.baudRate = baudRate;
-
-    const uartHardware_t *hardware = uartdev->hardware;
-
-    s->USARTx = hardware->reg;
-
-    s->port.rxBuffer = hardware->rxBuffer;
-    s->port.txBuffer = hardware->txBuffer;
-    s->port.rxBufferSize = hardware->rxBufferSize;
-    s->port.txBufferSize = hardware->txBufferSize;
-
-    s->checkUsartTxOutput = checkUsartTxOutput;
-
-#ifdef USE_DMA
-    uartConfigureDma(uartdev);
-#endif
-
-    s->Handle.Instance = hardware->reg;
-
-    if (hardware->rcc) {
-        RCC_ClockCmd(hardware->rcc, ENABLE);
-    }
-
-    IO_t txIO = IOGetByTag(uartdev->tx.pin);
-    IO_t rxIO = IOGetByTag(uartdev->rx.pin);
-
-    uartdev->txPinState = TX_PIN_IGNORE;
-
-    if ((options & SERIAL_BIDIR) && txIO) {
-        ioConfig_t ioCfg = IO_CONFIG(
-            ((options & SERIAL_INVERTED) || (options & SERIAL_BIDIR_PP) || (options & SERIAL_BIDIR_PP_PD)) ? GPIO_MODE_AF_PP : GPIO_MODE_AF_OD,
-            GPIO_SPEED_FREQ_HIGH,
-            ((options & SERIAL_INVERTED) || (options & SERIAL_BIDIR_PP_PD)) ? GPIO_PULLDOWN : GPIO_PULLUP
-        );
-
-        IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
-        IOConfigGPIOAF(txIO, ioCfg, uartdev->tx.af);
-    } else {
-        if ((mode & MODE_TX) && txIO) {
-            IOInit(txIO, OWNER_SERIAL_TX, RESOURCE_INDEX(device));
-
-            if (options & SERIAL_CHECK_TX) {
-                uartdev->txPinState = TX_PIN_ACTIVE;
-                // Switch TX to an input with pullup so it's state can be monitored
-                uartTxMonitor(s);
-            } else {
-                IOConfigGPIOAF(txIO, IOCFG_AF_PP, uartdev->tx.af);
-            }
-        }
-
-        if ((mode & MODE_RX) && rxIO) {
-            IOInit(rxIO, OWNER_SERIAL_RX, RESOURCE_INDEX(device));
-            IOConfigGPIOAF(rxIO, IOCFG_AF_PP, uartdev->rx.af);
-        }
-    }
-
-#ifdef USE_DMA
-    if (!s->rxDMAResource)
-#endif
-    {
-        HAL_NVIC_SetPriority(hardware->rxIrq, NVIC_PRIORITY_BASE(hardware->rxPriority), NVIC_PRIORITY_SUB(hardware->rxPriority));
-        HAL_NVIC_EnableIRQ(hardware->rxIrq);
-    }
-
-    return s;
-}
 #endif // USE_UART
diff --git a/src/platform/STM32/target/STM32F405/target.h b/src/platform/STM32/target/STM32F405/target.h
index 94271c1ffa..884b17135f 100644
--- a/src/platform/STM32/target/STM32F405/target.h
+++ b/src/platform/STM32/target/STM32F405/target.h
@@ -38,12 +38,6 @@
 
 #define USE_VCP
 
-#ifdef USE_SOFTSERIAL
-#define UNIFIED_SERIAL_PORT_COUNT       3
-#else
-#define UNIFIED_SERIAL_PORT_COUNT       1
-#endif
-
 #define USE_UART1
 #define USE_UART2
 #define USE_UART3
@@ -51,8 +45,6 @@
 #define USE_UART5
 #define USE_UART6
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 6)
-
 #define USE_INVERTER
 
 #define USE_SPI_DEVICE_1
diff --git a/src/platform/STM32/target/STM32F411/target.h b/src/platform/STM32/target/STM32F411/target.h
index 9c12aee299..0c93771a80 100644
--- a/src/platform/STM32/target/STM32F411/target.h
+++ b/src/platform/STM32/target/STM32F411/target.h
@@ -34,18 +34,10 @@
 
 #define USE_VCP
 
-#ifdef USE_SOFTSERIAL
-#define UNIFIED_SERIAL_PORT_COUNT       3
-#else
-#define UNIFIED_SERIAL_PORT_COUNT       1
-#endif
-
 #define USE_UART1
 #define USE_UART2
 #define USE_UART6
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 3)
-
 #define USE_INVERTER
 
 #define USE_SPI_DEVICE_1
diff --git a/src/platform/STM32/target/STM32F446/target.h b/src/platform/STM32/target/STM32F446/target.h
index b7f45caec6..056fa20243 100644
--- a/src/platform/STM32/target/STM32F446/target.h
+++ b/src/platform/STM32/target/STM32F446/target.h
@@ -35,18 +35,10 @@
 
 #define USE_VCP
 
-#ifdef USE_SOFTSERIAL
-#define UNIFIED_SERIAL_PORT_COUNT       3
-#else
-#define UNIFIED_SERIAL_PORT_COUNT       1
-#endif
-
 #define USE_UART1
 #define USE_UART2
 // #define USE_UART6
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 2)
-
 #define USE_INVERTER
 
 #define USE_SPI_DEVICE_1
diff --git a/src/platform/STM32/target/STM32F745/target.h b/src/platform/STM32/target/STM32F745/target.h
index 968f3348ba..2c92b9909a 100644
--- a/src/platform/STM32/target/STM32F745/target.h
+++ b/src/platform/STM32/target/STM32F745/target.h
@@ -39,12 +39,6 @@
 
 #define USE_VCP
 
-#ifdef USE_SOFTSERIAL
-#define UNIFIED_SERIAL_PORT_COUNT       3
-#else
-#define UNIFIED_SERIAL_PORT_COUNT       1
-#endif
-
 #define USE_UART1
 #define USE_UART2
 #define USE_UART3
@@ -54,8 +48,6 @@
 #define USE_UART7
 #define USE_UART8
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 8)
-
 #define USE_SPI_DEVICE_1
 #define USE_SPI_DEVICE_2
 #define USE_SPI_DEVICE_3
diff --git a/src/platform/STM32/target/STM32F7X2/target.h b/src/platform/STM32/target/STM32F7X2/target.h
index d730d9aa96..af9abdb825 100644
--- a/src/platform/STM32/target/STM32F7X2/target.h
+++ b/src/platform/STM32/target/STM32F7X2/target.h
@@ -34,12 +34,6 @@
 
 #define USE_VCP
 
-#ifdef USE_SOFTSERIAL
-#define UNIFIED_SERIAL_PORT_COUNT       3
-#else
-#define UNIFIED_SERIAL_PORT_COUNT       1
-#endif
-
 #define USE_UART1
 #define USE_UART2
 #define USE_UART3
@@ -47,8 +41,6 @@
 #define USE_UART5
 #define USE_UART6
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 6)
-
 #define USE_SPI_DEVICE_1
 #define USE_SPI_DEVICE_2
 #define USE_SPI_DEVICE_3
diff --git a/src/platform/STM32/target/STM32G47X/target.h b/src/platform/STM32/target/STM32G47X/target.h
index 4f7f6899ba..c7f9e944a4 100644
--- a/src/platform/STM32/target/STM32G47X/target.h
+++ b/src/platform/STM32/target/STM32G47X/target.h
@@ -35,12 +35,6 @@
 
 #define USE_VCP
 
-#ifdef USE_SOFTSERIAL
-#define UNIFIED_SERIAL_PORT_COUNT       3
-#else
-#define UNIFIED_SERIAL_PORT_COUNT       1
-#endif
-
 #define USE_UART1
 #define USE_UART2
 #define USE_UART3
@@ -48,8 +42,6 @@
 #define USE_UART5
 #define USE_LPUART1
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 6)
-
 #define USE_SPI_DEVICE_1
 #define USE_SPI_DEVICE_2
 #define USE_SPI_DEVICE_3
diff --git a/src/platform/STM32/target/STM32H563/target.h b/src/platform/STM32/target/STM32H563/target.h
index 971bed8bae..5af44b3962 100644
--- a/src/platform/STM32/target/STM32H563/target.h
+++ b/src/platform/STM32/target/STM32H563/target.h
@@ -101,8 +101,6 @@
 //#define USE_UART7
 //#define USE_UART8
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 1)
-
 //#define USE_SPI_DEVICE_1
 //#define USE_SPI_DEVICE_2
 //#define USE_SPI_DEVICE_3
diff --git a/src/platform/STM32/target/STM32H723/target.h b/src/platform/STM32/target/STM32H723/target.h
index 4153e0e2ef..fb90791d44 100644
--- a/src/platform/STM32/target/STM32H723/target.h
+++ b/src/platform/STM32/target/STM32H723/target.h
@@ -54,12 +54,6 @@
 
 #define USE_VCP
 
-#ifdef USE_SOFTSERIAL
-#define UNIFIED_SERIAL_PORT_COUNT       3
-#else
-#define UNIFIED_SERIAL_PORT_COUNT       1
-#endif
-
 #define USE_UART1
 #define USE_UART2
 #define USE_UART3
@@ -71,8 +65,6 @@
 #define USE_UART9
 #define USE_LPUART1
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 10)
-
 #define TARGET_IO_PORTA 0xffff
 #define TARGET_IO_PORTB 0xffff
 #define TARGET_IO_PORTC 0xffff
diff --git a/src/platform/STM32/target/STM32H725/target.h b/src/platform/STM32/target/STM32H725/target.h
index 0cc8b21997..394c299a5e 100644
--- a/src/platform/STM32/target/STM32H725/target.h
+++ b/src/platform/STM32/target/STM32H725/target.h
@@ -63,8 +63,6 @@
 #define USE_UART9
 #define USE_LPUART1
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 10)
-
 #define TARGET_IO_PORTA 0xffff
 #define TARGET_IO_PORTB 0xffff
 #define TARGET_IO_PORTC 0xffff
@@ -83,12 +81,6 @@
 
 #define USE_VCP
 
-#ifdef USE_SOFTSERIAL
-#define UNIFIED_SERIAL_PORT_COUNT       3
-#else
-#define UNIFIED_SERIAL_PORT_COUNT       1
-#endif
-
 #define USE_USB_DETECT
 
 #define USE_ESCSERIAL
diff --git a/src/platform/STM32/target/STM32H730/target.h b/src/platform/STM32/target/STM32H730/target.h
index e77b42a41f..0049d92390 100644
--- a/src/platform/STM32/target/STM32H730/target.h
+++ b/src/platform/STM32/target/STM32H730/target.h
@@ -68,8 +68,6 @@
 
 #define USE_VCP
 
-#define UNIFIED_SERIAL_PORT_COUNT       1
-
 #define USE_UART1
 #define USE_UART2
 #define USE_UART3
@@ -82,8 +80,6 @@
 #define USE_UART10
 #define USE_LPUART1
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 11)
-
 // Disable OCTOSPI pins PB2/CLK, PB6/NCS, PD11/IO0, PD12/IO1, PD13/IO3, PE2/IO2
 // PE7/IO4, PE8/IO5, PE9/IO6, PE10/IO7
 
diff --git a/src/platform/STM32/target/STM32H743/target.h b/src/platform/STM32/target/STM32H743/target.h
index 390949d25e..a1ed4202de 100644
--- a/src/platform/STM32/target/STM32H743/target.h
+++ b/src/platform/STM32/target/STM32H743/target.h
@@ -35,12 +35,6 @@
 
 #define USE_VCP
 
-#ifdef USE_SOFTSERIAL
-#define UNIFIED_SERIAL_PORT_COUNT       3
-#else
-#define UNIFIED_SERIAL_PORT_COUNT       1
-#endif
-
 #define USE_UART1
 #define USE_UART2
 #define USE_UART3
@@ -51,8 +45,6 @@
 #define USE_UART8
 #define USE_LPUART1
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 9)
-
 #define USE_SPI_DEVICE_1
 #define USE_SPI_DEVICE_2
 #define USE_SPI_DEVICE_3
diff --git a/src/platform/STM32/target/STM32H750/target.h b/src/platform/STM32/target/STM32H750/target.h
index 546abca265..2acdc643f4 100644
--- a/src/platform/STM32/target/STM32H750/target.h
+++ b/src/platform/STM32/target/STM32H750/target.h
@@ -68,12 +68,6 @@
 
 #define USE_VCP
 
-#ifdef USE_SOFTSERIAL
-#define UNIFIED_SERIAL_PORT_COUNT       3
-#else
-#define UNIFIED_SERIAL_PORT_COUNT       1
-#endif
-
 #define USE_UART1
 #define USE_UART2
 #define USE_UART3
@@ -84,8 +78,6 @@
 #define USE_UART8
 #define USE_LPUART1
 
-#define SERIAL_PORT_COUNT       (UNIFIED_SERIAL_PORT_COUNT + 9)
-
 #define TARGET_IO_PORTA 0xffff
 #define TARGET_IO_PORTB 0xffff
 #define TARGET_IO_PORTC 0xffff
diff --git a/src/test/Makefile b/src/test/Makefile
index d5f1a7f910..7555a7b8e6 100644
--- a/src/test/Makefile
+++ b/src/test/Makefile
@@ -117,9 +117,11 @@ cli_unittest_SRC := \
 		$(USER_DIR)/common/gps_conversion.c \
 		$(USER_DIR)/config/feature.c \
 		$(USER_DIR)/io/gps.c \
+		$(USER_DIR)/io/serial_resource.c \
 		$(USER_DIR)/pg/pg.c \
 		$(USER_DIR)/fc/runtime_config.c \
 		$(USER_DIR)/drivers/serial.c \
+		$(USER_DIR)/drivers/serial_impl.c \
 		$(USER_DIR)/common/typeconversion.c
 
 cli_unittest_DEFINES := \
@@ -175,6 +177,7 @@ gps_conversion_unittest_SRC := \
 
 io_serial_unittest_SRC := \
 		$(USER_DIR)/io/serial.c \
+		$(USER_DIR)/io/serial_resource.c \
 		$(USER_DIR)/drivers/serial_pinconfig.c
 
 
@@ -232,6 +235,7 @@ link_quality_unittest_SRC := \
 		$(USER_DIR)/common/vector.c \
 		$(USER_DIR)/drivers/display.c \
 		$(USER_DIR)/drivers/serial.c \
+		$(USER_DIR)/drivers/serial_impl.c \
 		$(USER_DIR)/fc/rc_modes.c \
 		$(USER_DIR)/fc/runtime_config.c \
 		$(USER_DIR)/pg/pg.c \
@@ -267,7 +271,9 @@ rx_crsf_unittest_SRC := \
 		$(USER_DIR)/common/printf.c \
 		$(USER_DIR)/common/typeconversion.c \
 		$(USER_DIR)/common/streambuf.c \
-		$(USER_DIR)/drivers/serial.c
+		$(USER_DIR)/drivers/serial.c \
+		$(USER_DIR)/drivers/serial_impl.c
+
 
 
 rx_ibus_unittest_SRC := \
@@ -347,6 +353,7 @@ telemetry_crsf_msp_unittest_SRC := \
 		$(USER_DIR)/common/printf.c \
 		$(USER_DIR)/common/streambuf.c \
 		$(USER_DIR)/drivers/serial.c \
+		$(USER_DIR)/drivers/serial_impl.c \
 		$(USER_DIR)/common/typeconversion.c \
 		$(USER_DIR)/telemetry/crsf.c \
 		$(USER_DIR)/common/gps_conversion.c \
@@ -359,6 +366,7 @@ telemetry_crsf_msp_unittest_DEFINES := \
 
 telemetry_hott_unittest_SRC := \
 		$(USER_DIR)/telemetry/hott.c \
+		$(USER_DIR)/io/serial_resource.c \
 		$(USER_DIR)/common/gps_conversion.c
 
 
diff --git a/src/test/unit/io_serial_unittest.cc b/src/test/unit/io_serial_unittest.cc
index 5e53baa373..b8dd4bc604 100644
--- a/src/test/unit/io_serial_unittest.cc
+++ b/src/test/unit/io_serial_unittest.cc
@@ -70,11 +70,11 @@ extern "C" {
 
     serialPort_t *usbVcpOpen(void) { return NULL; }
 
-    serialPort_t *uartOpen(UARTDevice_e, serialReceiveCallbackPtr, void *, uint32_t, portMode_e, portOptions_e) {
+    serialPort_t *uartOpen(serialPortIdentifier_e, serialReceiveCallbackPtr, void *, uint32_t, portMode_e, portOptions_e) {
       return NULL;
     }
 
-    serialPort_t *openSoftSerial(softSerialPortIndex_e, serialReceiveCallbackPtr, void *, uint32_t, portMode_e, portOptions_e) {
+    serialPort_t *softSerialOpen(serialPortIdentifier_e, serialReceiveCallbackPtr, void *, uint32_t, portMode_e, portOptions_e) {
       return NULL;
     }
 
diff --git a/src/test/unit/target.h b/src/test/unit/target.h
index de179360fe..90c20c4e31 100644
--- a/src/test/unit/target.h
+++ b/src/test/unit/target.h
@@ -66,7 +66,6 @@
 #define USE_UART5
 #define USE_SOFTSERIAL
 
-#define SERIAL_PORT_COUNT 8
 
 #define DEFAULT_AUX_CHANNEL_COUNT       MAX_AUX_CHANNEL_COUNT
 #define MAX_SIMULTANEOUS_ADJUSTMENT_COUNT 6  // needed for unittest
@@ -79,3 +78,4 @@
 #define TARGET_IO_PORTB         0xffff
 #define TARGET_IO_PORTC         0xffff
 
+#include "target/serial_post.h"
diff --git a/src/utils/gen-serial-j2.py b/src/utils/gen-serial-j2.py
new file mode 100644
index 0000000000..daefa9654d
--- /dev/null
+++ b/src/utils/gen-serial-j2.py
@@ -0,0 +1,94 @@
+from jinja2 import Environment, FileSystemLoader
+import jinja2
+import os
+from datetime import datetime
+import pprint
+
+# generate normalization preprocessor file for serial ports
+
+# configuration for template generation
+serials = {
+    "UART": {"ids": [i + 1 for i in range(10)],
+             "inverter": True,
+             },
+    "LPUART": {"ids": [1],
+               "depends": {"UART"},
+#               "inverter": True,   # TODO: old code compatibility only, disabled
+               },
+    "SOFTSERIAL": {"ids": [i + 1 for i in range(2)],
+                   "use_enables_all": True,
+                   "force_continuous": True,
+                   },
+    "VCP": {"singleton": True,
+            "no_pins": True}
+}
+
+def flatten_config(data):
+    flattened_list = []
+    for key, value in data.items():
+        flattened_dict = {'typ': key}
+        # Update this new dictionary with the inner dictionary's items
+        flattened_dict.update(value)
+        flattened_list.append(flattened_dict)
+    return flattened_list
+
+def pprint_filter(value, indent=4):
+    return pprint.pformat(value, indent=indent)
+
+def rdepends_filter(cfg, typ):
+    return list(set([ c['typ'] for c in cfg if typ in c['depends'] ]))
+
+def main():
+    # Setup Jinja2 environment
+    current_dir = os.path.dirname(os.path.abspath(__file__))
+    # Set the template directory relative to the current script
+    template_dir = os.path.join(current_dir, 'templates')
+    env = Environment(loader=FileSystemLoader(template_dir),
+                      autoescape=True,
+                      undefined=jinja2.StrictUndefined,  # Throws an error on undefined variables
+                      trim_blocks = True,
+                      )
+    env.filters['pprint'] = pprint_filter
+    env.filters['zip'] = zip
+    env.filters['rdepends'] = rdepends_filter
+    template = env.get_template('serial_post.h')
+
+    # Read license file
+    license_path = 'DEFAULT_LICENSE.md'
+    with open(license_path, 'r') as file:
+        t_license = file.read()
+
+    context = {}
+    context['license'] = t_license
+    context['date_generated'] = datetime.now().strftime('%Y-%m-%d')
+    context['user_config'] = serials
+    config = flatten_config(serials)
+    context['config'] = config
+
+    for cfg in config:
+        singleton = cfg.setdefault('singleton', False)
+        no_pins = cfg.setdefault('no_pins', False)
+        inverter = cfg.setdefault('inverter', False)
+        cfg.setdefault("use_enables_all", False)
+        cfg.setdefault("force_continuous", False)
+        cfg.setdefault("depends", {})
+        typ = cfg['typ']
+        if singleton:
+            cfg['ports']= [ f"{typ}" ]
+        else:
+            cfg['ports'] = [ f"{typ}{i}" for i in cfg["ids"] ]
+
+    # Render the template with the license content
+    output = template.render(**context)
+
+    if False:
+        # Output or save to a file
+        output_path = './src/main/target/serial_post.h'
+        with open(output_path, 'w') as file:
+            file.write(output)
+        print(f"Generated file saved to {output_path}")
+    else:
+        print(output)
+
+if __name__ == '__main__':
+    main()
diff --git a/src/utils/templates/serial_post.h b/src/utils/templates/serial_post.h
new file mode 100644
index 0000000000..f6455ee68b
--- /dev/null
+++ b/src/utils/templates/serial_post.h
@@ -0,0 +1,118 @@
+{# serial_post.h #}
+{# DEFAULT_LICENCE.md is used #}
+{{ license|safe }}
+
+/*
+{# Start with generated warning. It you want to change something, edit this file #}
+This file is automatically generated by src/utils/gen-serial.py script from src/utils/templates/serial_post.h jinja2 template.
+Do not modify this file directly, your changes will be eventually lost.
+See template{# THIS #} file for aditional documentation.
+
+To generate this file again, run
+> python ./src/utils/gen-serial-j2.py > ./src/main/target/serial_post.h
+in Betaflight topmost directory.
+
+This include will provide following defines:
+SERIAL_<type><n>_USED 0/1 - always defined, value depends on target configuration
+SERIAL_<type>_MASK        - bitmask of used ports or given type. <port>1 is BIT(0)
+SERIAL_<type>_COUNT       - number of enabled ports of given type
+SERIAL_<type>_MAX         - <index of highest used port> + 1, 0 when no port is enabled
+
+All <type><n>_(RX|TX)_PINS are normalized too:
+ - if port is enabled, both will be defined (possibly as NONE)
+ - if port is not enable, both will be undefined, possibly with warning
+  - pass -DWARN_UNUSED_SERIAL_PORT to compiler to check pin defined without corresponding port being enabled.
+
+{# add some usefull info #}
+Generated on {{ date_generated }}
+
+Configuration used:
+{# TODO - maybe store configuration in this file, not Python one #}
+{# TODO - pretty is not enough pretty #}
+{{ user_config|pprint|safe }}
+
+*/
+
+#include "common/utils.h" // BIT, LOG2
+{# config array is passed to this script. It is flattened version of user_config, with default fileld in #}
+{% for cfg in config %}
+
+/****                                {{ cfg.typ }}                                 *****/
+{#   use_enables_all - USE_<type> enables all ports of this type #}
+{%   if cfg.use_enables_all %}
+#if defined(USE_{{cfg.typ}})
+{%     for port in cfg.ports %}
+# if !defined(USE_{{port}})
+#  define USE_{{port}}
+# endif
+{%     endfor %}
+#endif
+{%   endif %}
+
+{#   USE_<port> - SERIAL_<port>_USED 0/1 #}
+{%   for port in cfg.ports %}
+#if defined(USE_{{port}})
+# define SERIAL_{{port}}_USED 1
+#else
+# define SERIAL_{{port}}_USED 0
+#endif
+{%   endfor %}
+
+{#   SERIAL_<port>_* summary macros #}
+{%   if not cfg.singleton %}
+{%     set pipe = joiner(' | ') %}
+#define SERIAL_{{ cfg.typ }}_MASK ({% for port, i in cfg.ports|zip(cfg.ids) %}{{ pipe() }}(SERIAL_{{ port }}_USED * BIT({{ i }} - 1)){% endfor %})
+{%   else %}
+{#     one port without number is defined #}
+// set one bit if port is enabled for consistency
+#define SERIAL_{{ cfg.typ }}_MASK (SERIAL_{{ cfg.ports[0] }}_USED * BIT(0))
+{%   endif %}
+{%   set plus = joiner(' + ') %}
+#define SERIAL_{{ cfg.typ }}_COUNT ({% for port in cfg.ports %}{{ plus() }}SERIAL_{{ port }}_USED{% endfor %})
+{# LOG2 is simpler than chaining MAX(SERIAL_x1_USED * 1, MAX(SERIAL_x2_USED * 2, ... #}
+// 0 if no port is defined
+#define SERIAL_{{ cfg.typ }}_MAX (SERIAL_{{cfg.typ}}_MASK ? LOG2(SERIAL_{{cfg.typ}}_MASK) + 1 : 0)
+
+{#   for softserial, we don't want softserial2 only #}
+{%   if cfg.force_continuous %}
+#if SERIAL_{{cfg.typ}}_COUNT != SERIAL_{{cfg.typ}}_MAX
+# error {{cfg.typ}} ports must start with {{cfg.typ}}1 and be continuous
+#endif
+{%   endif %}
+
+{#   backward compatibility, code did set USE_INVERTER this way. It must be done before normalizing to NONE #}
+{%   if cfg.inverter %}
+// enable USE_INVERTED first, before normalization
+{%     set pipe2 = joiner(' || ') %}
+#if !defined(USE_INVERTER) && ({% for port in cfg.ports %}{{ pipe2() }}INVERTER_PIN_{{ port }}{% endfor %})
+# define USE_INVERTER
+#endif
+{%   endif %}
+{#   no pins for VCP port #}
+{%   if not cfg.no_pins %}
+// Normalize {{cfg.typ}} TX/RX{{ "/INVERTER" if cfg.inverter else "" }}
+{%     for port in cfg.ports %}
+{%       set pins = [  port ~ '_RX_PIN', port ~ '_TX_PIN' ] + (['INVERTER_PIN_' ~ port]  if cfg.inverter else []) %}
+{%       for pin in pins %}
+#if SERIAL_{{port}}_USED && !defined({{pin}})
+# define {{ pin }} NONE
+#endif
+#if defined(WARN_UNUSED_SERIAL_PORT) && !SERIAL_{{ port }}_USED && defined({{ pin }})
+# warning "{{ pin }} is defined but {{ port }} is not enabled"
+#endif
+#if !SERIAL_{{ port }}_USED &&  defined({{ pin }})
+# undef {{ pin }}
+#endif
+{%       endfor %}
+{%     endfor %}
+{%   endif %}
+{% endfor %}
+
+// normalize USE_x after all ports are enumerated (x_COUNT of dependencies must be available)
+{% for cfg in config %}
+{%   set depends = [cfg.typ] + config|rdepends(cfg.typ) %}
+{%   set pipe2 = joiner(' || ') %}
+#if !defined(USE_{{cfg.typ}}) && ({% for typ in depends %}{{ pipe2() }}SERIAL_{{ typ }}_COUNT{% endfor %})
+# define USE_{{cfg.typ}}
+#endif
+{% endfor %}