diff --git a/Makefile b/Makefile
index 99bf159fac..684dc1bfca 100644
--- a/Makefile
+++ b/Makefile
@@ -560,10 +560,19 @@ HIGHEND_SRC = \
             flight/gtune.c \
             flight/navigation.c \
             flight/gps_conversion.c \
-            io/gps.c \
-            io/ledstrip.c \
+            io/canvas.c \
+            io/cms.c \
+            io/cms_builtin.c \
+            io/cms_imu.c \
+            io/cms_blackbox.c \
+            io/cms_vtx.c \
+            io/cms_ledstrip.c \
             io/displayport_oled.c \
             io/dashboard.c \
+            io/gps.c \
+            io/ledstrip.c \
+            io/osd.c \
+            io/osd_max7456.c \
             sensors/sonar.c \
             sensors/barometer.c \
             telemetry/telemetry.c \
diff --git a/src/main/drivers/display.c b/src/main/drivers/display.c
index 753afacf76..2b247022d9 100644
--- a/src/main/drivers/display.c
+++ b/src/main/drivers/display.c
@@ -35,16 +35,25 @@ void displayOpen(displayPort_t *instance)
 {
     instance->vTable->open(instance);
     instance->vTable->clear(instance);
-    instance->inCMS = true;
+    instance->isOpen = true;
 }
 
 void displayClose(displayPort_t *instance)
 {
     instance->vTable->close(instance);
-    instance->inCMS = false;
+    instance->isOpen = false;
 }
 
-int displayWrite(displayPort_t *instance, uint8_t x, uint8_t y, char *s)
+bool displayIsOpen(const displayPort_t *instance)
+{
+    if (instance && instance->isOpen) { // can be called before initialised
+        return true;
+    } else {
+        return false;
+    }
+}
+
+int displayWrite(displayPort_t *instance, uint8_t x, uint8_t y, const char *s)
 {
     return instance->vTable->write(instance, x, y, s);
 }
@@ -59,7 +68,7 @@ void displayResync(displayPort_t *instance)
     instance->vTable->resync(instance);
 }
 
-uint16_t displayTxBytesFree(displayPort_t *instance)
+uint16_t displayTxBytesFree(const displayPort_t *instance)
 {
     return instance->vTable->txBytesFree(instance);
 }
diff --git a/src/main/drivers/display.h b/src/main/drivers/display.h
index f0075ff264..aabf8517bc 100644
--- a/src/main/drivers/display.h
+++ b/src/main/drivers/display.h
@@ -26,23 +26,24 @@ typedef struct displayPort_s {
     // CMS state
     bool cleared;
     int8_t cursorRow;
-    bool inCMS;
+    bool isOpen;
 } displayPort_t;
 
 typedef struct displayPortVTable_s {
     int (*open)(displayPort_t *displayPort);
     int (*close)(displayPort_t *displayPort);
     int (*clear)(displayPort_t *displayPort);
-    int (*write)(displayPort_t *displayPort, uint8_t col, uint8_t row, char *text);
+    int (*write)(displayPort_t *displayPort, uint8_t x, uint8_t y, const char *text);
     int (*heartbeat)(displayPort_t *displayPort);
     void (*resync)(displayPort_t *displayPort);
-    uint32_t (*txBytesFree)(displayPort_t *displayPort);
+    uint32_t (*txBytesFree)(const displayPort_t *displayPort);
 } displayPortVTable_t;
 
 void displayOpen(displayPort_t *instance);
 void displayClose(displayPort_t *instance);
+bool displayIsOpen(const displayPort_t *instance);
 void displayClear(displayPort_t *instance);
-int displayWrite(displayPort_t *instance, uint8_t x, uint8_t y, char *s);
+int displayWrite(displayPort_t *instance, uint8_t x, uint8_t y, const char *s);
 void displayHeartbeat(displayPort_t *instance);
 void displayResync(displayPort_t *instance);
-uint16_t displayTxBytesFree(displayPort_t *instance);
+uint16_t displayTxBytesFree(const displayPort_t *instance);
diff --git a/src/main/drivers/max7456.c b/src/main/drivers/max7456.c
index a552673556..10cc071411 100755
--- a/src/main/drivers/max7456.c
+++ b/src/main/drivers/max7456.c
@@ -294,7 +294,7 @@ void max7456WriteChar(uint8_t x, uint8_t y, uint8_t c)
 	screenBuffer[y*30+x] = c;
 }
 
-void max7456Write(uint8_t x, uint8_t y, char *buff)
+void max7456Write(uint8_t x, uint8_t y, const char *buff)
 {
 	uint8_t i = 0;
 	for (i = 0; *(buff+i); i++)
@@ -387,7 +387,7 @@ void max7456RefreshAll(void)
     }
 }
 
-void max7456WriteNvm(uint8_t char_address, uint8_t *font_data)
+void max7456WriteNvm(uint8_t char_address, const uint8_t *font_data)
 {
     uint8_t x;
 
diff --git a/src/main/drivers/max7456.h b/src/main/drivers/max7456.h
index 6663b12934..a4ebe0ab4e 100755
--- a/src/main/drivers/max7456.h
+++ b/src/main/drivers/max7456.h
@@ -146,9 +146,9 @@ extern uint16_t maxScreenSize;
 
 void    max7456Init(uint8_t system);
 void    max7456DrawScreen(void);
-void    max7456WriteNvm(uint8_t char_address, uint8_t *font_data);
+void    max7456WriteNvm(uint8_t char_address, const uint8_t *font_data);
 uint8_t max7456GetRowsCount(void);
-void    max7456Write(uint8_t x, uint8_t y, char *buff);
+void    max7456Write(uint8_t x, uint8_t y, const char *buff);
 void    max7456WriteChar(uint8_t x, uint8_t y, uint8_t c);
 void    max7456ClearScreen(void);
 void    max7456RefreshAll(void);
diff --git a/src/main/fc/fc_msp.c b/src/main/fc/fc_msp.c
index 57a011a1a5..d5aedd7a15 100755
--- a/src/main/fc/fc_msp.c
+++ b/src/main/fc/fc_msp.c
@@ -1010,7 +1010,7 @@ static bool mspFcProcessOutCommand(uint8_t cmdMSP, sbuf_t *dst, mspPostProcessFn
         sbufWriteU16(dst, masterConfig.osdProfile.time_alarm);
         sbufWriteU16(dst, masterConfig.osdProfile.alt_alarm);
 
-        for (i = 0; i < OSD_MAX_ITEMS; i++) {
+        for (i = 0; i < OSD_ITEM_COUNT; i++) {
             sbufWriteU16(dst, masterConfig.osdProfile.item_pos[i]);
         }
 #else
diff --git a/src/main/fc/fc_tasks.c b/src/main/fc/fc_tasks.c
index d9ca1c027e..9e31554249 100644
--- a/src/main/fc/fc_tasks.c
+++ b/src/main/fc/fc_tasks.c
@@ -40,13 +40,11 @@
 #include "flight/pid.h"
 #include "flight/altitudehold.h"
 
-#include "io/cms.h"
-
 #include "io/beeper.h"
+#include "io/cms.h"
 #include "io/dashboard.h"
 #include "io/gps.h"
 #include "io/ledstrip.h"
-#include "io/cms.h"
 #include "io/osd.h"
 #include "io/serial.h"
 #include "io/serial_cli.h"
diff --git a/src/main/fc/rc_controls.c b/src/main/fc/rc_controls.c
index 016c4287ec..91123768e3 100644
--- a/src/main/fc/rc_controls.c
+++ b/src/main/fc/rc_controls.c
@@ -40,8 +40,6 @@
 #include "fc/rc_curves.h"
 #include "fc/runtime_config.h"
 
-#include "io/cms.h"
-
 #include "io/gps.h"
 #include "io/beeper.h"
 #include "io/motors.h"
diff --git a/src/main/io/canvas.c b/src/main/io/canvas.c
index f805c862cf..85f0232ba7 100644
--- a/src/main/io/canvas.c
+++ b/src/main/io/canvas.c
@@ -1,3 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
@@ -22,47 +39,47 @@
 
 static displayPort_t canvasDisplayPort;
 
-static int canvasOutput(displayPort_t *displayPort, uint8_t cmd, uint8_t *buf, int len)
+static int canvasOutput(displayPort_t *displayPort, uint8_t cmd, const uint8_t *buf, int len)
 {
     UNUSED(displayPort);
-    mspSerialPush(cmd, buf, len);
-
-    return 6 + len;
+    return mspSerialPush(cmd, buf, len);
 }
 
-static int canvasBegin(displayPort_t *displayPort)
+static int canvasOpen(displayPort_t *displayPort)
 {
-    uint8_t subcmd[] = { 0 };
+    const uint8_t subcmd[] = { 0 };
 
     return canvasOutput(displayPort, MSP_CANVAS, subcmd, sizeof(subcmd));
 }
 
 static int canvasHeartBeat(displayPort_t *displayPort)
 {
-    return canvasBegin(displayPort);
+    return canvasOpen(displayPort);
 }
 
-static int canvasEnd(displayPort_t *displayPort)
+static int canvasClose(displayPort_t *displayPort)
 {
-    uint8_t subcmd[] = { 1 };
+    const uint8_t subcmd[] = { 1 };
 
     return canvasOutput(displayPort, MSP_CANVAS, subcmd, sizeof(subcmd));
 }
 
 static int canvasClear(displayPort_t *displayPort)
 {
-    uint8_t subcmd[] = { 2 };
+    const uint8_t subcmd[] = { 2 };
 
     return canvasOutput(displayPort, MSP_CANVAS, subcmd, sizeof(subcmd));
 }
 
-static int canvasWrite(displayPort_t *displayPort, uint8_t col, uint8_t row, char *string)
+static int canvasWrite(displayPort_t *displayPort, uint8_t col, uint8_t row, const char *string)
 {
-    int len;
-    uint8_t buf[30 + 4];
+#define MSP_CANVAS_MAX_STRING_LENGTH 30
+    uint8_t buf[MSP_CANVAS_MAX_STRING_LENGTH + 4];
 
-    if ((len = strlen(string)) >= 30)
-        len = 30;
+    int len = strlen(string);
+    if (len >= MSP_CANVAS_MAX_STRING_LENGTH) {
+        len = MSP_CANVAS_MAX_STRING_LENGTH;
+    }
 
     buf[0] = 3;
     buf[1] = row;
@@ -79,27 +96,27 @@ static void canvasResync(displayPort_t *displayPort)
     displayPort->cols = 30;
 }
 
-static uint32_t canvasTxBytesFree(displayPort_t *displayPort)
+static uint32_t canvasTxBytesFree(const displayPort_t *displayPort)
 {
     UNUSED(displayPort);
     return mspSerialTxBytesFree();
 }
 
 static const displayPortVTable_t canvasVTable = {
-    canvasBegin,
-    canvasEnd,
-    canvasClear,
-    canvasWrite,
-    canvasHeartBeat,
-    canvasResync,
-    canvasTxBytesFree,
+    .open = canvasOpen,
+    .close = canvasClose,
+    .clear = canvasClear,
+    .write = canvasWrite,
+    .heartbeat = canvasHeartBeat,
+    .resync = canvasResync,
+    .txBytesFree = canvasTxBytesFree
 };
 
-void canvasInit()
+displayPort_t *canvasInit(void)
 {
     canvasDisplayPort.vTable = &canvasVTable;
-    canvasDisplayPort.inCMS = false;
+    canvasDisplayPort.isOpen = false;
     canvasResync(&canvasDisplayPort);
-    cmsDisplayPortRegister(&canvasDisplayPort);
+    return &canvasDisplayPort;
 }
 #endif
diff --git a/src/main/io/canvas.h b/src/main/io/canvas.h
index d288656f6a..7a5520e23f 100644
--- a/src/main/io/canvas.h
+++ b/src/main/io/canvas.h
@@ -1,3 +1,21 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #pragma once
-void canvasInit(void);
-void canvasCmsInit(displayPort_t *dPort);
+
+struct displayPort_s;
+struct displayPort_s *canvasInit(void);
diff --git a/src/main/io/cms_blackbox.c b/src/main/io/cms_blackbox.c
index 0de1ac8eb1..a3ab982f13 100644
--- a/src/main/io/cms_blackbox.c
+++ b/src/main/io/cms_blackbox.c
@@ -1,3 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 //
 // CMS things for blackbox and flashfs.
 // 
diff --git a/src/main/io/cms_blackbox.h b/src/main/io/cms_blackbox.h
index 11f8b1b450..a35ac4211b 100644
--- a/src/main/io/cms_blackbox.h
+++ b/src/main/io/cms_blackbox.h
@@ -1 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
 extern CMS_Menu cmsx_menuBlackbox;
diff --git a/src/main/io/cms_builtin.c b/src/main/io/cms_builtin.c
index ba42784d4c..3275f8ac9a 100644
--- a/src/main/io/cms_builtin.c
+++ b/src/main/io/cms_builtin.c
@@ -1,3 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 //
 // Built-in menu contents and support functions
 //
diff --git a/src/main/io/cms_builtin.h b/src/main/io/cms_builtin.h
index f5ef1e0fc7..7717c5998d 100644
--- a/src/main/io/cms_builtin.h
+++ b/src/main/io/cms_builtin.h
@@ -1 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
 extern CMS_Menu menuMain;
diff --git a/src/main/io/cms_imu.c b/src/main/io/cms_imu.c
index 92329f9d57..d2772a62ef 100644
--- a/src/main/io/cms_imu.c
+++ b/src/main/io/cms_imu.c
@@ -1,3 +1,19 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
 
 // Menu contents for PID, RATES, RC preview, misc
 // Should be part of the relevant .c file.
diff --git a/src/main/io/cms_imu.h b/src/main/io/cms_imu.h
index 9fb44f05b9..a5e05e3103 100644
--- a/src/main/io/cms_imu.h
+++ b/src/main/io/cms_imu.h
@@ -1 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
 extern CMS_Menu cmsx_menuImu;
diff --git a/src/main/io/cms_ledstrip.c b/src/main/io/cms_ledstrip.c
index 284dd50b58..08186a1af6 100644
--- a/src/main/io/cms_ledstrip.c
+++ b/src/main/io/cms_ledstrip.c
@@ -1,3 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
diff --git a/src/main/io/cms_ledstrip.h b/src/main/io/cms_ledstrip.h
index 52081b0177..f740b8911c 100644
--- a/src/main/io/cms_ledstrip.h
+++ b/src/main/io/cms_ledstrip.h
@@ -1 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
 extern CMS_Menu cmsx_menuLedstrip;
diff --git a/src/main/io/cms_osd.h b/src/main/io/cms_osd.h
index 9e780ecc4e..9b0b001d28 100644
--- a/src/main/io/cms_osd.h
+++ b/src/main/io/cms_osd.h
@@ -1,2 +1,21 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
 extern CMS_Menu cmsx_menuAlarms;
 extern CMS_Menu cmsx_menuOsdLayout;
diff --git a/src/main/io/cms_types.h b/src/main/io/cms_types.h
index 5dbafd6e02..a2336e2c77 100644
--- a/src/main/io/cms_types.h
+++ b/src/main/io/cms_types.h
@@ -1,3 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 //
 // Menu element types
 // XXX Upon separation, all OME would be renamed to CME_ or similar.
diff --git a/src/main/io/cms_vtx.c b/src/main/io/cms_vtx.c
index 903d5acdf6..cf0333830c 100644
--- a/src/main/io/cms_vtx.c
+++ b/src/main/io/cms_vtx.c
@@ -1,3 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include <stdbool.h>
 #include <stdint.h>
 #include <ctype.h>
diff --git a/src/main/io/cms_vtx.h b/src/main/io/cms_vtx.h
index f0541c0370..2e15372cad 100644
--- a/src/main/io/cms_vtx.h
+++ b/src/main/io/cms_vtx.h
@@ -1 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
 extern CMS_Menu cmsx_menuVtx;
diff --git a/src/main/io/dashboard.c b/src/main/io/dashboard.c
index 5800f216f1..017ea4cfff 100644
--- a/src/main/io/dashboard.c
+++ b/src/main/io/dashboard.c
@@ -83,6 +83,7 @@ static uint32_t nextDisplayUpdateAt = 0;
 static bool dashboardPresent = false;
 
 static rxConfig_t *rxConfig;
+static displayPort_t *displayPort;
 
 #define PAGE_TITLE_LINE_COUNT 1
 
@@ -588,7 +589,7 @@ void dashboardUpdate(uint32_t currentTime)
     static uint8_t previousArmedState = 0;
 
 #ifdef OLEDCMS
-    if (oledDisplayPort.inCMS) {
+    if (displayIsOpen(displayPort)) {
         return;
     }
 #endif
@@ -704,8 +705,9 @@ void dashboardInit(rxConfig_t *rxConfigToUse)
     resetDisplay();
     delay(200);
 
+    displayPort = displayPortOledInit();
 #if defined(CMS) && defined(OLEDCMS)
-    displayPortOledInit();
+    cmsDisplayPortRegister(displayPort);
 #endif
 
     rxConfig = rxConfigToUse;
diff --git a/src/main/io/displayport_oled.c b/src/main/io/displayport_oled.c
index e77abb5cea..68a6552689 100644
--- a/src/main/io/displayport_oled.c
+++ b/src/main/io/displayport_oled.c
@@ -20,18 +20,12 @@
 
 #include "platform.h"
 
-#ifdef OLEDCMS
-
 #include "common/utils.h"
 
 #include "drivers/display.h"
 #include "drivers/display_ug2864hsweg01.h"
 
-#include "io/cms.h"
-#include "io/displayport_oled.h"
-
-// Exported
-displayPort_t oledDisplayPort;
+static displayPort_t oledDisplayPort;
 
 static int oledOpen(displayPort_t *displayPort)
 {
@@ -52,7 +46,7 @@ static int oledClear(displayPort_t *displayPort)
     return 0;
 }
 
-static int oledWrite(displayPort_t *displayPort, uint8_t x, uint8_t y, char *s)
+static int oledWrite(displayPort_t *displayPort, uint8_t x, uint8_t y, const char *s)
 {
     UNUSED(displayPort);
     i2c_OLED_set_xy(x, y);
@@ -71,7 +65,7 @@ static void oledResync(displayPort_t *displayPort)
     UNUSED(displayPort);
 }
 
-static uint32_t oledTxBytesFree(displayPort_t *displayPort)
+static uint32_t oledTxBytesFree(const displayPort_t *displayPort)
 {
     UNUSED(displayPort);
     return UINT32_MAX;
@@ -87,13 +81,11 @@ static const displayPortVTable_t oledVTable = {
     .txBytesFree = oledTxBytesFree
 };
 
-void displayPortOledInit()
+displayPort_t *displayPortOledInit(void)
 {
     oledDisplayPort.vTable = &oledVTable;
     oledDisplayPort.rows = SCREEN_CHARACTER_ROW_COUNT;
     oledDisplayPort.cols = SCREEN_CHARACTER_COLUMN_COUNT;
-    oledDisplayPort.inCMS = false;
-
-    cmsDisplayPortRegister(&oledDisplayPort);
+    oledDisplayPort.isOpen = false;
+    return &oledDisplayPort;
 }
-#endif // OLEDCMS
diff --git a/src/main/io/displayport_oled.h b/src/main/io/displayport_oled.h
index 2d0bc20509..4daa6de1cd 100644
--- a/src/main/io/displayport_oled.h
+++ b/src/main/io/displayport_oled.h
@@ -17,6 +17,4 @@
 
 #pragma once
 
-void displayPortOledInit(void);
-
-extern displayPort_t oledDisplayPort;
+displayPort_t *displayPortOledInit(void);
diff --git a/src/main/io/gps.c b/src/main/io/gps.c
index d4bdc01261..2cd9873baf 100755
--- a/src/main/io/gps.c
+++ b/src/main/io/gps.c
@@ -38,8 +38,6 @@
 
 #include "sensors/sensors.h"
 
-#include "io/cms.h"
-
 #include "io/serial.h"
 #include "io/dashboard.h"
 #include "io/gps.h"
diff --git a/src/main/io/osd.c b/src/main/io/osd.c
index 903cbb5b95..cf70094d15 100755
--- a/src/main/io/osd.c
+++ b/src/main/io/osd.c
@@ -74,14 +74,24 @@ bool blinkState = true;
 //extern uint8_t RSSI; // TODO: not used?
 
 static uint16_t flyTime = 0;
-uint8_t statRssi;
+static uint8_t statRssi;
 
-statistic_t stats;
+typedef struct statistic_s {
+    int16_t max_speed;
+    int16_t min_voltage; // /10
+    int16_t max_current; // /10
+    int16_t min_rssi;
+    int16_t max_altitude;
+} statistic_t;
+
+static statistic_t stats;
 
 uint16_t refreshTimeout = 0;
 #define REFRESH_1S    12
 
-uint8_t armState;
+static uint8_t armState;
+
+static displayPort_t *osd7456DisplayPort;
 
 // OSD forwards
 
@@ -109,7 +119,7 @@ void osdDrawElements(void)
         ;
 #endif
 #ifdef CMS
-    else if (sensors(SENSOR_ACC) || osd7456DisplayPort.inCMS)
+    else if (sensors(SENSOR_ACC) || displayIsOpen(osd7456DisplayPort))
 #else
     else if (sensors(SENSOR_ACC))
 #endif
@@ -132,7 +142,7 @@ void osdDrawElements(void)
 
 #ifdef GPS
 #ifdef CMS
-    if (sensors(SENSOR_GPS) || osd7456DisplayPort.inCMS)
+    if (sensors(SENSOR_GPS) || displayIsOpen(osd7456DisplayPort))
 #else
     if (sensors(SENSOR_GPS))
 #endif
@@ -406,8 +416,9 @@ void osdInit(void)
 
     refreshTimeout = 4 * REFRESH_1S;
 
+    osd7456DisplayPort = osd7456DisplayPortInit();
 #ifdef CMS
-    osd7456DisplayPortInit();
+    cmsDisplayPortRegister(osd7456DisplayPort);
 #endif
 }
 
@@ -584,8 +595,9 @@ void updateOsd(uint32_t currentTime)
 
 #ifdef CMS
     // do not allow ARM if we are in menu
-    if (osd7456DisplayPort.inCMS)
+    if (displayIsOpen(osd7456DisplayPort)) {
         DISABLE_ARMING_FLAG(OK_TO_ARM);
+    }
 #endif
 }
 
@@ -632,7 +644,7 @@ void osdUpdate(uint32_t currentTime)
     blinkState = (millis() / 200) % 2;
 
 #ifdef CMS
-    if (!osd7456DisplayPort.inCMS) {
+    if (!displayIsOpen(osd7456DisplayPort)) {
         osdUpdateAlarms();
         osdDrawElements();
 #ifdef OSD_CALLS_CMS
diff --git a/src/main/io/osd.h b/src/main/io/osd.h
index 3f4400d74d..b6600953cc 100755
--- a/src/main/io/osd.h
+++ b/src/main/io/osd.h
@@ -34,16 +34,16 @@ typedef enum {
     OSD_GPS_SPEED,
     OSD_GPS_SATS,
     OSD_ALTITUDE,
-    OSD_MAX_ITEMS, // MUST BE LAST
-} osd_items_t;
+    OSD_ITEM_COUNT // MUST BE LAST
+} osd_items_e;
 
 typedef enum {
     OSD_UNIT_IMPERIAL,
     OSD_UNIT_METRIC
-} osd_unit_t;
+} osd_unit_e;
 
-typedef struct {
-    uint16_t item_pos[OSD_MAX_ITEMS];
+typedef struct osd_profile_s {
+    uint16_t item_pos[OSD_ITEM_COUNT];
 
     // Alarms
     uint8_t rssi_alarm;
@@ -54,26 +54,14 @@ typedef struct {
     uint8_t video_system;
     uint8_t row_shiftdown;
 
-    osd_unit_t units;
+    osd_unit_e units;
 } osd_profile_t;
 
-typedef struct {
-    int16_t max_speed;
-    int16_t min_voltage; // /10
-    int16_t max_current; // /10
-    int16_t min_rssi;
-    int16_t max_altitude;
-} statistic_t;
-
 void updateOsd(uint32_t currentTime);
 void osdInit(void);
 void resetOsdConfig(osd_profile_t *osdProfile);
 void osdResetAlarms(void);
 
-#ifdef CMS
-void osdCmsInit(displayPort_t *);
-#endif
-
 // Character coordinate and attributes
 
 #define OSD_POS(x,y)  (x | (y << 5))
diff --git a/src/main/io/osd_max7456.c b/src/main/io/osd_max7456.c
index 52ac8d6bc2..246eb37215 100644
--- a/src/main/io/osd_max7456.c
+++ b/src/main/io/osd_max7456.c
@@ -1,3 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include <stdbool.h>
 #include <stdint.h>
 
@@ -16,20 +33,20 @@ displayPort_t osd7456DisplayPort; // Referenced from osd.c
 
 extern uint16_t refreshTimeout;
 
-static int osdMenuBegin(displayPort_t *displayPort)
+static int osdMenuOpen(displayPort_t *displayPort)
 {
     UNUSED(displayPort);
     osdResetAlarms();
-    displayPort->inCMS = true;
+    displayPort->isOpen = true;
     refreshTimeout = 0;
 
     return 0;
 }
 
-static int osdMenuEnd(displayPort_t *displayPort)
+static int osdMenuClose(displayPort_t *displayPort)
 {
     UNUSED(displayPort);
-    displayPort->inCMS = false;
+    displayPort->isOpen = false;
 
     return 0;
 }
@@ -42,7 +59,7 @@ static int osdClearScreen(displayPort_t *displayPort)
     return 0;
 }
 
-static int osdWrite(displayPort_t *displayPort, uint8_t x, uint8_t y, char *s)
+static int osdWrite(displayPort_t *displayPort, uint8_t x, uint8_t y, const char *s)
 {
     UNUSED(displayPort);
     max7456Write(x, y, s);
@@ -64,27 +81,27 @@ static int osdHeartbeat(displayPort_t *displayPort)
     return 0;
 }
 
-static uint32_t osdTxBytesFree(displayPort_t *displayPort)
+static uint32_t osdTxBytesFree(const displayPort_t *displayPort)
 {
     UNUSED(displayPort);
     return UINT32_MAX;
 }
 
 static displayPortVTable_t osdVTable = {
-    osdMenuBegin,
-    osdMenuEnd,
-    osdClearScreen,
-    osdWrite,
-    osdHeartbeat,
-    osdResync,
-    osdTxBytesFree,
+    .open = osdMenuOpen,
+    .close = osdMenuClose,
+    .clear = osdClearScreen,
+    .write = osdWrite,
+    .heartbeat = osdHeartbeat,
+    .resync = osdResync,
+    .txBytesFree = osdTxBytesFree,
 };
 
-void osd7456DisplayPortInit(void)
+displayPort_t *osd7456DisplayPortInit(void)
 {
     osd7456DisplayPort.vTable = &osdVTable;
-    osd7456DisplayPort.inCMS = false;
+    osd7456DisplayPort.isOpen = false;
     osdResync(&osd7456DisplayPort);
-    cmsDisplayPortRegister(&osd7456DisplayPort);
+    return &osd7456DisplayPort;
 }
 #endif // OSD
diff --git a/src/main/io/osd_max7456.h b/src/main/io/osd_max7456.h
index 22c64faa79..a116a6e4ff 100644
--- a/src/main/io/osd_max7456.h
+++ b/src/main/io/osd_max7456.h
@@ -1,5 +1,20 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it 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.
+ *
+ * Cleanflight 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 Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #pragma once
 
-extern displayPort_t osd7456DisplayPort;
-
-void osd7456DisplayPortInit(void);
+displayPort_t *osd7456DisplayPortInit(void);
diff --git a/src/main/io/serial_cli.c b/src/main/io/serial_cli.c
index 6dd51d2250..2d9c9f5dab 100755
--- a/src/main/io/serial_cli.c
+++ b/src/main/io/serial_cli.c
@@ -945,7 +945,7 @@ const clivalue_t valueTable[] = {
 
 #ifdef OSD
     { "osd_video_system",           VAR_UINT8  | MASTER_VALUE, &masterConfig.osdProfile.video_system, .config.minmax = { 0, 2 } },
-    { "osd_row_shiftdown",             VAR_UINT8  | MASTER_VALUE, &masterConfig.osdProfile.row_shiftdown, .config.minmax = { 0, 1 } },
+    { "osd_row_shiftdown",          VAR_UINT8  | MASTER_VALUE, &masterConfig.osdProfile.row_shiftdown, .config.minmax = { 0, 1 } },
     { "osd_units",                  VAR_UINT8  | MASTER_VALUE | MODE_LOOKUP, &masterConfig.osdProfile.units, .config.lookup = { TABLE_UNIT } },
 
     { "osd_rssi_alarm",             VAR_UINT8  | MASTER_VALUE, &masterConfig.osdProfile.rssi_alarm, .config.minmax = { 0, 100 } },
diff --git a/src/main/main.c b/src/main/main.c
index 0fefddfaaf..5e5b27ec72 100644
--- a/src/main/main.c
+++ b/src/main/main.c
@@ -463,7 +463,7 @@ void init(void)
 
 #ifdef CANVAS
     if (feature(FEATURE_CANVAS)) {
-        canvasInit();
+        cmsDisplayPortRegister(canvasInit());
     }
 #endif
 
diff --git a/src/main/msp/msp.h b/src/main/msp/msp.h
index eaca6e2868..b322ee7df6 100644
--- a/src/main/msp/msp.h
+++ b/src/main/msp/msp.h
@@ -35,4 +35,3 @@ typedef struct mspPacket_s {
 struct serialPort_s;
 typedef void (*mspPostProcessFnPtr)(struct serialPort_s *port); // msp post process function, used for gracefully handling reboots, etc.
 typedef mspResult_e (*mspProcessCommandFnPtr)(mspPacket_t *cmd, mspPacket_t *reply, mspPostProcessFnPtr *mspPostProcessFn);
-typedef void (*mspPushCommandFnPtr)(mspPacket_t *push, uint8_t *, int);
diff --git a/src/main/msp/msp_serial.c b/src/main/msp/msp_serial.c
index 409e60afc8..9b38932bfd 100644
--- a/src/main/msp/msp_serial.c
+++ b/src/main/msp/msp_serial.c
@@ -120,7 +120,7 @@ static uint8_t mspSerialChecksumBuf(uint8_t checksum, const uint8_t *data, int l
 
 #define JUMBO_FRAME_SIZE_LIMIT 255
 
-static void mspSerialEncode(mspPort_t *msp, mspPacket_t *packet)
+static int mspSerialEncode(mspPort_t *msp, mspPacket_t *packet)
 {
     serialBeginWrite(msp->port);
     const int len = sbufBytesRemaining(&packet->buf);
@@ -140,6 +140,7 @@ static void mspSerialEncode(mspPort_t *msp, mspPacket_t *packet)
     }
     serialWrite(msp->port, checksum);
     serialEndWrite(msp->port);
+    return sizeof(hdr) + len + 1; // header, data, and checksum
 }
 
 static mspPostProcessFnPtr mspSerialProcessReceivedCommand(mspPort_t *msp, mspProcessCommandFnPtr mspProcessCommandFn)
@@ -211,9 +212,10 @@ void mspSerialInit(void)
     mspSerialAllocatePorts();
 }
 
-void mspSerialPush(uint8_t cmd, uint8_t *data, int datalen)
+int mspSerialPush(uint8_t cmd, const uint8_t *data, int datalen)
 {
     static uint8_t pushBuf[30];
+    int ret = 0;
 
     mspPacket_t push = {
         .buf = { .ptr = pushBuf, .end = ARRAYEND(pushBuf), },
@@ -221,7 +223,7 @@ void mspSerialPush(uint8_t cmd, uint8_t *data, int datalen)
         .result = 0,
     };
 
-    for (uint8_t portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
+    for (int portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
         mspPort_t * const mspPort = &mspPorts[portIndex];
         if (!mspPort->port) {
             continue;
@@ -236,15 +238,16 @@ void mspSerialPush(uint8_t cmd, uint8_t *data, int datalen)
 
         sbufSwitchToReader(&push.buf, pushBuf);
 
-        mspSerialEncode(mspPort, &push);
+        ret = mspSerialEncode(mspPort, &push);
     }
+    return ret; // return the number of bytes written
 }
 
 uint32_t mspSerialTxBytesFree()
 {
-    uint32_t minroom = UINT16_MAX;
+    uint32_t ret = UINT32_MAX;
 
-    for (uint8_t portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
+    for (int portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
         mspPort_t * const mspPort = &mspPorts[portIndex];
         if (!mspPort->port) {
             continue;
@@ -255,12 +258,11 @@ uint32_t mspSerialTxBytesFree()
             continue;
         }
 
-        uint32_t room = serialTxBytesFree(mspPort->port);
-
-        if (room < minroom) {
-            minroom = room;
+        const uint32_t bytesFree = serialTxBytesFree(mspPort->port);
+        if (bytesFree < ret) {
+            ret = bytesFree;
         }
     }
 
-    return minroom;
+    return ret;
 }
diff --git a/src/main/msp/msp_serial.h b/src/main/msp/msp_serial.h
index 0f1c8a2fff..f6e2954a24 100644
--- a/src/main/msp/msp_serial.h
+++ b/src/main/msp/msp_serial.h
@@ -66,5 +66,5 @@ void mspSerialInit(void);
 void mspSerialProcess(mspEvaluateNonMspData_e evaluateNonMspData, mspProcessCommandFnPtr mspProcessCommandFn);
 void mspSerialAllocatePorts(void);
 void mspSerialReleasePortIfAllocated(struct serialPort_s *serialPort);
-void mspSerialPush(uint8_t cmd, uint8_t *data, int datalen);
+int mspSerialPush(uint8_t cmd, const uint8_t *data, int datalen);
 uint32_t mspSerialTxBytesFree(void);
diff --git a/src/main/target/OMNIBUS/target.h b/src/main/target/OMNIBUS/target.h
index b47914d1ae..6f7e839b2b 100644
--- a/src/main/target/OMNIBUS/target.h
+++ b/src/main/target/OMNIBUS/target.h
@@ -1,4 +1,3 @@
-#define USE_DPRINTF
 /*
  * This file is part of Cleanflight.
  *
diff --git a/src/main/target/OMNIBUS/target.mk b/src/main/target/OMNIBUS/target.mk
index 756617182c..5878246a44 100644
--- a/src/main/target/OMNIBUS/target.mk
+++ b/src/main/target/OMNIBUS/target.mk
@@ -9,17 +9,8 @@ TARGET_SRC = \
             drivers/compass_ak8963.c \
             drivers/compass_ak8975.c \
             drivers/compass_hmc5883l.c \
+            drivers/max7456.c \
             drivers/serial_usb_vcp.c \
             drivers/transponder_ir.c \
             drivers/transponder_ir_stm32f30x.c \
-            io/transponder_ir.c \
-            drivers/max7456.c \
-            io/osd.c \
-            io/osd_max7456.c \
-            io/canvas.c \
-            io/cms.c \
-            io/cms_builtin.c \
-            io/cms_imu.c \
-            io/cms_blackbox.c \
-            io/cms_vtx.c \
-            io/cms_ledstrip.c
+            io/transponder_ir.c
diff --git a/src/main/target/OMNIBUSF4/target.mk b/src/main/target/OMNIBUSF4/target.mk
index d805edc7f7..333e4cdcb9 100644
--- a/src/main/target/OMNIBUSF4/target.mk
+++ b/src/main/target/OMNIBUSF4/target.mk
@@ -5,13 +5,5 @@ TARGET_SRC = \
             drivers/accgyro_spi_mpu6000.c \
             drivers/barometer_ms5611.c \
             drivers/compass_hmc5883l.c \
-            drivers/max7456.c \
-            io/osd.c \
-            io/osd_max7456.c \
-            io/cms.c \
-            io/cms_builtin.c \
-            io/cms_imu.c \
-            io/cms_blackbox.c \
-            io/cms_ledstrip.c \
-            io/canvas.c
+            drivers/max7456.c
 
diff --git a/src/main/target/SIRINFPV/target.mk b/src/main/target/SIRINFPV/target.mk
index f123795910..23a8b46be3 100644
--- a/src/main/target/SIRINFPV/target.mk
+++ b/src/main/target/SIRINFPV/target.mk
@@ -11,13 +11,4 @@ TARGET_SRC = \
             drivers/compass_hmc5883l.c \
             drivers/flash_m25p16.c \
             drivers/vtx_soft_spi_rtc6705.c \
-            drivers/max7456.c \
-            io/osd.c \
-            io/osd_max7456.c \
-            io/canvas.c \
-            io/cms.c \
-            io/cms_builtin.c \
-            io/cms_imu.c \
-            io/cms_blackbox.c \
-            io/cms_vtx.c \
-            io/cms_ledstrip.c
+            drivers/max7456.c
diff --git a/src/main/target/SPRACINGF3/target.mk b/src/main/target/SPRACINGF3/target.mk
index b37d1b2b0e..5b3a330295 100644
--- a/src/main/target/SPRACINGF3/target.mk
+++ b/src/main/target/SPRACINGF3/target.mk
@@ -8,12 +8,5 @@ TARGET_SRC = \
             drivers/barometer_bmp085.c \
             drivers/barometer_bmp280.c \
             drivers/compass_ak8975.c \
-            drivers/compass_hmc5883l.c \
-            io/canvas.c \
-            io/cms.c \
-            io/cms_builtin.c \
-            io/cms_imu.c \
-            io/cms_blackbox.c \
-            io/cms_vtx.c \
-            io/cms_ledstrip.c
+            drivers/compass_hmc5883l.c
 
diff --git a/src/main/target/STM32F3DISCOVERY/target.mk b/src/main/target/STM32F3DISCOVERY/target.mk
index 8189f15f4a..cef064b7e3 100644
--- a/src/main/target/STM32F3DISCOVERY/target.mk
+++ b/src/main/target/STM32F3DISCOVERY/target.mk
@@ -25,14 +25,4 @@ TARGET_SRC = \
             drivers/compass_ak8975.c \
             drivers/compass_hmc5883l.c \
             drivers/flash_m25p16.c \
-            drivers/max7456.c \
-            io/osd.c \
-            io/osd_max7456.c \
-            io/canvas.c \
-            io/cms.c \
-            io/cms_builtin.c \
-            io/cms_imu.c \
-            io/cms_blackbox.c \
-            io/cms_vtx.c \
-            io/cms_ledstrip.c
-
+            drivers/max7456.c