Use slightly flatter directory structure since some developers did not

like too many folders.
Extracted code from some files into separate files to fit with the new
layout.

src/drivers/system_common.c

@@ -0,0 +1,225 @@
+#include "board.h"
+
+// cycles per microsecond
+static volatile uint32_t usTicks = 0;
+// current uptime for 1kHz systick timer. will rollover after 49 days. hopefully we won't care.
+static volatile uint32_t sysTickUptime = 0;
+// from system_stm32f10x.c
+void SetSysClock(void);
+#ifdef BUZZER
+void systemBeep(bool onoff);
+static void beepRev4(bool onoff);
+static void beepRev5(bool onoff);
+void (* systemBeepPtr)(bool onoff) = NULL;
+#endif
+
+static void cycleCounterInit(void)
+{
+    RCC_ClocksTypeDef clocks;
+    RCC_GetClocksFreq(&clocks);
+    usTicks = clocks.SYSCLK_Frequency / 1000000;
+}
+
+// SysTick
+void SysTick_Handler(void)
+{
+    sysTickUptime++;
+}
+
+// Return system uptime in microseconds (rollover in 70minutes)
+uint32_t micros(void)
+{
+    register uint32_t ms, cycle_cnt;
+    do {
+        ms = sysTickUptime;
+        cycle_cnt = SysTick->VAL;
+    } while (ms != sysTickUptime);
+    return (ms * 1000) + (usTicks * 1000 - cycle_cnt) / usTicks;
+}
+
+// Return system uptime in milliseconds (rollover in 49 days)
+uint32_t millis(void)
+{
+    return sysTickUptime;
+}
+
+void systemInit(void)
+{
+    struct {
+        GPIO_TypeDef *gpio;
+        gpio_config_t cfg;
+    } gpio_setup[] = {
+#ifdef LED0
+        {
+            .gpio = LED0_GPIO,
+            .cfg = { LED0_PIN, Mode_Out_PP, Speed_2MHz }
+        },
+#endif
+#ifdef LED1
+
+        {
+            .gpio = LED1_GPIO,
+            .cfg = { LED1_PIN, Mode_Out_PP, Speed_2MHz }
+        },
+#endif
+#ifdef BUZZER
+        {
+            .gpio = BEEP_GPIO,
+            .cfg = { BEEP_PIN, Mode_Out_OD, Speed_2MHz }
+        },
+#endif
+    };
+    gpio_config_t gpio;
+    uint32_t i;
+    uint8_t gpio_count = sizeof(gpio_setup) / sizeof(gpio_setup[0]);
+
+    // Configure the System clock frequency, HCLK, PCLK2 and PCLK1 prescalers
+    // Configure the Flash Latency cycles and enable prefetch buffer
+    SetSysClock();
+
+    // Turn on clocks for stuff we use
+    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 | RCC_APB1Periph_TIM3 | RCC_APB1Periph_TIM4 | RCC_APB1Periph_I2C2, ENABLE);
+    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC | RCC_APB2Periph_TIM1 | RCC_APB2Periph_ADC1 | RCC_APB2Periph_USART1, ENABLE);
+    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
+    RCC_ClearFlag();
+
+    // Make all GPIO in by default to save power and reduce noise
+    gpio.pin = Pin_All;
+    gpio.mode = Mode_AIN;
+    gpioInit(GPIOA, &gpio);
+    gpioInit(GPIOB, &gpio);
+    gpioInit(GPIOC, &gpio);
+
+    // Turn off JTAG port 'cause we're using the GPIO for leds
+#define AFIO_MAPR_SWJ_CFG_NO_JTAG_SW            (0x2 << 24)
+    AFIO->MAPR |= AFIO_MAPR_SWJ_CFG_NO_JTAG_SW;
+
+#ifdef BUZZER
+    // Configure gpio
+    // rev5 needs inverted beeper. oops.
+    if (hse_value == 12000000)
+        systemBeepPtr = beepRev5;
+    else
+        systemBeepPtr = beepRev4;
+    BEEP_OFF;
+#endif
+    LED0_OFF;
+    LED1_OFF;
+
+    for (i = 0; i < gpio_count; i++) {
+        if (hse_value == 12000000 && gpio_setup[i].cfg.mode == Mode_Out_OD)
+            gpio_setup[i].cfg.mode = Mode_Out_PP;
+        gpioInit(gpio_setup[i].gpio, &gpio_setup[i].cfg);
+    }
+
+    // Init cycle counter
+    cycleCounterInit();
+
+    // SysTick
+    SysTick_Config(SystemCoreClock / 1000);
+
+    // Configure the rest of the stuff
+#ifndef FY90Q
+    i2cInit(I2C2);
+#endif
+    spiInit();
+
+    // sleep for 100ms
+    delay(100);
+}
+
+#if 1
+void delayMicroseconds(uint32_t us)
+{
+    uint32_t now = micros();
+    while (micros() - now < us);
+}
+#else
+void delayMicroseconds(uint32_t us)
+{
+    uint32_t elapsed = 0;
+    uint32_t lastCount = SysTick->VAL;
+
+    for (;;) {
+        register uint32_t current_count = SysTick->VAL;
+        uint32_t elapsed_us;
+
+        // measure the time elapsed since the last time we checked
+        elapsed += current_count - lastCount;
+        lastCount = current_count;
+
+        // convert to microseconds
+        elapsed_us = elapsed / usTicks;
+        if (elapsed_us >= us)
+            break;
+
+        // reduce the delay by the elapsed time
+        us -= elapsed_us;
+
+        // keep fractional microseconds for the next iteration
+        elapsed %= usTicks;
+    }
+}
+#endif
+
+void delay(uint32_t ms)
+{
+    while (ms--)
+        delayMicroseconds(1000);
+}
+
+void failureMode(uint8_t mode)
+{
+    LED1_ON;
+    LED0_OFF;
+    while (1) {
+        LED1_TOGGLE;
+        LED0_TOGGLE;
+        delay(475 * mode - 2);
+        BEEP_ON
+        delay(25);
+        BEEP_OFF;
+    }
+}
+
+#define AIRCR_VECTKEY_MASK    ((uint32_t)0x05FA0000)
+
+void systemReset(bool toBootloader)
+{
+    if (toBootloader) {
+        // 1FFFF000 -> 20000200 -> SP
+        // 1FFFF004 -> 1FFFF021 -> PC
+        *((uint32_t *)0x20004FF0) = 0xDEADBEEF; // 20KB STM32F103
+    }
+
+    // Generate system reset
+    SCB->AIRCR = AIRCR_VECTKEY_MASK | (uint32_t)0x04;
+}
+
+#ifdef BUZZER
+static void beepRev4(bool onoff)
+{
+    if (onoff) {
+        digitalLo(BEEP_GPIO, BEEP_PIN);
+    } else {
+        digitalHi(BEEP_GPIO, BEEP_PIN);
+    }
+}
+
+static void beepRev5(bool onoff)
+{
+    if (onoff) {
+        digitalHi(BEEP_GPIO, BEEP_PIN);
+    } else {
+        digitalLo(BEEP_GPIO, BEEP_PIN);
+    }
+}
+#endif
+
+void systemBeep(bool onoff)
+{
+#ifdef BUZZER
+    systemBeepPtr(onoff);
+#endif
+}
+