Implement bootloader #137 (#142)

* Boot: switch to DFU routines. Implements #132 part 1 of 2.

* Boot: boot to DFU shortcut, hard reset USB on each boot. Implements #132 part 2 of 2.

* Deploy scripts: fix path for deploy dfu.

* Bootloader: initial version. Target_f2: rebase, update deployment scripts.

* Bootloader: cleanup, refactor switch2 proc. Readme,wiki: document bootloader.

* Wiki: deploy symlinks as files, bootloader info.

* Target_f2: valid flash size in linker script.

* Github CI: bootloader build and artifacts.

* Bootloader: rename platforms to targets.

* Bootloader: change dfu/os colors.

* disable set -e

* lint code

* add bootloader testing page

Co-authored-by: Aleksandr Kutuzov <aku@plooks.com>
Co-authored-by: aanper <mail@s3f.ru>

target_f2/Src/boot.c

@@ -0,0 +1,19 @@
+#include "boot.h"
+#include "stm32l4xx_ll_bus.h"
+#include "stm32l4xx_ll_rcc.h"
+#include "stm32l4xx_ll_rtc.h"
+#include "stm32l4xx_ll_pwr.h"
+
+#define BOOT_REQUEST_DFU 0xDF00B000
+
+void boot_restart_in_dfu() {
+    // Request DFU on boot
+    LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_PWR);
+    LL_PWR_EnableBkUpAccess();
+    // Enable RTC
+    LL_RCC_EnableRTC();
+    // Write backup registry
+    LL_RTC_BAK_SetRegister(RTC, LL_RTC_BKP_DR0, BOOT_REQUEST_DFU);
+    // Reset
+    NVIC_SystemReset();
+}

target_f2/Src/main.c

@@ -20,6 +20,7 @@
 
 /* Includes ------------------------------------------------------------------*/
 #include "main.h"
+#include "boot.h"
 #include "cmsis_os.h"
 #include "usb_device.h"
 
@@ -89,7 +90,6 @@ void StartDefaultTask(void const* argument);
   */
 int main(void) {
     /* USER CODE BEGIN 1 */
-
     /* USER CODE END 1 */
 
     /* MCU Configuration--------------------------------------------------------*/

target_f2/Src/system_stm32l4xx.c

@@ -123,6 +123,8 @@
 /*!< Uncomment the following line if you need to relocate your vector Table in
      Internal SRAM. */
 /* #define VECT_TAB_SRAM */
+#define VECT_TAB_OFFSET \
+    0x8000 /*!< Vector Table base offset field.
 #define VECT_TAB_OFFSET \
     0x00 /*!< Vector Table base offset field.
                                    This value must be a multiple of 0x200. */