stm32: Support custom reset to bootloader via board config define.

iabdalkader · iabdalkader · commit 74e3a512ea3f · 2022-04-22T14:53:53.000+02:00
diff --git a/ports/stm32/boards/ARDUINO_PORTENTA_H7/mpconfigboard.h b/ports/stm32/boards/ARDUINO_PORTENTA_H7/mpconfigboard.h
@@ -27,17 +27,22 @@ typedef unsigned int mp_uint_t;     // must be pointer size
 #define MICROPY_HW_ENABLE_TIMER     (1)
 #define MICROPY_HW_ENABLE_SDCARD    (1)
 #define MICROPY_HW_ENABLE_MMCARD    (0)
+
+// Flash storage config
 #define MICROPY_HW_SPIFLASH_ENABLE_CACHE            (1)
 #define MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE    (0)
 
+// Using a custom bootloader
+#define MICROPY_HW_ENTER_BOOTLOADER_VIA_RESET       (0)
+
 #define MICROPY_BOARD_STARTUP       PORTENTA_board_startup
 void PORTENTA_board_startup(void);
 
 #define MICROPY_BOARD_EARLY_INIT    PORTENTA_board_early_init
 void PORTENTA_board_early_init(void);
 
 #define MICROPY_RESET_TO_BOOTLOADER PORTENTA_reboot_to_bootloader
-void PORTENTA_reboot_to_bootloader(void);
+void PORTENTA_reboot_to_bootloader(void) __attribute__((noreturn));
 
 void PORTENTA_board_low_power(int mode);
 #define MICROPY_BOARD_LEAVE_STOP    PORTENTA_board_low_power(0);
diff --git a/ports/stm32/powerctrl.c b/ports/stm32/powerctrl.c
@@ -107,6 +107,7 @@ NORETURN void powerctrl_mcu_reset(void) {
     NVIC_SystemReset();
 }
 
+#if MICROPY_HW_ENTER_BOOTLOADER_VIA_RESET || !defined(MICROPY_RESET_TO_BOOTLOADER)
 NORETURN static __attribute__((naked)) void branch_to_bootloader(uint32_t r0, uint32_t bl_addr) {
     __asm volatile (
         "ldr r2, [r1, #0]\n"    // get address of stack pointer
@@ -116,9 +117,14 @@ NORETURN static __attribute__((naked)) void branch_to_bootloader(uint32_t r0, ui
         );
     MP_UNREACHABLE;
 }
+#endif
 
 NORETURN void powerctrl_enter_bootloader(uint32_t r0, uint32_t bl_addr) {
-    #if MICROPY_HW_ENTER_BOOTLOADER_VIA_RESET
+    #if defined(MICROPY_RESET_TO_BOOTLOADER)
+
+    MICROPY_RESET_TO_BOOTLOADER();
+
+    #elif MICROPY_HW_ENTER_BOOTLOADER_VIA_RESET
 
     // Enter the bootloader via a reset, so everything is reset (including WDT).
     // Upon reset powerctrl_check_enter_bootloader() will jump to the bootloader.
