feat(legacy): pushing 'go to bootloader flag' to bootloader main

legacy/bootloader/bootloader.c

@@ -31,6 +31,7 @@
 #include "rng.h"
 #include "setup.h"
 #include "signatures.h"
+#include "supervise.h"
 #include "usb.h"
 #include "util.h"
 
@@ -123,6 +124,12 @@ int main(void) {
 
   mpu_config_bootloader();
 
+  register uint32_t go_to_bootloader_flag __asm__("r11");
+
+  if (go_to_bootloader_flag == RETURN_TO_BOOTLOADER_FLAG) {
+    goto bootloader_loop_start;
+  }
+
 #ifndef APPVER
   bool left_pressed = (buttonRead() & BTN_PIN_NO) == 0;
 
@@ -149,6 +156,8 @@ int main(void) {
   }
 #endif
 
+bootloader_loop_start:
+
   bootloader_loop();
 
   return 0;

legacy/startup.S

@@ -32,6 +32,9 @@ reset_handler:
   isb
 #endif
 
+  ldr r0, =_go_to_bootloader_flag_addr  // r0 - address of storage for "go to bootloader" flag
+  ldr r11, [r0]        // r11 - keep in register and hope it gets to main
+
   ldr r0, =_ram_start // r0 - point to beginning of SRAM
   ldr r1, =_ram_end   // r1 - point to byte after the end of SRAM
   ldr r2, =0          // r2 - the byte-sized value to be written