Start bootloader from firmware

Question

I wish to be able to start the bootloader directly from the code without having to have a pin high and reset the microcontroller to access it. The idea below is that the bootloader binary is stored in a char array. When Start_BootLoader() is called, the bootloader is copied into SRAM and executed.

However, the code copies into RAM but when it attempts to execute the code at the location I have copied it to, it does nothing.

The micro. is an Energy Micro EFM32380f1024. The code below that I am using is based on Energy Micro's application note AN0042.

void Start_Bootloader(void)
{
  /* Diable interrupts */
  INT_Disable();

  __set_MSP( ( 0x20000000 + sizeof( bootloader ) + 0x400 ) & 0xFFFFFFF0 );

  /* Load the entire bootloader into SRAM. */

  memcpy( (void*)0x20000000, bootloader, sizeof( bootloader ) );

  /* Start executing the bootloader. */

  BOOT_jump( *(uint32_t*)0x20000000, *(uint32_t*)0x20000004 );
}

Answer 1

The code ships with ROM and RAM linker settings - but only the RAM version will likely work in your case. Try to read the second word (32 Bit little endian) from your binary - it should point to an odd address in the 0x20000000 range, as it is the new PC value.