Bootloader jump to app not working on STM32G491

[Yves Bmnt]

Hi all,

I am trying to launch the app from a bootloader code that I copied from a project on an STM32L0 and STM32F446, it worked fine there but somehow my app doesn't start on the STM32G491.

Here's the code for the jump:

static void bootloader_jump_to_app(void)
{
    uint32_t  JumpAddress = *(__IO uint32_t*)(APP_ADDRESS + 4u);

    pFunction Jump = (pFunction)JumpAddress;


    if (!bootloader_check_integrity())
    {
        bootloader_send_message("Abort\r", 8u);
        bootloader_init();
    }
    else
    {
		bootloader_send_message("Starting\r", 9u);

		HAL_FLASH_Lock(); // lock flash after memory erase + write

		HAL_RCC_DeInit();
		HAL_DeInit();

		SysTick->CTRL = 0u;
		SysTick->LOAD = 0u;
		SysTick->VAL  = 0u;

		SCB->VTOR = (__IO uint32_t)APP_ADDRESS;

		__set_MSP(*(__IO uint32_t*)APP_ADDRESS);

		Jump();
		while(1);
    }
}

I have modified my .ld file accordingly with app start address 0x08003000, I compared the memory part with the app to the bin file and it's similar, I don't understand where the problem comes from, even though I noticed some differences in the APIs between STM32L0 and G4 series, all the code examples seem to match, or maybe I missed something, can anybody help please?

[FShah.1]

I appreciate your response.

I checked the memory regions where the code is being written and identified an issue with how the data was being written to the flash memory—specifically, little-endian / big-endian issue. After addressing this, the application is now successfully loading and working.

Thanks for being responsive. I will reach out to you for assistance with other parts of the bootloader process during my development.

Thanks again,
FS