Jump to Freertos application

[Qusai]

Hi all,

I have developed a bootloader for STM32F412, the bootloader works perfectly, however, when I change the user app to be FreeRTOS based, it ceases to work.

I added a blink led in the Hard Fault in both the bootloader and app, but both were not triggered.

Any idea what is going on?

void jump_to_application(void) {
    void (*app_reset_handler)(void);
    uint32_t msp_value = *(volatile uint32_t*)(APP_START_ADDRESS + APP_HEADER_SIZE);
    uint32_t reset_handler_address = *(volatile uint32_t*)(APP_START_ADDRESS + APP_HEADER_SIZE + 4);

    __disable_irq();

    HAL_RCC_DeInit();
    HAL_DeInit();

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


    for (uint32_t i = 0; i < 8; i++)
    {
        NVIC->ICER[i] = 0xFFFFFFFF;
        NVIC->ICPR[i] = 0xFFFFFFFF;
    }

    __enable_irq();

    __set_MSP(msp_value);
    __set_PSP(msp_value);
    __set_CONTROL(0);
    app_reset_handler = (void*)reset_handler_address;
    app_reset_handler();
} 

Thanks in advance.

Regards, 

[Qusai]

Yes. The bootloader is setting the MSP to the app. 

Moreover, I have changed the VECT_TAB_OFFSET on the application side. Still not working.

I suspect, cleaning and de-initialization is the problem here. But not able to figure out where exactly is the problem.

Looks like FreeRTOS is not having a fresh start.

[Qusai]

Hi all,

Few updates:

I did many experiments, unfortunetly none of them worked.

1- Now the FreeRTOS applications start at 0x08040000
2- I use GDB to debug the application, and it shows that the jump was done, but stuck in the hard fault.

3- These are my registers

(gdb) info registers
r0 0x1 1
r1 0xe000e100 -536813312
r2 0x8041e04 134487556
r3 0xbe1fc 778748
r4 0xbe1fd 778749
r5 0x0 0
r6 0x0 0
r7 0x2003ffe0 537133024
r8 0x0 0
r9 0x0 0
r10 0x0 0
r11 0x0 0
r12 0x80000000 -2147483648
sp 0x2003ffe0 0x2003ffe0
lr 0xfffffff9 -7
pc 0x804075c 0x804075c <HardFault_Handler+4>
xPSR 0x1000003 16777219
fpscr 0x0 0
msp 0x2003ffe0 0x2003ffe0
--Type <RET> for more, q to quit, c to continue without paging--
psp 0x0 0x0
primask 0x1 1
basepri 0x0 0
faultmask 0x0 0
control 0x0 0
(gdb) x/x $pc
0x804075c <HardFault_Handler+4>: 0xb480e7fd
(gdb) 

4- The final version of my jump function

void jump_to_application(void) {
void (*app_reset_handler)(void);
uint32_t app_msp = *(volatile uint32_t*)(APP_START_ADDRESS + APP_HEADER_SIZE);
uint32_t reset_handler = *(volatile uint32_t*)(APP_START_ADDRESS + APP_HEADER_SIZE + 4);

__disable_irq();

// Stop SysTick
SysTick->CTRL = 0;
SysTick->LOAD = 0;
SysTick->VAL = 0;

HAL_RCC_DeInit();
HAL_DeInit();

for (uint32_t i = 0; i < 8; i++) {
NVIC->ICER[i] = 0xFFFFFFFF;
NVIC->ICPR[i] = 0xFFFFFFFF;
}

// Optionally clear DMA/USB specific IRQs
__HAL_RCC_USB_OTG_FS_CLK_DISABLE();
HAL_NVIC_DisableIRQ(OTG_FS_IRQn);

__HAL_RCC_DMA1_FORCE_RESET();
__HAL_RCC_DMA1_RELEASE_RESET();

// Set vector table to application
SCB->VTOR = APP_START_ADDRESS + APP_HEADER_SIZE;
__DSB();
__ISB();

__set_MSP(app_msp);
__set_CONTROL(0); // Privileged + use MSP
__DSB();
__ISB();

app_reset_handler = (void (*)(void))reset_handler;
app_reset_handler();
}

5- VTOR value is 0x08040000
6- My linker script is

MEMORY
{
  RAM    (xrw)    : ORIGIN = 0x20000000,   LENGTH = 256K
  FLASH    (rx)    : ORIGIN = 0x8040000,   LENGTH = 128K
}

[KnarfB]

> the jump was done, but stuck in the hard fault

in the next step or somewhere later? Can you find our where? Call stack?

Segger has a nice kb article about fault analysis and a diagnostic fault handler: https://kb.segger.com/Cortex-M_Fault

hth

KnarfB