STM32F072CBT6 - Entering bootloader from application

[ERODR.1]

I need to enter into the bootloader from my application during runtime.

I found an example code to achieve this for another family series and followed the instructions to determine the specific memory region I should jump to based on my particular MCU.

Below is the resulting code.

typedef void jumpFunc(void);
 
void Bootloader_Start(uint32_t run)
{
  /* Set the address of the entry point to bootloader */
  volatile uint32_t BootAddr = 0x1FFFC800;
 
  /* Set up the jump to booloader address + 4 */
  jumpFunc* SysMemBoot = (jumpFunc*)0x1FFFC804;
 
  if (run == 1)
  {
    // Shut down any task running
    HAL_RCC_DeInit();
    SysTick->CTRL = 0; // reset the SysTick Timer
    SysTick->LOAD = 0;
    SysTick->VAL = 0;
 
    __disable_irq(); // Disable interrupts
 
    /* Set the main stack pointer to the bootloader stack */
    __set_MSP(*(uint32_t *)BootAddr);
 
    SysMemBoot();
 
    while (1);
  }
}

However, this code is not working for me. Executing it always results in a Hard fault interrupt.

What am I missing?

Thanks

[MM..1]

Tutorial - Jump to system memory from software on STM32 - STM32F4 Discovery (stm32f4-discovery.net)

[ERODR.1]

Thank you very much. Very helpful. It looks like I was missing this:

SYSCFG->CFGR1 = 0x01;

So now it doesn't end up in a Hard Fault interrupt. However, I haven't been able to connect using the Flash Loader Demonstrator. I have tried all 3 options for Echo without luck.

Using the STM32CubeProgrammer UART, I get it to connect, but haven't been able to flash anything. It stays with the loading bar ping-ponging without ever increasing from 0%.

 

What am I missing here?

[MM..1]

Try ommit the call to __disable_irq();

[ERODR.1]

Thanks for the follow up. I tried, but if the interrupts are not disabled, for some reason it resets after calling the SysMemBootJump.

[MM..1]

You need disable interrupts one by one before call Bootloader start.

[ERODR.1]

Thanks for your assistance. Based on your input I decided to call the DeInit functions for each and every peripheral currently used by my application as well as disabling all interrupts enabled by my application. I followed the reverse Initialization order while doing it.

Here's the final code tested to work using the Flash Demonstrator app:

void Bootloader_Start(uint32_t run) {
  void (*SysMemBootJump)(void);
 
  /**
   * Set system memory address.
   *
   * For STM32F072, system memory is on 0x1FFF C800
   * For other families, check AN2606 document table 155 with descriptions of memory addresses
   */
  volatile uint32_t addr = 0x1FFFC800;
 
  if (run == 1)
  {
    // De-initialize all peripherals configured for this Application
    HAL_TIM_Base_DeInit(&htim1);
    HAL_TIM_Base_DeInit(&htim6);
    HAL_TIM_Base_DeInit(&htim7);
    HAL_TIM_Base_DeInit(&htim14);
 
    HAL_TIM_PWM_DeInit(&htim15);
    HAL_TIM_Base_DeInit(&htim15);
 
    HAL_CRC_DeInit(&hcrc);
 
    HAL_NVIC_DisableIRQ(DMA1_Channel1_IRQn);
    HAL_NVIC_DisableIRQ(DMA1_Channel2_3_IRQn);
    HAL_NVIC_DisableIRQ(DMA1_Channel4_5_6_7_IRQn);
    HAL_DMA_DeInit(&hdma_memtomem_dma1_channel2);
 
    HAL_PCD_DeInit(&hpcd_USB_FS);
    HAL_UART_DeInit(&huart2);
    HAL_UART_DeInit(&huart1);
    
    HAL_ADC_DeInit(&hadc);
 
    // Disable GPIO interrupts
    HAL_NVIC_DisableIRQ(EXTI0_1_IRQn);
    HAL_NVIC_DisableIRQ(EXTI2_3_IRQn);
    HAL_NVIC_DisableIRQ(EXTI4_15_IRQn);
 
    // Disable RCC, set it to default (after reset) settings
    //       Internal clock, no PLL, etc.
    HAL_RCC_DeInit();
 
    // Disable systick timer and reset it to default values
    SysTick->CTRL = 0;
    SysTick->LOAD = 0;
    SysTick->VAL = 0;
 
    // Disable all interrupts
    __disable_irq();
 
    /**
     * Remap system memory to address 0x0000 0000 in address space
     * For each family registers may be different.
     * Check reference manual for each family.
     *
     * For STM32F4xx, MEMRMP register in SYSCFG is used (bits[1:0])
     * For STM32F0xx, CFGR1 register in SYSCFG is used (bits[1:0])
     * For others, check family reference manual
     */
    //Remap by hand... {
  #if defined(STM32F4)
    SYSCFG->MEMRMP = 0x01;
  #endif
  #if defined(STM32F0)
    SYSCFG->CFGR1 = 0x01;
  #endif
    //} ...or if you use HAL drivers
    //__HAL_SYSCFG_REMAPMEMORY_SYSTEMFLASH(); //Call HAL macro to do this for you
 
    // Set jump memory location for system memory
    // Use address with 4 bytes offset which specifies jump location where program starts
    SysMemBootJump = (void (*)(void)) (*((uint32_t *)(addr + 4)));
 
    /**
     * Set main stack pointer.
     * This step must be done last otherwise local variables in this function
     * don't have proper value since stack pointer is located on different position
     *
     * Set direct address location which specifies stack pointer in SRAM location
     */
    __set_MSP(*(uint32_t *)addr);
 
    /**
     * Call our function to jump to set location
     * This will start system memory execution
     */
    SysMemBootJump();
  }
}