STM32 boot option bytes

kvk · April 1, 2024, 11:50pm

Hi

I have a board where I am using the STM32G051.

I have code running on the eval board. When I work in the target, I get a hard fault.

I think it is since I have not tied the BOOT0 pin down, and I am using SWCLK on the same pin (PA14).

In a google search this is mentioned:

I am using STM32cube IDE. Anyone know how to set the Option bytes to run from flash and ignore the BOOT0 pin?

Thanks

Klaus

manny · April 2, 2024, 12:37am

Section 2.5 references FLASH_SECR register

Take a look at section 3.7.21

manny · April 2, 2024, 12:55am

if you’d like to use the HAL driver:

github.com

STMicroelectronics/stm32g0xx_hal_driver/blob/master/Src/stm32g0xx_hal_flash_ex.c#L1215


      
            * @param  BootEntry  specifies if boot scheme is forced to Flash (System or user) or not
            *         This parameter can be one of the following values:
            *           @arg @ref OB_BOOT_ENTRY_FORCED_NONE No boot entry forced
            *           @arg @ref OB_BOOT_ENTRY_FORCED_FLASH Flash selected as unique entry boot
            * @param  SecSize specifies number of pages to protect as securable memory area, starting from
            *         beginning of Bank1 (page 0).
            * @param  SecSize2 specifies number of pages to protect as securable memory area, starting from
            *         beginning of Bank2 (page 0).
            * @retval None
            */
          static void FLASH_OB_SecMemConfig(uint32_t BootEntry, uint32_t SecSize, uint32_t SecSize2)
          {
            uint32_t secmem;
          
            /* Check the parameters */
            assert_param(IS_OB_SEC_BOOT_LOCK(BootEntry));
            assert_param(IS_OB_SEC_SIZE(SecSize));
          
            if ((FLASH_BANK_NB == 2U))
            {
              assert_param(IS_OB_SEC_SIZE(SecSize2));

kvk · April 3, 2024, 11:38pm

Many thanks for the help, Manny.

I eventually found that the hard fault was due to something else than the option bytes.

manny · April 4, 2024, 4:05am

Hi Klaus,
What was it? RCC initialization issue?

Manny

kvk · April 4, 2024, 6:30am

Accessing a peripheral that did not exist, it seems. Downgraded the project to a smaller controller, and it worked (could also be a memory issue)