Hi,
I'm a bit stuck. I'm trying to program watermarks for BANK2 (to make the entire bank secure so I can read the whole area using secure alias) for a custom boot-loader.
The code below is executing in secure context from BANK1 (and no bank swap). It runs without error, but after a reset, the option bytes are still unchanged.
Im calling it with (FLASH_BANK_2, 0, 63, 0) as arguments. (63 being the last flash page of a 512KB bank - device is 1MB)
I am pretty sure I misunderstand something.
Kind Regards, Nick
/**
* @brief Configures or Disables Secure Watermark for a specific bank.
* @PArambank: FLASH_BANK_1 or FLASH_BANK_2
* @PAramstart_page: Start page (Set > end_page to disable)
* @PAramlaunch: If SET, triggers a System Reset immediately to apply changes.
* @return true if the operation was successful, false otherwise
* @note to disable WM, set start_page > end_page (eg start_page=1, end_page=0)
*/
bool FLASH_OB_configure_watermarks(uint32_t bank, uint8_t start_page, uint8_t end_page, uint8_t launch)
{
HAL_FLASH_Unlock();
HAL_FLASH_OB_Unlock();
FLASH_OBProgramInitTypeDef obInit = {0};
obInit.OptionType = OPTIONBYTE_WMSEC;
// Set Area Config
if (bank == FLASH_BANK_1)
obInit.WMSecConfig = OB_WMSEC_SECURE_AREA_CONFIG | OB_WMSEC_AREA1;
else if (bank == FLASH_BANK_2)
obInit.WMSecConfig = OB_WMSEC_SECURE_AREA_CONFIG | OB_WMSEC_AREA2;
else {
HAL_FLASH_OB_Lock();
HAL_FLASH_Lock();
return false;
}
obInit.WMSecStartPage = start_page;
obInit.WMSecEndPage = end_page;
// HAL_FLASHEx_OBProgram handles unlock, set, program, and wait (BSY flag)
if (HAL_FLASHEx_OBProgram(&obInit) != HAL_OK)
{
HAL_FLASH_OB_Lock();
HAL_FLASH_Lock();
return false;
}
// 5. Finalize and Reset if requested
if (launch)
{
HAL_FLASH_OB_Launch();
}
HAL_FLASH_OB_Lock();
HAL_FLASH_Lock();
return true;
}
