Solved
Problems using the Cache and SCB_DisableDCache in Bootloader before jumping to Application
I have a question about the usage of the Cache in a Bootloader for the STM32H730
I am using:
- STM32H7
- external Flash connected to over OCTOSPI in QSPI Mode
- CMISIS version V5.0.8
- I first run a Bootloader that initialized the OCTOSPI/QSPI and then loads the Application from Flash and jumps to the Application
- I have based my Code on the example for the STMH735G-DK which comes with STM32CubeMX in the Folder "C:\Users\<Username>\STM32Cube\Repository\STM32Cube_FW_H7_V1.9.0\Projects\STM32H750B-DK\Templates\ExtMem_Boot\Src "
- I am using Code generated by CubeMX and the following USER CODE:
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* Enable I-Cache---------------------------------------------------------*/
SCB_EnableICache();
/* Enable D-Cache---------------------------------------------------------*/
SCB_EnableDCache();
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
__enable_irq();
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_DMA_Init();
MX_CRC_Init();
MX_OCTOSPI1_Init();
/* USER CODE BEGIN 2 */
...
*init QSPI*
*set QSPI to memory mapped mode*
...
/* Disable all interrupts */
NVIC->ICER[0] = NVIC->ICER[1] = NVIC->ICER[2] = NVIC->ICER[3] = NVIC->ICER[4] = NVIC->ICER[5] = 0xFFFFFFFF;
SCB_DisableICache();
SCB_DisableDCache(); /************* DOES NOT WORK ***************/
SysTick->CTRL = 0;
*jump to application*
}My Problem:
- Before jumping to the Application I try to call SCB_DisableDCache but this doesn't work (get stuck on function for longer time). The function SCB_DisableICache works fine
- When debugging I get an infinite loop but I have read that this can actually occur while debugging and usually does not.
- Strangely when I call SCB_CleanInvalidateDCache before SCB_DisableDCache AND use an older version of SCB_DisableDCache (here) then it somehow works fine.
My Question:
- Am I missing something like enabling SDRAM or should I disable the DMA or something or interrupts?
- Should I call something like Clean or Invalidate before disabling or a combination thereof?
Thank you for any help!