Hard Fault calling SCB_DisableDCache() or SCB_CleanDCache()

Question

Hi there.As usual, I'm there with a new issue... :grinning_face_with_sweat:Developing a custom Bootloader, I'm trying to disable both Instruction and Data chaches.As I read on the ST AN4839, before deactivating the DCache, I would also Clean it.No problem with the Icache, but I'm experiencing Hard Fault adding Dcache cleaning and/or disabling.void DoJump2App(u32t uiAPPaddress)
{
	/*.-.-.| Local Varibles |.-.-.*/

/*.-.-.| Execution |.-.-.*/
	SCB_DisableICache();
	SCB_CleanDCache();
	SCB_DisableDCache();
	
	uiResetKey = RESET_DRV_BTL_KEY;							// Clear RESET key
	pJump2App = (pFunction)(*(volatile u32t*)(uiAPPaddress + 4));

__set_MSP(*(volatile u32t*)uiAPPaddress);				// Initialize user application's Stack Pointer
	__ISB();												// Instruction Synchronization Barrier
	pJump2App();
}Above the example of the routine I'm testing.To be noticed that:This routine is called just once in the main program after peripheral initialization (inside a more complex wrapping function)Cache memories are enabled in the main (as usual)If I move SCB_DisableDCache() and/or SCB_CleanDCache() functions call directly in the main program, prior this function, there is no problem...What I'm mistaking?Context: I'm working on a custom board quipped with an STM32H755BIT MCU, using CubeIDE 1.13.2, CubeMX6.9.2 and Firmware package STM32Cube FW_H7 V1.11.0Thanks in advance for your support!iTTy

STea · Answer

Hello @iTTy ,You can try to add some memory barrier and instruction barrier instructions here is an example form which you can inspire:void DoJump2App(uint32_t uiAPPaddress){ /*.-.-.| Local Variables |.-.-.*/ typedef void (*pFunction)(void); pFunction pJump2App; /*.-.-.| Execution |.-.-.*/ __disable_irq(); // Disable interrupts // Disable ICache SCB_DisableICache(); // Clean and disable DCache SCB_CleanDCache(); __DSB(); // Data Synchronization Barrier SCB_DisableDCache(); __DSB(); // Data Synchronization Barrier __ISB(); // Instruction Synchronization Barrier // Clear RESET key uiResetKey = RESET_DRV_BTL_KEY; // Set the jump address pJump2App = (pFunction)(*(volatile uint32_t*)(uiAPPaddress + 4)); // Initialize user application's Stack Pointer __set_MSP(*(volatile uint32_t*)uiAPPaddress); // Instruction Synchronization Barrier __ISB(); // Jump to application pJump2App();} check also this article for tips on Hardfault debugging.Regards

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