LPC4357 FreeRTOS cause fault after SoftReset

[alessioschisano]

Hi, 

I have a little problem on a LPC4357 running FreeRTOS 8.2.

Problem is that when I execute a SoftReset MCU restart but during EMC SDRAM initialization it stop working, with loss of LPC-Link 2 debugger control. So, no HardFault, olny stop ecxecution.

The function where CPU stop working is this: SystemInit_ExtMemCtl (void)

From some research I think it should be a Stack Pointer problem, but not sure about that, FreeRTOS Heap in my application is located in External SDRAM, and if I call the SoftReset routine before FreeRTOS start no problem with EMC init.

If I made a SoftReset after these instruction, system stop working during initialization in the Reset ISR. 

The same code work right with a LPC4088 in the same condition (Ext RAM FreeRTOS Heap, same reset routine) with no problem.

In LPC 4357 I'm working only with Core M4

Thanks in advance to anyone who could help me.

[alessioschisano · Accepted solution]

Fixed it! Below the solution, hope it helps others in future. Simply need to relocate the MSP and PSP register before resetting:

void (*user_code_entry)(void);
unsigned *p;

void SoftReset(void){

   __disable_irq();

   SysTick->CTRL = 0; // Disable System timer

   // disable and clear pending IRQs
   for (uint32_t i = 0; i < 8; i++)
   {
      NVIC->ICER[i] = 0xFFFFFFFF; // disable IRQ
      NVIC->ICPR[i] = 0xFFFFFFFF; // clear pending IRQ
   }

   // Barriers
   __DSB(); // data synchronization barrier
   __ISB(); // instruction synchronization barrier

   SCB->VTOR = 0x1A010000 & 0x1FFFFF80;

   // Rebase the Stack Pointer
   __set_MSP(*(uint32_t *) (0x1A010000 & 0x1FFFFF80));
   __set_PSP(*(uint32_t *) (0x1A010000 & 0x1FFFFF80));

   p = (unsigned *)(0x1A010000 + 4);
   user_code_entry = (void *) *p;

   __DSB();
   __ISB();

   user_code_entry();
}