STM32F4xx Rebooting to bootloader when setup to boot to App.

Posted on June 22, 2015 at 23:36

I have a F4 chip that calls ,    The function initiates a system reset request to reset the MCU.

__STATIC_INLINE void NVIC_SystemReset(void)

 

{

 

  __DSB();                                                     /* Ensure all outstanding memory accesses included

 

                                                                  buffered write are completed before reset */

 

  SCB->AIRCR  = ((0x5FA << SCB_AIRCR_VECTKEY_Pos)      |

 

                 (SCB->AIRCR & SCB_AIRCR_PRIGROUP_Msk) |

 

                 SCB_AIRCR_SYSRESETREQ_Msk);                   /* Keep priority group unchanged */

 

  __DSB();                                                     /* Ensure completion of memory access */

 

  while(1);                                                    /* wait until reset */

 

}

with MEMRM = 0. - should map Flash to 0x0000, thus rebooting into my App.

However, the ST bootloader is called at (0 +4) = 0x1fff5163 (stbootloader).

This then trashes the SRAM value that is placed there to provide information to the App for the reason there was a reset. The STbootloader is using the SRAM as scratch pad.

My app is called by the STbloader but the RAM is now full of left overs.

Is my re-maping correct or am I missing something else. (BOOT0 is pulled low).

thanks in advance,

  Garry.