Proper way to share peripherals between bootloader and UserApp in SBSFU. STM32WB CPU2 getting stuck.

[MBuen.1]

Hello guys, how are you?

Currently i have an interesting problem happening with my STM32WB5M. I have a project that uses SBSFU alongside with a firmware that uses the BLE peripheral with CPU2 and etc. I don't use the BLE loader, i developed i customize USB loader.

The only peripheral that is shared between bootloader and my user app are 3 GPIOS that i use for a RGB led. The thing is, when i share this resource, sometimes CPU2 get stuck in my main firmware and it doesn't initialize. I need my WDT to kick in and reset the firmware, then CPU2 initializes. The only way things work smooth is when i have my debug connected to the board (i tought this very very weird).

If i remove the GPIO from my bootloader, everything works fine with or without my debug probe. I think the CPU2 behaviour on STM32WB5M very strange. CPU2 get stuck sometimes because of a problem that is not even related to it.

Any suggestion about what this could be? Is there something relevant that i should do to "share" this GPIO's between bootloader and main firmware? Anyone would have a hint about why the CPU2 get stuck for somethings that it doesn't have anything to do with it?

Regards,

Matheus

[Remy ISSALYS]

Hello,

It would be interesting to look Flash memory status register (FLASH_SR).

Best Regards,

[MBuen.1]

HI @Remy ISSALYS​ 

I know its been a long time but i'm facing this issue again. Its not relating to the GPIO sharing but my CPU2 is actually hardfaulting again and i would like to know why.

I debugged some FLASH Flags and here's what i have:

FLASH_FLAG_MISERR: 0

FLASH_FLAG_PGSERR: 1 (Is 1 with or without hardfault)

FLASH_FLAG_PGAERR: 1 (Is 1 with or without hardfault)

FLASH_FLAG_SIZERR: 0

FLASH_FLAG_FASTERR: 0

FLASH_FLAG_OPTNV: 0

FLASH_FLAG_RDERR: 0

FLASH_FLAG_OPTVERR: 0

FLASH_FLAG_BSY: 0

FLASH_FLAG_CFGBSY: 1 (When hardfault) 0 (when CPU2 boots normal)

FLASH_FLAG_WRPERR: 0

FLASH_FLAG_PROGERR: 0

FLASH_FLAG_OPERR: 0

FLASH_FLAG_EOP: 0

FLASH_FLAG_PESD: 0

FLASH_FLAG_ECCC: 0

FLASH_FLAG_ECCD: 0

A weird behavior is that if i add a static variable of 4 bytes during compilation, it changes binary size and these CPU2 hardfaults stop happening. Even with that 4 bytes adding to the binary and no more CPU2 hardfaulting happening, both FLASH_FLAG_PGSERR and FLASH_FLAG_PGAERR are still in 1.

Could you give me any hint?

Regards, Matheus