STM32H563: Unable to detect DBGMCU Mailbox ST

[gh_rcl]

Hi,

On a custom board I get the following message: Unable to detect DBGMCU Mailbox ST

when i run regression.bat.

I did several test (provisionning, regression) before and i didn't notice any issues

DA with password and TZ disabled

A program is running on my custom board but i cannot come back to OPEN state with the regression script.

I tried with HRST wired to my STLINK with no success ...

Any ideas ?

Regards

[Jocelyn RICARD]

Hello @gh_rcl ,

So I understand the regression script was working before while you were in provisioning state.

Do you know in which state you changed the device ?

If you have set it to LOCKED then this behaviour is normal.

Best regards

Jocelyn

[gh_rcl]

Thanks for your feedback.

I set the state to "CLOSED"

Do you know if i can reflash a new firmware from the internal bootloader via an UART even if the STM32H563 is CLOSED or LOCKED ? 

Regards,

[Jocelyn RICARD]

Hello @gh_rcl ,

when device is closed you will boot to flash unconditionally.

There is a possibility to jump to bootloader from application but only when you have enabled TrustZone. But this is not recommended.

Your embedded firmware can trigger a regression by changing product_state if it is running in HDP Level 1.

Now, in your case I would double check the reset connection, checking that reset is well propagated to the chip when Debug Authentication is launched.

Best regards

Jocelyn

[gh_rcl]

Hi Jocelyn,

Thanks for your feedback.

I succeeded to unbrick my board by wiring HW reset.

However when i try to flash my program by following the recipe below: (https://wiki.st.com/stm32mcu/wiki/File:SECURITY_PROVISIONING_Script_Image_Flashing.png)
it doesn't work...

When i program the same binary without "Debug authentication", it works !!!

However the program seems to run normally (led blinking task is ok) but the other tasks are not working (tftp download)

In the programming step (DA provisionning), do we need to reset the board after programming ?

Any idea ?

Regards,

[gh_rcl]

Jocelyn,

I found the problem.

Indeed in my code i check the product state value, but i had forgotten to switch from OPEN to CLOSED.

Just one question : If i want to use debug authentication, i need to wired nRST to the programming connector ?

Thanks again for your support.