stm32h7 Brownout reset config via FLASH option bytes

[GarrettCarter-eaton]

Hello,

I'm trying to configure the brownout reset on an STM32H7 series. From reading the reference manual, this is done by writing to the flash option bytes:

During power-on, the Brownout reset (BOR) keeps the system under reset until the VDD
supply voltage reaches the specified VBOR threshold.
The VBOR threshold is configured through system option bytes. By default, BOR is OFF. The
following programmable VBOR thresholds can be selected:
• BOR OFF (VBOR0)
• BOR Level 1 (VBOR1)
• BOR Level 2 (VBOR2)
• BOR Level 3 (VBOR3)

I would be pursuing this method to write the bytes via the code:

3. Dedicated option byte reloading by the application
   When the user application successfully modifies the option byte content through the
   embedded Flash memory registers, the non-volatile option bytes are programmed and
   the embedded Flash memory automatically reloads all option bytes to update the
   option registers.

Is there a way to do this in Zephyr?

[erwango]

Unfortunately, this is not yet possible using Zephyr.
This could be acheived by developping something similar to #52980
Otherwise, you can use STM32Cube API directly in your application, cf https://github.com/zephyrproject-rtos/hal_stm32#use-stm32cube-in-your-application