Hello,
I’m working with an STM32MP255 and want to access GPIOs from the Cortex-M33 coprocessor (not from the A-core/Linux side). I’m trying to understand the correct workflow and configuration steps so M33 firmware can drive/read GPIO pins. Specifically:
1. Are there any reference examples or official documentation showing how to assign GPIO pins to the Cortex-M33 coprocessor (M33 execution context) using device tree and RIFSC configuration on STM32MP255 / STM32MP2 devices?
2. Is there a step-by-step for RIFSC/firewall, resource assignment, or device tree overlays that shows how to move ownership of a GPIO from the Linux/A-core domain to the M33?
3. I’m using STM32CubeIDE to build the M33 firmware. Under SystemCore → GPIO there is no checkbox to select the Cortex-M33 execution context for a GPIO. Is that expected? If so, how should I configure ownership (is it a device tree / RIFSC setting rather than a CubeIDE option)?
