Hi all, I am thinking of using the STM32H747XI for a project I'm working on. This particular chip has a CortexM7 and a Cortex M4. The chips access the same memory map and can access and even share the same peripherals.
Part of the problem, however, is that NuttX resets many registers/peripherals on boot. This is fine for when the M7 boots, but when the M4 boots, resetting the RCC registers will ruin all the initialization work the M7 has already done. Temporarily, I added a config variable to disable the clock reset on boot, but that's not the only place I'll need to disable logic. So I have 2 questions: 1. Does anyone have any suggestions or comments for how to disable some of the standard bring-up logic such as rcc_reset() or other peripheral resets? I can add CONFIG options, but I'm afraid of how many options willl wind up needing to be added and it feels a little hacky. 2. Organizationally, how to handle the 2 cores? Currently, I've added an option to the STM32H747I-Disco board that allows you to specify which core you are using. Really all that does is switch which flash bank you are targeting by switching the linker script. The M4 and M7 can share instructions as long as double FPU is disabled for the M4. Does a switch at the board level make sense? Or should this switch be at the arch level since it's technically the processor that's got the 2 cores? Thanks! -Anthony
