Add minimal watchdog functionnalities to the H7

[lvanasse]

This add the functionnalities to use the independant watchdog of the H743 inside PX4 modules. This allow to reset the PX4 FMU CPU when there's a module that get stuck.

Solved Problem

I had an ongoing issue with a closed source module that was doing run-away CPU usage (using all the available CPU). By adding the independent watchdog to the H7, this allows me to configure the watchdog inside my module and if it starts behaving incorrectly, the watchdog will reset the board. I understand this is an improper solution, but it is valuable for us.

Fixes internal issue. But I've post in one of the Q&A session about it, please see: https://discuss.px4.io/t/px4-sync-q-a-july-10-2024/39614/2?u=ludovicvanasse

Solution

• Add the necessary files to utilise the IWDG in the H7.

Changelog Entry

For release notes:

Feature: Add minimal iwdg functionnalities to the FMU Processor (H7) for the Pixhawk 6C 

Alternatives

We could finding the bug inside my module (?) 🥲

Test coverage

• I did test it on my own, here's a GIF of it:
  

Context

The forum post and the GIF gives a bit of context. But more than happy to provide more.

[lvanasse]

I just notice that the commits are not authored by my account. I'll try to fix it.