How to identify the function/line that triggered a watchdog reset?

Archive Plane 4.1
1

Hi :airplane:,
I’m using ArduPilot 4.1-dev. After a watchdog reset, I would like to know which function or line of code actually triggered the problem.

For example, during my test on experimental hardware (where I intentionally trigger the watchdog with an infinite loop), I get a message like this:

WDG: T27 SL0 FL217 FT3 FA3001E7B0 FTP183 FLR1E000007

What we have tried so far:

  • Reading PC and LR register values and checking them against the .map file, but we couldn’t reliably resolve them to the exact function/line.
  • Attempted to use task.function to get the function address, but in this version it’s a functor and doesn’t give a reliable raw function address.
  • At the moment we can only log task.name.

My question is:

  • What is the recommended or correct way in ArduPilot to determine which function/line caused the watchdog reset?
  • Is there an alternative mechanism besides PC/LR, or does this require using debug symbols or another approach?

Thanks!

2

First, update to 4.6.x, there is no reason to sit on such old version of Ardupilot.

Watchdog reset log message is described on the wiki.

3

I have the same problem in 4.7, it still does not give the error line.