I am still learning about debugging C using python within gdb (arm-none-eabi-gdb, in my case). I am trying to use this facility to get thread information of a real-time OS running on ARM Cortex-M. Reading some OS structures, I can access the thread control blocks of the OS. I know the PC and the SP of each thread. How can I use gdb's Python to dump the threads' backtrace. Is there a generic API that can traverse the stack when given PC and SP?
I have read https://sourceware.org/gdb/current/onlinedocs/gdb/Unwinding-Frames-in-Python.html#Unwinding-Frames-in-Python and I feel there might be a way to achieve that but I need some help.
Also, if possible, can I make gdb aware of the different threads of the OS? This link:
https://sourceware.org/gdb/current/onlinedocs/gdb/Threads-In-Python.html#Threads-In-Python touches on threads but relies on OS info. Can these be overload with what I know about the different OS threads from their respective control blocks?
After some more reading and trying to make use of old debugger knowledge that I have accumulated over the years, I managed to get this working. It lacks optimization but for now, I'm very please. This can be considered a poor-man's debugger making use of GDB's Python support to track the active threads in the system. It's generic, I assume, but the implementation targeted RTX (Keil's OS). It worked on Cortex-M0. It may need some tweaking to fit other operating systems or different cores.
The main idea:
The script can be found here:
It was a very good exercise to explore the power of GDB's Python extension!