Stack Tracer

A tool for RTEMS basic stack trace information extraction

What are the dependencies?

The Stack Tracer is written in Python (>= 2.6), and that's your only dependency.

How do I use this script?

You'll need:

• A memory dump from the binary you want to debug
• The stack trace

Obtaining the memory dump

Use objdump to obtain the file. If cross-compiling, you may need to look around for the right binary, eg: powerpc-rtems4.10-objdump. Then run it like this, for example:

objdump -g -S --line-numbers --demangle <binary-file> > memmap

-g will show debugging information, while -S intermixes source code with the disassembly. --line-numbers will make it easier to find the code in the source files. Finally, use --demangle for getting human-readable names from C++ objects.

Stack trace format

The typical exception dump from RTEMS contains information about the type of exception, registers, and a stack trace. This last part is the only one of interest for us:

Stack Trace:
 IP: 0x0012EFC8, LR: 0x0011D450
--^ 0x0001A48C--^ 0x00018F9C--^ 0x000EC690--^ 0x000F0E64--^ 0x000EE044
--^ 0x000E0AB8--^ 0x000E7094--^ 0x00136048--^ 0x00135F6C
Suspending faulting task (0x0A010012)

The script will capture the information between the first line starting with Stack Trace and the one starting with Suspending. The rest of the file is ignored, meaning that you can remove the register information, add comments, or whatever.

Usage

Finally, to use the stack-tracer script:

stack-tracer.py <path-to-memmap> <path-to-stack-trace>