Related project for inspiration

[matthijskooijman]

I just came across this project, which looks good! A while ago, I wrote something with a similar goal, which might be interesting to you: https://github.com/3devo/AvrMemoryAnalyzer

My project is not just about dumping the return value, but a full stack dump. The focus of that project is a tool which can analyze a stack dump and piece together a (not always completely accurate) stacktrace, but it also contains some Arduino code to make the stackdump, which operates in the same area as your code (but is a lot more rough and more of an example, and doesn't have this nice EEPROM saving of reports).

Looking at your code, particular ideas you could borrow from mine are:

• Using __AVR_3_BYTE_PC__ to detect 2 vs 3 byte program counter.
• Using the get_return_address() builtin (or some custom assembler for 3-byte PC units), which I think is more robust against the SP being modified, and doesn't need the ISR to be naked: https://github.com/3devo/AvrMemoryAnalyzer/blob/master/dump_memory.h#L101-L133

[PaulMartinsen]

I like the idea of using the built-ins to locate the SP and program counter size. I'll look at incorporating those when I get a chance. That would make the crash monitor more useful for other devices.

Thanks.