Debugging user-code on xv6 with gdb

Question

I'm doing an OS class that's based on xv6 and I wrote a program that needs to run on it.

I know that I can debug kernel code with make qemu-gdb but I'm not sure how to debug my own user program.

Lets say I want to debug cat, how would I go about doing that?

Thanks

P.S. isn't there an xv6 tag? should this question even go here?

Answer 1

From the xv6 top-level dir:

1. Run the emulator in debug mode (assuming no X11): make qemu-nox-gdb

2. In other terminal just run the debugger loading the kernel symbols with: gdb kernel This is important, otherwise the debugger will be confused between kernel and and user program symbols, for example main()

3. From the gdb interface run: (gdb) target remote localhost:26000 where 26000 is the TCP port that the step #1 report at the end (this might change).

4. Load the user exec with (gdb)file user_program

5. Place a breakpoint (gdb) break main and continue with (gdb) continue

6. etc...

Answer 2

file cat, break main, continue

semi reference running and debugging xv6