debug_riscv.md

QEMU GDB STUB

To debug user space processes for non-native isa (e.g. riscv), we need to use gdb stub from qemu launch. In order to do this, do the following (inst is the example program to debug):

qemu-riscv64 -g 12345 ./inst &

Separately run gdb for riscv (which should be available in the riscv toolchain):

 /opt/riscv/bin/riscv64-unknown-linux-gnu-gdb inst
 
 #Inside gdb window:
 
 target remote localhost:12345

summary of some useful gdb commands:

info local: to list local variables in the current context.

ptype class/struct: to print out the definition (ptype /o to print all offsets and sizes)

stepi: step through a single instruction

step: step through a line of code