5. gdbserver
Step debug userland processes to understand how they are talking to the kernel.
First build gdbserver into the root filesystem:
./build-buildroot --config 'BR2_PACKAGE_GDB=y'
Then on guest, to debug userland/linux/rand_check.c:
./gdbserver.sh ./c/command_line_arguments.out asdf qwer
Source: rootfs_overlay/lkmc/gdbserver.sh.
And on host:
./run-gdb --gdbserver --userland userland/c/command_line_arguments.c main
or alternatively with the path to the executable itself:
./run --gdbserver --userland "$(./getvar userland_build_dir)/c/command_line_arguments.out"