easylkb is a simple script designed to make Linux Kernel Debugging easier and more accessible.
easylkb is best run on a bare metal Linux system. You need the following things installed in order to use it:
- python3
- curl
- gcc
- make
- qemu
You can clone this repo and run from the easylkb directory, or you can install with pip (not yet lol).
pip install easylkb
Build a specific mainline kernel version:
easylkb -k 6.2
Build some other kernel in a directory:
easylkb -p path/to/linux/
Command line flags are tied to specific parts of the build process.
To (d)ownload, (c)onfigure, and co(m)pile a kernel
easylkb -k 6.2 -dcm
To build a Debian (i)mage from this kernel
easylkb -k 6.2 -i
To (r)un the generated image:
easylkb -k 6.2 -r
Combine all of these steps into one:
easylkb -k 6.2 -a
When it's running, it will run qemu with the Debian image and expose ssh and GDB debugging features accessible via localhost.
The image, keys, and run script are stored in the img/ directory within the kernel source.
You can ssh into your image like so:
ssh root@localhost -p 10021 -i ~/kernel/linux-6.2/img/bullseye.id_rsa
The default login for the resulting image is the user "root" with no password.
This is an example ssh config entry for the resulting image, which you can add to your ~/.ssh/config file.
Host linux62
HostName localhost
User root
Port 10021
IdentityFile ~/kernel/linux-6.2/img/bullseye.id_rsa
StrictHostKeyChecking no
Now you can ssh into your kernel by doing:
ssh linux62
You can scp files by doing
scp myfile.bin linux62:
To debug the kernel, you need $KERNEL_DIR/scripts/gdb/vmlinux-gdb.py
Add this to your ~/.gdbinit file if you want to debug this kernel, changing the path to the kernel source you're working with.
add-auto-load-safe-path /home/user/kernel/linux-6.2/scripts/gdb/vmlinux-gdb.py
Now to debug just do
cd /path/to/your/kernel/
gdb ./vmlinux
Once you're in gdb just do this:
(gdb) lx-symbols
(gdb) target remote :1234
Wow! You're debugging the kernel you just built, pretty neat.
For more info on kernel debugging with gdb: