1.9 KiB
1.9 KiB
Setup env
On NixOS:
- Ensure Linux Kernel is the same as you configuration. Otherwise, change linux_dev variable with you kernel variant and change flake.lock nixpkgs with your version.
- Use direnv allow or nix develop to setup shell.
On other distros:
-
With direnv, in .envrc, change line by
use flake .#other -
With nix only, use
nix develop .#other -
Otherwise, you need to setup LINUX_MODULES_FOLDER to linux modules folder of your distro (ex:
/lib/modules/$(uname -r)) in your shell (ex: .bashrc)
make : targets list
- all : Compiling kernel (by default)
- clean : Cleaning build folder
All subfolder is configured to use LINUX_MODULES_FOLDER env variable set by flake develop
How test module
Step 1: Load module
sudo insmod [module_name].ko
Warning: Can fail if secure boot is enabled (see notes about secure boot in below)
Step 2: Check logs
sudo dmesg | tail
Step 3: Unload module
sudo rmmod [module_name].ko
Usefull links
Notes
- Find required headers files
nix shell nixpkgs#bear
cd 01_basic_module/
bear --append --output ../.vscode/compile_commands.json -- make -C $LINUX_MODULES_FOLDER/build M=$PWD modules
Search -I args and -D args
Sign kernel module for testing with secure boot enabled
Prerequisites: Own secure boot keys configured.
Secure boot keys can be found in :
- Fedora :
/etc/pki/akmods - With sbctl :
/var/lib/sbctl
sign-file sha256 $SECUREBOOT_KEYS_PATH/private_key.priv $SECUREBOOT_KEYS_PATH/public_key.der <module_file>.ko
sign-file executable is in /usr/src/kernels/$(uname -r)/scripts
Full example (run as root):
- Fedora
/usr/src/kernels/$(uname -r)/scripts/sign-file sha256 /etc/pki/akmods/private/private_key.priv /etc/pki/akmods/certs/public_key.der <module_file>.ko