ikconfig

This is a Rust re-implementation of extract-ikconfig from Linux kernel, to extract the .config file from a kernel image.

This will only work when the kernel was compiled with CONFIG_IKCONFIG, which is enabled on Arch Linux by default but not on Ubuntu.

It supports all 7 compression algorithms in Linux kernel:

• CONFIG_KERNEL_GZIP
• CONFIG_KERNEL_BZIP2
• CONFIG_KERNEL_LZMA
• CONFIG_KERNEL_XZ
• CONFIG_KERNEL_LZO
• CONFIG_KERNEL_LZ4
• CONFIG_KERNEL_ZSTD

Prerequisites

This crate requires liblzma being present in the system before installation and pkg-config is used to find liblzma and other libraries during the build.

Arch Linux

sudo pacman -S pkgconf xz

Ubuntu

sudo apt install pkg-config liblzma-dev

Please refer to system manuals for other distributions. You can check if liblzma is installed by running:

$ pkg-config --libs liblzma

And it should output -llzma if liblzma is correctly installed.

Install

This crate has been published onto crates.io, so you can use the following command to install ikconfig executable in ~/.cargo/bin directory:

cargo install ikconfig

Usage

ikconfig <path_of_kernel_image>

The extracted config file will be printed on standard output as the original shell script does. Please use output redirection to save as a file if needed, e.g.:

ikconfig /boot/vmlinuz-linux > .config

Tests

The integration tests in this repository will compare the execution time of ikconfig and extract-ikconfig shell script. The latter uses the commands on system to accomplish corresponding decompression, most of which are pre-installed except lzop(1), so you might need to install it before running cargo test.

Arch Linux

sudo pacman -S lzop

Ubuntu

sudo apt install lzop

License

This project is licensed under GPL-3.0 or MIT license.