genkernel

Automatically compile and install a generic kernel

$ sudo genkernel all

$ sudo genkernel [bzImage|initramfs|kernel|ramdisk]

$ sudo genkernel --menuconfig all

$ sudo genkernel --kernname=[custom_name] all

$ sudo genkernel --kerneldir=[path/to/directory] all

genkernel [options] {all|linux|initramfs|clean|help} [kernel-args...] [-- --kernel-config=/path/to/.config]

--menuconfig
    Invoke interactive kernel menuconfig before build

--oldconfig
    Use existing .config with defaults for new options

--gconfig
    Use graphical gconfig interface

--install
    Install kernel and modules after building

--no-clean
    Skip kernel tree cleanup before compile

--kerneldir=PATH
    Specify kernel source directory (default: /usr/src/linux)

--config=PATH
    Use alternate genkernel.conf

--makeopts=OPTS
    Pass extra options to make

--bootdir=PATH
    Set /boot directory

--zimage
    Build zImage instead of bzImage (some arches)

--symlink
    Create symlink to latest kernel image

--firmware
    Include all firmware modules

genkernel is a Gentoo Linux utility that automates building, compiling, and installing custom Linux kernels with matching initramfs images. It simplifies kernel management by handling configuration, module compilation, firmware inclusion, and bootloader updates.

Ideal for Gentoo users, it supports complex setups like LVM, RAID, encryption (LUKS), and filesystems (Btrfs, XFS). Run genkernel all for a full build-install cycle from kernel sources in /usr/src/linux. Options allow customization, such as interactive config via --menuconfig or using existing configs with --oldconfig.

genkernel reads /etc/genkernel.conf for defaults like CFLAGS, MAKEOPTS, and feature modules. It generates initramfs-genkernel-arch.img and symlinks kernels to /boot. Post-build, update GRUB or other bootloaders manually.

This tool reduces errors in manual kernel workflows, supports cross-compilation, and integrates with Portage for easy source management via emerge sys-kernel/gentoo-sources.

Gentoo-specific; requires kernel sources and Portage. May overwrite manual configs. Always verify bootloader after genkernel all. Cross-compiles need TOOLCHAIN_PREFIX.

Edit /etc/genkernel.conf for defaults like LUKS=1, RAID=1, MODULES_LOAD=(module1 module2).

all: full build+install; linux: kernel only; initramfs: image only; clean: cleanup.

Developed for Gentoo Linux around 2004-2005 to ease kernel compilation amid frequent updates. Evolved with initramfs support post-2.6 kernels; now at version 4.x with Btrfs, ZFS modules.

dracut(8), mkinitcpio(8), update-initramfs(8), depmod(8)