Installkernel

Below an overview is provided of the available commands in systemd's kernel-install .

(Re-)installs a kernel version. This command is called by sys-kernel/installkernel if the systemd USE flag is enabled.

Uninstalls a kernel version. This command is called by app-admin/eclean-kernel if it is available.

Prints an overview of parameters that will be used when installing a kernel version.

Prints an overview of all installed kernel versions. Meaning all kernel versions for which a directory is present in /lib/modules .

(Re-)installs all kernel versions. Iterates kernel-install add over each kernel for which a vmlinuz file is present in the associated /lib/modules directory.

When the dracut and ukify plugins are enabled (i.e. the dracut and/or ukify USE flags are enabled) they may be skipped at runtime by overriding the default configuration provided by sys-kernel/installkernel at /usr/lib/kernel/install.conf with a custom configuration at /etc/kernel/install.conf . This may be useful on systems that have both the distribution kernels installed and manually configured kernels where the former enforces the enablement of the dracut USE flag but the latter might not require an initramfs at all.

Note that this override will apply to all installed kernels. It is also possible to specify several different configurations and switch between them at runtime using the KERNEL_INSTALL_CONF_ROOT environment variable.

Another method of overriding the default kernel installation is to use the KERNEL_INSTALL_PLUGINS environment variable. When this variable is set, only the specified plugins are run.

In exection order, the install.d plugins

/usr/lib/kernel/install.d/00-00machineid-directory.install

Create the ENTRY_DIR_ABS directory where kernels will be installed for systemd-boot .

Installed by: sys-kernel/installkernel

Executed if: layout=bls and kernel-install command is add

/usr/lib/kernel/install.d/10-copy-prebuilt.install

Copy prebuilt initramfs and Unified Kernel Image to the staging area if they exist. A prebuilt initramfs and Unified Kernel Image are present when the distribution kernels are installed with the generic-uki USE flag enabled.

Installed by: sys-kernel/installkernel

Executed if: kernel-install command is add

/usr/lib/kernel/install.d/35-amd-microcode-systemd.install

Builds an AMD CPU microcode early initramfs if an initramfs generator is used that does not already bundle the CPU microcode.

Installed by: sys-kernel/linux-firmware if the initramfs is enabled.

Executed if: kernel-install command is add and initrd_generator!=dracut .

/usr/lib/kernel/install.d/35-intel-microcode-systemd.install

Builds an Intel CPU microcode early initramfs if an initramfs generator is used that does not already bundle the CPU microcode.

Installed by: sys-firmware/intel-microcode if the initramfs is enabled.

Executed if: kernel-install command is add and initrd_generator!=dracut .

/usr/lib/kernel/install.d/40-dkms.install

Automatically rebuild kernel modules registered with DKMS on kernel installation, and clean them up on kernel removal.

Installed by: sys-kernel/dkms

Executed if: Always

/usr/lib/kernel/install.d/50-depmod.install

Update kernel module dependencies on kernel installation, and cleanup depmod files on kernel removal.

Installed by: sys-apps/systemd or sys-apps/systemd-utils

Executed if: Always

/usr/lib/kernel/install.d/50-dracut.install

Builds a initramfs or Unified Kernel Image (UKI) with dracut . A initramfs is built if initrd_generator=dracut . If uki_generator=dracut and not layout=bls then an UKI is built, this will be the case if the uki USE flag is enabled on sys-kernel/installkernel but the ukify USE flag is disabled.

Installed by: sys-kernel/dracut

Executed if: kernel-install command is add and initrd_generator=dracut (USE dracut ) or uki_generator=dracut (USE dracut and USE uki but not USE ukify ). Also executed if layout is set to an unsupported value.

/usr/lib/kernel/install.d/51-dracut-rescue.install

Build a dracut rescue initramfs image, currently not supported in combination with Unified Kernel Images.

Installed by: sys-kernel/dracut

Executed if: kernel-install command is add and dracut_rescue_image=yes in any dracut configuration file

/usr/lib/kernel/install.d/52-ugrd.install

Builds an initramfs using the ugrd initramfs generator.

Installed by: sys-kernel/ugrd

Executed if: kernel-install command is add and initrd_generator=ugrd .

/usr/lib/kernel/install.d/85-check-diskspace.install

Checks if there is enough disk space on the target partition to install the kernel.

Installed by: sys-kernel/installkernel

Executed if: Always

/usr/lib/kernel/install.d/90-compat.install

Install the staged (unified) kernel image (and initramfs) in a backwards compatibility layout similar to Debian's installkernel. And clean them up when the kernel is removed.

Installed by: sys-kernel/installkernel

Executed if: layout=compat or layout=grub

/usr/lib/kernel/install.d/90-loaderentry.install

Install the staged kernel image (and initramfs) in systemd-boot 's native format and register the new kernel with systemd-boot. And clean up these files when the kernel is removed.

Installed by: sys-apps/systemd or sys-apps/systemd-utils

Executed if: layout=bls

/usr/lib/kernel/install.d/90-runlilo.install

Update LILO 's configuration.

Installed by: sys-boot/lilo

Executed if: Always

/usr/lib/kernel/install.d/90-uki-copy.install

Copy the staged Unified Kernel Image to the EFI/Linux directory on the EFI System Partition . And clean it up on kernel removal. This plugin script will exit fatally if there is no UKI to install.

Installed by: sys-apps/systemd or sys-apps/systemd-utils

Executed if: layout=uki

/usr/lib/kernel/install.d/90-zz-update-static.install

Update version-less files or symlinks if they exist at the target location.

Installed by: sys-kernel/installkernel

Executed if: kernel-install command is add and layout=uki or layout=efistub or layout=compat or layout=grub

/usr/lib/kernel/install.d/91-grub-mkconfig.install

Update GRUB 's configuration by running grub-mkconfig . Automatically finds Unified Kernel Images in the EFI/Linux directory on the EFI System Partition . Which grub.cfg to use is overridable with the GRUB_CFG environment variable.

Installed by: sys-kernel/installkernel with grub

Executed if: layout=uki or layout=grub

/usr/lib/kernel/install.d/91-sbctl.install

Sign the installed (unified) kernel image with sbctl's keys and add it to the sbctl database. Upon kernel removal it is removed from the database. The plugin script will exit fatally if sbctl's keys are not already setup. Note that both dracut and ukify are capable of signing generated unified kernel images by themselves and distribution kernels can already be signed using the secureboot USE flag. This plugin may be useful however for manually compiled kernels.

Installed by: app-crypt/sbctl

Executed if: Always

/usr/lib/kernel/install.d/95-efistub-kernel-bootcfg.install

Adds and removes UEFI boot entries on kernel installation or removal using kernel-bootcfg from app-emulation/virt-firmware .

Installed by: sys-kernel/installkernel with USE efistub

Executed if: layout=efistub or layout=uki

/usr/lib/kernel/install.d/95-refind-copy-icon.install

Install a Gentoo icon for the rEFInd bootloader alongside the (unified) kernel image. Which icon file to use is overridable with the REFIND_ICON environment variable.

Installed by: sys-kernel/installkernel with USE refind

Executed if: layout=uki or layout=compat

/usr/lib/kernel/install.d/99-write-log.install

Appends last installed kernel to /var/log/installkernel.log and updates state file at /var/lib/installkernel .

Installed by: sys-kernel/installkernel

Executed if: Always

The code boxes below maps possible sys-kernel/installkernel USE configurations to how the kernel and related files will be installed. It may be useful for users who are unsure which USE configuration suits their setup. ESP refers to the mount point of the EFI System Partition which may be /efi , /boot , /boot/efi or {{Path|/boot/EFI}. generic-uki refers to the generic-uki USE flag on the Distribution kernels .

Plain kernel image installation.

Plain kernel image installation, with initramfs generated by dracut.

Plain kernel image installation, initramfs is pregenerated by the distribution kernel package.

Unified kernel image installation, uki is generated with ukify and is then installed to the ESP.

Unified kernel image installation, uki is generated with dracut and is then installed to the ESP.

/boot/grub/grub.cfg
</div>

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/boot/grub/grub.cfg
 
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/boot/grub/grub.cfg
 
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

systemd-boot 使用時のレイアウト

/${ESP}/gentoo/x.y.z-gentoo-dist/linux
/${ESP}/loader/entries/gentoo-x.y.z-gentoo-dist.conf

/${ESP}/gentoo/x.y.z-gentoo-dist/initrd
/${ESP}/gentoo/x.y.z-gentoo-dist/linux
/${ESP}/loader/entries/gentoo-x.y.z-gentoo-dist.conf

/${ESP}/gentoo/x.y.z-gentoo-dist/initrd
/${ESP}/gentoo/x.y.z-gentoo-dist/linux
/${ESP}/loader/entries/gentoo-x.y.z-gentoo-dist.conf

Unified カーネルイメージ使用時のレイアウト

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

rEFInd 使用時のレイアウト

/boot/kernel-x.y.z-gentoo-dist
/boot/kernel-x.y.z-gentoo-dist.png

/boot/initramfs-x.y.z-gentoo-dist.img
/boot/kernel-x.y.z-gentoo-dist
/boot/kernel-x.y.z-gentoo-dist.png

/boot/initramfs-x.y.z-gentoo-dist.img
/boot/kernel-x.y.z-gentoo-dist
/boot/kernel-x.y.z-gentoo-dist.png

Unified カーネルイメージ使用時のレイアウト

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.png

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.png

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.png

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.png

GRUB/systemd-boot/rEFInd (またはその他のブートローダ) 不使用時のレイアウト

/boot/kernel-x.y.z-gentoo-dist

/boot/initramfs-x.y.z-gentoo-dist.img
/boot/kernel-x.y.z-gentoo-dist

/boot/initramfs-x.y.z-gentoo-dist.img
/boot/kernel-x.y.z-gentoo-dist

Unified カーネルイメージ使用時のレイアウト

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

伝統的な installkernel (USE=-systemd)

GRUB 使用時のレイアウト

/boot/System.map-x.y.z-gentoo-dist
/boot/config-x.y.z-gentoo-dist
/boot/grub/grub.cfg
/boot/vmlinuz-x.y.z-gentoo-dist

/boot/System.map-x.y.z-gentoo-dist
/boot/config-x.y.z-gentoo-dist
/boot/grub/grub.cfg
/boot/initramfs-x.y.z-gentoo-dist.img
/boot/vmlinuz-x.y.z-gentoo-dist

/boot/System.map-x.y.z-gentoo-dist
/boot/config-x.y.z-gentoo-dist
/boot/grub/grub.cfg
/boot/initramfs-x.y.z-gentoo-dist.img
/boot/vmlinuz-x.y.z-gentoo-dist

Unified カーネルイメージ使用時のレイアウト

/boot/grub/grub.cfg
 
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/boot/grub/grub.cfg
 
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/boot/grub/grub.cfg
 
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/boot/grub/grub.cfg
 
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

rEFInd 使用時のレイアウト

/boot/System.map-x.y.z-gentoo-dist
/boot/config-x.y.z-gentoo-dist
/boot/vmlinuz-x.y.z-gentoo-dist
/boot/vmlinuz-x.y.z-gentoo-dist.png

/boot/System.map-x.y.z-gentoo-dist
/boot/config-x.y.z-gentoo-dist
/boot/initramfs-x.y.z-gentoo-dist.img
/boot/vmlinuz-x.y.z-gentoo-dist
/boot/vmlinuz-x.y.z-gentoo-dist.png

/boot/System.map-x.y.z-gentoo-dist
/boot/config-x.y.z-gentoo-dist
/boot/initramfs-x.y.z-gentoo-dist.img
/boot/vmlinuz-x.y.z-gentoo-dist
/boot/vmlinuz-x.y.z-gentoo-dist.png

Unified カーネルイメージ使用時のレイアウト

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.png

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.png

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.png

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi
/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.png

GRUB/systemd-boot/rEFInd (またはその他のブートローダ) 不使用時のレイアウト

/boot/System.map-x.y.z-gentoo-dist
/boot/config-x.y.z-gentoo-dist
/boot/vmlinuz-x.y.z-gentoo-dist

/boot/System.map-x.y.z-gentoo-dist
/boot/config-x.y.z-gentoo-dist
/boot/initramfs-x.y.z-gentoo-dist.img
/boot/vmlinuz-x.y.z-gentoo-dist

/boot/System.map-x.y.z-gentoo-dist
/boot/config-x.y.z-gentoo-dist
/boot/initramfs-x.y.z-gentoo-dist.img
/boot/vmlinuz-x.y.z-gentoo-dist

Unified カーネルイメージ使用時のレイアウト

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

/${ESP}/EFI/Linux/gentoo-x.y.z-gentoo-dist.efi

関連項目

• GRUB — 多くのシステムアーキテクチャ上で、様々な ファイルシステム からカーネルをロードすることができる、マルチブート 2 次 ブートローダ です。
• systemd-boot — a minimal UEFI boot manager.
• EFI stub — EFI スタブカーネル、つまり、UEFI から直接実行可能なカーネルについて記載します。
• initramfs — is used to prepare Linux systems during boot before the init process starts.
• Project:Distribution_Kernel — aims to maintain sys-kernel/*-kernel packages.