kernel-installsystemdkernel-install8kernel-installAdd and remove kernel and initramfs images to and from /bootkernel-installCOMMANDOPTIONSKERNEL-VERSIONKERNEL-IMAGEINITRD-FILEDescriptionkernel-install is used to install and remove kernel and initramfs images to and
from the boot loader partition, referred to as $BOOT here. It will usually be one of
/boot/, /efi/, or /boot/efi/, see below.
kernel-install will execute the files
located in the directory /usr/lib/kernel/install.d/
and the local administration directory /etc/kernel/install.d/.
All files are collectively sorted and executed in lexical order, regardless of the directory in
which they live. However, files with identical filenames replace each other.
Files in /etc/kernel/install.d/ take precedence over files with the same name
in /usr/lib/kernel/install.d/. This can be used to override a system-supplied
executables with a local file if needed; a symbolic link in /etc/kernel/install.d/
with the same name as an executable in /usr/lib/kernel/install.d/,
pointing to /dev/null, disables the executable entirely. Executables must have the
extension .install; other extensions are ignored.An executable should return 0 on success. It may also
return 77 to cause the whole operation to terminate
(executables later in lexical order will be skipped).CommandsThe following commands are understood:add KERNEL-VERSIONKERNEL-IMAGE [INITRD-FILE ...]This command expects a kernel version string and a path to a kernel image file as
arguments. kernel-install calls the executables from
/usr/lib/kernel/install.d/*.install and
/etc/kernel/install.d/*.install with the following arguments:
add KERNEL-VERSION$BOOT/MACHINE-ID/KERNEL-VERSION/KERNEL-IMAGE [INITRD-FILE ...]Three default plugins execute the following operations in this case:00-entry-directory.install creates the directory
$BOOT/MACHINE-ID/KERNEL-VERSION/
if $BOOT/MACHINE-ID/ already exists.
50-depmod.install runs
depmod8 for the
KERNEL-VERSION.90-loaderentry.install copies KERNEL-IMAGE
to
$BOOT/MACHINE-ID/KERNEL-VERSION/linux.
If an INITRD-FILE is provided, it also copies INITRD-FILE
to
$BOOT/MACHINE-ID/KERNEL_VERSION/INITRD-FILE.
It also creates a boot loader entry according to the Boot Loader Specification in
$BOOT/loader/entries/MACHINE-ID-KERNEL-VERSION.conf.
The title of the entry is the PRETTY_NAME parameter specified in
/etc/os-release or /usr/lib/os-release (if the former is
missing), or "Linux KERNEL-VERSION", if unset.If the entry directory
$BOOT/MACHINE-ID/KERNEL-VERSION/
does not exist, this plugin does nothing.remove KERNEL-VERSIONThis command expects a kernel version string as single argument. This calls executables from
/usr/lib/kernel/install.d/*.install and
/etc/kernel/install.d/*.install with the following arguments:
remove KERNEL-VERSION$BOOT/MACHINE-ID/KERNEL-VERSION/Afterwards, kernel-install removes the directory
$BOOT/MACHINE-ID/KERNEL-VERSION/
and its contents.Two default plugins execute the following operations in this case:50-depmod.install removes the files generated by depmod for this kernel again.90-loaderentry.install removes the file
$BOOT/loader/entries/MACHINE-ID-KERNEL-VERSION.conf.The $BOOT partitionThe partition where the kernels and Boot
Loader Specification snippets are located is called $BOOT.
kernel-install determines the location of this partition by checking
/efi/, /boot/, and /boot/efi/
in turn. The first location where $BOOT/loader/entries/ or
$BOOT/$MACHINE_ID/ exists is used.OptionsThe following options are understood:Output additional information about operations being performed.Environment variablesIf is used, $KERNEL_INSTALL_VERBOSE=1 will be set for
the plugins. They may output additional logs in this case.If MACHINE_ID= is set and not empty, it will be used as MACHINE-ID,
overriding any automatic detection attempts. The value must be a valid machine ID (32 hexadecimal characters).KERNEL_INSTALL_MACHINE_ID= is set for the plugins to the desired MACHINE-ID –
either 32 hexadecimal characters or the special value Default.KERNEL_INSTALL_BOOT_ROOT= is set for the plugins to the root directory (mount point, usually) of the hierarchy
where boot-loader entries, kernel images, and associated resources should be placed. Can be overridden by setting BOOT_ROOT=.Exit statusIf every executable returns 0 or 77, 0 is returned, and a non-zero failure code otherwise.Files/usr/lib/kernel/install.d/*.install/etc/kernel/install.d/*.installDrop-in files which are executed by kernel-install./usr/lib/kernel/cmdline/etc/kernel/cmdline/proc/cmdlineRead by 90-loaderentry.install. The content of the file
/etc/kernel/cmdline specifies the kernel command line to use. If that file does not
exist, /usr/lib/kernel/cmdline is used. If that also does not exist,
/proc/cmdline is used./etc/kernel/triesRead by 90-loaderentry.install. If this file exists a numeric value is read from
it and the naming of the generated entry file is slightly altered to include it as
$BOOT/loader/entries/MACHINE-ID-KERNEL-VERSION+TRIES.conf. This
is useful for boot loaders such as
systemd-boot7 which
implement boot attempt counting with a counter embedded in the entry file name./etc/machine-idThe content of this file specifies the machine identification
MACHINE-ID. If /etc/machine-id
cannot be read or is temporary (backed by a file on tmpfs),
kernel-install will use Default instead./etc/os-release/usr/lib/os-releaseRead by 90-loaderentry.install.
If available, PRETTY_NAME is read from these files and used as the title of the boot menu entry.
Otherwise, Linux KERNEL-VERSION will be used.See Alsomachine-id5,
os-release5,
depmod8,
systemd-boot7,
Boot Loader Specification