kernel-installsystemdkernel-install8kernel-installAdd and remove kernel and initrd images to and from /bootkernel-installOPTIONSaddKERNEL-VERSIONKERNEL-IMAGEINITRD-FILEkernel-installOPTIONSremoveKERNEL-VERSIONkernel-installOPTIONSinspectKERNEL-IMAGEDescriptionkernel-install is used to install and remove kernel and initrd images
Nowadays actually CPIO archives used as an "initramfs", rather than "initrd". See
bootup7 for an
explanation.
to and from the boot loader partition, referred to as $BOOT here. It will usually be
one of /boot/, /efi/, or /boot/efi/, see
below.kernel-install will run the executable files ("plugins") located in the
directory /usr/lib/kernel/install.d/ and the local administration directory
/etc/kernel/install.d/. All files are collectively sorted and executed in lexical
order, regardless of the directory in which they live. However, files with identical filenames replace
each other. Files in /etc/kernel/install.d/ take precedence over files with the
same name in /usr/lib/kernel/install.d/. This can be used to override a
system-supplied executables with a local file if needed; a symbolic link in
/etc/kernel/install.d/ with the same name as an executable in
/usr/lib/kernel/install.d/, pointing to /dev/null, disables the
executable entirely. Executables must have the extension .install; other extensions
are ignored.An executable placed in these directories should return 0 on success. It may
also return 77 to cause the whole operation to terminate (executables later in
lexical order will be skipped).CommandsThe following commands are understood:add KERNEL-VERSIONKERNEL-IMAGE [INITRD-FILE ...]This command expects a kernel version string and a path to a kernel image file as arguments.
Optionally, one or more initrd images may be specified as well (note that plugins might generate
additional ones). kernel-install calls the executable files from
/usr/lib/kernel/install.d/*.install and
/etc/kernel/install.d/*.install (i.e. the plugins) with the following
arguments:add KERNEL-VERSION$BOOT/ENTRY-TOKEN/KERNEL-VERSION/KERNEL-IMAGE [INITRD-FILE ...]The third argument directly refers to the path where to place kernel images, initrd
images and other resources for Boot
Loader Specification Type #1 entries (the "entry directory"). If other boot loader schemes
are used the parameter may be ignored. The ENTRY-TOKEN string is
typically the machine ID and is supposed to identify the local installation on the system. For
details see below.Two default plugins execute the following operations in this case:kernel-install creates
$BOOT/ENTRY-TOKEN/KERNEL-VERSION,
if enabled (see $KERNEL_INSTALL_LAYOUT).50-depmod.install runs
depmod8 for the
KERNEL-VERSION.90-loaderentry.install copies
KERNEL-IMAGE to
$BOOT/ENTRY-TOKEN/KERNEL-VERSION/linux.
If INITRD-FILEs are provided, it also copies them to
$BOOT/ENTRY-TOKEN/KERNEL_VERSION/INITRD-FILE.
It also creates a boot loader entry according to the Boot Loader Specification (Type #1) in
$BOOT/loader/entries/ENTRY-TOKEN-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 $KERNEL_INSTALL_LAYOUT is not "bls", this plugin does nothing.90-uki-copy.install copies a file
uki.efi from $KERNEL_INSTALL_STAGING_AREA or if it does
not exist the KERNEL-IMAGE argument, only if it has a
.efi extension, to
$BOOT/EFI/Linux/ENTRY-TOKEN-KERNEL-VERSION.efi.If $KERNEL_INSTALL_LAYOUT is not "uki", this plugin does nothing.remove KERNEL-VERSIONThis command expects a kernel version string as single argument. This calls executables from
/usr/lib/kernel/install.d/*.install and
/etc/kernel/install.d/*.install with the following arguments:
remove KERNEL-VERSION$BOOT/ENTRY-TOKEN/KERNEL-VERSION/Afterwards, kernel-install removes the entry directory
$BOOT/ENTRY-TOKEN/KERNEL-VERSION/
and its contents, if it exists.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/ENTRY-TOKEN-KERNEL-VERSION.conf.90-uki-copy.install removes the file
$BOOT/EFI/Linux/ENTRY-TOKEN-KERNEL-VERSION.efi.inspect [KERNEL-IMAGE]Shows the various paths and parameters configured or auto-detected. In particular shows the
values of the various $KERNEL_INSTALL_* environment variables listed
below.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/ENTRY-TOKEN/ exists is used.OptionsThe following options are understood:Output additional information about operations being performed.Environment variablesEnvironment variables exported for pluginsIf is used, $KERNEL_INSTALL_VERBOSE=1 will be
exported for plugins. They may output additional logs in this case.$KERNEL_INSTALL_MACHINE_ID is set for the plugins to the desired machine-id to
use. It's always a 128-bit ID. Normally it's read from /etc/machine-id, but it can
also be overridden via $MACHINE_ID (see below). If not specified via these methods,
a fallback value will generated by kernel-install and used only for a single
invocation.$KERNEL_INSTALL_ENTRY_TOKEN is set for the plugins to the desired entry
"token" to use. It's an identifier that shall be used to identify the local installation, and is often
the machine ID, i.e. same as $KERNEL_INSTALL_MACHINE_ID, but might also be a
different type of identifier, for example a fixed string or the ID=,
IMAGE_ID= values from /etc/os-release. The string passed here
will be used to name Boot Loader Specification entries, or the directories the kernel image and initial
RAM disk images are placed into.Note that while $KERNEL_INSTALL_ENTRY_TOKEN and
$KERNEL_INSTALL_MACHINE_ID are often set to the same value, the latter is guaranteed
to be a valid 32 character ID in lowercase hexadecimals while the former can be any short string. The
entry token to use is read from /etc/kernel/entry-token, if it exists. Otherwise a
few possible candidates below $BOOT are checked for Boot Loader Specification Type 1
entry directories, and if found the entry token is derived from that. If that is not successful,
$KERNEL_INSTALL_MACHINE_ID is used as fallback.$KERNEL_INSTALL_BOOT_ROOT is set for the plugins to the absolute path of the
root directory (mount point, usually) of the hierarchy where boot loader entries, kernel images, and
associated resources should be placed. This usually is the path where the XBOOTLDR partition or the ESP
(EFI System Partition) are mounted, and also conceptually referred to as $BOOT. Can
be overridden by setting $BOOT_ROOT (see below).$KERNEL_INSTALL_LAYOUT=auto|bls|uki|other|... is set for the plugins to specify the
installation layout. Additional layout names may be defined by convention. If a plugin uses a special layout,
it's encouraged to declare its own layout name and configure layout= in
install.conf upon initial installation. The following values are currently
understood:blsStandard Boot Loader
Specification Type #1 layout, compatible with
systemd-boot7:
entries in
$BOOT/loader/entries/ENTRY-TOKEN-KERNEL-VERSION[+TRIES].conf,
kernel and initrds under
$BOOT/ENTRY-TOKEN/KERNEL-VERSION/Implemented by 90-loaderentry.install.ukiStandard Boot Loader
Specification Type #2 layout, compatible with
systemd-boot7:
unified kernel images under $BOOT/EFI/Linux as
$BOOT/EFI/Linux/ENTRY-TOKEN-KERNEL-VERSION[+TRIES].efi.Implemented by 90-uki-copy.install.otherSome other layout not understood natively by kernel-install.autoPick the layout automatically. If the kernel is a UKI set layout to
. If not default to if
$BOOT/loader/entries.srel with content type1 or
$BOOT/ENTRY-TOKEN exists, or
otherwise.Leaving layout blank has the same effect. This is the default.$KERNEL_INSTALL_INITRD_GENERATOR and $KERNEL_INSTALL_UKI_GENERATOR
are set for plugins to select the initrd and/or UKI generator. This may be configured as
initrd_generator= and uki_generator= in install.conf, see below.$KERNEL_INSTALL_STAGING_AREA is set for plugins to a path to a directory.
Plugins may drop files in that directory, and they will be installed as part of the loader entry, based
on the file name and extension.Environment variables understood by kernel-install$KERNEL_INSTALL_CONF_ROOT can be set to override the location of the
configuration files read by kernel-install. When set,
install.conf, entry-token, and other files will be
read from this directory.$KERNEL_INSTALL_PLUGINS can be set to override the list of plugins executed by
kernel-install. The argument is a whitespace-separated list of paths.
KERNEL_INSTALL_PLUGINS=: may be used to prevent any plugins from running.
$MACHINE_ID can be set for kernel-install to override
$KERNEL_INSTALL_MACHINE_ID, the machine ID.$BOOT_ROOT can be set for kernel-install to override
$KERNEL_INSTALL_BOOT_ROOT, the installation location for boot entries.The last two variables may also be set in install.conf. Variables set in the
environment take precedence over the values specified in the config file.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. $KERNEL_INSTALL_CONF_ROOT
may be used to override the path./etc/kernel/triesRead by 90-loaderentry.install and
90-uki-copy.install. If this file exists a numeric value is read from it
and the naming of the generated entry file or UKI is slightly altered to include it as
$BOOT/loader/entries/ENTRY-TOKEN-KERNEL-VERSION+TRIES.conf
or
$BOOT/EFI/Linux/ENTRY-TOKEN-KERNEL-VERSION+TRIES.efi, respectively. This
is useful for boot loaders such as
systemd-boot7
which implement boot attempt counting with a counter embedded in the entry file name.
$KERNEL_INSTALL_CONF_ROOT may be used to override the path./etc/kernel/entry-tokenIf this file exists it is read and used as "entry token" for this system, i.e. is used for
naming Boot Loader Specification entries, see $KERNEL_INSTALL_ENTRY_TOKEN
above for details. $KERNEL_INSTALL_CONF_ROOT may be used to override the
path./etc/machine-idThe content of this file specifies the machine identification
MACHINE-ID./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./usr/lib/kernel/install.conf/etc/kernel/install.confConfiguration options for kernel-install, as a series of
KEY=VALUE assignments, compatible with shell
syntax, following the same rules as described in
os-release5.
/etc/kernel/install.conf will be read if present, and
/usr/lib/kernel/install.conf otherwise. This file is optional.
$KERNEL_INSTALL_CONF_ROOT may be used to override the path.
Currently, the following keys are supported:
MACHINE_ID=,
BOOT_ROOT=,
layout=,
initrd_generator=,
uki_generator=.
See the Environment variables section above for details.See Alsomachine-id5,
os-release5,
depmod8,
systemd-boot7,
Boot Loader Specification