kernel-install(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | COMMANDS | THE $BOOT PARTITION | OPTIONS | ENVIRONMENT VARIABLES | EXIT STATUS | FILES | SEE ALSO | NOTES | COLOPHON

KERNEL-INSTALL(8)            kernel-install            KERNEL-INSTALL(8)

NAME         top

       kernel-install - Add and remove kernel and initramfs images to
       and from /boot

SYNOPSIS         top

       kernel-install COMMAND [OPTIONS...] KERNEL-VERSION KERNEL-IMAGE
                      [INITRD-FILE...]

DESCRIPTION         top

       kernel-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).

COMMANDS         top

       The following commands are understood:

       add KERNEL-VERSION KERNEL-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 depmod(8) 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[1] 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-VERSION
           This 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 PARTITION         top

       The partition where the kernels and Boot Loader Specification[1]
       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.

OPTIONS         top

       The following options are understood:

       -v, --verbose
           Output additional information about operations being
           performed.

       -h, --help
           Print a short help text and exit.

ENVIRONMENT VARIABLES         top

       If --verbose is used, $KERNEL_INSTALL_VERBOSE=1 will be set for
       the plugins. They may output additional logs in this case.

EXIT STATUS         top

       If every executable returns 0 or 77, 0 is returned, and a
       non-zero failure code otherwise.

FILES         top

       /usr/lib/kernel/install.d/*.install
       /etc/kernel/install.d/*.install
           Drop-in files which are executed by kernel-install.

       /etc/kernel/cmdline /proc/cmdline
           Read 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, /proc/cmdline is used.

       /etc/kernel/tries
           Read 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-boot(7) which
           implement boot attempt counting with a counter embedded in
           the entry file name.

       /etc/machine-id
           The content of this file specifies the machine identification
           MACHINE-ID. If it cannot read /etc/machine-id, kernel-install
           will use "Linux" as the machine ID instead.

       /etc/os-release /usr/lib/os-release
           The content of the file specifies the operating system title
           PRETTY_NAME.

SEE ALSO         top

       machine-id(5), os-release(5), depmod(8), systemd-boot(7), Boot
       Loader Specification[1]

NOTES         top

        1. Boot Loader Specification
           https://systemd.io/BOOT_LOADER_SPECIFICATION

COLOPHON         top

       This page is part of the systemd (systemd system and service
       manager) project.  Information about the project can be found at
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have
       a bug report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2021-08-27.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-08-27.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

systemd 249                                            KERNEL-INSTALL(8)

Pages that refer to this page: bootctl(1)systemd-firstboot(1)systemd-boot(7)