Provided by: systemd_245.4-4ubuntu3_amd64
kernel-install - Add and remove kernel and initramfs images to and from /boot
kernel-install COMMAND [OPTIONS...] KERNEL-VERSION KERNEL-IMAGE [INITRD-FILE...]
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).
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 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
The 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.
The following options are understood: -v, --verbose Output additional information about operations being performed. -h, --help Print a short help text and exit.
If --verbose is used, $KERNEL_INSTALL_VERBOSE=1 will be set for the plugins. They may output additional logs in this case.
If every executable returns 0 or 77, 0 is returned, and a non-zero failure code otherwise.
/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 the file specifies the machine identification MACHINE-ID. /etc/os-release /usr/lib/os-release The content of the file specifies the operating system title PRETTY_NAME.
machine-id(5), os-release(5), depmod(8), systemd-boot(7), Boot Loader Specification
1. Boot Loader Specification https://systemd.io/BOOT_LOADER_SPECIFICATION