# phpman > man > kernel-install(8) [KERNEL-INSTALL(8)](https://www.chedong.com/phpMan.php/man/KERNEL-INSTALL/8/markdown) kernel-install [KERNEL-INSTALL(8)](https://www.chedong.com/phpMan.php/man/KERNEL-INSTALL/8/markdown) ## NAME kernel-install - Add and remove kernel and initramfs images to and from /boot ## SYNOPSIS **kernel-install** COMMAND [OPTIONS...] _KERNEL-VERSION_ _KERNEL-IMAGE_ [_INITRD-FILE_...] ## DESCRIPTION **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 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)](https://www.chedong.com/phpMan.php/man/depmod/8/markdown) 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 $BOOT PARTITION The partition where the kernels and **Boot** **Loader** **Specification**[1] snippets are located is called _$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 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 If **--verbose** is used, _$KERNEL_INSTALL_VERBOSE=1_ will be set for the plugins. They may output additional logs in this case. ## EXIT STATUS If 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/*.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)](https://www.chedong.com/phpMan.php/man/systemd-boot/7/markdown) 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 [**machine-id**(5)](https://www.chedong.com/phpMan.php/man/machine-id/5/markdown), [**os-release**(5)](https://www.chedong.com/phpMan.php/man/os-release/5/markdown), [**depmod**(8)](https://www.chedong.com/phpMan.php/man/depmod/8/markdown), [**systemd-boot**(7)](https://www.chedong.com/phpMan.php/man/systemd-boot/7/markdown), **Boot** **Loader** **Specification**[1] ## NOTES 1. Boot Loader Specification systemd 249 [KERNEL-INSTALL(8)](https://www.chedong.com/phpMan.php/man/KERNEL-INSTALL/8/markdown)