systemd kernel-install 8 kernel-install Add and remove kernel and initramfs images to and from /boot kernel-install COMMAND KERNEL-VERSION KERNEL-IMAGE kernel-install is used to install and remove kernel and initramfs images to and from /boot. 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 This command expects a kernel version string and a path to a kernel image file as arguments. kernel-install creates the directory /boot/MACHINE-ID/KERNEL-VERSION/ and 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 Two default plugins execute the following operations in this case: 50-depmod.install runs depmod8 for the KERNEL-VERSION. 90-loaderentry.install copies KERNEL-IMAGE to /boot/MACHINE-ID/KERNEL-VERSION/linux. 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 file initrd is found next to the kernel image file, the initrd will be added to the configuration. 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. 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-boot7 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-id5, os-release5, depmod8, systemd-boot7, Boot Loader Specification