kernel-install man page
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
kernel-install creates the directory /boot/MACHINE-ID/KERNEL-VERSION/ and calls every executable /usr/lib/kernel/install.d/*.install and /etc/kernel/install.d/*.install with the arguments
add KERNEL-VERSION /boot/MACHINE-ID/KERNEL-VERSION/
The kernel-install plugin 50-depmod.install runs depmod for the KERNEL-VERSION.
The kernel-install plugin 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 linux file, the initrd will be added to the configuration.
Calls every executable /usr/lib/kernel/install.d/*.install and /etc/kernel/install.d/*.install with the arguments
remove KERNEL-VERSION /boot/MACHINE-ID/KERNEL-VERSION/
kernel-install removes the entire directory /boot/MACHINE-ID/KERNEL-VERSION/ afterwards.
The kernel-install plugin 90-loaderentry.install removes the file /boot/loader/entries/MACHINE-ID-KERNEL-VERSION.conf.
If every executable returns with 0, 0 is returned, a non-zero failure code otherwise.
Drop-in files which are executed by kernel-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.
The content of the file specifies the machine identification MACHINE-ID.
The content of the file specifies the operating system title PRETTY_NAME.
machine-id(5), os-release(5), Boot loader specification
Boot loader specification