1KERNEL-INSTALL(8)               kernel-install               KERNEL-INSTALL(8)
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NAME

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

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

14       kernel-install is used to install and remove kernel and initramfs
15       images to and from the boot loader partition, referred to as $BOOT
16       here. It will usually be one of /boot/, /efi/, or /boot/efi/, see
17       below.
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19       kernel-install will execute the files located in the directory
20       /usr/lib/kernel/install.d/ and the local administration directory
21       /etc/kernel/install.d/. All files are collectively sorted and executed
22       in lexical order, regardless of the directory in which they live.
23       However, files with identical filenames replace each other. Files in
24       /etc/kernel/install.d/ take precedence over files with the same name in
25       /usr/lib/kernel/install.d/. This can be used to override a
26       system-supplied executables with a local file if needed; a symbolic
27       link in /etc/kernel/install.d/ with the same name as an executable in
28       /usr/lib/kernel/install.d/, pointing to /dev/null, disables the
29       executable entirely. Executables must have the extension ".install";
30       other extensions are ignored.
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32       An executable should return 0 on success. It may also return 77 to
33       cause the whole operation to terminate (executables later in lexical
34       order will be skipped).
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COMMANDS

37       The following commands are understood:
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39       add KERNEL-VERSION KERNEL-IMAGE [INITRD-FILE ...]
40           This command expects a kernel version string and a path to a kernel
41           image file as arguments.  kernel-install calls the executables from
42           /usr/lib/kernel/install.d/*.install and
43           /etc/kernel/install.d/*.install with the following arguments:
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45               add KERNEL-VERSION $BOOT/MACHINE-ID/KERNEL-VERSION/ KERNEL-IMAGE [INITRD-FILE ...]
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47           Three default plugins execute the following operations in this
48           case:
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50           •   00-entry-directory.install creates the directory
51               $BOOT/MACHINE-ID/KERNEL-VERSION/ if $BOOT/MACHINE-ID/ already
52               exists.
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54           •   50-depmod.install runs depmod(8) for the KERNEL-VERSION.
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56           •   90-loaderentry.install copies KERNEL-IMAGE to
57               $BOOT/MACHINE-ID/KERNEL-VERSION/linux. If an INITRD-FILE is
58               provided, it also copies INITRD-FILE to
59               $BOOT/MACHINE-ID/KERNEL_VERSION/INITRD-FILE. It also creates a
60               boot loader entry according to the Boot Loader Specification[1]
61               in $BOOT/loader/entries/MACHINE-ID-KERNEL-VERSION.conf. The
62               title of the entry is the PRETTY_NAME parameter specified in
63               /etc/os-release or /usr/lib/os-release (if the former is
64               missing), or "Linux KERNEL-VERSION", if unset.
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66               If the entry directory $BOOT/MACHINE-ID/KERNEL-VERSION/ does
67               not exist, this plugin does nothing.
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69       remove KERNEL-VERSION
70           This command expects a kernel version string as single argument.
71           This calls executables from /usr/lib/kernel/install.d/*.install and
72           /etc/kernel/install.d/*.install with the following arguments:
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74               remove KERNEL-VERSION $BOOT/MACHINE-ID/KERNEL-VERSION/
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76           Afterwards, kernel-install removes the directory
77           $BOOT/MACHINE-ID/KERNEL-VERSION/ and its contents.
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79           Two default plugins execute the following operations in this case:
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81           •   50-depmod.install removes the files generated by depmod for
82               this kernel again.
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84           •   90-loaderentry.install removes the file
85               $BOOT/loader/entries/MACHINE-ID-KERNEL-VERSION.conf.
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THE $BOOT PARTITION

88       The partition where the kernels and Boot Loader Specification[1]
89       snippets are located is called $BOOT.  kernel-install determines the
90       location of this partition by checking /efi/, /boot/, and /boot/efi/ in
91       turn. The first location where $BOOT/loader/entries/ or
92       $BOOT/$MACHINE_ID/ exists is used.
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OPTIONS

95       The following options are understood:
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97       -v, --verbose
98           Output additional information about operations being performed.
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100       -h, --help
101           Print a short help text and exit.
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ENVIRONMENT VARIABLES

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

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

112       /usr/lib/kernel/install.d/*.install /etc/kernel/install.d/*.install
113           Drop-in files which are executed by kernel-install.
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115       /etc/kernel/cmdline /proc/cmdline
116           Read by 90-loaderentry.install. The content of the file
117           /etc/kernel/cmdline specifies the kernel command line to use. If
118           that file does not exist, /proc/cmdline is used.
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120       /etc/kernel/tries
121           Read by 90-loaderentry.install. If this file exists a numeric value
122           is read from it and the naming of the generated entry file is
123           slightly altered to include it as
124           $BOOT/loader/entries/MACHINE-ID-KERNEL-VERSION+TRIES.conf. This is
125           useful for boot loaders such as systemd-boot(7) which implement
126           boot attempt counting with a counter embedded in the entry file
127           name.
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129       /etc/machine-id
130           The content of this file specifies the machine identification
131           MACHINE-ID. If it cannot read /etc/machine-id, kernel-install will
132           use "Linux" as the machine ID instead.
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134       /etc/os-release /usr/lib/os-release
135           The content of the file specifies the operating system title
136           PRETTY_NAME.
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SEE ALSO

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

143        1. Boot Loader Specification
144           https://systemd.io/BOOT_LOADER_SPECIFICATION
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148systemd 248                                                  KERNEL-INSTALL(8)
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