man/kernel-install.xml

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   5 <!--
   6   SPDX-License-Identifier: LGPL-2.1+
   7
   8   Copyright 2013 Harald Hoyer
   9 -->
  10
  11 <refentry id="kernel-install">
  12
  13   <refentryinfo>
  14     <title>kernel-install</title>
  15     <productname>systemd</productname>
  16
  17     <authorgroup>
  18       <author>
  19         <contrib>Developer</contrib>
  20         <firstname>Harald</firstname>
  21         <surname>Hoyer</surname>
  22         <email>harald@redhat.com</email>
  23       </author>
  24     </authorgroup>
  25   </refentryinfo>
  26
  27   <refmeta>
  28     <refentrytitle>kernel-install</refentrytitle>
  29     <manvolnum>8</manvolnum>
  30   </refmeta>
  31
  32   <refnamediv>
  33     <refname>kernel-install</refname>
  34     <refpurpose>Add and remove kernel and initramfs images to and from /boot</refpurpose>
  35   </refnamediv>
  36
  37   <refsynopsisdiv>
  38     <cmdsynopsis>
  39       <command>kernel-install</command>
  40       <arg choice="plain">COMMAND</arg>
  41       <arg choice="plain"><replaceable>KERNEL-VERSION</replaceable></arg>
  42       <arg choice="opt"><replaceable>KERNEL-IMAGE</replaceable></arg>
  43     </cmdsynopsis>
  44   </refsynopsisdiv>
  45
  46   <refsect1>
  47     <title>Description</title>
  48     <para>
  49       <command>kernel-install</command> is used to install and remove kernel and
  50       initramfs images to and from <filename>/boot</filename>.
  51     </para>
  52
  53     <para><command>kernel-install</command> will execute the files
  54     located in the directory <filename>/usr/lib/kernel/install.d/</filename>
  55     and the local administration directory <filename>/etc/kernel/install.d/</filename>.
  56     All files are collectively sorted and executed in lexical order, regardless of the directory in
  57     which they live. However, files with identical filenames replace each other.
  58     Files in <filename>/etc/kernel/install.d/</filename> take precedence over files with the same name
  59     in <filename>/usr/lib/kernel/install.d/</filename>. This can be used to override a system-supplied
  60     executables with a local file if needed; a symbolic link in <filename>/etc/kernel/install.d/</filename>
  61     with the same name as an executable in <filename>/usr/lib/kernel/install.d/</filename>,
  62     pointing to <filename>/dev/null</filename>, disables the executable entirely. Executables must have the
  63     extension <literal>.install</literal>; other extensions are ignored.</para>
  64
  65     <para>An executable should return <constant>0</constant> on success. It may also
  66     return <constant>77</constant> to cause the whole operation to terminate
  67     (executables later in lexical order will be skipped).</para>
  68   </refsect1>
  69
  70   <refsect1>
  71     <title>Commands</title>
  72     <para>The following commands are understood:</para>
  73     <variablelist>
  74       <varlistentry>
  75         <term><command>add <replaceable>KERNEL-VERSION</replaceable> <replaceable>KERNEL-IMAGE</replaceable></command></term>
  76         <listitem>
  77           <para><command>kernel-install</command> creates the directory
  78           <filename>/boot/<replaceable>MACHINE-ID</replaceable>/<replaceable>KERNEL-VERSION</replaceable>/</filename>
  79           and calls executables from
  80           <filename>/usr/lib/kernel/install.d/*.install</filename> and
  81           <filename>/etc/kernel/install.d/*.install</filename> with
  82           the arguments
  83           <programlisting>add <replaceable>KERNEL-VERSION</replaceable> \
  84     <filename>/boot/<replaceable>MACHINE-ID</replaceable>/<replaceable>KERNEL-VERSION</replaceable>/</filename> <replaceable>KERNEL-IMAGE</replaceable></programlisting>
  85           </para>
  86
  87           <para>The kernel-install plugin <filename>50-depmod.install</filename> runs depmod for the <replaceable>KERNEL-VERSION</replaceable>.</para>
  88
  89           <para>The kernel-install plugin
  90           <filename>90-loaderentry.install</filename> copies
  91           <replaceable>KERNEL-IMAGE</replaceable> to
  92           <filename>/boot/<replaceable>MACHINE-ID</replaceable>/<replaceable>KERNEL-VERSION</replaceable>/linux</filename>.
  93           It also creates a boot loader entry according to the boot
  94           loader specification in
  95           <filename>/boot/loader/entries/<replaceable>MACHINE-ID</replaceable>-<replaceable>KERNEL-VERSION</replaceable>.conf</filename>.
  96           The title of the entry is the
  97           <replaceable>PRETTY_NAME</replaceable> parameter specified
  98           in <filename>/etc/os-release</filename> or
  99           <filename>/usr/lib/os-release</filename> (if the former is
 100           missing), or "Linux
 101           <replaceable>KERNEL-VERSION</replaceable>", if unset.  If
 102           the file <filename>initrd</filename> is found next to the
 103           <filename>linux</filename> file, the initrd will be added to
 104           the configuration.</para>
 105         </listitem>
 106       </varlistentry>
 107       <varlistentry>
 108         <term><command>remove <replaceable>KERNEL-VERSION</replaceable></command></term>
 109         <listitem>
 110           <para>Calls executables from <filename>/usr/lib/kernel/install.d/*.install</filename>
 111           and <filename>/etc/kernel/install.d/*.install</filename> with the arguments
 112           <programlisting>remove <replaceable>KERNEL-VERSION</replaceable> <filename>/boot/<replaceable>MACHINE-ID</replaceable>/<replaceable>KERNEL-VERSION</replaceable>/</filename></programlisting>
 113           </para>
 114
 115           <para><command>kernel-install</command> removes the entire directory
 116           <filename>/boot/<replaceable>MACHINE-ID</replaceable>/<replaceable>KERNEL-VERSION</replaceable>/</filename> afterwards.</para>
 117
 118           <para>The kernel-install plugin <filename>90-loaderentry.install</filename> removes the file
 119           <filename>/boot/loader/entries/<replaceable>MACHINE-ID</replaceable>-<replaceable>KERNEL-VERSION</replaceable>.conf</filename>.</para>
 120         </listitem>
 121       </varlistentry>
 122
 123     </variablelist>
 124
 125   </refsect1>
 126
 127   <refsect1>
 128     <title>Exit status</title>
 129     <para>If every executable returns 0 or 77, 0 is returned, and a non-zero failure code otherwise.</para>
 130   </refsect1>
 131
 132   <refsect1>
 133     <title>Files</title>
 134     <variablelist>
 135       <varlistentry>
 136         <term>
 137           <filename>/usr/lib/kernel/install.d/*.install</filename>
 138           <filename>/etc/kernel/install.d/*.install</filename>
 139         </term>
 140           <listitem>
 141             <para>Drop-in files which are executed by kernel-install.</para>
 142           </listitem>
 143       </varlistentry>
 144       <varlistentry>
 145         <term>
 146           <filename>/etc/kernel/cmdline</filename>
 147           <filename>/proc/cmdline</filename>
 148         </term>
 149           <listitem>
 150             <para>The content of the file <filename>/etc/kernel/cmdline</filename> specifies the kernel command line to use.
 151             If that file does not exist, <filename>/proc/cmdline</filename> is used.</para>
 152           </listitem>
 153       </varlistentry>
 154       <varlistentry>
 155         <term>
 156           <filename>/etc/machine-id</filename>
 157         </term>
 158           <listitem>
 159             <para>The content of the file specifies the machine identification <replaceable>MACHINE-ID</replaceable>.</para>
 160           </listitem>
 161       </varlistentry>
 162       <varlistentry>
 163         <term>
 164           <filename>/etc/os-release</filename>
 165           <filename>/usr/lib/os-release</filename>
 166         </term>
 167           <listitem>
 168             <para>The content of the file specifies the operating system title <replaceable>PRETTY_NAME</replaceable>.</para>
 169           </listitem>
 170       </varlistentry>
 171     </variablelist>
 172   </refsect1>
 173
 174   <refsect1>
 175     <title>See Also</title>
 176     <para>
 177       <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 178       <citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 179       <ulink url="https://www.freedesktop.org/wiki/Specifications/BootLoaderSpec">Boot loader specification</ulink>
 180     </para>
 181   </refsect1>
 182
 183 </refentry>