man/kernel-install.xml

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   5 <!--
   6   SPDX-License-Identifier: LGPL-2.1+
   7
   8   This file is part of systemd.
   9
  10   Copyright 2013 Harald Hoyer
  11 -->
  12
  13 <refentry id="kernel-install">
  14
  15   <refentryinfo>
  16     <title>kernel-install</title>
  17     <productname>systemd</productname>
  18
  19     <authorgroup>
  20       <author>
  21         <contrib>Developer</contrib>
  22         <firstname>Harald</firstname>
  23         <surname>Hoyer</surname>
  24         <email>harald@redhat.com</email>
  25       </author>
  26     </authorgroup>
  27   </refentryinfo>
  28
  29   <refmeta>
  30     <refentrytitle>kernel-install</refentrytitle>
  31     <manvolnum>8</manvolnum>
  32   </refmeta>
  33
  34   <refnamediv>
  35     <refname>kernel-install</refname>
  36     <refpurpose>Add and remove kernel and initramfs images to and from /boot</refpurpose>
  37   </refnamediv>
  38
  39   <refsynopsisdiv>
  40     <cmdsynopsis>
  41       <command>kernel-install</command>
  42       <arg choice="plain">COMMAND</arg>
  43       <arg choice="plain"><replaceable>KERNEL-VERSION</replaceable></arg>
  44       <arg choice="opt"><replaceable>KERNEL-IMAGE</replaceable></arg>
  45     </cmdsynopsis>
  46   </refsynopsisdiv>
  47
  48   <refsect1>
  49     <title>Description</title>
  50     <para>
  51       <command>kernel-install</command> is used to install and remove kernel and
  52       initramfs images to and from <filename>/boot</filename>.
  53     </para>
  54
  55     <para><command>kernel-install</command> will execute the files
  56     located in the directory <filename>/usr/lib/kernel/install.d/</filename>
  57     and the local administration directory <filename>/etc/kernel/install.d/</filename>.
  58     All files are collectively sorted and executed in lexical order, regardless of the directory in
  59     which they live. However, files with identical filenames replace each other.
  60     Files in <filename>/etc/kernel/install.d/</filename> take precedence over files with the same name
  61     in <filename>/usr/lib/kernel/install.d/</filename>. This can be used to override a system-supplied
  62     executables with a local file if needed; a symbolic link in <filename>/etc/kernel/install.d/</filename>
  63     with the same name as an executable in <filename>/usr/lib/kernel/install.d/</filename>,
  64     pointing to <filename>/dev/null</filename>, disables the executable entirely. Executables must have the
  65     extension <literal>.install</literal>; other extensions are ignored.</para>
  66
  67     <para>An executable should return <constant>0</constant> on success. It may also
  68     return <constant>77</constant> to cause the whole operation to terminate
  69     (executables later in lexical order will be skipped).</para>
  70   </refsect1>
  71
  72   <refsect1>
  73     <title>Commands</title>
  74     <para>The following commands are understood:</para>
  75     <variablelist>
  76       <varlistentry>
  77         <term><command>add <replaceable>KERNEL-VERSION</replaceable> <replaceable>KERNEL-IMAGE</replaceable></command></term>
  78         <listitem>
  79           <para><command>kernel-install</command> creates the directory
  80           <filename>/boot/<replaceable>MACHINE-ID</replaceable>/<replaceable>KERNEL-VERSION</replaceable>/</filename>
  81           and calls executables from
  82           <filename>/usr/lib/kernel/install.d/*.install</filename> and
  83           <filename>/etc/kernel/install.d/*.install</filename> with
  84           the arguments
  85           <programlisting>add <replaceable>KERNEL-VERSION</replaceable> \
  86     <filename>/boot/<replaceable>MACHINE-ID</replaceable>/<replaceable>KERNEL-VERSION</replaceable>/</filename> <replaceable>KERNEL-IMAGE</replaceable></programlisting>
  87           </para>
  88
  89           <para>The kernel-install plugin <filename>50-depmod.install</filename> runs depmod for the <replaceable>KERNEL-VERSION</replaceable>.</para>
  90
  91           <para>The kernel-install plugin
  92           <filename>90-loaderentry.install</filename> copies
  93           <replaceable>KERNEL-IMAGE</replaceable> to
  94           <filename>/boot/<replaceable>MACHINE-ID</replaceable>/<replaceable>KERNEL-VERSION</replaceable>/linux</filename>.
  95           It also creates a boot loader entry according to the boot
  96           loader specification in
  97           <filename>/boot/loader/entries/<replaceable>MACHINE-ID</replaceable>-<replaceable>KERNEL-VERSION</replaceable>.conf</filename>.
  98           The title of the entry is the
  99           <replaceable>PRETTY_NAME</replaceable> parameter specified
 100           in <filename>/etc/os-release</filename> or
 101           <filename>/usr/lib/os-release</filename> (if the former is
 102           missing), or "Linux
 103           <replaceable>KERNEL-VERSION</replaceable>", if unset.  If
 104           the file <filename>initrd</filename> is found next to the
 105           <filename>linux</filename> file, the initrd will be added to
 106           the configuration.</para>
 107         </listitem>
 108       </varlistentry>
 109       <varlistentry>
 110         <term><command>remove <replaceable>KERNEL-VERSION</replaceable></command></term>
 111         <listitem>
 112           <para>Calls executables from <filename>/usr/lib/kernel/install.d/*.install</filename>
 113           and <filename>/etc/kernel/install.d/*.install</filename> with the arguments
 114           <programlisting>remove <replaceable>KERNEL-VERSION</replaceable> <filename>/boot/<replaceable>MACHINE-ID</replaceable>/<replaceable>KERNEL-VERSION</replaceable>/</filename></programlisting>
 115           </para>
 116
 117           <para><command>kernel-install</command> removes the entire directory
 118           <filename>/boot/<replaceable>MACHINE-ID</replaceable>/<replaceable>KERNEL-VERSION</replaceable>/</filename> afterwards.</para>
 119
 120           <para>The kernel-install plugin <filename>90-loaderentry.install</filename> removes the file
 121           <filename>/boot/loader/entries/<replaceable>MACHINE-ID</replaceable>-<replaceable>KERNEL-VERSION</replaceable>.conf</filename>.</para>
 122         </listitem>
 123       </varlistentry>
 124
 125     </variablelist>
 126
 127   </refsect1>
 128
 129   <refsect1>
 130     <title>Exit status</title>
 131     <para>If every executable returns 0 or 77, 0 is returned, and a non-zero failure code otherwise.</para>
 132   </refsect1>
 133
 134   <refsect1>
 135     <title>Files</title>
 136     <variablelist>
 137       <varlistentry>
 138         <term>
 139           <filename>/usr/lib/kernel/install.d/*.install</filename>
 140           <filename>/etc/kernel/install.d/*.install</filename>
 141         </term>
 142           <listitem>
 143             <para>Drop-in files which are executed by kernel-install.</para>
 144           </listitem>
 145       </varlistentry>
 146       <varlistentry>
 147         <term>
 148           <filename>/etc/kernel/cmdline</filename>
 149           <filename>/proc/cmdline</filename>
 150         </term>
 151           <listitem>
 152             <para>The content of the file <filename>/etc/kernel/cmdline</filename> specifies the kernel command line to use.
 153             If that file does not exist, <filename>/proc/cmdline</filename> is used.</para>
 154           </listitem>
 155       </varlistentry>
 156       <varlistentry>
 157         <term>
 158           <filename>/etc/machine-id</filename>
 159         </term>
 160           <listitem>
 161             <para>The content of the file specifies the machine identification <replaceable>MACHINE-ID</replaceable>.</para>
 162           </listitem>
 163       </varlistentry>
 164       <varlistentry>
 165         <term>
 166           <filename>/etc/os-release</filename>
 167           <filename>/usr/lib/os-release</filename>
 168         </term>
 169           <listitem>
 170             <para>The content of the file specifies the operating system title <replaceable>PRETTY_NAME</replaceable>.</para>
 171           </listitem>
 172       </varlistentry>
 173     </variablelist>
 174   </refsect1>
 175
 176   <refsect1>
 177     <title>See Also</title>
 178     <para>
 179       <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 180       <citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 181       <ulink url="https://www.freedesktop.org/wiki/Specifications/BootLoaderSpec">Boot loader specification</ulink>
 182     </para>
 183   </refsect1>
 184
 185 </refentry>