systemd/man/sd-boot.xml

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  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<!-- SPDX-License-Identifier: LGPL-2.1+ -->

<refentry id="sd-boot" conditional='ENABLE_EFI'
    xmlns:xi="http://www.w3.org/2001/XInclude">
  <refentryinfo>
    <title>sd-boot</title>
    <productname>systemd</productname>

    <authorgroup>
      <author>
        <contrib>I wrote this page</contrib>
        <firstname>Zbigniew</firstname>
        <surname>Jędrzejewski-Szmek</surname>
        <email>zbyszek@in.waw.pl</email>
      </author>
    </authorgroup>
  </refentryinfo>

  <refmeta>
    <refentrytitle>sd-boot</refentrytitle>
    <manvolnum>7</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>sd-boot</refname>
    <refpurpose>A simple UEFI boot manager</refpurpose>
  </refnamediv>

  <refsect1>
    <title>Description</title>

    <para><command>systemd-boot</command> or <command>sd-boot</command> is a simple
    UEFI boot manager, previously known as <command>gummiboot</command>. It provides
    a graphical menu to select the entry to boot and an editor for the kernel command
    line. sd-boot is only useful on machines using UEFI.
    </para>

    <para>sd-boot loads information from the EFI system partition (ESP), usually
    mounted at <filename>/boot</filename>, <filename>/efi</filename>, or
    <filename>/boot/efi</filename>. Configuration file fragments, kernels, initrds,
    other EFI images need to reside on the ESP. Linux kernels must be built with
    <option>CONFIG_EFI_STUB</option> to be able to be directly executed as an EFI
    image. sd-boot will automatically list other boot entries registered as EFI boot
    variables, and a list of kernels from configuration files following the <ulink
    url="https://www.freedesktop.org/wiki/Specifications/BootLoaderSpec">Boot Loader
    Specification</ulink> located under <filename>/loader/entries/</filename> on the
    ESP.</para>

    <para><citerefentry><refentrytitle>kernel-install</refentrytitle><manvolnum>8</manvolnum></citerefentry>
    may be used to copy kernel images onto the ESP and to generate entries compliant
    with the Boot Loader Specification.
    <citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
    may be used from a running system to locate the ESP, list available entries, and
    install sd-boot itself.</para>

    <para>sd-boot will provide information about the time spent in UEFI firmware
    using the
    <ulink url="https://www.freedesktop.org/wiki/Software/systemd/BootLoaderInterface">Boot Loader Interface</ulink>.
    This information can be displayed using
    <citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
    </para>
  </refsect1>

  <refsect1>
    <title>Configuration</title>

    <para>sd-boot reads configuration like the timeout and default entry from
    <filename>/loader/loader.conf</filename> on the ESP and from EFI variables. See
    <citerefentry><refentrytitle>loader.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
    </para>
  </refsect1>

  <refsect1>
    <title>Key bindings</title>
    <para>The following keys may be used in the boot menu:</para>

    <variablelist>
      <varlistentry>
        <term>↑ (Up)</term>
        <term>↓ (Down)</term>
        <term>j</term>
        <term>k</term>
        <term>PageUp</term>
        <term>PageDown</term>
        <term>Home</term>
        <term>End</term>
        <listitem><para>Navigate up/down in the entry list</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>↵ (Enter)</term>
        <listitem><para>Boot selected entry</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>d</term>
        <listitem><para>Make selected entry the default</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>e</term>
        <listitem><para>Edit the kernel command line for selected entry</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>+</term>
        <term>t</term>
        <listitem><para>Increase the timeout before default entry is booted</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>-</term>
        <term>T</term>
        <listitem><para>Decrease the timeout</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>v</term>
        <listitem><para>Show sd-boot, UEFI, and firmware versions</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>P</term>
        <listitem><para>Print status</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>Q</term>
        <listitem><para>Quit</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>h</term>
        <term>?</term>
        <listitem><para>Show a help screen</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>Ctrl + l</term>
        <listitem><para>Reprint the screen</para></listitem>
      </varlistentry>
    </variablelist>

    <para>The following keys may be used during bootup or in the boot menu to
    directly boot a specific entry:</para>

    <variablelist>
      <varlistentry>
        <term>l</term>
        <listitem><para>Linux</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>w</term>
        <listitem><para>Windows</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>a</term>
        <listitem><para>OS X</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>s</term>
        <listitem><para>EFI shell</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>1</term>
        <term>2</term>
        <term>3</term>
        <term>4</term>
        <term>5</term>
        <term>6</term>
        <term>7</term>
        <term>8</term>
        <term>9</term>
        <listitem><para>Entry number 1 .. 9</para></listitem>
      </varlistentry>
    </variablelist>

    <para>In the editor, most keys simply insert themselves, but the following keys
    may be used to perform additional actions:</para>

    <variablelist>
      <varlistentry>
        <term>← (Left)</term>
        <term>→ (Right)</term>
        <term>Home</term>
        <term>End</term>
        <listitem><para>Navigate left/right</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>Esc</term>
        <listitem><para>Abort the edit and quit the editor</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>Ctrl + k</term>
        <listitem><para>Clear the command line</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>Ctrl + w</term>
        <term>Alt + Backspace</term>
        <listitem><para>Delete word backwards</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>Alt + d </term>
        <listitem><para>Delete word forwards</para></listitem>
      </varlistentry>

      <varlistentry>
        <term>↵ (Enter)</term>
        <listitem><para>Boot entry with the edited command line</para></listitem>
      </varlistentry>
    </variablelist>

    <para>Note that unless configured otherwise in the UEFI firmware, sd-boot will
    use the US keyboard layout, so key labels might not match for keys like +/-.
    </para>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>loader.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
      <ulink url="https://www.freedesktop.org/wiki/Specifications/BootLoaderSpec">Boot Loader Specification</ulink>,
      <ulink url="https://www.freedesktop.org/wiki/Software/systemd/BootLoaderInterface">Boot Loader Interface</ulink>,
      <ulink url="https://www.freedesktop.org/wiki/Software/systemd/systemd-boot/">upstream wiki page</ulink>
    </para>
  </refsect1>
</refentry>