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systemd-stable/man/bootctl.xml
Lennart Poettering 351de38e4b bootctl: make 'random-seed' handle inability to write system token EFI variable gracefully
Apparently some firmwares don't allow us to write this token, and refuse
it with EINVAL. We should normally consider that a fatal error, but not
really in the case of "bootctl random-seed" when called from the
systemd-boot-system-token.service since it's called as "best effort"
service after boot on various systems, and hence we shouldn't fail
loudly.

Similar, when we cannot find the ESP don't fail either, since there are
systems (arch install ISOs) that carry a boot loader capable of the
random seed logic but don't mount it after boot.

Fixes: #13603
2019-11-21 19:55:17 +01:00

223 lines
10 KiB
XML

<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1+ -->
<refentry id="bootctl" conditional='ENABLE_EFI'
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>bootctl</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>bootctl</refentrytitle>
<manvolnum>1</manvolnum>
</refmeta>
<refnamediv>
<refname>bootctl</refname>
<refpurpose>Control the firmware and boot manager settings</refpurpose>
</refnamediv>
<refsynopsisdiv>
<cmdsynopsis>
<command>bootctl</command>
<arg choice="opt" rep="repeat">OPTIONS</arg>
<arg choice="req">COMMAND</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><command>bootctl</command> can check the EFI boot loader status, list available boot loaders and boot loader
entries, and install, update, or remove the
<citerefentry><refentrytitle>systemd-boot</refentrytitle><manvolnum>7</manvolnum></citerefentry> boot loader on the
current system.</para>
</refsect1>
<refsect1>
<title>Commands</title>
<variablelist>
<varlistentry>
<term><option>status</option></term>
<listitem><para>Shows brief information about the system firmware, the boot loader that was used to boot the
system, the boot loaders currently available in the ESP, the boot loaders listed in the firmware's list of boot
loaders and the current default boot loader entry. If no command is specified, this is the implied
default.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>install</option></term>
<listitem><para>Installs <command>systemd-boot</command> into the EFI system partition. A copy of
<command>systemd-boot</command> will be stored as the EFI default/fallback loader at
<filename><replaceable>ESP</replaceable>/EFI/BOOT/BOOT*.EFI</filename>. The boot loader is then added
to the top of the firmware's boot loader list.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>update</option></term>
<listitem><para>Updates all installed versions of
<citerefentry><refentrytitle>systemd-boot</refentrytitle><manvolnum>7</manvolnum></citerefentry>, if the
available version is newer than the version installed in the EFI system partition. This also includes the EFI
default/fallback loader at <filename><replaceable>ESP</replaceable>/EFI/BOOT/BOOT*.EFI</filename>. The boot
loader is then added to end of the firmware's boot loader list if missing.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>remove</option></term>
<listitem><para>Removes all installed versions of <command>systemd-boot</command> from the EFI system partition
and the firmware's boot loader list.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>is-installed</option></term>
<listitem><para>Checks whether <command>systemd-boot</command> is installed in the ESP. Note that a
single ESP might host multiple boot loaders; this hence checks whether
<command>systemd-boot</command> is one (of possibly many) installed boot loaders — and neither
whether it is the default nor whether it is registered in any EFI variables.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>random-seed</option></term>
<listitem><para>Generates a random seed and stores it in the EFI System Partition, for use by the
<command>systemd-boot</command> boot loader. Also, generates a random 'system token' and stores it
persistently as an EFI variable, if one has not been set before. If the boot loader finds the random
seed in the ESP and the system token in the EFI variable it will derive a random seed to pass to the
OS and a new seed to store in the ESP from the combination of both. The random seed passed to the OS
is credited to the kernel's entropy pool by the system manager during early boot, and permits
userspace to boot up with an entropy pool fully initialized very early on. Also see
<citerefentry><refentrytitle>systemd-boot-system-token.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
<para>See <ulink url="https://systemd.io/RANDOM_SEEDS">Random Seeds</ulink> for further
information.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>systemd-efi-options</option> <optional><replaceable>VALUE</replaceable></optional></term>
<listitem><para>When called without the optional argument, prints the current value of the
<literal>SystemdOptions</literal> EFI variable. When called with an argument, sets the
variable to that value. See
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
for the meaning of that variable.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>list</option></term>
<listitem><para>Shows all available boot loader entries implementing the <ulink
url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader
Specification</ulink>, as well as any other entries discovered or automatically generated by the boot
loader.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>set-default</option> <replaceable>ID</replaceable></term>
<term><option>set-oneshot</option> <replaceable>ID</replaceable></term>
<listitem><para>Sets the default boot loader entry. Takes a single boot loader entry ID string as argument. The
<option>set-oneshot</option> command will set the default entry only for the next boot, the
<option>set-default</option> will set it persistently for all future boots.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Options</title>
<para>The following options are understood:</para>
<variablelist>
<varlistentry>
<term><option>--esp-path=</option></term>
<listitem><para>Path to the EFI System Partition (ESP). If not specified, <filename>/efi/</filename>,
<filename>/boot/</filename>, and <filename>/boot/efi/</filename> are checked in turn. It is
recommended to mount the ESP to <filename>/efi/</filename>, if possible.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--boot-path=</option></term>
<listitem><para>Path to the Extended Boot Loader partition, as defined in the <ulink
url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink>. If not
specified, <filename>/boot/</filename> is checked. It is recommended to mount the Extended Boot
Loader partition to <filename>/boot/</filename>, if possible.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-p</option></term>
<term><option>--print-esp-path</option></term>
<listitem><para>This option modifies the behaviour of <command>status</command>. Only prints the path
to the EFI System Partition (ESP) to standard output and exits.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-x</option></term>
<term><option>--print-boot-path</option></term>
<listitem><para>This option modifies the behaviour of <command>status</command>. Only prints the path
to the Extended Boot Loader partition if it exists, and the path to the ESP otherwise to standard
output and exit. This command is useful to determine where to place boot loader entries, as they are
preferably placed in the Extended Boot Loader partition if it exists and in the ESP otherwise.</para>
<para>Boot Loader Specification Type #1 entries should generally be placed in the directory
<literal>$(bootctl -x)/loader/entries/</literal>. Existence of that directory may also be used as
indication that boot loader entry support is available on the system. Similarly, Boot Loader
Specification Type #2 entries should be placed in the directory <literal>$(bootctl
-x)/EFI/Linux/</literal>.</para>
<para>Note that this option (similar to the <option>--print-booth-path</option> option mentioned
above), is available independently from the boot loader used, i.e. also without
<command>systemd-boot</command> being installed.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--no-variables</option></term>
<listitem><para>Do not touch the firmware's boot loader list stored in EFI variables.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--graceful</option></term>
<listitem><para>Ignore failure when the EFI System Partition cannot be found, or when EFI variables
cannot be written. Currently only applies to random seed operations.</para></listitem>
</varlistentry>
<xi:include href="standard-options.xml" xpointer="no-pager"/>
<xi:include href="standard-options.xml" xpointer="help"/>
<xi:include href="standard-options.xml" xpointer="version"/>
</variablelist>
</refsect1>
<refsect1>
<title>Exit status</title>
<para>On success, 0 is returned, a non-zero failure code otherwise.</para>
</refsect1>
<refsect1>
<title>Environment</title>
<para>If <varname>$SYSTEMD_RELAX_ESP_CHECKS=1</varname> is set the validation checks for the ESP are
relaxed, and the path specified with <option>--esp-path=</option> may refer to any kind of file system on
any kind of partition.</para>
<para>Similarly, <varname>$SYSTEMD_RELAX_XBOOTLDR_CHECKS=1</varname> turns off some validation checks for
the Extended Boot Loader partition.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd-boot</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<ulink url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink>,
<ulink url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader Interface</ulink>,
<citerefentry><refentrytitle>systemd-boot-system-token.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>