<?xml version='1.0'?> <!--*-nxml-*-->
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+<!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+
-
- This file is part of systemd.
-
- Copyright 2012 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
--->
+<!-- SPDX-License-Identifier: LGPL-2.1+ -->
<refentry id="kernel-command-line">
<refentryinfo>
<title>kernel-command-line</title>
<productname>systemd</productname>
-
- <authorgroup>
- <author>
- <contrib>Developer</contrib>
- <firstname>Lennart</firstname>
- <surname>Poettering</surname>
- <email>lennart@poettering.net</email>
- </author>
- </authorgroup>
</refentryinfo>
<refmeta>
<refsect1>
<title>Description</title>
- <para>The kernel, the initial RAM disk (initrd) and
- basic userspace functionality may be configured at boot via
- kernel command line arguments.</para>
+ <para>The kernel, the initial RAM disk (initrd) and basic userspace functionality may be configured at
+ boot via kernel command line arguments. In addition, various systemd tools look at the EFI variable
+ <literal>SystemdOptions</literal> (if available). Both sources are combined, but the kernel command line
+ has higher priority. Please note that <emphasis>the EFI variable is only used by systemd tools, and is
+ ignored by the kernel and other user space tools</emphasis>, so it is not a replacement for the kernel
+ command line.</para>
<para>For command line parameters understood by the kernel, please
see
<term><varname>systemd.unit=</varname></term>
<term><varname>rd.systemd.unit=</varname></term>
<term><varname>systemd.dump_core</varname></term>
+ <term><varname>systemd.early_core_pattern=</varname></term>
<term><varname>systemd.crash_chvt</varname></term>
<term><varname>systemd.crash_shell</varname></term>
<term><varname>systemd.crash_reboot</varname></term>
<term><varname>systemd.confirm_spawn</varname></term>
+ <term><varname>systemd.service_watchdogs</varname></term>
<term><varname>systemd.show_status</varname></term>
+ <term><varname>systemd.status_unit_format=</varname></term>
<term><varname>systemd.log_target=</varname></term>
<term><varname>systemd.log_level=</varname></term>
<term><varname>systemd.log_location=</varname></term>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>systemd.run=</varname></term>
+ <term><varname>systemd.run_success_action=</varname></term>
+ <term><varname>systemd.run_failure_action=</varname></term>
+ <listitem>
+ <para>Additional parameters understood by
+ <citerefentry><refentrytitle>systemd-run-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>, to
+ run a command line specified on the kernel command line as system service after booting up.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>systemd.early_core_pattern=</varname></term>
+ <listitem>
+ <para>During early boot, the generation of core dump files is disabled until a core dump handler (if any)
+ takes over. This parameter allows specifying an absolute path where core dump files should be stored until
+ a handler is installed. The path should be absolute and may contain specifiers, see
+ <citerefentry><refentrytitle>core</refentrytitle><manvolnum>5</manvolnum></citerefentry> for details.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>systemd.restore_state=</varname></term>
<listitem>
enables fully state-less boots were the vendor-supplied OS is used as shipped, with only default
configuration and no stored state in effect, as <filename>/etc</filename> and <filename>/var</filename> (as
well as all other resources shipped in the root file system) are reset at boot and lost on shutdown. If this
- setting is set to <literal>state</literal> the root file system is mounted as usual, however
+ setting is set to <literal>state</literal> the root file system is mounted read-only, however
<filename>/var</filename> is mounted as a volatile memory file system (<literal>tmpfs</literal>), so that the
- system boots up with the normal configuration applied, but all state reset at boot and lost at shutdown. For details,
- see
+ system boots up with the normal configuration applied, but all state reset at boot and lost at shutdown. If
+ this setting is set to <literal>overlay</literal> the root file system is set up as
+ <literal>overlayfs</literal> mount combining the read-only root directory with a writable
+ <literal>tmpfs</literal>, so that no modifications are made to disk, but the file system may be modified
+ nonetheless with all changes being lost at reboot. For details, see
<citerefentry><refentrytitle>systemd-volatile-root.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
and
<citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
<term><varname>udev.event_timeout=</varname></term>
<term><varname>rd.udev.event_timeout=</varname></term>
<term><varname>net.ifnames=</varname></term>
+ <term><varname>net.naming-scheme=</varname></term>
<listitem>
<para>Parameters understood by the device event managing
<listitem>
<para>Configures the root file system and its file system
type and mount options, as well as whether it shall be
- mounted read-only or read-writable initially. For details,
+ mounted read-only or read-write initially. For details,
see
<citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
</listitem>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>systemd.watchdog_device=</varname></term>
+
+ <listitem>
+ <para>Overwrites the watchdog device path <varname>WatchdogDevice=</varname>. For details, see
+ <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>systemd.cpu_affinity=</varname></term>
+
+ <listitem>
+ <para>Overrides the CPU affinity mask for the service manager and the default for all child
+ processes it forks. This takes precedence over <varname>CPUAffinity=</varname>, see
+ <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>modules_load=</varname></term>
<term><varname>rd.modules_load=</varname></term>
<varlistentry>
<term><varname>resume=</varname></term>
+ <term><varname>resumeflags=</varname></term>
<listitem>
<para>Enables resume from hibernation using the specified
- device. All
+ device and mount options. All
<citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>-like
paths are supported. For details, see
<citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
<listitem><para>Takes a boolean argument, defaults to on. If off,
<citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
- will not query the user for basic system settings, even if the system boots up for the first time and the
- relevant settings are not initialized yet.</para></listitem>
+ will not query the user for basic system settings, even if the system boots up for the first time and
+ the relevant settings are not initialized yet. Not to be confused with
+ <varname>systemd.condition-first-boot=</varname> (see below), which overrides the result of the
+ <varname>ConditionFirstBoot=</varname> unit file condition, and thus controls more than just
+ <filename>systemd-firstboot.service</filename> behaviour.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>systemd.condition-needs-update=</varname></term>
+
+ <listitem><para>Takes a boolean argument. If specified, overrides the result of
+ <varname>ConditionNeedsUpdate=</varname> unit condition checks. See
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+ details.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>systemd.condition-first-boot=</varname></term>
+
+ <listitem><para>Takes a boolean argument. If specified, overrides the result of
+ <varname>ConditionFirstBoot=</varname> unit condition checks. See
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+ details. Not to be confused with <varname>systemd.firstboot=</varname> which only controls behaviour
+ of the <filename>systemd-firstboot.service</filename> system service but has no effect on the
+ condition check (see above).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>systemd.clock-usec=</varname></term>
+
+ <listitem><para>Takes a decimal, numeric timestamp in µs since January 1st 1970, 00:00am, to set the
+ system clock to. The system time is set to the specified timestamp early during
+ boot. It is not propagated to the hardware clock (RTC).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>systemd.hostname=</varname></term>
+
+ <listitem><para>Accepts a hostname to set during early boot. If specified takes precedence over what
+ is set in <filename>/etc/hostname</filename>. Note that this does not bar later runtime changes to
+ the hostname, it simply controls the initial hostname set during early boot.</para></listitem>
</varlistentry>
</variablelist>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry project='man-pages'><refentrytitle>bootparam</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry project='man-pages'><refentrytitle>dracut.cmdline</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-rfkill.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>bootctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
</para>
</refsect1>