1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
6 This file is part of systemd.
8 Copyright 2012 Lennart Poettering
10 systemd is free software; you can redistribute it and/or modify it
11 under the terms of the GNU Lesser General Public License as published by
12 the Free Software Foundation; either version 2.1 of the License, or
13 (at your option) any later version.
15 systemd is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 Lesser General Public License for more details.
20 You should have received a copy of the GNU Lesser General Public License
21 along with systemd; If not, see <http://www.gnu.org/licenses/>.
24 <refentry id="kernel-command-line">
27 <title>kernel-command-line</title>
28 <productname>systemd</productname>
32 <contrib>Developer</contrib>
33 <firstname>Lennart</firstname>
34 <surname>Poettering</surname>
35 <email>lennart@poettering.net</email>
41 <refentrytitle>kernel-command-line</refentrytitle>
42 <manvolnum>7</manvolnum>
46 <refname>kernel-command-line</refname>
47 <refpurpose>Kernel command line parameters</refpurpose>
51 <para><filename>/proc/cmdline</filename></para>
55 <title>Description</title>
57 <para>The kernel, the initial RAM disk (initrd) and
58 basic userspace functionality may be configured at boot via
59 kernel command line arguments.</para>
61 <para>For command line parameters understood by the kernel, please
63 url="https://www.kernel.org/doc/Documentation/kernel-parameters.txt"><filename>kernel-parameters.txt</filename></ulink>
65 <citerefentry project='man-pages'><refentrytitle>bootparam</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
67 <para>For command line parameters understood by the initial RAM
69 <citerefentry project='die-net'><refentrytitle>dracut.cmdline</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
70 or the documentation of the specific initrd implementation of your
75 <title>Core OS Command Line Arguments</title>
77 <variablelist class='kernel-commandline-options'>
79 <term><varname>systemd.unit=</varname></term>
80 <term><varname>rd.systemd.unit=</varname></term>
81 <term><varname>systemd.dump_core=</varname></term>
82 <term><varname>systemd.crash_shell=</varname></term>
83 <term><varname>systemd.crash_chvt=</varname></term>
84 <term><varname>systemd.confirm_spawn=</varname></term>
85 <term><varname>systemd.show_status=</varname></term>
86 <term><varname>systemd.log_target=</varname></term>
87 <term><varname>systemd.log_level=</varname></term>
88 <term><varname>systemd.log_color=</varname></term>
89 <term><varname>systemd.log_location=</varname></term>
90 <term><varname>systemd.default_standard_output=</varname></term>
91 <term><varname>systemd.default_standard_error=</varname></term>
92 <term><varname>systemd.setenv=</varname></term>
94 <para>Parameters understood by the system and service
95 manager to control system behavior. For details, see
96 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
101 <term><varname>systemd.mask=</varname></term>
102 <term><varname>systemd.wants=</varname></term>
103 <term><varname>systemd.debug-shell</varname></term>
105 <para>Additional parameters understood by
106 <citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
107 to mask or start specific units at boot, or invoke a debug
108 shell on tty9.</para>
113 <term><varname>systemd.restore_state=</varname></term>
115 <para>This parameter is understood by several system tools
116 to control whether or not they should restore system state
117 from the previous boot. For details, see
118 <citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
120 <citerefentry><refentrytitle>systemd-rfkill@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
126 <term><varname>quiet</varname></term>
128 <para>Parameter understood by both the kernel and the system
129 and service manager to control console log verbosity. For
131 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
136 <term><varname>debug</varname></term>
138 <para>Parameter understood by both the kernel and the system
139 and service manager to control console log verbosity. For
141 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
146 <term><varname>-b</varname></term>
147 <term><varname>emergency</varname></term>
148 <term><varname>rescue</varname></term>
149 <term><varname>single</varname></term>
150 <term><varname>s</varname></term>
151 <term><varname>S</varname></term>
152 <term><varname>1</varname></term>
153 <term><varname>2</varname></term>
154 <term><varname>3</varname></term>
155 <term><varname>4</varname></term>
156 <term><varname>5</varname></term>
158 <para>Parameters understood by the system and service
159 manager, as compatibility options. For details, see
160 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
165 <term><varname>locale.LANG=</varname></term>
166 <term><varname>locale.LANGUAGE=</varname></term>
167 <term><varname>locale.LC_CTYPE=</varname></term>
168 <term><varname>locale.LC_NUMERIC=</varname></term>
169 <term><varname>locale.LC_TIME=</varname></term>
170 <term><varname>locale.LC_COLLATE=</varname></term>
171 <term><varname>locale.LC_MONETARY=</varname></term>
172 <term><varname>locale.LC_MESSAGES=</varname></term>
173 <term><varname>locale.LC_PAPER=</varname></term>
174 <term><varname>locale.LC_NAME=</varname></term>
175 <term><varname>locale.LC_ADDRESS=</varname></term>
176 <term><varname>locale.LC_TELEPHONE=</varname></term>
177 <term><varname>locale.LC_MEASUREMENT=</varname></term>
178 <term><varname>locale.LC_IDENTIFICATION=</varname></term>
180 <para>Parameters understood by the system and service
181 manager to control locale and language settings. For
183 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
188 <term><varname>fsck.mode=</varname></term>
189 <term><varname>fsck.repair=</varname></term>
192 <para>Parameters understood by the file system checker
193 services. For details, see
194 <citerefentry><refentrytitle>systemd-fsck@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
199 <term><varname>quotacheck.mode=</varname></term>
202 <para>Parameter understood by the file quota checker
203 service. For details, see
204 <citerefentry><refentrytitle>systemd-quotacheck.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
209 <term><varname>systemd.journald.forward_to_syslog=</varname></term>
210 <term><varname>systemd.journald.forward_to_kmsg=</varname></term>
211 <term><varname>systemd.journald.forward_to_console=</varname></term>
212 <term><varname>systemd.journald.forward_to_wall=</varname></term>
215 <para>Parameters understood by the journal service. For
217 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
222 <term><varname>vconsole.keymap=</varname></term>
223 <term><varname>vconsole.keymap.toggle=</varname></term>
224 <term><varname>vconsole.font=</varname></term>
225 <term><varname>vconsole.font.map=</varname></term>
226 <term><varname>vconsole.font.unimap=</varname></term>
229 <para>Parameters understood by the virtual console setup
230 logic. For details, see
231 <citerefentry><refentrytitle>systemd-vconsole-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
236 <term><varname>udev.log-priority=</varname></term>
237 <term><varname>rd.udev.log-priority=</varname></term>
238 <term><varname>udev.children-max=</varname></term>
239 <term><varname>rd.udev.children-max=</varname></term>
240 <term><varname>udev.exec-delay=</varname></term>
241 <term><varname>rd.udev.exec-delay=</varname></term>
242 <term><varname>udev.event-timeout=</varname></term>
243 <term><varname>rd.udev.event-timeout=</varname></term>
244 <term><varname>net.ifnames=</varname></term>
247 <para>Parameters understood by the device event managing
248 daemon. For details, see
249 <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
254 <term><varname>plymouth.enable=</varname></term>
257 <para>May be used to disable the Plymouth boot splash. For
259 <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
264 <term><varname>luks=</varname></term>
265 <term><varname>rd.luks=</varname></term>
266 <term><varname>luks.crypttab=</varname></term>
267 <term><varname>rd.luks.crypttab=</varname></term>
268 <term><varname>luks.name=</varname></term>
269 <term><varname>rd.luks.name=</varname></term>
270 <term><varname>luks.uuid=</varname></term>
271 <term><varname>rd.luks.uuid=</varname></term>
272 <term><varname>luks.options=</varname></term>
273 <term><varname>rd.luks.options=</varname></term>
274 <term><varname>luks.key=</varname></term>
275 <term><varname>rd.luks.key=</varname></term>
278 <para>Configures the LUKS full-disk encryption logic at
279 boot. For details, see
280 <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
285 <term><varname>fstab=</varname></term>
286 <term><varname>rd.fstab=</varname></term>
289 <para>Configures the <filename>/etc/fstab</filename> logic
290 at boot. For details, see
291 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
296 <term><varname>root=</varname></term>
297 <term><varname>rootfstype=</varname></term>
298 <term><varname>rootfsflags=</varname></term>
299 <term><varname>ro</varname></term>
300 <term><varname>rw</varname></term>
303 <para>Configures the root file system and its file system
304 type and mount options, as well as whether it shall be
305 mounted read-only or read-writable initially. For details,
307 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
312 <term><varname>systemd.gpt_auto=</varname></term>
313 <term><varname>rd.systemd.gpt_auto=</varname></term>
316 <para>Configures whether GPT based partition auto-discovery
317 shall be attempted. For details, see
318 <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
323 <term><varname>modules-load=</varname></term>
324 <term><varname>rd.modules-load=</varname></term>
327 <para>Load a specific kernel module early at boot. For
329 <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
334 <term><varname>resume=</varname></term>
337 <para>Enables resume from hibernation using the specified
339 <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>-like
340 paths are supported. For details, see
341 <citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
349 <title>See Also</title>
351 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
352 <citerefentry project='man-pages'><refentrytitle>bootparam</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
353 <citerefentry project='die-net'><refentrytitle>dracut.cmdline</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
354 <citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
355 <citerefentry><refentrytitle>systemd-fsck@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
356 <citerefentry><refentrytitle>systemd-quotacheck.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
357 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
358 <citerefentry><refentrytitle>systemd-vconsole-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
359 <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
360 <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
361 <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
362 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
363 <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
364 <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
365 <citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
366 <citerefentry><refentrytitle>systemd-rfkill@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
367 <citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>