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
62 kernel, please see <ulink
63 url="https://www.kernel.org/doc/Documentation/kernel-parameters.txt"><filename>kernel-parameters.txt</filename></ulink>
65 <citerefentry><refentrytitle>bootparam</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
67 <para>For command line parameters understood by the
68 initial RAM disk, please see
69 <citerefentry><refentrytitle>dracut.cmdline</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
70 or the documentation of the specific initrd
71 implementation of your installation.</para>
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
95 the system and service manager
96 to control system behavior. For details, see
97 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
102 <term><varname>systemd.mask=</varname></term>
103 <term><varname>systemd.wants=</varname></term>
104 <term><varname>systemd.debug-shell</varname></term>
106 <para>Additional parameters
108 <citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
109 to mask or start specific
110 units at boot, or invoke a
111 debug shell on tty9.</para>
116 <term><varname>systemd.restore_state=</varname></term>
118 <para>This parameter is understood by
119 several system tools to control
120 whether or not they should restore
121 system state from the previous boot.
123 <citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
125 <citerefentry><refentrytitle>systemd-rfkill@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
131 <term><varname>quiet</varname></term>
133 <para>Parameter understood by
134 both the kernel and the system
135 and service manager to control
136 console log verbosity. For
138 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
143 <term><varname>debug</varname></term>
145 <para>Parameter understood by
146 both the kernel and the system
147 and service manager to control
148 console log verbosity. For
150 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
155 <term><varname>-b</varname></term>
156 <term><varname>emergency</varname></term>
157 <term><varname>single</varname></term>
158 <term><varname>s</varname></term>
159 <term><varname>S</varname></term>
160 <term><varname>1</varname></term>
161 <term><varname>2</varname></term>
162 <term><varname>3</varname></term>
163 <term><varname>4</varname></term>
164 <term><varname>5</varname></term>
166 <para>Parameters understood by
167 the system and service
168 manager, as compatibility
169 options. For details, see
170 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
175 <term><varname>locale.LANG=</varname></term>
176 <term><varname>locale.LANGUAGE=</varname></term>
177 <term><varname>locale.LC_CTYPE=</varname></term>
178 <term><varname>locale.LC_NUMERIC=</varname></term>
179 <term><varname>locale.LC_TIME=</varname></term>
180 <term><varname>locale.LC_COLLATE=</varname></term>
181 <term><varname>locale.LC_MONETARY=</varname></term>
182 <term><varname>locale.LC_MESSAGES=</varname></term>
183 <term><varname>locale.LC_PAPER=</varname></term>
184 <term><varname>locale.LC_NAME=</varname></term>
185 <term><varname>locale.LC_ADDRESS=</varname></term>
186 <term><varname>locale.LC_TELEPHONE=</varname></term>
187 <term><varname>locale.LC_MEASUREMENT=</varname></term>
188 <term><varname>locale.LC_IDENTIFICATION=</varname></term>
190 <para>Parameters understood by
191 the system and service manager
192 to control locale and language
193 settings. For details, see
194 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
199 <term><varname>fsck.mode=</varname></term>
200 <term><varname>fsck.repair=</varname></term>
203 <para>Parameters understood by
204 the file system checker
205 services. For details, see
206 <citerefentry><refentrytitle>systemd-fsck@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
211 <term><varname>quotacheck.mode=</varname></term>
214 <para>Parameter understood by
215 the file quota checker
216 service. For details, see
217 <citerefentry><refentrytitle>systemd-quotacheck.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
222 <term><varname>systemd.journald.forward_to_syslog=</varname></term>
223 <term><varname>systemd.journald.forward_to_kmsg=</varname></term>
224 <term><varname>systemd.journald.forward_to_console=</varname></term>
225 <term><varname>systemd.journald.forward_to_wall=</varname></term>
228 <para>Parameters understood by
229 the journal service. For
231 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
236 <term><varname>vconsole.keymap=</varname></term>
237 <term><varname>vconsole.keymap.toggle=</varname></term>
238 <term><varname>vconsole.font=</varname></term>
239 <term><varname>vconsole.font.map=</varname></term>
240 <term><varname>vconsole.font.unimap=</varname></term>
243 <para>Parameters understood by
244 the virtual console setup logic. For
246 <citerefentry><refentrytitle>systemd-vconsole-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
251 <term><varname>udev.log-priority=</varname></term>
252 <term><varname>rd.udev.log-priority=</varname></term>
253 <term><varname>udev.children-max=</varname></term>
254 <term><varname>rd.udev.children-max=</varname></term>
255 <term><varname>udev.exec-delay=</varname></term>
256 <term><varname>rd.udev.exec-delay=</varname></term>
257 <term><varname>net.ifnames=</varname></term>
260 <para>Parameters understood by
261 the device event managing daemon. For
263 <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
268 <term><varname>plymouth.enable=</varname></term>
271 <para>May be used to disable
272 the Plymouth boot splash. For
274 <citerefentry><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
279 <term><varname>luks=</varname></term>
280 <term><varname>rd.luks=</varname></term>
281 <term><varname>luks.crypttab=</varname></term>
282 <term><varname>rd.luks.crypttab=</varname></term>
283 <term><varname>luks.uuid=</varname></term>
284 <term><varname>rd.luks.uuid=</varname></term>
285 <term><varname>luks.options=</varname></term>
286 <term><varname>rd.luks.options=</varname></term>
287 <term><varname>luks.key=</varname></term>
288 <term><varname>rd.luks.key=</varname></term>
291 <para>Configures the LUKS
292 full-disk encryption logic at
293 boot. For details, see
294 <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
299 <term><varname>fstab=</varname></term>
300 <term><varname>rd.fstab=</varname></term>
304 <filename>/etc/fstab</filename>
305 logic at boot. For details, see
306 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
311 <term><varname>root=</varname></term>
312 <term><varname>rootfstype=</varname></term>
313 <term><varname>rootfsflags=</varname></term>
314 <term><varname>ro</varname></term>
315 <term><varname>rw</varname></term>
318 <para>Configures the root file
319 system and its file system
320 type and mount options, as
321 well as whether it shall be
323 read-writable initially. For
325 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
330 <term><varname>systemd.gpt_auto=</varname></term>
331 <term><varname>rd.systemd.gpt_auto=</varname></term>
334 <para>Configures whether GPT
335 based partition auto-discovery
336 shall be attempted. For
338 <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
343 <term><varname>modules-load=</varname></term>
344 <term><varname>rd.modules-load=</varname></term>
347 <para>Load a specific kernel
348 module early at boot. For
350 <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
359 <title>See Also</title>
361 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
362 <citerefentry><refentrytitle>bootparam</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
363 <citerefentry><refentrytitle>dracut.cmdline</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
364 <citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
365 <citerefentry><refentrytitle>systemd-fsck@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
366 <citerefentry><refentrytitle>systemd-quotacheck.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
367 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
368 <citerefentry><refentrytitle>systemd-vconsole-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
369 <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
370 <citerefentry><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
371 <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
372 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
373 <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
374 <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
375 <citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
376 <citerefentry><refentrytitle>systemd-rfkill@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>