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.debug-shell</varname></term>
105 <para>Additional parameters
107 <citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
108 to mask specific units at
109 boot, or invoke a debug shell
115 <term><varname>systemd.restore_state=</varname></term>
117 <para>This parameter is understood by
118 several system tools to control
119 whether or not they should restore
120 system state from the previous boot.
122 <citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
124 <citerefentry><refentrytitle>systemd-rfkill@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
130 <term><varname>quiet</varname></term>
132 <para>Parameter understood by
133 both the kernel and the system
134 and service manager to control
135 console log verbosity. For
137 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
142 <term><varname>debug</varname></term>
144 <para>Parameter understood by
145 both the kernel and the system
146 and service manager to control
147 console log verbosity. For
149 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
154 <term><varname>-b</varname></term>
155 <term><varname>emergency</varname></term>
156 <term><varname>single</varname></term>
157 <term><varname>s</varname></term>
158 <term><varname>S</varname></term>
159 <term><varname>1</varname></term>
160 <term><varname>2</varname></term>
161 <term><varname>3</varname></term>
162 <term><varname>4</varname></term>
163 <term><varname>5</varname></term>
165 <para>Parameters understood by
166 the system and service
167 manager, as compatibility
168 options. For details, see
169 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
174 <term><varname>locale.LANG=</varname></term>
175 <term><varname>locale.LANGUAGE=</varname></term>
176 <term><varname>locale.LC_CTYPE=</varname></term>
177 <term><varname>locale.LC_NUMERIC=</varname></term>
178 <term><varname>locale.LC_TIME=</varname></term>
179 <term><varname>locale.LC_COLLATE=</varname></term>
180 <term><varname>locale.LC_MONETARY=</varname></term>
181 <term><varname>locale.LC_MESSAGES=</varname></term>
182 <term><varname>locale.LC_PAPER=</varname></term>
183 <term><varname>locale.LC_NAME=</varname></term>
184 <term><varname>locale.LC_ADDRESS=</varname></term>
185 <term><varname>locale.LC_TELEPHONE=</varname></term>
186 <term><varname>locale.LC_MEASUREMENT=</varname></term>
187 <term><varname>locale.LC_IDENTIFICATION=</varname></term>
189 <para>Parameters understood by
190 the system and service manager
191 to control locale and language
192 settings. For details, see
193 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
198 <term><varname>fsck.mode=</varname></term>
199 <term><varname>fsck.repair=</varname></term>
202 <para>Parameters understood by
203 the file system checker
204 services. For details, see
205 <citerefentry><refentrytitle>systemd-fsck@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
210 <term><varname>quotacheck.mode=</varname></term>
213 <para>Parameter understood by
214 the file quota checker
215 service. For details, see
216 <citerefentry><refentrytitle>systemd-quotacheck.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
221 <term><varname>systemd.journald.forward_to_syslog=</varname></term>
222 <term><varname>systemd.journald.forward_to_kmsg=</varname></term>
223 <term><varname>systemd.journald.forward_to_console=</varname></term>
224 <term><varname>systemd.journald.forward_to_wall=</varname></term>
227 <para>Parameters understood by
228 the journal service. For
230 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
235 <term><varname>vconsole.keymap=</varname></term>
236 <term><varname>vconsole.keymap.toggle=</varname></term>
237 <term><varname>vconsole.font=</varname></term>
238 <term><varname>vconsole.font.map=</varname></term>
239 <term><varname>vconsole.font.unimap=</varname></term>
242 <para>Parameters understood by
243 the virtual console setup logic. For
245 <citerefentry><refentrytitle>systemd-vconsole-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
250 <term><varname>udev.log-priority=</varname></term>
251 <term><varname>rd.udev.log-priority=</varname></term>
252 <term><varname>udev.children-max=</varname></term>
253 <term><varname>rd.udev.children-max=</varname></term>
254 <term><varname>udev.exec-delay=</varname></term>
255 <term><varname>rd.udev.exec-delay=</varname></term>
256 <term><varname>net.ifnames=</varname></term>
259 <para>Parameters understood by
260 the device event managing daemon. For
262 <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
267 <term><varname>plymouth.enable=</varname></term>
270 <para>May be used to disable
271 the Plymouth boot splash. For
273 <citerefentry><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
278 <term><varname>luks=</varname></term>
279 <term><varname>rd.luks=</varname></term>
280 <term><varname>luks.crypttab=</varname></term>
281 <term><varname>rd.luks.crypttab=</varname></term>
282 <term><varname>luks.uuid=</varname></term>
283 <term><varname>rd.luks.uuid=</varname></term>
284 <term><varname>luks.options=</varname></term>
285 <term><varname>rd.luks.options=</varname></term>
286 <term><varname>luks.key=</varname></term>
287 <term><varname>rd.luks.key=</varname></term>
290 <para>Configures the LUKS
291 full-disk encryption logic at
292 boot. For details, see
293 <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
298 <term><varname>fstab=</varname></term>
299 <term><varname>rd.fstab=</varname></term>
303 <filename>/etc/fstab</filename>
304 logic at boot. For details, see
305 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
310 <term><varname>root=</varname></term>
311 <term><varname>rootfstype=</varname></term>
312 <term><varname>rootfsflags=</varname></term>
313 <term><varname>ro</varname></term>
314 <term><varname>rw</varname></term>
317 <para>Configures the root file
318 system and its file system
319 type and mount options, as
320 well as whether it shall be
322 read-writable initially. For
324 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
329 <term><varname>systemd.gpt_auto=</varname></term>
330 <term><varname>rd.systemd.gpt_auto=</varname></term>
333 <para>Configures whether GPT
334 based partition auto-discovery
335 shall be attempted. For
337 <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
342 <term><varname>modules-load=</varname></term>
343 <term><varname>rd.modules-load=</varname></term>
346 <para>Load a specific kernel
347 module early at boot. For
349 <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
358 <title>See Also</title>
360 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
361 <citerefentry><refentrytitle>bootparam</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
362 <citerefentry><refentrytitle>dracut.cmdline</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
363 <citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
364 <citerefentry><refentrytitle>systemd-fsck@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
365 <citerefentry><refentrytitle>systemd-quotacheck.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
366 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
367 <citerefentry><refentrytitle>systemd-vconsole-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
368 <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
369 <citerefentry><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
370 <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
371 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
372 <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
373 <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
374 <citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
375 <citerefentry><refentrytitle>systemd-rfkill@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>