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 project='man-pages'
><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 project='die-net'
><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>rescue
</varname></term>
158 <term><varname>single
</varname></term>
159 <term><varname>s
</varname></term>
160 <term><varname>S
</varname></term>
161 <term><varname>1</varname></term>
162 <term><varname>2</varname></term>
163 <term><varname>3</varname></term>
164 <term><varname>4</varname></term>
165 <term><varname>5</varname></term>
167 <para>Parameters understood by
168 the system and service
169 manager, as compatibility
170 options. For details, see
171 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
</para>
176 <term><varname>locale.LANG=
</varname></term>
177 <term><varname>locale.LANGUAGE=
</varname></term>
178 <term><varname>locale.LC_CTYPE=
</varname></term>
179 <term><varname>locale.LC_NUMERIC=
</varname></term>
180 <term><varname>locale.LC_TIME=
</varname></term>
181 <term><varname>locale.LC_COLLATE=
</varname></term>
182 <term><varname>locale.LC_MONETARY=
</varname></term>
183 <term><varname>locale.LC_MESSAGES=
</varname></term>
184 <term><varname>locale.LC_PAPER=
</varname></term>
185 <term><varname>locale.LC_NAME=
</varname></term>
186 <term><varname>locale.LC_ADDRESS=
</varname></term>
187 <term><varname>locale.LC_TELEPHONE=
</varname></term>
188 <term><varname>locale.LC_MEASUREMENT=
</varname></term>
189 <term><varname>locale.LC_IDENTIFICATION=
</varname></term>
191 <para>Parameters understood by
192 the system and service manager
193 to control locale and language
194 settings. For details, see
195 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
</para>
200 <term><varname>fsck.mode=
</varname></term>
201 <term><varname>fsck.repair=
</varname></term>
204 <para>Parameters understood by
205 the file system checker
206 services. For details, see
207 <citerefentry><refentrytitle>systemd-fsck@.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
212 <term><varname>quotacheck.mode=
</varname></term>
215 <para>Parameter understood by
216 the file quota checker
217 service. For details, see
218 <citerefentry><refentrytitle>systemd-quotacheck.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
223 <term><varname>systemd.journald.forward_to_syslog=
</varname></term>
224 <term><varname>systemd.journald.forward_to_kmsg=
</varname></term>
225 <term><varname>systemd.journald.forward_to_console=
</varname></term>
226 <term><varname>systemd.journald.forward_to_wall=
</varname></term>
229 <para>Parameters understood by
230 the journal service. For
232 <citerefentry><refentrytitle>systemd-journald.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
237 <term><varname>vconsole.keymap=
</varname></term>
238 <term><varname>vconsole.keymap.toggle=
</varname></term>
239 <term><varname>vconsole.font=
</varname></term>
240 <term><varname>vconsole.font.map=
</varname></term>
241 <term><varname>vconsole.font.unimap=
</varname></term>
244 <para>Parameters understood by
245 the virtual console setup logic. For
247 <citerefentry><refentrytitle>systemd-vconsole-setup.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
252 <term><varname>udev.log-priority=
</varname></term>
253 <term><varname>rd.udev.log-priority=
</varname></term>
254 <term><varname>udev.children-max=
</varname></term>
255 <term><varname>rd.udev.children-max=
</varname></term>
256 <term><varname>udev.exec-delay=
</varname></term>
257 <term><varname>rd.udev.exec-delay=
</varname></term>
258 <term><varname>udev.event-timeout=
</varname></term>
259 <term><varname>rd.udev.event-timeout=
</varname></term>
260 <term><varname>net.ifnames=
</varname></term>
263 <para>Parameters understood by
264 the device event managing daemon. For
266 <citerefentry><refentrytitle>systemd-udevd.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
271 <term><varname>plymouth.enable=
</varname></term>
274 <para>May be used to disable
275 the Plymouth boot splash. For
277 <citerefentry project='die-net'
><refentrytitle>plymouth
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
282 <term><varname>luks=
</varname></term>
283 <term><varname>rd.luks=
</varname></term>
284 <term><varname>luks.crypttab=
</varname></term>
285 <term><varname>rd.luks.crypttab=
</varname></term>
286 <term><varname>luks.uuid=
</varname></term>
287 <term><varname>rd.luks.uuid=
</varname></term>
288 <term><varname>luks.options=
</varname></term>
289 <term><varname>rd.luks.options=
</varname></term>
290 <term><varname>luks.key=
</varname></term>
291 <term><varname>rd.luks.key=
</varname></term>
294 <para>Configures the LUKS
295 full-disk encryption logic at
296 boot. For details, see
297 <citerefentry><refentrytitle>systemd-cryptsetup-generator
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
302 <term><varname>fstab=
</varname></term>
303 <term><varname>rd.fstab=
</varname></term>
307 <filename>/etc/fstab
</filename>
308 logic at boot. For details, see
309 <citerefentry><refentrytitle>systemd-fstab-generator
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
314 <term><varname>root=
</varname></term>
315 <term><varname>rootfstype=
</varname></term>
316 <term><varname>rootfsflags=
</varname></term>
317 <term><varname>ro
</varname></term>
318 <term><varname>rw
</varname></term>
321 <para>Configures the root file
322 system and its file system
323 type and mount options, as
324 well as whether it shall be
326 read-writable initially. For
328 <citerefentry><refentrytitle>systemd-fstab-generator
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
333 <term><varname>systemd.gpt_auto=
</varname></term>
334 <term><varname>rd.systemd.gpt_auto=
</varname></term>
337 <para>Configures whether GPT
338 based partition auto-discovery
339 shall be attempted. For
341 <citerefentry><refentrytitle>systemd-gpt-auto-generator
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
346 <term><varname>modules-load=
</varname></term>
347 <term><varname>rd.modules-load=
</varname></term>
350 <para>Load a specific kernel
351 module early at boot. For
353 <citerefentry><refentrytitle>systemd-modules-load.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
358 <term><varname>resume=
</varname></term>
361 <para>Enables resume from hibernation
362 using the specified device.
363 All
<citerefentry><refentrytitle>fstab
</refentrytitle><manvolnum>5</manvolnum></citerefentry>-like
364 paths are supported. For details, see
365 <citerefentry><refentrytitle>systemd-hibernate-resume-generator
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
373 <title>See Also
</title>
375 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
376 <citerefentry project='man-pages'
><refentrytitle>bootparam
</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
377 <citerefentry project='die-net'
><refentrytitle>dracut.cmdline
</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
378 <citerefentry><refentrytitle>systemd-debug-generator
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
379 <citerefentry><refentrytitle>systemd-fsck@.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
380 <citerefentry><refentrytitle>systemd-quotacheck.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
381 <citerefentry><refentrytitle>systemd-journald.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
382 <citerefentry><refentrytitle>systemd-vconsole-setup.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
383 <citerefentry><refentrytitle>systemd-udevd.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
384 <citerefentry project='die-net'
><refentrytitle>plymouth
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
385 <citerefentry><refentrytitle>systemd-cryptsetup-generator
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
386 <citerefentry><refentrytitle>systemd-fstab-generator
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
387 <citerefentry><refentrytitle>systemd-gpt-auto-generator
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
388 <citerefentry><refentrytitle>systemd-modules-load.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
389 <citerefentry><refentrytitle>systemd-backlight@.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
390 <citerefentry><refentrytitle>systemd-rfkill@.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
391 <citerefentry><refentrytitle>systemd-hibernate-resume-generator
</refentrytitle><manvolnum>8</manvolnum></citerefentry>