man/kernel-command-line.xml

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   8   Copyright 2012 Lennart Poettering
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  23
  24 <refentry id="kernel-command-line">
  25
  26   <refentryinfo>
  27     <title>kernel-command-line</title>
  28     <productname>systemd</productname>
  29
  30     <authorgroup>
  31       <author>
  32         <contrib>Developer</contrib>
  33         <firstname>Lennart</firstname>
  34         <surname>Poettering</surname>
  35         <email>lennart@poettering.net</email>
  36       </author>
  37     </authorgroup>
  38   </refentryinfo>
  39
  40   <refmeta>
  41     <refentrytitle>kernel-command-line</refentrytitle>
  42     <manvolnum>7</manvolnum>
  43   </refmeta>
  44
  45   <refnamediv>
  46     <refname>kernel-command-line</refname>
  47     <refpurpose>Kernel command line parameters</refpurpose>
  48   </refnamediv>
  49
  50   <refsynopsisdiv>
  51     <para><filename>/proc/cmdline</filename></para>
  52   </refsynopsisdiv>
  53
  54   <refsect1>
  55     <title>Description</title>
  56
  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>
  60
  61     <para>For command line parameters understood by the kernel, please
  62     see <ulink
  63     url="https://www.kernel.org/doc/Documentation/kernel-parameters.txt"><filename>kernel-parameters.txt</filename></ulink>
  64     and
  65     <citerefentry project='man-pages'><refentrytitle>bootparam</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
  66
  67     <para>For command line parameters understood by the initial RAM
  68     disk, please see
  69     <citerefentry project='man-pages'><refentrytitle>dracut.cmdline</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
  70     or the documentation of the specific initrd implementation of your
  71     installation.</para>
  72   </refsect1>
  73
  74   <refsect1>
  75     <title>Core OS Command Line Arguments</title>
  76
  77     <variablelist class='kernel-commandline-options'>
  78       <varlistentry>
  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_chvt=</varname></term>
  83         <term><varname>systemd.crash_shell=</varname></term>
  84         <term><varname>systemd.crash_reboot=</varname></term>
  85         <term><varname>systemd.confirm_spawn=</varname></term>
  86         <term><varname>systemd.show_status=</varname></term>
  87         <term><varname>systemd.log_target=</varname></term>
  88         <term><varname>systemd.log_level=</varname></term>
  89         <term><varname>systemd.log_color=</varname></term>
  90         <term><varname>systemd.log_location=</varname></term>
  91         <term><varname>systemd.default_standard_output=</varname></term>
  92         <term><varname>systemd.default_standard_error=</varname></term>
  93         <term><varname>systemd.setenv=</varname></term>
  94         <term><varname>systemd.machine_id=</varname></term>
  95         <listitem>
  96           <para>Parameters understood by the system and service
  97           manager to control system behavior. For details, see
  98           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
  99         </listitem>
 100       </varlistentry>
 101
 102       <varlistentry>
 103         <term><varname>systemd.mask=</varname></term>
 104         <term><varname>systemd.wants=</varname></term>
 105         <term><varname>systemd.debug_shell</varname></term>
 106         <listitem>
 107           <para>Additional parameters understood by
 108           <citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 109           to mask or start specific units at boot, or invoke a debug
 110           shell on tty9.</para>
 111         </listitem>
 112       </varlistentry>
 113
 114       <varlistentry>
 115         <term><varname>systemd.restore_state=</varname></term>
 116         <listitem>
 117           <para>This parameter is understood by several system tools
 118           to control whether or not they should restore system state
 119           from the previous boot. For details, see
 120           <citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 121           and
 122           <citerefentry><refentrytitle>systemd-rfkill.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 123           </para>
 124         </listitem>
 125       </varlistentry>
 126
 127       <varlistentry>
 128         <term><varname>quiet</varname></term>
 129         <listitem>
 130           <para>Parameter understood by both the kernel and the system
 131           and service manager to control console log verbosity. For
 132           details, see
 133           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
 134         </listitem>
 135       </varlistentry>
 136
 137       <varlistentry>
 138         <term><varname>debug</varname></term>
 139         <listitem>
 140           <para>Parameter understood by both the kernel and the system
 141           and service manager to control console log verbosity. For
 142           details, see
 143           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
 144         </listitem>
 145       </varlistentry>
 146
 147       <varlistentry>
 148         <term><varname>-b</varname></term>
 149         <term><varname>rd.emergency</varname></term>
 150         <term><varname>emergency</varname></term>
 151         <term><varname>rd.rescue</varname></term>
 152         <term><varname>rescue</varname></term>
 153         <term><varname>single</varname></term>
 154         <term><varname>s</varname></term>
 155         <term><varname>S</varname></term>
 156         <term><varname>1</varname></term>
 157         <term><varname>2</varname></term>
 158         <term><varname>3</varname></term>
 159         <term><varname>4</varname></term>
 160         <term><varname>5</varname></term>
 161         <listitem>
 162           <para>Parameters understood by the system and service
 163           manager, as compatibility and convenience options. For details, see
 164           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
 165         </listitem>
 166       </varlistentry>
 167
 168       <varlistentry>
 169         <term><varname>locale.LANG=</varname></term>
 170         <term><varname>locale.LANGUAGE=</varname></term>
 171         <term><varname>locale.LC_CTYPE=</varname></term>
 172         <term><varname>locale.LC_NUMERIC=</varname></term>
 173         <term><varname>locale.LC_TIME=</varname></term>
 174         <term><varname>locale.LC_COLLATE=</varname></term>
 175         <term><varname>locale.LC_MONETARY=</varname></term>
 176         <term><varname>locale.LC_MESSAGES=</varname></term>
 177         <term><varname>locale.LC_PAPER=</varname></term>
 178         <term><varname>locale.LC_NAME=</varname></term>
 179         <term><varname>locale.LC_ADDRESS=</varname></term>
 180         <term><varname>locale.LC_TELEPHONE=</varname></term>
 181         <term><varname>locale.LC_MEASUREMENT=</varname></term>
 182         <term><varname>locale.LC_IDENTIFICATION=</varname></term>
 183         <listitem>
 184           <para>Parameters understood by the system and service
 185           manager to control locale and language settings. For
 186           details, see
 187           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
 188         </listitem>
 189       </varlistentry>
 190
 191       <varlistentry>
 192         <term><varname>fsck.mode=</varname></term>
 193         <term><varname>fsck.repair=</varname></term>
 194
 195         <listitem>
 196           <para>Parameters understood by the file system checker
 197           services. For details, see
 198           <citerefentry><refentrytitle>systemd-fsck@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 199         </listitem>
 200       </varlistentry>
 201
 202       <varlistentry>
 203         <term><varname>quotacheck.mode=</varname></term>
 204
 205         <listitem>
 206           <para>Parameter understood by the file quota checker
 207           service. For details, see
 208           <citerefentry><refentrytitle>systemd-quotacheck.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 209         </listitem>
 210       </varlistentry>
 211
 212       <varlistentry>
 213         <term><varname>systemd.journald.forward_to_syslog=</varname></term>
 214         <term><varname>systemd.journald.forward_to_kmsg=</varname></term>
 215         <term><varname>systemd.journald.forward_to_console=</varname></term>
 216         <term><varname>systemd.journald.forward_to_wall=</varname></term>
 217
 218         <listitem>
 219           <para>Parameters understood by the journal service. For
 220           details, see
 221           <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 222         </listitem>
 223       </varlistentry>
 224
 225       <varlistentry>
 226         <term><varname>vconsole.keymap=</varname></term>
 227         <term><varname>vconsole.keymap_toggle=</varname></term>
 228         <term><varname>vconsole.font=</varname></term>
 229         <term><varname>vconsole.font_map=</varname></term>
 230         <term><varname>vconsole.font_unimap=</varname></term>
 231
 232         <listitem>
 233           <para>Parameters understood by the virtual console setup logic. For details, see
 234           <citerefentry><refentrytitle>vconsole.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 235         </listitem>
 236       </varlistentry>
 237
 238       <varlistentry>
 239         <term><varname>udev.log_priority=</varname></term>
 240         <term><varname>rd.udev.log_priority=</varname></term>
 241         <term><varname>udev.children_max=</varname></term>
 242         <term><varname>rd.udev.children_max=</varname></term>
 243         <term><varname>udev.exec_delay=</varname></term>
 244         <term><varname>rd.udev.exec_delay=</varname></term>
 245         <term><varname>udev.event_timeout=</varname></term>
 246         <term><varname>rd.udev.event_timeout=</varname></term>
 247         <term><varname>net.ifnames=</varname></term>
 248
 249         <listitem>
 250           <para>Parameters understood by the device event managing
 251           daemon. For details, see
 252           <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 253         </listitem>
 254       </varlistentry>
 255
 256       <varlistentry>
 257         <term><varname>plymouth.enable=</varname></term>
 258
 259         <listitem>
 260           <para>May be used to disable the Plymouth boot splash. For
 261           details, see
 262           <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 263         </listitem>
 264       </varlistentry>
 265
 266       <varlistentry>
 267         <term><varname>luks=</varname></term>
 268         <term><varname>rd.luks=</varname></term>
 269         <term><varname>luks.crypttab=</varname></term>
 270         <term><varname>rd.luks.crypttab=</varname></term>
 271         <term><varname>luks.name=</varname></term>
 272         <term><varname>rd.luks.name=</varname></term>
 273         <term><varname>luks.uuid=</varname></term>
 274         <term><varname>rd.luks.uuid=</varname></term>
 275         <term><varname>luks.options=</varname></term>
 276         <term><varname>rd.luks.options=</varname></term>
 277         <term><varname>luks.key=</varname></term>
 278         <term><varname>rd.luks.key=</varname></term>
 279
 280         <listitem>
 281           <para>Configures the LUKS full-disk encryption logic at
 282           boot. For details, see
 283           <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 284         </listitem>
 285       </varlistentry>
 286
 287       <varlistentry>
 288         <term><varname>fstab=</varname></term>
 289         <term><varname>rd.fstab=</varname></term>
 290
 291         <listitem>
 292           <para>Configures the <filename>/etc/fstab</filename> logic
 293           at boot. For details, see
 294           <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 295         </listitem>
 296       </varlistentry>
 297
 298       <varlistentry>
 299         <term><varname>root=</varname></term>
 300         <term><varname>rootfstype=</varname></term>
 301         <term><varname>rootflags=</varname></term>
 302         <term><varname>ro</varname></term>
 303         <term><varname>rw</varname></term>
 304
 305         <listitem>
 306           <para>Configures the root file system and its file system
 307           type and mount options, as well as whether it shall be
 308           mounted read-only or read-writable initially. For details,
 309           see
 310           <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 311         </listitem>
 312       </varlistentry>
 313
 314       <varlistentry>
 315         <term><varname>systemd.gpt_auto=</varname></term>
 316         <term><varname>rd.systemd.gpt_auto=</varname></term>
 317
 318         <listitem>
 319           <para>Configures whether GPT based partition auto-discovery
 320           shall be attempted. For details, see
 321           <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 322         </listitem>
 323       </varlistentry>
 324
 325       <varlistentry>
 326         <term><varname>systemd.default_timeout_start_sec=</varname></term>
 327
 328         <listitem>
 329           <para>Overwrites the default start job timeout <varname>DefaultTimeoutStartSec=</varname> at boot. For details,
 330           see <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
 331         </listitem>
 332       </varlistentry>
 333
 334       <varlistentry>
 335         <term><varname>modules_load=</varname></term>
 336         <term><varname>rd.modules_load=</varname></term>
 337
 338         <listitem>
 339           <para>Load a specific kernel module early at boot. For
 340           details, see
 341           <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 342         </listitem>
 343       </varlistentry>
 344
 345       <varlistentry>
 346         <term><varname>resume=</varname></term>
 347
 348         <listitem>
 349           <para>Enables resume from hibernation using the specified
 350           device. All
 351           <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>-like
 352           paths are supported. For details, see
 353           <citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 354         </listitem>
 355       </varlistentry>
 356
 357       <varlistentry>
 358         <term><varname>systemd.firstboot=</varname></term>
 359
 360         <listitem><para>Takes a boolean argument, defaults to on. If off,
 361         <citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 362         will not query the user for basic system settings, even if the system boots up for the first time and the
 363         relevant settings are not initialized yet.</para></listitem>
 364       </varlistentry>
 365     </variablelist>
 366
 367   </refsect1>
 368
 369   <refsect1>
 370       <title>See Also</title>
 371       <para>
 372         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 373         <citerefentry project='man-pages'><refentrytitle>bootparam</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 374         <citerefentry project='man-pages'><refentrytitle>dracut.cmdline</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 375         <citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 376         <citerefentry><refentrytitle>systemd-fsck@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 377         <citerefentry><refentrytitle>systemd-quotacheck.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 378         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 379         <citerefentry><refentrytitle>systemd-vconsole-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 380         <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 381         <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 382         <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 383         <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 384         <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 385         <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 386         <citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 387         <citerefentry><refentrytitle>systemd-rfkill.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 388         <citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 389         <citerefentry><refentrytitle>systemd-firstboot.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 390       </para>
 391   </refsect1>
 392
 393 </refentry>