man/kernel-command-line.xml

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   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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   6   This file is part of systemd.
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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
  62                 kernel, please 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
  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>
  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_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>
  93                                 <listitem>
  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>
  98                                 </listitem>
  99                         </varlistentry>
 100
 101                         <varlistentry>
 102                                 <term><varname>systemd.mask=</varname></term>
 103                                 <term><varname>systemd.wants=</varname></term>
 104                                 <term><varname>systemd.debug-shell</varname></term>
 105                                 <listitem>
 106                                         <para>Additional parameters
 107                                         understood by
 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>
 112                                 </listitem>
 113                         </varlistentry>
 114
 115                         <varlistentry>
 116                                 <term><varname>systemd.restore_state=</varname></term>
 117                                 <listitem>
 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.
 122                                         For details, see
 123                                         <citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 124                                         and
 125                                         <citerefentry><refentrytitle>systemd-rfkill@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 126                                         </para>
 127                                 </listitem>
 128                         </varlistentry>
 129
 130                         <varlistentry>
 131                                 <term><varname>quiet</varname></term>
 132                                 <listitem>
 133                                         <para>Parameter understood by
 134                                         both the kernel and the system
 135                                         and service manager to control
 136                                         console log verbosity. For
 137                                         details, see
 138                                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
 139                                 </listitem>
 140                         </varlistentry>
 141
 142                         <varlistentry>
 143                                 <term><varname>debug</varname></term>
 144                                 <listitem>
 145                                         <para>Parameter understood by
 146                                         both the kernel and the system
 147                                         and service manager to control
 148                                         console log verbosity. For
 149                                         details, see
 150                                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
 151                                 </listitem>
 152                         </varlistentry>
 153
 154                         <varlistentry>
 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>
 165                                 <listitem>
 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>
 171                                 </listitem>
 172                         </varlistentry>
 173
 174                         <varlistentry>
 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>
 189                                 <listitem>
 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>
 195                                 </listitem>
 196                         </varlistentry>
 197
 198                         <varlistentry>
 199                                 <term><varname>fsck.mode=</varname></term>
 200                                 <term><varname>fsck.repair=</varname></term>
 201
 202                                 <listitem>
 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>
 207                                 </listitem>
 208                         </varlistentry>
 209
 210                         <varlistentry>
 211                                 <term><varname>quotacheck.mode=</varname></term>
 212
 213                                 <listitem>
 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>
 218                                 </listitem>
 219                         </varlistentry>
 220
 221                         <varlistentry>
 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>
 226
 227                                 <listitem>
 228                                         <para>Parameters understood by
 229                                         the journal service. For
 230                                         details, see
 231                                         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 232                                 </listitem>
 233                         </varlistentry>
 234
 235                         <varlistentry>
 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>
 241
 242                                 <listitem>
 243                                         <para>Parameters understood by
 244                                         the virtual console setup logic. For
 245                                         details, see
 246                                         <citerefentry><refentrytitle>systemd-vconsole-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 247                                 </listitem>
 248                         </varlistentry>
 249
 250                         <varlistentry>
 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>
 258
 259                                 <listitem>
 260                                         <para>Parameters understood by
 261                                         the device event managing daemon. For
 262                                         details, see
 263                                         <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 264                                 </listitem>
 265                         </varlistentry>
 266
 267                         <varlistentry>
 268                                 <term><varname>plymouth.enable=</varname></term>
 269
 270                                 <listitem>
 271                                         <para>May be used to disable
 272                                         the Plymouth boot splash. For
 273                                         details, see
 274                                         <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 275                                 </listitem>
 276                         </varlistentry>
 277
 278                         <varlistentry>
 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>
 289
 290                                 <listitem>
 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>
 295                                 </listitem>
 296                         </varlistentry>
 297
 298                         <varlistentry>
 299                                 <term><varname>fstab=</varname></term>
 300                                 <term><varname>rd.fstab=</varname></term>
 301
 302                                 <listitem>
 303                                         <para>Configures the
 304                                         <filename>/etc/fstab</filename>
 305                                         logic at boot. For details, see
 306                                         <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 307                                 </listitem>
 308                         </varlistentry>
 309
 310                         <varlistentry>
 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>
 316
 317                                 <listitem>
 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
 322                                         mounted read-only or
 323                                         read-writable initially. For
 324                                         details, see
 325                                         <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 326                                 </listitem>
 327                         </varlistentry>
 328
 329                         <varlistentry>
 330                                 <term><varname>systemd.gpt_auto=</varname></term>
 331                                 <term><varname>rd.systemd.gpt_auto=</varname></term>
 332
 333                                 <listitem>
 334                                         <para>Configures whether GPT
 335                                         based partition auto-discovery
 336                                         shall be attempted. For
 337                                         details, see
 338                                         <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 339                                 </listitem>
 340                         </varlistentry>
 341
 342                         <varlistentry>
 343                                 <term><varname>modules-load=</varname></term>
 344                                 <term><varname>rd.modules-load=</varname></term>
 345
 346                                 <listitem>
 347                                         <para>Load a specific kernel
 348                                         module early at boot. For
 349                                         details, see
 350                                         <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 351                                 </listitem>
 352                         </varlistentry>
 353
 354                         <varlistentry>
 355                                 <term><varname>resume=</varname></term>
 356
 357                                 <listitem>
 358                                         <para>Enables resume from hibernation
 359                                         using the specified device.
 360                                         All <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>-like
 361                                         paths are supported. For details, see
 362                                         <citerefentry><refentrytitle>systemd-hibernate-resume-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 363                                 </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='die-net'><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                   </para>
 390         </refsect1>
 391
 392 </refentry>