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
   9
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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><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><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.debug-shell</varname></term>
 104                                 <listitem>
 105                                         <para>Additional parameters
 106                                         understood by
 107                                         <citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 108                                         to mask specific units at
 109                                         boot, or invoke a debug shell
 110                                         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
 118                                         several system tools to control
 119                                         whether or not they should restore
 120                                         system state from the previous boot.
 121                                         For details, see
 122                                         <citerefentry><refentrytitle>systemd-backlight@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 123                                         and
 124                                         <citerefentry><refentrytitle>systemd-rfkill@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
 125                                         </para>
 126                                 </listitem>
 127                         </varlistentry>
 128
 129                         <varlistentry>
 130                                 <term><varname>quiet</varname></term>
 131                                 <listitem>
 132                                         <para>Parameter understood by
 133                                         both the kernel and the system
 134                                         and service manager to control
 135                                         console log verbosity. For
 136                                         details, see
 137                                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
 138                                 </listitem>
 139                         </varlistentry>
 140
 141                         <varlistentry>
 142                                 <term><varname>debug</varname></term>
 143                                 <listitem>
 144                                         <para>Parameter understood by
 145                                         both the kernel and the system
 146                                         and service manager to control
 147                                         console log verbosity. For
 148                                         details, see
 149                                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.</para>
 150                                 </listitem>
 151                         </varlistentry>
 152
 153                         <varlistentry>
 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>
 164                                 <listitem>
 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>
 170                                 </listitem>
 171                         </varlistentry>
 172
 173                         <varlistentry>
 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>
 188                                 <listitem>
 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>
 194                                 </listitem>
 195                         </varlistentry>
 196
 197                         <varlistentry>
 198                                 <term><varname>fsck.mode=</varname></term>
 199                                 <term><varname>fsck.repair=</varname></term>
 200
 201                                 <listitem>
 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>
 206                                 </listitem>
 207                         </varlistentry>
 208
 209                         <varlistentry>
 210                                 <term><varname>quotacheck.mode=</varname></term>
 211
 212                                 <listitem>
 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>
 217                                 </listitem>
 218                         </varlistentry>
 219
 220                         <varlistentry>
 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>
 225
 226                                 <listitem>
 227                                         <para>Parameters understood by
 228                                         the journal service. For
 229                                         details, see
 230                                         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 231                                 </listitem>
 232                         </varlistentry>
 233
 234                         <varlistentry>
 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>
 240
 241                                 <listitem>
 242                                         <para>Parameters understood by
 243                                         the virtual console setup logic. For
 244                                         details, see
 245                                         <citerefentry><refentrytitle>systemd-vconsole-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 246                                 </listitem>
 247                         </varlistentry>
 248
 249                         <varlistentry>
 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>
 257
 258                                 <listitem>
 259                                         <para>Parameters understood by
 260                                         the device event managing daemon. For
 261                                         details, see
 262                                         <citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 263                                 </listitem>
 264                         </varlistentry>
 265
 266                         <varlistentry>
 267                                 <term><varname>plymouth.enable=</varname></term>
 268
 269                                 <listitem>
 270                                         <para>May be used to disable
 271                                         the Plymouth boot splash. For
 272                                         details, see
 273                                         <citerefentry><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 274                                 </listitem>
 275                         </varlistentry>
 276
 277                         <varlistentry>
 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>
 288
 289                                 <listitem>
 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>
 294                                 </listitem>
 295                         </varlistentry>
 296
 297                         <varlistentry>
 298                                 <term><varname>fstab=</varname></term>
 299                                 <term><varname>rd.fstab=</varname></term>
 300
 301                                 <listitem>
 302                                         <para>Configures the
 303                                         <filename>/etc/fstab</filename>
 304                                         logic at boot. For details, see
 305                                         <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 306                                 </listitem>
 307                         </varlistentry>
 308
 309                         <varlistentry>
 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>
 315
 316                                 <listitem>
 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
 321                                         mounted read-only or
 322                                         read-writable initially. For
 323                                         details, see
 324                                         <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 325                                 </listitem>
 326                         </varlistentry>
 327
 328                         <varlistentry>
 329                                 <term><varname>systemd.gpt_auto=</varname></term>
 330                                 <term><varname>rd.systemd.gpt_auto=</varname></term>
 331
 332                                 <listitem>
 333                                         <para>Configures whether GPT
 334                                         based partition auto-discovery
 335                                         shall be attempted. For
 336                                         details, see
 337                                         <citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 338                                 </listitem>
 339                         </varlistentry>
 340
 341                         <varlistentry>
 342                                 <term><varname>modules-load=</varname></term>
 343                                 <term><varname>rd.modules-load=</varname></term>
 344
 345                                 <listitem>
 346                                         <para>Load a specific kernel
 347                                         module early at boot. For
 348                                         details, see
 349                                         <citerefentry><refentrytitle>systemd-modules-load.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
 350                                 </listitem>
 351                         </varlistentry>
 352
 353                 </variablelist>
 354
 355         </refsect1>
 356
 357         <refsect1>
 358                   <title>See Also</title>
 359                   <para>
 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>
 376                   </para>
 377         </refsect1>
 378
 379 </refentry>