man/systemd-debug-generator.xml

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   5   SPDX-License-Identifier: LGPL-2.1+
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   7 <refentry id="systemd-debug-generator">
   8
   9   <refentryinfo>
  10     <title>systemd-debug-generator</title>
  11     <productname>systemd</productname>
  12
  13     <authorgroup>
  14       <author>
  15         <contrib>Developer</contrib>
  16         <firstname>Lennart</firstname>
  17         <surname>Poettering</surname>
  18         <email>lennart@poettering.net</email>
  19       </author>
  20     </authorgroup>
  21   </refentryinfo>
  22
  23   <refmeta>
  24     <refentrytitle>systemd-debug-generator</refentrytitle>
  25     <manvolnum>8</manvolnum>
  26   </refmeta>
  27
  28   <refnamediv>
  29     <refname>systemd-debug-generator</refname>
  30     <refpurpose>Generator for enabling a runtime debug shell and
  31     masking specific units at boot</refpurpose>
  32   </refnamediv>
  33
  34   <refsynopsisdiv>
  35     <para><filename>/usr/lib/systemd/system-generators/systemd-debug-generator</filename></para>
  36   </refsynopsisdiv>
  37
  38   <refsect1>
  39     <title>Description</title>
  40
  41     <para><filename>systemd-debug-generator</filename> is a generator
  42     that reads the kernel command line and understands three
  43     options:</para>
  44
  45     <para>If the <option>systemd.mask=</option> option is specified
  46     and followed by a unit name, this unit is masked for the runtime,
  47     similar to the effect of
  48     <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
  49     <command>mask</command> command. This is useful to boot with
  50     certain units removed from the initial boot transaction for
  51     debugging system startup. May be specified more than once.</para>
  52
  53     <para>If the <option>systemd.wants=</option> option is specified
  54     and followed by a unit name, a start job for this unit is added to
  55     the initial transaction. This is useful to start one or more
  56     additional units at boot. May be specified more than once.</para>
  57
  58     <para>If the <option>systemd.debug_shell</option> option is
  59     specified, the debug shell service
  60     <literal>debug-shell.service</literal> is pulled into the boot
  61     transaction. It will spawn a debug shell on tty9 during early
  62     system startup. Note that the shell may also be turned on
  63     persistently by enabling it with
  64     <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
  65     <command>enable</command> command.</para>
  66
  67     <para><filename>systemd-debug-generator</filename> implements
  68     <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
  69   </refsect1>
  70
  71   <refsect1>
  72     <title>See Also</title>
  73     <para>
  74       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
  75       <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
  76       <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>
  77     </para>
  78   </refsect1>
  79
  80 </refentry>