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