man/systemd-debug-generator.xml

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   7   This file is part of systemd.
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   9   Copyright 2014 Lennart Poettering
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  24 <refentry id="systemd-debug-generator">
  25
  26   <refentryinfo>
  27     <title>systemd-debug-generator</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>systemd-debug-generator</refentrytitle>
  42     <manvolnum>8</manvolnum>
  43   </refmeta>
  44
  45   <refnamediv>
  46     <refname>systemd-debug-generator</refname>
  47     <refpurpose>Generator for enabling a runtime debug shell and
  48     masking specific units at boot</refpurpose>
  49   </refnamediv>
  50
  51   <refsynopsisdiv>
  52     <para><filename>/usr/lib/systemd/system-generators/systemd-debug-generator</filename></para>
  53   </refsynopsisdiv>
  54
  55   <refsect1>
  56     <title>Description</title>
  57
  58     <para><filename>systemd-debug-generator</filename> is a generator
  59     that reads the kernel command line and understands three
  60     options:</para>
  61
  62     <para>If the <option>systemd.mask=</option> option is specified
  63     and followed by a unit name, this unit is masked for the runtime,
  64     similar to the effect of
  65     <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
  66     <command>mask</command> command. This is useful to boot with
  67     certain units removed from the initial boot transaction for
  68     debugging system startup. May be specified more than once.</para>
  69
  70     <para>If the <option>systemd.wants=</option> option is specified
  71     and followed by a unit name, a start job for this unit is added to
  72     the initial transaction. This is useful to start one or more
  73     additional units at boot. May be specified more than once.</para>
  74
  75     <para>If the <option>systemd.debug_shell</option> option is
  76     specified, the debug shell service
  77     <literal>debug-shell.service</literal> is pulled into the boot
  78     transaction. It will spawn a debug shell on tty9 during early
  79     system startup. Note that the shell may also be turned on
  80     persistently by enabling it with
  81     <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
  82     <command>enable</command> command.</para>
  83
  84     <para><filename>systemd-debug-generator</filename> implements
  85     <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
  86   </refsect1>
  87
  88   <refsect1>
  89     <title>See Also</title>
  90     <para>
  91       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
  92       <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
  93       <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>
  94     </para>
  95   </refsect1>
  96
  97 </refentry>