man: add documentation for systemd-debug-generator

Makefile-man.am

@@ -58,6 +58,7 @@ MANPAGES += \
 	man/systemd-cat.1 \
 	man/systemd-cgls.1 \
 	man/systemd-cgtop.1 \
+	man/systemd-debug-generator.8 \
 	man/systemd-delta.1 \
 	man/systemd-detect-virt.1 \
 	man/systemd-efi-boot-generator.8 \
@@ -1577,6 +1578,7 @@ EXTRA_DIST += \
 	man/systemd-cgtop.xml \
 	man/systemd-cryptsetup-generator.xml \
 	man/systemd-cryptsetup@.service.xml \
+	man/systemd-debug-generator.xml \
 	man/systemd-delta.xml \
 	man/systemd-detect-virt.xml \
 	man/systemd-efi-boot-generator.xml \

man/systemd-debug-generator.xml

@@ -0,0 +1,90 @@
+<?xml version="1.0"?>
+<!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!--
+  This file is part of systemd.
+
+  Copyright 2014 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+<refentry id="systemd-debug-generator">
+
+        <refentryinfo>
+                <title>systemd-debug-generator</title>
+                <productname>systemd</productname>
+
+                <authorgroup>
+                        <author>
+                                <contrib>Developer</contrib>
+                                <firstname>Lennart</firstname>
+                                <surname>Poettering</surname>
+                                <email>lennart@poettering.net</email>
+                        </author>
+                </authorgroup>
+        </refentryinfo>
+
+        <refmeta>
+                <refentrytitle>systemd-debug-generator</refentrytitle>
+                <manvolnum>8</manvolnum>
+        </refmeta>
+
+        <refnamediv>
+                <refname>systemd-debug-generator</refname>
+                <refpurpose>Generator for enabling a runtime debug shell and masking specific units at boot</refpurpose>
+        </refnamediv>
+
+        <refsynopsisdiv>
+                <para><filename>/usr/lib/systemd/system-generators/systemd-debug-generator</filename></para>
+        </refsynopsisdiv>
+
+        <refsect1>
+                <title>Description</title>
+
+                <para><filename>systemd-debug-generator</filename> is
+                a generator that reads the kernel command line and understands two options:</para>
+
+                <para>If the <option>systemd.mask=</option> option is
+                specified and followed by a unit name this unit is
+                masked for the runtime, similar to the effect of
+                <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
+                <command>mask</command> command. This is useful to
+                boot with certain units removed from the initial boot
+                transaction for debugging system startup.</para>
+
+                <para>If the <option>systemd.debug-shell</option>
+                option is specified the debug shell service
+                <literal>debug-shell.service</literal> is pulled into
+                the boot transaction. It will spawn a debug shell on
+                tty9 during early system startup. Note that the shell
+                may also be turned on persistently by enabling it with
+                <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
+                <command>enable</command> command.</para>
+
+                <para><filename>systemd-debug-generator</filename>
+                implements the <ulink
+                url="http://www.freedesktop.org/wiki/Software/systemd/Generators">generator
+                specification</ulink>.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>See Also</title>
+                <para>
+                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+                </para>
+        </refsect1>
+
+</refentry>