X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fbootup.xml;h=a1fe3d81cdced8cd38849231ff90697ca1ea5b0a;hp=ed72acfda9fba326017d9b47d6e7a6431e845f6c;hb=c17ec25e4d9bd6c8e8617416f813e25b2ebbafc5;hpb=5231084b479455e6cc892ec3c37c9f599c5bea58

diff --git a/man/bootup.xml b/man/bootup.xml
index ed72acfda..a1fe3d81c 100644
--- a/man/bootup.xml
+++ b/man/bootup.xml
@@ -44,7 +44,7 @@
 
         <refnamediv>
                 <refname>bootup</refname>
-                <refpurpose>The System Bootup Process</refpurpose>
+                <refpurpose>System bootup process</refpurpose>
         </refnamediv>
 
         <refsect1>
@@ -53,7 +53,7 @@
                 <para>A number of different components are involved in the
                 system boot. Immediately after power-up, the system
                 BIOS will do minimal hardware initialization, and hand
-                control over to a boot loader stored on a persistant
+                control over to a boot loader stored on a persistent
                 storage device. This boot loader will then invoke an
                 OS kernel from disk (or the network). In the Linux
                 case this kernel now (optionally) extracts and
@@ -111,7 +111,7 @@
                 target units are available, as listed on
                 <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
 
-                <para>The follow chart is a structural overview of
+                <para>The following chart is a structural overview of
                 these well-known units and their position in the
                 boot-up logic. The arrows describe which units are
                 pulled in and ordered before which other units. Units
@@ -173,6 +173,78 @@
                 to them.</para>
         </refsect1>
 
+        <refsect1>
+                <title>Initrd System Manager Bootup</title>
+                <para>The default target in the initrd is the initrd-fs.target. The bootup process is
+                identical to the System Manager Bootup until it reaches basic.target. From there,
+                systemd approaches the special initrd.target. If the root device can be mounted at
+                /sysroot, the sysroot.mount unit becomes active and the initrd-root-fs.target is
+                reached.
+                The initrd-parse-etc.service scans /sysroot/etc/fstab for a possible /usr mountpoint
+                and additional entries marked with the <emphasis>x-initrd.mount</emphasis> option.
+                All entries found are mounted below /sysroot, and the initrd-fs.target is reached.
+                The initrd-cleanup.service isolates to the initrd-switch-root.target, where cleanup
+                services can run. As the very last step, the initrd-switch-root.service is activated,
+                which will cause the system to switch its root to /sysroot.
+                </para>
+
+<programlisting>
+                             (identical to System Manager Bootup)
+                                               :
+                                               :
+                                               v
+                                         basic.target
+                                               |                                 emergency.service
+                        ______________________/|                                         |
+                       /                       |                                         v
+                       |                  sysroot.mount                          <emphasis>emergency.target</emphasis>
+                       |                       |
+                       |                       v
+                       |             initrd-root-fs.target
+                       |                       |
+                       |                       v
+                       |            initrd-parse-etc.service
+           (custom initrd services)            |
+                       |                       v
+                       |            (sysroot-usr.mount and
+                       |             various mounts marked
+                       |               with fstab option
+                       |                x-initrd.mount)
+                       |                       |
+                       |                       v
+                       |                initrd-fs.target
+                       |                       |
+                       \______________________ |
+                                              \|
+                                               v
+                                          initrd.target
+                                               |
+                                               v
+                                     initrd-cleanup.service
+                                          isolates to
+                                    initrd-switch-root.target
+                                               |
+                                               v
+                        ______________________/|
+                       /                       |
+                       |        initrd-udevadm-cleanup-db.service
+                       |                       |
+           (custom initrd services)            |
+                       |                       |
+                       \______________________ |
+                                              \|
+                                               v
+                                   initrd-switch-root.target
+                                               |
+                                               v
+                                   initrd-switch-root.service
+                                               |
+                                               v
+                                          switch-root
+</programlisting>
+        </refsect1>
+
+
         <refsect1>
                 <title>System Manager Shutdown</title>
 
@@ -219,7 +291,8 @@ systemd-reboot.service   systemd-poweroff.service   systemd-halt.service   syste
                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>boot</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
-                        <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+                        <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>dracut</refentrytitle><manvolnum>8</manvolnum></citerefentry>
                 </para>
         </refsect1>