r1676 - / trunk/BOOK/chroot/common

jim at linuxfromscratch.org jim at linuxfromscratch.org
Mon May 29 04:58:52 PDT 2006

Author: jim
Date: 2006-05-29 05:58:52 -0600 (Mon, 29 May 2006)
New Revision: 1676

 r3688 at server (orig r1724):  jeremy | 2006-05-29 02:45:38 -0700
 Mount --bind host /dev to LFS's dev on chroot builds - fixes ticket #27

Property changes on: 
Name: svk:merge
   - b6734a72-470d-0410-b049-f317dca95413:/:1723
   + b6734a72-470d-0410-b049-f317dca95413:/:1724

Modified: trunk/BOOK/chroot/common/devices.xml
--- trunk/BOOK/chroot/common/devices.xml	2006-05-29 11:58:42 UTC (rev 1675)
+++ trunk/BOOK/chroot/common/devices.xml	2006-05-29 11:58:52 UTC (rev 1676)
@@ -8,69 +8,16 @@
 <sect1 id="ch-chroot-devices">
   <?dbhtml filename="devices.html"?>
-  <title>Populating /dev</title>
+  <title>Mounting Kernel Filesystems</title>
   <indexterm zone="ch-chroot-devices">
     <primary sortas="e-/dev/*">/dev/*</primary>
-    <title>Creating Initial Device Nodes</title>
+    <title>Mounting Additional Kernel Filesystems</title>
-    <xi:include xmlns:xi="http://www.w3.org/2003/XInclude"
-    href="../../boot/common/devices.xml"
-    xpointer="xpointer(//*[@os='b'])"/>
-<screen><userinput>mknod -m 600 /dev/console c 5 1
-mknod -m 666 /dev/null c 1 3</userinput></screen>
-  </sect2>
-  <sect2>
-    <title>Mounting tmpfs and Populating /dev</title>
-    <para>The recommended method of populating the <filename
-    class="directory">/dev</filename> directory with devices is to
-    mount a virtual filesystem (such as <systemitem
-    class="filesystem">tmpfs</systemitem>) on the <filename
-    class="directory">/dev</filename> directory, and allow the devices
-    to be created dynamically on that virtual filesystem as they are
-    detected or accessed. This is generally done during the boot process.
-    Since this new system has not been booted, it is necessary to do what
-    the LFS-Bootscripts package would otherwise do by mounting <filename
-    class="directory">/dev</filename>:</para>
-<screen><userinput>mount -n -vt tmpfs none /dev</userinput></screen>
-    <para>The Udev package is what actually creates the devices in the
-    <filename class="directory">/dev</filename> directory. Since it will
-    not be installed until later on in the process, manually create the
-    minimal set of device nodes needed to complete the building of this
-    system:</para>
-<screen><userinput>mknod -m 622 /dev/console c 5 1
-mknod -m 666 /dev/null c 1 3
-mknod -m 666 /dev/zero c 1 5
-mknod -m 666 /dev/ptmx c 5 2
-mknod -m 666 /dev/tty c 5 0
-mknod -m 444 /dev/random c 1 8
-mknod -m 444 /dev/urandom c 1 9
-chown -v root:tty /dev/{console,ptmx,tty}</userinput></screen>
-    <para>There are some symlinks and directories required by LFS that
-    are created during system startup by the LFS-Bootscripts package. Since
-    this is a chroot environment and not a booted environment, those symlinks
-    and directories need to be created here:</para>
-<screen><userinput>ln -sv /proc/self/fd /dev/fd
-ln -sv /proc/self/fd/0 /dev/stdin
-ln -sv /proc/self/fd/1 /dev/stdout
-ln -sv /proc/self/fd/2 /dev/stderr
-ln -sv /proc/kcore /dev/core
-mkdir -v /dev/pts
-mkdir -v /dev/shm</userinput></screen>
-    <para>Finally, mount the proper virtual (kernel) file systems on the
+    <para>Mount the proper virtual (kernel) file systems on the
     newly-created directories:</para>
 <screen><userinput>mount -vt devpts -o gid=4,mode=620 none /dev/pts

Modified: trunk/BOOK/chroot/common/kernfs.xml
--- trunk/BOOK/chroot/common/kernfs.xml	2006-05-29 11:58:42 UTC (rev 1675)
+++ trunk/BOOK/chroot/common/kernfs.xml	2006-05-29 11:58:52 UTC (rev 1676)
@@ -33,12 +33,27 @@
   and start again later, it is important to check that these file systems
   are mounted again before entering the chroot environment.</para>
-  <para>Additional file systems will soon be mounted from within the
-  chroot environment. To keep the host up to date, perform a <quote>fake
-  mount</quote> for each of these now:</para>
+  <para>Two device nodes, /dev/console and /dev/null, are required to be
+  present on the filesystem.  These are needed by the kernel even before
+  starting Udev early in the boot process, so we create them here:</para>
-<screen><userinput>mount -f -vt tmpfs tmpfs $LFS/dev
-mount -f -vt tmpfs tmpfs $LFS/dev/shm
+<screen><userinput>mknod -m 600 $LFS/dev/console c 5 1
+mknod -m 666 $LFS/dev/null c 1 3</userinput></screen>
+  <para>Once the system is complete and booting, the rest of our device
+  nodes are created by the Udev package.  Since this package is not
+  available to us right now, we must take other steps to provide device
+  nodes under on the LFS filesystem.  We will use the <quote>bind</quote>
+  option in the mount command to make our host system's /dev structure
+  appear in the new LFS filesystem:</para>
+<screen><userinput>/tools/bin/mount -o bind /dev $LFS/dev</userinput></screen>
+  <para>Additional file systems will soon be mounted from within the chroot 
+  environment. To keep the host up to date, perform a <quote>fake mount</quote>
+  for each of these now:</para>
+<screen><userinput>mount -f -vt tmpfs tmpfs $LFS/dev/shm
 mount -f -vt devpts -o gid=10,mode=620 devpts $LFS/dev/pts</userinput></screen>

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