Changes in chapter07/kernfs.xml [ac47b25:d35dc01]

File:

• chapter07/kernfs.xml (modified) (2 diffs)

chapter07/kernfs.xml

@@ -23 +23 @@
     mounted:</para>
 
-<screen><userinput>mkdir -pv $LFS/{dev,proc,sys,run}</userinput></screen>
-
-  <sect2 id="ch-tools-bindmount">
-    <title>Mounting and Populating /dev</title>
-
-      <para>During a normal boot, the kernel automatically mounts the
-      <systemitem class="filesystem">devtmpfs</systemitem> filesystem 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. Device creation is generally done during the
-      boot process by the kernel and Udev.
-      Since this new system does not yet have Udev and
-      has not yet been booted, it is necessary to mount and populate
-      <filename class="directory">/dev</filename> manually. This is
-      accomplished by bind mounting the host system's
-      <filename class="directory">/dev</filename> directory. A bind mount is
-      a special type of mount that allows you to create a mirror of a
-      directory or mount point to some other location. Use the following
-      command to achieve this:</para>
-
-<screen><userinput>mount -v --bind /dev $LFS/dev</userinput></screen>
-
-  </sect2>
+<screen><userinput>mkdir -pv /{proc,sys,run}</userinput></screen>
 
   <sect2 id="ch-tools-kernfsmount">
     <title>Mounting Virtual Kernel File Systems</title>
 
-      <para>Now mount the remaining virtual kernel filesystems:</para>
+    <para>The kernel has already mounted
+    <systemitem class="filesystem">devtmpfs</systemitem>.
+    Mount the remaining virtual kernel filesystems:</para>
 
-<screen><userinput>mount -v --bind /dev/pts $LFS/dev/pts
-mount -vt proc proc $LFS/proc
-mount -vt sysfs sysfs $LFS/sys
-mount -vt tmpfs tmpfs $LFS/run</userinput></screen>
-<!--
+<screen><userinput>mkdir -pv /dev/{pts,shm}
+mount -vt devpts /dev/pts /dev/pts -o gid=5,mode=620
+mount -vt proc  proc  /proc
+mount -vt sysfs sysfs /sys
+mount -vt tmpfs tmpfs /run
+mount -vt tmpfs tmpfs /dev/shm</userinput></screen>
+
     <variablelist>
       <title>The meaning of the mount options for devpts:</title>
@@ -84 +66 @@
 
     </variablelist>
--->
-      <para>In some host systems, <filename>/dev/shm</filename> is a
-      symbolic link to <filename class="directory">/run/shm</filename>.
-      The /run tmpfs was mounted above so in this case only a
-      directory needs to be created.</para>
 
-<screen><userinput>if [ -h $LFS/dev/shm ]; then
-  mkdir -pv $LFS/$(readlink $LFS/dev/shm)
-fi</userinput></screen>
+  </sect2>
+
+  <sect2 id="ch-tools-devadjust">
+    <title>Adjusting devtmpfs</title>
+
+    <para>Now <systemitem class='filesystem'>proc</systemitem> filesystem
+    is mounted, we can replace the device nodes for standard I/O streams
+    with symlinks to pseudo files in
+    <filename class="directory">/proc/self/fd</filename> (which are symlinks
+    to the files connected to the standard I/O streams for the current
+    process).  And, create another symlink recommended by the kernel
+    documentation.  These are necessary for I/O redirection in the building
+    system of some packages to function properly:</para>
+
+<screen><userinput>ln -sfv /proc/self/fd/0 /dev/stdin
+ln -sfv /proc/self/fd/1 /dev/stdout
+ln -sfv /proc/self/fd/2 /dev/stderr
+ln -sv  /proc/self/fd   /dev</userinput></screen>
 
   </sect2>