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Diffstat (limited to 'chapter06/kernfs.xml')
| -rw-r--r-- | chapter06/kernfs.xml | 79 |
1 files changed, 59 insertions, 20 deletions
diff --git a/chapter06/kernfs.xml b/chapter06/kernfs.xml index 2bdf9f9c3..3c9e68c0b 100644 --- a/chapter06/kernfs.xml +++ b/chapter06/kernfs.xml @@ -8,33 +8,72 @@ <sect1 id="ch-system-kernfs"> <?dbhtml filename="kernfs.html"?> - <title>Mounting Virtual Kernel File Systems</title> + <title>Preparing Virtual Kernel File Systems</title> - <para>Various file systems exported by the kernel are used to communicate to and - from the kernel itself. These file systems are virtual in that no disk space is - used for them. The content of the file systems resides in memory.</para> + <indexterm zone="ch-system-kernfs"> + <primary sortas="e-/dev/">/dev/*</primary> + </indexterm> - <para>Begin by creating directories onto which the file systems will be - mounted:</para> + <para>Various file systems exported by the kernel are used to communicate to + and from the kernel itself. These file systems are virtual in that no disk + space is used for them. The content of the file systems resides in + memory.</para> -<screen><userinput>mkdir -pv $LFS/{proc,sys}</userinput></screen> + <para>Begin by creating directories onto which the file systems will be + mounted:</para> - <para>Now mount the file systems:</para> +<screen><userinput>mkdir -pv $LFS/{dev,proc,sys}</userinput></screen> -<screen><userinput>mount -vt proc proc $LFS/proc -mount -vt sysfs sysfs $LFS/sys</userinput></screen> + <sect2> + <title>Creating Initial Device Nodes</title> + + <para>When the kernel boots the system, it requires the presence of a few + device nodes, in particular the <filename + class="devicefile">console</filename> and <filename + class="devicefile">null</filename> devices. The device nodes will be created + on the hard disk so that they are available before <command>udev</command> + has been started, and additionally when Linux is started in single user mode + (hence the restrictive permissions on <filename + class="devicefile">console</filename>). Create the devices by running the + following commands:</para> + +<screen><userinput>mknod -m 600 $LFS/dev/console c 5 1 +mknod -m 666 $LFS/dev/null c 1 3</userinput></screen> + + </sect2> + + <sect2 id="ch-system-bindmount"> + <title>Mounting and Populating /dev</title> - <para>Remember that if for any reason you stop working on the LFS - system and start again later, it is important to check that these file - systems are mounted again before entering the chroot - environment.</para> + <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 by 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> - <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 --bind /dev $LFS/dev</userinput></screen> + + </sect2> + + <sect2 id="ch-system-kernfsmount"> + <title>Mounting Virtual Kernel File Systems</title> + + <para>Now mount the remaining virtual kernel filesystems:</para> + +<screen><userinput>mount -vt devpts devpts $LFS/dev/pts +mount -vt tmpfs shm $LFS/dev/shm +mount -vt proc proc $LFS/proc +mount -vt sysfs sysfs $LFS/sys</userinput></screen> -<screen><userinput>mount -vft tmpfs tmpfs $LFS/dev -mount -vft tmpfs tmpfs $LFS/dev/shm -mount -vft devpts -o gid=4,mode=620 devpts $LFS/dev/pts</userinput></screen> + </sect2> </sect1> |