[9dfc02f] | 1 | <?xml version="1.0" encoding="ISO-8859-1"?>
|
---|
| 2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN" "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" [
|
---|
| 3 | <!ENTITY % general-entities SYSTEM "../general.ent">
|
---|
| 4 | %general-entities;
|
---|
| 5 | ]>
|
---|
| 6 | <sect1 id="ch-system-devices" xreflabel="devices">
|
---|
[4f74577] | 7 | <title>Populating /dev</title>
|
---|
[9dfc02f] | 8 | <?dbhtml filename="devices.html"?>
|
---|
| 9 |
|
---|
[3c928f1] | 10 | <indexterm zone="ch-system-devices"><primary sortas="e-Devices">Devices</primary></indexterm>
|
---|
[9dfc02f] | 11 |
|
---|
| 12 | <sect2>
|
---|
| 13 | <title>Creating initial device nodes</title>
|
---|
| 14 |
|
---|
| 15 | <para>When the kernel boots the system, it requires the presence of a few device
|
---|
[3c928f1] | 16 | nodes, in particular the <filename class="devicefile">console</filename> and
|
---|
| 17 | <filename class="devicefile">null</filename> devices:</para>
|
---|
[9dfc02f] | 18 |
|
---|
| 19 | <screen><userinput>mknod -m 600 /dev/console c 5 1
|
---|
| 20 | mknod -m 666 /dev/null c 1 3</userinput></screen>
|
---|
| 21 | </sect2>
|
---|
| 22 |
|
---|
| 23 | <sect2>
|
---|
| 24 | <title>Mounting ramfs and populating /dev</title>
|
---|
| 25 |
|
---|
[3c928f1] | 26 | <para>The ideal way to populate <filename class="directory">/dev</filename> is
|
---|
| 27 | to mount a <systemitem class="filesystem">ramfs</systemitem> onto <filename class="directory">/dev </filename>
|
---|
| 28 | like <systemitem class="filesystem">tmpfs</systemitem>, but it
|
---|
[9dfc02f] | 29 | cannot be swapped) and create the devices on there during each bootup. Since we haven't
|
---|
| 30 | booted the system, we have to do what the bootscripts would otherwise do for us, and
|
---|
[3c928f1] | 31 | populate <filename class="directory">/dev</filename> ourselves. Begin by mounting <filename class="directory">/dev</filename>:</para>
|
---|
[9dfc02f] | 32 |
|
---|
| 33 | <screen><userinput>mount -n -t ramfs none /dev</userinput></screen>
|
---|
| 34 |
|
---|
[6135b95] | 35 | <para>Since we do not have the Udev package installed yet, we'll create a
|
---|
| 36 | minimal set of device nodes to use for building:</para>
|
---|
[9dfc02f] | 37 |
|
---|
[0a9b2e0] | 38 | <screen><userinput>mknod -m 622 /dev/console c 5 1
|
---|
| 39 | mknod -m 666 /dev/null c 1 3
|
---|
| 40 | mknod -m 666 /dev/zero c 1 5
|
---|
| 41 | mknod -m 666 /dev/ptmx c 5 2
|
---|
[84dee3b4] | 42 | mknod -m 666 /dev/tty c 5 0
|
---|
| 43 | mknod -m 444 /dev/random c 1 8
|
---|
| 44 | mknod -m 444 /dev/urandom c 1 9
|
---|
| 45 | chown root:tty /dev/{console,ptmx,tty}</userinput></screen>
|
---|
[9dfc02f] | 46 |
|
---|
| 47 | <para>There are some symlinks and directories required by LFS that are not created by
|
---|
| 48 | Udev, so we create those ourselves here:</para>
|
---|
| 49 |
|
---|
| 50 | <screen><userinput>ln -s /proc/self/fd /dev/fd
|
---|
| 51 | ln -s /proc/self/fd/0 /dev/stdin
|
---|
| 52 | ln -s /proc/self/fd/1 /dev/stdout
|
---|
| 53 | ln -s /proc/self/fd/2 /dev/stderr
|
---|
| 54 | ln -s /proc/kcore /dev/core
|
---|
| 55 | mkdir /dev/pts
|
---|
| 56 | mkdir /dev/shm</userinput></screen>
|
---|
| 57 |
|
---|
| 58 | <para>Finally, mount the proper virtual (kernel) file systems on the directories we just
|
---|
| 59 | created:</para>
|
---|
| 60 |
|
---|
| 61 | <screen><userinput>mount -t devpts -o gid=4,mode=620 none /dev/pts
|
---|
| 62 | mount -t tmpfs none /dev/shm</userinput></screen>
|
---|
[af133c3] | 63 |
|
---|
| 64 | <para>The <command>mount</command> commands executed above may result in the
|
---|
| 65 | following warning message:</para>
|
---|
| 66 |
|
---|
| 67 | <screen><computeroutput>can't open /etc/fstab: No such file or directory.</computeroutput></screen>
|
---|
| 68 |
|
---|
| 69 | <para>This file—<filename>/etc/fstab</filename>—has not
|
---|
| 70 | been created yet but is also not required for the file systems to be
|
---|
| 71 | properly mounted. As such, the warning can be safely ignored.</para>
|
---|
[9dfc02f] | 72 | </sect2>
|
---|
| 73 |
|
---|
| 74 |
|
---|
| 75 | </sect1>
|
---|