1 | <?xml version="1.0" encoding="ISO-8859-1"?> |
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2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" |
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3 | "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [ |
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4 | <!ENTITY % general-entities SYSTEM "../../general.ent"> |
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5 | %general-entities; |
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6 | ]> |
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7 | |
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8 | <sect1 id="ch-boot-devices"> |
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9 | <?dbhtml filename="devices.html"?> |
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10 | |
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11 | <title>Populating /dev</title> |
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12 | |
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13 | <indexterm zone="ch-boot-devices"> |
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14 | <primary sortas="e-/dev/*">/dev/*</primary> |
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15 | </indexterm> |
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16 | |
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17 | <sect2> |
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18 | <title>Creating Initial Device Nodes</title> |
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19 | |
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20 | <note os="a"> |
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21 | <para>The commands in the remainder of the book should be run as |
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22 | the <systemitem class="username">root</systemitem> user. Also, |
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23 | double-check that ${CLFS} is set as |
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24 | <systemitem class="username">root</systemitem>.</para> |
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25 | </note> |
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26 | |
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27 | <para os="b">When the kernel boots the system, it requires the presence |
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28 | of a few device nodes, in particular the <filename |
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29 | class="devicefile">console</filename> and <filename |
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30 | class="devicefile">null</filename> devices. The device nodes will |
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31 | be created on the hard disk so that they are available before |
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32 | <command>udev</command> has been started, and additionally when Linux |
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33 | is started in single user mode (hence the restrictive permissions on |
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34 | <filename class="devicefile">console</filename>). Create these by running |
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35 | the following commands:</para> |
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36 | |
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37 | <screen><userinput>mknod -m 0600 ${CLFS}/dev/console c 5 1 |
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38 | mknod -m 0666 ${CLFS}/dev/null c 1 3 |
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39 | mknod -m 0666 ${CLFS}/dev/zero c 1 5</userinput></screen> |
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40 | |
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41 | <para>When systemd starts a tmpfs filesystem is mounted over |
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42 | <filename class="directory">/dev</filename> and the previous entries are |
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43 | no-longer available. The folling command creates files that are copied |
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44 | over when udevd starts:</para> |
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45 | |
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46 | <screen><userinput>mkdir -pv ${CLFS}/lib/udev/devices/{pts,shm} |
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47 | mknod -m 0600 ${CLFS}/lib/udev/devices/console c 5 1 |
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48 | mknod -m 0666 ${CLFS}/lib/udev/devices/null c 1 3 |
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49 | mknod -m 0666 ${CLFS}/lib/udev/devices/zero c 1 5 |
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50 | mknod -m 0600 ${CLFS}/lib/udev/devices/kmsg c 1 11 |
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51 | ln -snvf /proc/self/fd ${CLFS}/lib/udev/devices/fd |
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52 | ln -snvf /proc/self/fd/0 ${CLFS}/lib/udev/devices/stdin |
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53 | ln -snvf /proc/self/fd/1 ${CLFS}/lib/udev/devices/stdout |
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54 | ln -snvf /proc/self/fd/2 ${CLFS}/lib/udev/devices/stderr |
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55 | ln -snvf /proc/kcore ${CLFS}/lib/udev/devices/core</userinput></screen> |
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56 | |
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57 | </sect2> |
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58 | |
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59 | </sect1> |
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