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@@ -1,63 +0,0 @@
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-<?xml version="1.0" encoding="ISO-8859-1"?>
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-<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
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- "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
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- <!ENTITY % general-entities SYSTEM "../general.ent">
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- %general-entities;
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-]>
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-
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-<sect1 id="ch-scripts-symlinks" revision="systemd">
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- <?dbhtml filename="symlinks.html"?>
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-
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- <title>Creating Custom Symlinks to Devices</title>
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-
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- <sect2>
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- <title>Dealing with duplicate devices</title>
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-
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- <para>As explained in <xref linkend="ch-scripts-udev"/>, the order in
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- which devices with the same function appear in
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- <filename class="directory">/dev</filename> is essentially random.
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- E.g., if you have a USB web camera and a TV tuner, sometimes
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- <filename>/dev/video0</filename> refers to the camera and
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- <filename>/dev/video1</filename> refers to the tuner, and sometimes
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- after a reboot the order changes to the opposite one.
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- For all classes of hardware except sound cards and network cards, this is
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- fixable by creating udev rules for custom persistent symlinks.
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- The case of network cards is covered separately in
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- <xref linkend="ch-scripts-network"/>, and sound card configuration can
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- be found in <ulink url="&blfs-book;postlfs/devices.html">BLFS</ulink>.</para>
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-
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- <para>For each of your devices that is likely to have this problem
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- (even if the problem doesn't exist in your current Linux distribution),
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- find the corresponding directory under
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- <filename class="directory">/sys/class</filename> or
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- <filename class="directory">/sys/block</filename>.
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- For video devices, this may be
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- <filename
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- class="directory">/sys/class/video4linux/video<replaceable>X</replaceable></filename>.
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- Figure out the attributes that identify the device uniquely (usually,
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- vendor and product IDs and/or serial numbers work):</para>
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-
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-<screen role="nodump"><userinput>udevadm info -a -p /sys/class/video4linux/video0</userinput></screen>
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-
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- <para>Then write rules that create the symlinks, e.g.:</para>
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-
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-<screen role="nodump"><userinput>cat > /etc/udev/rules.d/83-duplicate_devs.rules << "EOF"
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-<literal>
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-# Persistent symlinks for webcam and tuner
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-KERNEL=="video*", ATTRS{idProduct}=="1910", ATTRS{idVendor}=="0d81", \
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- SYMLINK+="webcam"
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-KERNEL=="video*", ATTRS{device}=="0x036f", ATTRS{vendor}=="0x109e", \
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- SYMLINK+="tvtuner"
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-</literal>
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-EOF</userinput></screen>
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-
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- <para>The result is that <filename>/dev/video0</filename> and
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- <filename>/dev/video1</filename> devices still refer randomly to the tuner
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- and the web camera (and thus should never be used directly), but there are
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- symlinks <filename>/dev/tvtuner</filename> and
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- <filename>/dev/webcam</filename> that always point to the correct
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- device.</para>
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-
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- </sect2>
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-
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-</sect1>
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