Changeset 416772a for BOOK/system-config


Ignore:
Timestamp:
Apr 26, 2014, 12:18:51 PM (11 years ago)
Author:
Chris Staub <chris@…>
Branches:
clfs-3.0.0-systemd, clfs-3.0.0-sysvinit, master, systemd, sysvinit
Children:
ec9b2de
Parents:
de0df04
Message:

Text updates to udev explanation page

File:
1 edited

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Added
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  • BOOK/system-config/common/udev.xml

    rde0df04 r416772a  
    9393
    9494    <sect3>
    95       <title>Udev Bootscript</title>
    96 
    97       <para>The <command>S10udev</command> initscript takes care of creating
    98       device nodes when Linux is booted. The script unsets the uevent handler
    99       from the default of <command>/sbin/hotplug</command>.  This is done
    100       because the kernel no longer needs to call out to an external binary.
    101       Instead <command>udevd</command> will listen on a netlink socket for
    102       uevents that the kernel raises. Next, the bootscript copies any static
    103       device nodes that exist in <filename
    104       class="directory">/lib/udev/devices</filename> to <filename
    105       class="directory">/dev</filename>. This is necessary because some devices,
    106       directories, and symlinks are needed before the dynamic device handling
    107       processes are available during the early stages of booting a system.
    108       Creating static device nodes in <filename
    109       class="directory">/lib/udev/devices</filename> also provides an easy
    110       workaround for devices that are not supported by the dynamic device
    111       handling infrastructure. The bootscript then starts the Udev daemon,
    112       <command>udevd</command>, which will act on any uevents it receives.
    113       Finally, the bootscript forces the kernel to replay uevents for any
    114       devices that have already been registered and then waits for
    115       <command>udevd</command> to handle them.</para>
    116 
    117     </sect3>
    118 
    119     <sect3>
    12095      <title>Device Node Creation</title>
    12196
    … …  
    129104      <emphasis>0</emphasis>. The names and permissions of the nodes created
    130105      under the <filename class="directory">/dev</filename> directory are
    131       determined by rules specified in the files within the <filename
    132       class="directory">/etc/udev/rules.d/</filename> directory. These are
    133       numbered in a similar fashion to the CLFS-Bootscripts package. If
    134       <command>udevd</command> can't find a rule for the device it is creating,
    135       it will default permissions to <emphasis>660</emphasis> and ownership to
    136       <emphasis>root:root</emphasis>. Documentation on the syntax of the Udev
    137       rules configuration files is available in
    138       <filename>/usr/share/doc/udev/writing_udev_rules/index.html</filename></para>
     106      determined by rules specified in the files within the
     107      <filename class="directory">/lib/udev/rules.d</filename> and <filename
     108      class="directory">/etc/udev/rules.d/</filename> directories. These files
     109      have names that start with numbers, and are evaluated in numerical order.
     110      If <command>udevd</command> can't find a rule for the device it is
     111      creating, it will default permissions to <emphasis>660</emphasis> and
     112      ownership to <emphasis>root:root</emphasis>. </para>
    139113
    140114    </sect3>
    … …  
    234208      sound cards available to OSS applications), configure
    235209      <command>modprobe</command> to load the wrapper after Udev loads the
    236       wrapped module. To do this, add an <quote>install</quote> line in
    237       <filename>/etc/modprobe.conf</filename>. For example:</para>
     210      wrapped module. To do this, add an <quote>install</quote> line to a file
     211      in <filename>/etc/modprobe.d</filename>. For example:</para>
    238212
    239213<screen role="nodump"><literal>install snd-pcm /sbin/modprobe -i snd-pcm ; \
    240214    /sbin/modprobe snd-pcm-oss ; true</literal></screen>
    241215
    242       <para>If the module in question is not a wrapper and is useful by itself,
    243       configure the <command>S05modules</command> bootscript to load this
    244       module on system boot. To do this, add the module name to the
    245       <filename>/etc/sysconfig/modules</filename> file on a separate line.
    246       This works for wrapper modules too, but is suboptimal in that case.</para>
    247 
    248216    </sect3>
    249217
    … …  
    252220
    253221      <para>Either don't build the module, or blacklist it in
    254       <filename>/etc/modprobe.conf</filename> file as done with the
     222      <filename>/etc/modprobe.d</filename> file as done with the
    255223      <emphasis>forte</emphasis> module in the example below:</para>
    256224
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