diff options
author | Bruce Dubbs <bdubbs@linuxfromscratch.org> | 2020-06-12 20:42:32 +0000 |
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committer | Bruce Dubbs <bdubbs@linuxfromscratch.org> | 2020-06-12 20:42:32 +0000 |
commit | a3d0817020eee2b1ea6ebfe10f3a0ea9e26829be (patch) | |
tree | 8464f035c71b9e91c990550b89cc3769f676ccc6 /chapter09/udev.xml | |
parent | 96f04d7906bb26ba31cc35c35e4cc82261bbad1d (diff) |
Text updated for cross2 chapter 9
git-svn-id: http://svn.linuxfromscratch.org/LFS/branches/cross2@11928 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689
Diffstat (limited to 'chapter09/udev.xml')
-rw-r--r-- | chapter09/udev.xml | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/chapter09/udev.xml b/chapter09/udev.xml index 6060849be..508795a03 100644 --- a/chapter09/udev.xml +++ b/chapter09/udev.xml @@ -15,7 +15,7 @@ <secondary>usage</secondary> </indexterm> - <para>In <xref linkend="chapter-building-system"/>, we installed the Udev + <para>In <xref linkend="chapter-building-system"/>, we installed the udev package when <phrase revision="sysv">eudev</phrase> <phrase revision="systemd">systemd</phrase> was built. Before we go into the details regarding how this works, a brief history of previous methods of @@ -30,7 +30,7 @@ major and minor device numbers for every possible device that might exist in the world.</para> - <para>Using the Udev method, only those devices which are detected by the + <para>Using the udev method, only those devices which are detected by the kernel get device nodes created for them. Because these device nodes will be created each time the system boots, they will be stored on a <systemitem class="filesystem">devtmpfs</systemitem> file system (a virtual file system @@ -135,7 +135,7 @@ <filename>/sys/bus/pci/devices/0000:00:0d.0/modalias</filename> file might contain the string <quote>pci:v00001319d00000801sv00001319sd00001319bc04sc01i00</quote>. - The default rules provided with Udev will cause <command>udevd</command> + The default rules provided with udev will cause <command>udevd</command> to call out to <command>/sbin/modprobe</command> with the contents of the <envar>MODALIAS</envar> uevent environment variable (which should be the same as the contents of the <filename>modalias</filename> file in sysfs), @@ -149,7 +149,7 @@ be prevented.</para> <para>The kernel itself is also able to load modules for network - protocols, filesystems and NLS support on demand.</para> + protocols, filesystems, and NLS support on demand.</para> </sect3> @@ -177,12 +177,12 @@ <para>Udev will only load a module if it has a bus-specific alias and the bus driver properly exports the necessary aliases to <systemitem class="filesystem">sysfs</systemitem>. In other cases, one should - arrange module loading by other means. With Linux-&linux-version;, Udev is + arrange module loading by other means. With Linux-&linux-version;, udev is known to load properly-written drivers for INPUT, IDE, PCI, USB, SCSI, SERIO, and FireWire devices.</para> <para>To determine if the device driver you require has the necessary - support for Udev, run <command>modinfo</command> with the module name as + support for udev, run <command>modinfo</command> with the module name as the argument. Now try locating the device directory under <filename class="directory">/sys/bus</filename> and check whether there is a <filename>modalias</filename> file there.</para> @@ -190,7 +190,7 @@ <para>If the <filename>modalias</filename> file exists in <systemitem class="filesystem">sysfs</systemitem>, the driver supports the device and can talk to it directly, but doesn't have the alias, it is a bug in the - driver. Load the driver without the help from Udev and expect the issue + driver. Load the driver without the help from udev and expect the issue to be fixed later.</para> <para>If there is no <filename>modalias</filename> file in the relevant @@ -206,7 +206,7 @@ </sect3> <sect3> - <title>A kernel module is not loaded automatically, and Udev is not + <title>A kernel module is not loaded automatically, and udev is not intended to load it</title> <para>If the <quote>wrapper</quote> module only enhances the @@ -214,7 +214,7 @@ <emphasis>snd-pcm-oss</emphasis> enhances the functionality of <emphasis>snd-pcm</emphasis> by making the sound cards available to OSS applications), configure <command>modprobe</command> to load the wrapper - after Udev loads the wrapped module. To do this, add a + after udev loads the wrapped module. To do this, add a <quote>softdep</quote> line to the corresponding <filename>/etc/modprobe.d/<replaceable><filename></replaceable>.conf</filename> file. For example:</para> @@ -279,7 +279,7 @@ <para>Further text assumes that the driver is built statically into the kernel or already loaded as a module, and that you have already checked - that Udev doesn't create a misnamed device.</para> + that udev doesn't create a misnamed device.</para> <para>Udev has no information needed to create a device node if a kernel driver does not export its data to @@ -297,12 +297,12 @@ <sect3> <title>Device naming order changes randomly after rebooting</title> - <para>This is due to the fact that Udev, by design, handles uevents and + <para>This is due to the fact that udev, by design, handles uevents and loads modules in parallel, and thus in an unpredictable order. This will never be <quote>fixed</quote>. You should not rely upon the kernel device names being stable. Instead, create your own rules that make symlinks with stable names based on some stable attributes of the device, such as a - serial number or the output of various *_id utilities installed by Udev. + serial number or the output of various *_id utilities installed by udev. See <xref linkend="ch-config-symlinks"/> and <xref linkend="ch-config-network"/> for examples.</para> |