1UDEV rules for DVB
2==================
3
4.. note::
5
6   #) This documentation is outdated. Udev on modern distributions auto-detect
7      the DVB devices.
8
9   #) **TODO:** change this document to explain how to make DVB devices
10      persistent, as, when a machine has multiple devices, they may be detected
11      on different orders, which could cause apps that relies on the device
12      numbers to fail.
13
14The DVB subsystem currently registers to the sysfs subsystem using the
15"class_simple" interface.
16
17This means that only the basic information like module loading parameters
18are presented through sysfs. Other things that might be interesting are
19currently **not** available.
20
21Nevertheless it's now possible to add proper udev rules so that the
22DVB device nodes are created automatically.
23
24We assume that you have udev already up and running and that have been
25creating the DVB device nodes manually up to now due to the missing sysfs
26support.
27
280. Don't forget to disable your current method of creating the
29device nodes manually.
30
311. Unfortunately, you'll need a helper script to transform the kernel
32sysfs device name into the well known dvb adapter / device naming scheme.
33The script should be called "dvb.sh" and should be placed into a script
34dir where udev can execute it, most likely /etc/udev/scripts/
35
36So, create a new file /etc/udev/scripts/dvb.sh and add the following:
37
38.. code-block:: none
39
40	#!/bin/sh
41	/bin/echo $1 | /bin/sed -e 's,dvb\([0-9]\)\.\([^0-9]*\)\([0-9]\),dvb/adapter\1/\2\3,'
42
43Don't forget to make the script executable with "chmod".
44
451. You need to create a proper udev rule that will create the device nodes
46like you know them. All real distributions out there scan the /etc/udev/rules.d
47directory for rule files. The main udev configuration file /etc/udev/udev.conf
48will tell you the directory where the rules are, most likely it's /etc/udev/rules.d/
49
50Create a new rule file in that directory called "dvb.rule" and add the following line:
51
52.. code-block:: none
53
54	KERNEL="dvb*", PROGRAM="/etc/udev/scripts/dvb.sh %k", NAME="%c"
55
56If you want more control over the device nodes (for example a special group membership)
57have a look at "man udev".
58
59For every device that registers to the sysfs subsystem with a "dvb" prefix,
60the helper script /etc/udev/scripts/dvb.sh is invoked, which will then
61create the proper device node in your /dev/ directory.
62