Specifications

If you are running a 2.4 series kernel, btaudio in the OSS "Sound" category is optional if you want to use
external speakers attached to the the card's audio out jack, and either (or both) OSS or ALSA sound system
btaudio drivers in the 2.6+ series.
3.3. Configuration Requirements for Use of your Bttv
Hardware
Once you know your kernel is enabled you can proceed to some minor tuning that may already be done for
you depending on your system and distributor and distribution features.
3.3.1. Device Files
If you are using Device Filesystem (devfs) or udev your work in this respect may be done for you
dynamically, but at the same time the devices may not exist until they are recognized by the kernel (i.e., the
necessary modules loaded), so be sure you have taken care of the previously outlined prerequisites first.
The Linux kernel requires a virtual device node be created to access and control a particular piece of
hardware. This node may have already been created for you automatically; ls −l /dev/video* (with an asterisk)
or alternatively find /dev −name video* or even visual inspection of the /dev directory with your favorite
file manager can give you an idea if the video devices exist. If so you can proceed to Section 3.4; if not you
will need to create them manually.
An easy way to create them, if available with your Linux distribution, is use of the MAKEDEV script, which
may be located in /dev or the usual places for storing executable commands (/bin,/sbin and so on). The
manual page for MAKEDEV (man MAKEDEV) can guide you further, but be aware of the device−specific
command options. If MAKEDEV doesn't work or doesn't exist, or you just prefer doing things the hard way,
move on to the next paragraph.
A device can be created as a block (such as a drive), a FIFO (file−in−file−out or pipe, as in xconsole) or a
character device, which represents other hardware. Each device has a major and a minor number "coordinate"
to tell the kernel what it is and where to access it. These numbers are not arbitrary. The major number 81 with
minor number 0, 1, 2, and so on are by convention assigned to Video4linux devices, including TV tuner
boards and webcams. In order to create the video device /dev/video0, use mknod at the command line:
# mknod /dev/video0 c 81 0
where c represents a character device.
You can use the following script, which I have borrowed from the kernel source (located in
linux/Documentation/video4linux/bttv/MAKEDEV of the source tree):
#!/bin/bash
function makedev () {
for dev in 0 1 2 3; do echo "/dev/$1$dev:
char 81 $[ $2 + $dev ]" rm −f /dev/$1$dev
mknod /dev/$1$dev c 81 $[ $2 + $dev ] chmod
666 /dev/$1$dev
done
# symlink for default device
rm −f /dev/$1 ln −s /dev/${1}0 /dev/$1
}
The BTTV HOWTO
3. Enabling Support for Your Bt8x8 Hardware in Linux 7