Linux Desktop Hacks

Graphics on the Console #9

Chapter 1, Booting Linux

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27

HACK

Bypassing X Windows

In some instances, certain Linux programs such as Mplayer can use the

frame buffer immediately, thus reducing the overhead of having to run

an X Windows desktop such as KDE or GNOME. This is suitable for

use on resource-limited embedded systems.

Setting Up the Kernel

Support for the frame buffer comes from the kernel itself. Most stock ker-

nels are supplied with frame-buffer support built into them, so this

shouldn’t be a problem for most people. To check if your kernel has sup-

port already, you can query it:

foo@bar:~$ grep -i config_fb /boot/config-$(uname -r)

CONFIG_FB=y

If you have frame buffers set, the line CONFIG_FB=y will be displayed (in

which case you can move on to the next section “Configuring the Boot-

loader”). If

# CONFIG_FB is not set is displayed instead, you will need to

compile support for the frame buffer into your kernel.

Configuring the Kernel

Details on compiling a kernel are discussed in “Compile a Kernel” [Hack #88],

and in this hack, I will simply discuss which options need to be included.

The first thing to do is to make sure development features have been

enabled within the “Code maturity level” options. Then, to enable frame

buffers, go to the “Console drivers” page and enable “VGA text console”

and “Video mode selection” support.

There is a subsection under Console called “Frame-buffer support.” ...