The frame buffer device provides an abstraction for the graphics
hardware. It represents the frame buffer of some video hardware and
allows application software to access the graphics hardware through
a well-defined interface, so the software doesn't need to know
anything about the low-level (hardware register) stuff.

Frame buffer devices work identically across the different
architectures supported by Linux and make the implementation of
application programs easier and more portable; at this point, an X
server exists which uses the frame buffer device exclusively.
On several non-X86 architectures, the frame buffer device is the
only way to use the graphics hardware.

The device is accessed through special device nodes, usually located
in the /dev directory, i.e. /dev/fb*.

You need an utility program called fbset to make full use of frame
buffer devices. Please read Documentation/fb/framebuffer.txt
and the Framebuffer-HOWTO at
<http://www.munted.org.uk/programming/Framebuffer-HOWTO-1.3.html> for more
information.

Say Y here and to the driver for your graphics board below if you
are compiling a kernel for a non-x86 architecture.

If you are compiling for the x86 architecture, you can say Y if you
want to play with it, but it is not essential. Please note that
running graphical applications that directly touch the hardware
(e.g. an accelerated X server) and that are not frame buffer
device-aware may cause unexpected results. If unsure, say N.

source code:

drivers/video/fbdev/core/