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 <file:Documentation/fb/framebuffer.rst>
and the Framebuffer-HOWTO at
<http://www.munted.org.uk/programming/Framebuffer-HOWTO-1.3.html> for more
information.

This enables support for native frame buffer device (fbdev) drivers.

The DRM subsystem provides support for emulated frame buffer devices
on top of KMS drivers, but this option allows legacy fbdev drivers to
be enabled as well.

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:

arch/sparc/video/fbdev.c