Documentation / fb / gxfb.rst


Based on kernel version 5.15. Page generated on 2021-11-01 09:19 EST.

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=============
What is gxfb?
=============

.. [This file is cloned from VesaFB/aty128fb]

This is a graphics framebuffer driver for AMD Geode GX2 based processors.

Advantages:

 * No need to use AMD's VSA code (or other VESA emulation layer) in the
   BIOS.
 * It provides a nice large console (128 cols + 48 lines with 1024x768)
   without using tiny, unreadable fonts.
 * You can run XF68_FBDev on top of /dev/fb0
 * Most important: boot logo :-)

Disadvantages:

 * graphic mode is slower than text mode...


How to use it?
==============

Switching modes is done using  gxfb.mode_option=<resolution>... boot
parameter or using `fbset` program.

See Documentation/fb/modedb.rst for more information on modedb
resolutions.


X11
===

XF68_FBDev should generally work fine, but it is non-accelerated.


Configuration
=============

You can pass kernel command line options to gxfb with gxfb.<option>.
For example, gxfb.mode_option=800x600@75.
Accepted options:

================ ==================================================
mode_option	 specify the video mode.  Of the form
		 <x>x<y>[-<bpp>][@<refresh>]
vram		 size of video ram (normally auto-detected)
vt_switch	 enable vt switching during suspend/resume.  The vt
		 switch is slow, but harmless.
================ ==================================================

Andres Salomon <dilinger@debian.org>