pvr2fb.txt

嵌入式系统设计与实验教材二源码linux内核移植与编译

$Id: pvr2fb.txt,v 1.1 2001/05/24 05:09:16 mrbrown Exp $

What is pvr2fb?
===============

This is a driver for PowerVR 2 based graphics frame buffers, such as the
one found in the Dreamcast.

Advantages:

 * It provides a nice large console (128 cols + 48 lines with 1024x768)
   without using tiny, unreadable fonts.
 * You can run XF86_FBDev on top of /dev/fb0
 * Most important: boot logo :-)

Disadvantages:

 * Driver is currently limited to the Dreamcast PowerVR 2 implementation
   at the time of this writing.

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

You can pass kernel command line options to pvr2fb with
`video=pvr2:option1,option2:value2,option3' (multiple options should be
separated by comma, values are separated from options by `:').
Accepted options:

font:X    - default font to use. All fonts are supported, including the
            SUN12x22 font which is very nice at high resolutions.

mode:X    - default video mode. The following video modes are supported:
            640x240-60, 640x480-60.
	    
            Note: the 640x240 mode is currently broken, and should not be
            used for any reason. It is only mentioned as a reference.

inverse   - invert colors on screen (for LCD displays)

nomtrr    - disables write combining on frame buffer. This slows down driver
            but there is reported minor incompatibility between GUS DMA and
            XFree under high loads if write combining is enabled (sound
            dropouts). MTRR is enabled by default on systems that have it
            configured and that support it.

cable:X   - cable type. This can be any of the following: vga, rgb, and
            composite. If none is specified, we guess.

output:X  - output type. This can be any of the following: pal, ntsc, and
            vga. If none is specified, we guess.

X11
===

XF86_FBDev should work, in theory. At the time of this writing it is
totally untested and may or may not even portray the beginnings of
working. If you end up testing this, please let me know!

--
Paul Mundt <[e-mail]>