xref: /OK3568_Linux_fs/kernel/Documentation/fb/pvr2fb.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun===============
2*4882a593SmuzhiyunWhat is pvr2fb?
3*4882a593Smuzhiyun===============
4*4882a593Smuzhiyun
5*4882a593SmuzhiyunThis is a driver for PowerVR 2 based graphics frame buffers, such as the
6*4882a593Smuzhiyunone found in the Dreamcast.
7*4882a593Smuzhiyun
8*4882a593SmuzhiyunAdvantages:
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun * It provides a nice large console (128 cols + 48 lines with 1024x768)
11*4882a593Smuzhiyun   without using tiny, unreadable fonts (NOT on the Dreamcast)
12*4882a593Smuzhiyun * You can run XF86_FBDev on top of /dev/fb0
13*4882a593Smuzhiyun * Most important: boot logo :-)
14*4882a593Smuzhiyun
15*4882a593SmuzhiyunDisadvantages:
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun * Driver is largely untested on non-Dreamcast systems.
18*4882a593Smuzhiyun
19*4882a593SmuzhiyunConfiguration
20*4882a593Smuzhiyun=============
21*4882a593Smuzhiyun
22*4882a593SmuzhiyunYou can pass kernel command line options to pvr2fb with
23*4882a593Smuzhiyun`video=pvr2fb:option1,option2:value2,option3` (multiple options should be
24*4882a593Smuzhiyunseparated by comma, values are separated from options by `:`).
25*4882a593Smuzhiyun
26*4882a593SmuzhiyunAccepted options:
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun==========  ==================================================================
29*4882a593Smuzhiyunfont:X      default font to use. All fonts are supported, including the
30*4882a593Smuzhiyun	    SUN12x22 font which is very nice at high resolutions.
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun
33*4882a593Smuzhiyunmode:X      default video mode with format [xres]x[yres]-<bpp>@<refresh rate>
34*4882a593Smuzhiyun	    The following video modes are supported:
35*4882a593Smuzhiyun	    640x640-16@60, 640x480-24@60, 640x480-32@60. The Dreamcast
36*4882a593Smuzhiyun	    defaults to 640x480-16@60. At the time of writing the
37*4882a593Smuzhiyun	    24bpp and 32bpp modes function poorly. Work to fix that is
38*4882a593Smuzhiyun	    ongoing
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun	    Note: the 640x240 mode is currently broken, and should not be
41*4882a593Smuzhiyun	    used for any reason. It is only mentioned here as a reference.
42*4882a593Smuzhiyun
43*4882a593Smuzhiyuninverse     invert colors on screen (for LCD displays)
44*4882a593Smuzhiyun
45*4882a593Smuzhiyunnomtrr      disables write combining on frame buffer. This slows down driver
46*4882a593Smuzhiyun	    but there is reported minor incompatibility between GUS DMA and
47*4882a593Smuzhiyun	    XFree under high loads if write combining is enabled (sound
48*4882a593Smuzhiyun	    dropouts). MTRR is enabled by default on systems that have it
49*4882a593Smuzhiyun	    configured and that support it.
50*4882a593Smuzhiyun
51*4882a593Smuzhiyuncable:X     cable type. This can be any of the following: vga, rgb, and
52*4882a593Smuzhiyun	    composite. If none is specified, we guess.
53*4882a593Smuzhiyun
54*4882a593Smuzhiyunoutput:X    output type. This can be any of the following: pal, ntsc, and
55*4882a593Smuzhiyun	    vga. If none is specified, we guess.
56*4882a593Smuzhiyun==========  ==================================================================
57*4882a593Smuzhiyun
58*4882a593SmuzhiyunX11
59*4882a593Smuzhiyun===
60*4882a593Smuzhiyun
61*4882a593SmuzhiyunXF86_FBDev has been shown to work on the Dreamcast in the past - though not yet
62*4882a593Smuzhiyunon any 2.6 series kernel.
63*4882a593Smuzhiyun
64*4882a593SmuzhiyunPaul Mundt <lethal@linuxdc.org>
65*4882a593Smuzhiyun
66*4882a593SmuzhiyunUpdated by Adrian McMenamin <adrian@mcmen.demon.co.uk>
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