Root/Documentation/fb/sstfb.txt

1
2Introduction
3
4      This is a frame buffer device driver for 3dfx' Voodoo Graphics
5    (aka voodoo 1, aka sst1) and Voodoo² (aka Voodoo 2, aka CVG) based
6    video boards. It's highly experimental code, but is guaranteed to work
7    on my computer, with my "Maxi Gamer 3D" and "Maxi Gamer 3d²" boards,
8    and with me "between chair and keyboard". Some people tested other
9    combinations and it seems that it works.
10      The main page is located at <http://sstfb.sourceforge.net>, and if
11    you want the latest version, check out the CVS, as the driver is a work
12    in progress, I feel uncomfortable with releasing tarballs of something
13    not completely working...Don't worry, it's still more than useable
14    (I eat my own dog food)
15
16      Please read the Bug section, and report any success or failure to me
17    (Ghozlane Toumi <gtoumi@laposte.net>).
18      BTW, If you have only one monitor , and you don't feel like playing
19    with the vga passthrou cable, I can only suggest borrowing a screen
20    somewhere...
21
22
23Installation
24
25      This driver (should) work on ix86, with "late" 2.2.x kernel (tested
26    with x = 19) and "recent" 2.4.x kernel, as a module or compiled in.
27      It has been included in mainstream kernel since the infamous 2.4.10.
28      You can apply the patches found in sstfb/kernel/*-2.{2|4}.x.patch,
29    and copy sstfb.c to linux/drivers/video/, or apply a single patch,
30    sstfb/patch-2.{2|4}.x-sstfb-yymmdd to your linux source tree.
31
32      Then configure your kernel as usual: choose "m" or "y" to 3Dfx Voodoo
33    Graphics in section "console". Compile, install, have fun... and please
34    drop me a report :)
35
36
37Module Usage
38    
39    Warnings.
40    # You should read completely this section before issuing any command.
41    # If you have only one monitor to play with, once you insmod the
42      module, the 3dfx takes control of the output, so you'll have to
43      plug the monitor to the "normal" video board in order to issue
44      the commands, or you can blindly use sst_dbg_vgapass
45          in the tools directory (See Tools). The latest solution is pass the
46      parameter vgapass=1 when insmodding the driver. (See Kernel/Modules
47      Options)
48
49    Module insertion:
50    # insmod sstfb.o
51      you should see some strange output from the board:
52      a big blue square, a green and a red small squares and a vertical
53      white rectangle. why? the function's name is self-explanatory:
54      "sstfb_test()"...
55      (if you don't have a second monitor, you'll have to plug your monitor
56      directly to the 2D videocard to see what you're typing)
57    # con2fb /dev/fbx /dev/ttyx
58      bind a tty to the new frame buffer. if you already have a frame
59      buffer driver, the voodoo fb will likely be /dev/fb1. if not,
60      the device will be /dev/fb0. You can check this by doing a
61      cat /proc/fb. You can find a copy of con2fb in tools/ directory.
62      if you don't have another fb device, this step is superfluous,
63      as the console subsystem automagicaly binds ttys to the fb.
64    # switch to the virtual console you just mapped. "tadaaa" ...
65
66    Module removal:
67    # con2fb /dev/fbx /dev/ttyx
68      bind the tty to the old frame buffer so the module can be removed.
69      (how does it work with vgacon ? short answer : it doesn't work)
70    # rmmod sstfb
71
72
73Kernel/Modules Options
74
75    You can pass some options to the sstfb module, and via the kernel
76    command line when the driver is compiled in:
77    for module : insmod sstfb.o option1=value1 option2=value2 ...
78    in kernel : video=sstfb:option1,option2:value2,option3 ...
79    
80    sstfb supports the following options :
81
82Module Kernel Description
83
84vgapass=0 vganopass Enable or disable VGA passthrou cable.
85vgapass=1 vgapass When enabled, the monitor will get the signal
86                from the VGA board and not from the voodoo.
87                Default: nopass
88
89mem=x mem:x Force frame buffer memory in MiB
90                allowed values: 0, 1, 2, 4.
91                Default: 0 (= autodetect)
92
93inverse=1 inverse Supposed to enable inverse console.
94                doesn't work yet...
95
96clipping=1 clipping Enable or disable clipping.
97clipping=0 noclipping With clipping enabled, all offscreen
98                reads and writes are discarded.
99                Default: enable clipping.
100
101gfxclk=x gfxclk:x Force graphic clock frequency (in MHz).
102                Be careful with this option, it may be
103                DANGEROUS.
104                Default: auto
105                    50Mhz for Voodoo 1,
106                    75MHz for Voodoo 2.
107
108slowpci=1 fastpci Enable or disable fast PCI read/writes.
109slowpci=1 slowpci Default : fastpci
110
111dev=x dev:x Attach the driver to device number x.
112                0 is the first compatible board (in
113                lspci order)
114
115Tools
116
117    These tools are mostly for debugging purposes, but you can
118    find some of these interesting :
119     - con2fb , maps a tty to a fbramebuffer .
120        con2fb /dev/fb1 /dev/tty5
121     - sst_dbg_vgapass , changes vga passthrou. You have to recompile the
122    driver with SST_DEBUG and SST_DEBUG_IOCTL set to 1
123        sst_dbg_vgapass /dev/fb1 1 (enables vga cable)
124        sst_dbg_vgapass /dev/fb1 0 (disables vga cable)
125     - glide_reset , resets the voodoo using glide
126        use this after rmmoding sstfb, if the module refuses to
127        reinsert .
128
129Bugs
130
131    - DO NOT use glide while the sstfb module is in, you'll most likely
132    hang your computer.
133    - If you see some artefacts (pixels not cleaning and stuff like that),
134    try turning off clipping (clipping=0), and/or using slowpci
135    - the driver don't detect the 4Mb frame buffer voodoos, it seems that
136    the 2 last Mbs wrap around. looking into that .
137    - The driver is 16 bpp only, 24/32 won't work.
138    - The driver is not your_favorite_toy-safe. this includes SMP...
139          [Actually from inspection it seems to be safe - Alan]
140    - When using XFree86 FBdev (X over fbdev) you may see strange color
141    patterns at the border of your windows (the pixels lose the lowest
142    byte -> basically the blue component and some of the green). I'm unable
143    to reproduce this with XFree86-3.3, but one of the testers has this
144    problem with XFree86-4. Apparently recent Xfree86-4.x solve this
145    problem.
146    - I didn't really test changing the palette, so you may find some weird
147    things when playing with that.
148    - Sometimes the driver will not recognise the DAC, and the
149        initialisation will fail. This is specifically true for
150    voodoo 2 boards, but it should be solved in recent versions. Please
151    contact me.
152    - The 24/32 is not likely to work anytime soon, knowing that the
153    hardware does ... unusual things in 24/32 bpp.
154    - When used with another video board, current limitations of the linux
155    console subsystem can cause some troubles, specifically, you should
156    disable software scrollback, as it can oops badly ...
157
158Todo
159
160    - Get rid of the previous paragraph.
161    - Buy more coffee.
162    - test/port to other arch.
163    - try to add panning using tweeks with front and back buffer .
164    - try to implement accel on voodoo2, this board can actually do a
165      lot in 2D even if it was sold as a 3D only board ...
166
167ghoz.
168
169--
170Ghozlane Toumi <gtoumi@laposte.net>
171
172
173$Date: 2002/05/09 20:11:45 $
174http://sstfb.sourceforge.net/README
175

Archive Download this file



interactive