Documentation/fb/sstfb.txt

   1
   2 Introduction
   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 usable
  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
  23 Installation
  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
  37 Module 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
  73 Kernel/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
  82 Module          Kernel          Description
  83
  84 vgapass=0       vganopass       Enable or disable VGA passthrou cable.
  85 vgapass=1       vgapass         When enabled, the monitor will get the signal
  86                                 from the VGA board and not from the voodoo.
  87                                 Default: nopass
  88
  89 mem=x           mem:x           Force frame buffer memory in MiB
  90                                 allowed values: 0, 1, 2, 4.
  91                                 Default: 0 (= autodetect)
  92
  93 inverse=1       inverse         Supposed to enable inverse console.
  94                                 doesn't work yet...
  95
  96 clipping=1      clipping        Enable or disable clipping.
  97 clipping=0      noclipping      With clipping enabled, all offscreen
  98                                 reads and writes are discarded.
  99                                 Default: enable clipping.
 100
 101 gfxclk=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
 108 slowpci=1       fastpci         Enable or disable fast PCI read/writes.
 109 slowpci=1       slowpci         Default : fastpci
 110
 111 dev=x           dev:x           Attach the driver to device number x.
 112                                 0 is the first compatible board (in
 113                                 lspci order)
 114
 115 Tools
 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
 129 Bugs
 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
 158 Todo
 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
 167 ghoz.
 168
 169 --
 170 Ghozlane Toumi <gtoumi@laposte.net>
 171
 172
 173 $Date: 2002/05/09 20:11:45 $
 174 http://sstfb.sourceforge.net/README