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Introduction

          This is a frame buffer device driver for 3dfx' Voodoo Graphics

        (aka voodoo 1, aka sst1) and VoodooČ (aka Voodoo 2, aka CVG) based

        video boards. It's highly experimental code, but is guaranteed to work

        on my computer, with my "Maxi Gamer 3D" and "Maxi Gamer 3dČ" boards,

        and with me "between chair and keyboard". Some people tested other

        combinations and it seems that it works.

          The main page is located at , and if

        you want the latest version, check out the CVS, as the driver is a work

        in progress, I feel incomfortable with releasing tarballs of something

        not completely working...Don't worry, it's still more than useable

        (I eat my own dog food)

          Please read the Bug section, and report any success or failure to me

        (Ghozlane Toumi ).

          BTW, If you have only one monitor , and you don't feel like playing

        with the vga passthrou cable, I can only suggest borrowing a screen

        somewhere...

Installation

          This driver (should) work on ix86, with "late" 2.2.x kernel (tested

        with x = 19) and "recent" 2.4.x kernel, as a module or compiled in.

          It has been included in mainstream kernel since the infamous 2.4.10.

          You can apply the patches found in sstfb/kernel/*-2.{2|4}.x.patch,

        and copy sstfb.c to linux/drivers/video/, or apply a single patch,

        sstfb/patch-2.{2|4}.x-sstfb-yymmdd to your linux source tree.

          Then configure your kernel as usual: choose "m" or "y" to 3Dfx Voodoo

        Graphics in section "console". Compile, install, have fun... and please

        drop me a report :)

Module Usage

        Warnings.

        # You should read completely this section before issuing any command.

        # If you have only one monitor to play with, once you insmod the

          module, the 3dfx takes control of the output, so you'll have to

          plug the monitor to the "normal" video board in order to issue

          the commands, or you can blindly use sst_dbg_vgapass

          in the tools directory (See Tools). The latest solution is pass the

          parameter vgapass=1 when insmodding the driver. (See Kernel/Modules

          Options)

        Module insertion:

        # insmod sstfb.o

          you should see some strange output frome the board:

          a big blue square, a green and a red small squares and a vertical

          white rectangle. why ? the function's name is self explanatory :

          "sstfb_test()"...

          (if you don't have a second monitor, you'll have to plug your monitor

          directely to the 2D videocard to see what you're typing)

        # con2fb /dev/fbx /dev/ttyx

          bind a tty to the new frame buffer. if you already have a frame

          buffer driver, the voodoo fb will likely be /dev/fb1. if not,

          the device will be /dev/fb0. You can check this by doing a

          cat /proc/fb. You can find a copy of con2fb in tools/ directory.

          if you don't have another fb device, this step is superfluous,

          as the console subsystem automagicaly binds ttys to the fb.

        # switch to the virtual console you just mapped. "tadaaa" ...

        Module removal:

        # con2fb /dev/fbx /dev/ttyx

          bind the tty to the old frame buffer so the module can be removed.

          (how does it work with vgacon ? short answer : it doesn't work)

        # rmmod sstfb

Kernel/Modules Options

        You can pass some otions to sstfb module, and via the kernel command

        line when the driver is compiled in :

        for module : insmod sstfb.o option1=value1 option2=value2 ...

        in kernel :  video=sstfb:option1,option2:value2,option3 ...

        sstfb supports the folowing options :

Module          Kernel          Description

vgapass=0       vganopass       Enable or disable VGA passthrou cable.

vgapass=1       vgapass         When enabled, the monitor will get the signal

                                from the VGA board and not from the voodoo.

                                Default: nopass

mem=x           mem:x           Force frame buffer memory in MiB

                                allowed values: 0, 1, 2, 4.

                                Default: 0 (= autodetect)

inverse=1       inverse         Supposed to enable inverse console.

                                doesn't work yet...

clipping=1      clipping        Enable or disable clipping.

clipping=0      noclipping      With clipping enabled, all offscreen

                                reads and writes are disgarded.

                                Default: enable clipping.

gfxclk=x        gfxclk:x        Force graphic clock frequency (in MHz).

                                Be carefull with this option, it may be

                                DANGEROUS.

                                Default: auto

                                        50Mhz for Voodoo 1,

                                        75MHz for Voodoo 2.

slowpci=1       fastpci         Enable or disable fast PCI read/writes.

slowpci=1       slowpci         Default : fastpci

dev=x           dev:x           Attach the driver to device number x.

                                lspci order)

Tools

        These tools are mostly for debugging purposes, but you can

        find some of these interesting :

         - con2fb , maps a tty to a fbramebuffer .

                con2fb /dev/fb1 /dev/tty5

         - sst_dbg_vgapass , changes vga passthrou. You have to recompile the

        driver with SST_DEBUG and SST_DEBUG_IOCTL set to 1

                sst_dbg_vgapass /dev/fb1 1 (enables vga cable)

                sst_dbg_vgapass /dev/fb1 0 (disables vga cable)

         - glide_reset , resets the voodoo using glide

                use this after rmmoding sstfb, if the module refuses to

                reinsert .

Bugs

        - DO NOT use glide while the sstfb module is in, you'll most likely

        hang your computer.

        - If you see some artefacts (pixels not cleaning and stuff like that),

        try turning off clipping (clipping=0), and/or using slowpci

        - the driver don't detect the 4Mb frame buffer voodoos, it seems that

        the 2 last Mbs wrap around. looking into that .

        - The driver is 16 bpp only, 24/32 won't work.

        - The driver is not your_favorite_toy-safe. this includes SMP...

          [Actually from inspection it seems to be safe - Alan]

        - when using XFree86 FBdev (X over fbdev) you may see strange color

        patterns at the border of your windows (the pixels loose the lowest

        byte -> basicaly the blue component nd some of the green) . I'm unable

        to reproduce this with XFree86-3.3, but one of the testers has this

        problem with XFree86-4. apparently recent Xfree86-4.x solve this

        problem.

        - I didn't really test changing the palette, so you may find some weird

        things when playing with that.

        - Sometimes the driver will not recognise the DAC , and the

        initialisation will fail. this is specificaly true for

        voodoo 2 boards , but it should be solved in recent versions. please

        contact me .

        - the 24/32 is not likely to work anytime soon , knowing that the

        hardware does ... unusual thigs in 24/32 bpp

        - When used with anther video board, current limitations of linux

        console subsystem can cause some troubles, specificaly, you should

        disable software scrollback , as it can oops badly ...

Todo

        - Get rid of the previous paragraph.

        - Buy more coffee.

        - test/port to other arch.

        - try to add panning using tweeks with front and back buffer .

        - try to implement accel on voodoo2 , this board can actualy do a

          lot in 2D even if it was sold as a 3D only board ...

ghoz.

--

Ghozlane Toumi 

$Date: 2004-04-15 02:32:00 $

http://sstfb.sourceforge.net/README