[9fans] What are the steps to add new video drivers?

[9fans] What are the steps to add new video drivers?

[Richard Greenblott]

Hi:
    I am tring to install Plan9 on a pentium III processor from DELL.
The video board is one that is not currently supported by the Plan9
project. How can I add a new driver without first having Plan9 running.
My card is a NVIDIA GeForce2 GTS. I have been able to get this card
working with Linux but not with Plan9.

The system does start to load the OS from my floppy but it stops and
dumps the video prom and ends with a "%" prompt.

Any help or suggestions would be great.

Thanks:

Rick G.

[9fans] status of the ide pseudo worm patches

[Sam Ducksworth]

have the ide pseudo worm patches been rolled into
latest release?

--sam

Re: [9fans] What are the steps to add new video drivers?

[jmk]

I should say that the kernel stub driver, once you have the linear mapping
done for whatever memory spaces the card needs, usually doesn't need to be changed
until you get to writing the hardware cursor code, and that's the last part of
writing a Plan 9 video driver.

--jim

Re: [9fans] What are the steps to add new video drivers?

[jmk]

On Fri Mar 30 09:47:25 EST 2001, mike@trolltech.com wrote:
> 
> jmk@plan9.bell-labs.com wrote:
> > My advice is to install Plan 9 on a machine that has a suitable video
> > board, then you can go through the driver development cycle in a more
> > friendly environment.
> > 
> > Having support for Nvidea cards would be great, by the way.
> 
> Indeed, I keep thinking that I'd like to take a whack at getting my TNT2 Ultra
> working. Unfortunately my Copious Free Time hasn't yet been copious enough to
> let me gather together the necessary computers; it seems like you're talking
> about at least three for something like a normal environment: an operational
> terminal for development, a file server, and a machine with the card you're
> developing for.
> 

Basically you need somewhere to compile aux/vga and a new kernel with a stub driver
for the card. The machine with the new card needs to be able to boot the newly compiled
kernel and be attached to the fileserver that has the hacked aux/vga binary somewhere.

Here's the kernel stub I used when I briefly looked at the GeForce256 when one arrived
in a server I'd ordered - vgageforce256.c:

#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "io.h"
#include "../port/error.h"

#define	Image	IMAGE
#include <draw.h>
#include <memdraw.h>
#include <cursor.h>
#include "screen.h"

static ulong
geforce245linear(VGAscr* scr, int* size, int* align)
{
	ulong aperture, oaperture;
	int oapsize, wasupamem;
	Pcidev *p;

	oaperture = scr->aperture;
	oapsize = scr->apsize;
	wasupamem = scr->isupamem;

	aperture = 0;
	if(p = pcimatch(nil, 0x10DE, 0)){
		switch(p->did){
		case 0x0101:
			aperture = p->mem[1].bar & ~0x0F;
			*size = p->mem[1].size;
			break;
		default:
			break;
		}
	}

	if(wasupamem){
		if(oaperture == aperture)
			return oaperture;
		upafree(oaperture, oapsize);
	}
	scr->isupamem = 0;

	aperture = upamalloc(aperture, *size, *align);
	if(aperture == 0){
		if(wasupamem && upamalloc(oaperture, oapsize, 0)){
			aperture = oaperture;
			scr->isupamem = 1;
		}
		else
			scr->isupamem = 0;
	}
	else
		scr->isupamem = 1;

	return aperture;
}

VGAdev vgageforce256dev = {
	"geforce256",

	nil,				/* enable */
	nil,				/* disable */
	nil,				/* page */
	geforce245linear,		/* linear */
	nil,				/* drawinit */
	nil,				/* fill */
};

and here's a stub for aux/vga - geforce256:

#include <u.h>
#include <libc.h>
#include <bio.h>

#include "vga.h"

/*
 * GeForce256.
 */
static void
snarf(Vga* vga, Ctlr* ctlr)
{
	USED(vga);
	ctlr->flag |= Fsnarf;
}

static void
options(Vga* vga, Ctlr* ctlr)
{
	USED(vga);
	ctlr->flag |= Foptions;
}

static void
init(Vga* vga, Ctlr* ctlr)
{
	USED(vga);
	ctlr->flag |= Finit;
}

static void
load(Vga* vga, Ctlr* ctlr)
{
	USED(vga);
	ctlr->flag |= Fload;
}

static void
dump(Vga* vga, Ctlr* ctlr)
{
	USED(vga, ctlr);
}

Ctlr geforce256 = {
	"geforce256",			/* name */
	snarf,				/* snarf */
	options,			/* options */
	init,				/* init */
	load,				/* load */
	dump,				/* dump */
};

At this point I usually write the snarf and dump functions; with the
GeForce256 I looked at the register set of the card as described in the
XFree86 code (the only 'documentation') and decided I didn't have the
strength.

--jim

Re: [9fans] What are the steps to add new video drivers?

[forsyth]

> let me gather together the necessary computers; it seems like you're talking
> about at least three for something like a normal environment: an operational
> terminal for development, a file server, and a machine with the card you're
> developing for.

if are developing a driver for a new AGP card, and you've got a working PCI card,
or vice versa, you can use one machine and switch between AGP and PCI
using the bios.  it's tedious but should work.

Re: [9fans] What are the steps to add new video drivers?

[Mike Acar]

jmk@plan9.bell-labs.com wrote:
> My advice is to install Plan 9 on a machine that has a suitable video
> board, then you can go through the driver development cycle in a more
> friendly environment.
> 
> Having support for Nvidea cards would be great, by the way.

Indeed, I keep thinking that I'd like to take a whack at getting my TNT2 Ultra
working. Unfortunately my Copious Free Time hasn't yet been copious enough to
let me gather together the necessary computers; it seems like you're talking
about at least three for something like a normal environment: an operational
terminal for development, a file server, and a machine with the card you're
developing for.

-- 
Brilliance and gorgeousness                        |   Mike Acar
And we tell ourselves we don't want the treasures  |   mike@trolltech.com
But we hate the glass anyway                       |

Re: [9fans] What are the steps to add new video drivers?

[jmk]

On Fri Mar 30 04:08:19 EST 2001, rgreenbl@nextabit.com wrote:
> Hi:
>     I am tring to install Plan9 on a pentium III processor from DELL.
> The video board is one that is not currently supported by the Plan9
> project. How can I add a new driver without first having Plan9 running.
> My card is a NVIDIA GeForce2 GTS. I have been able to get this card
> working with Linux but not with Plan9.
> 
> The system does start to load the OS from my floppy but it stops and
> dumps the video prom and ends with a "%" prompt.
> 
> Any help or suggestions would be great.
> 
> Thanks:
> 
> Rick G.

My advice is to install Plan 9 on a machine that has a suitable video
board, then you can go through the driver development cycle in a more
friendly environment.

Having support for Nvidea cards would be great, by the way.

--jim