Re: [fb-d] closer ...

[Jeff Garzik]

James wrote:
> > Also trying to get cl gd5480 up. Jeff, turns out on the L440GX if you plug
> > in a PCI video card the bios will execute a HLT. Yep, can't have two video
> > cards. Wonder why Intel did this?
>
> I love Intel.
>
> Ron, more seriously, there is a "VGA Disable" or "Video Disable" on the
> L440GX+ or whatever that mainboard was we were working on earlier; that
> should allow you to plug in a second PCI video card.
>
> Or: Many ATI cards that I've seen have a "BIOS disable" jumper on
> themselves (I would presume Matrox cards would do this too so you can run
> multiheaded).  If you short that, the PC BIOS won't see the ATI card at
> all.
>
> Either of these solutions will be easier than getting the Cirrus up; I
> would suggest flipping the motherboard jumper.
>
> I think Intel designed it like that because there is a single space where
> all the video card stuff goes, but I'm not sure...

Yep, sounds like you are right on the money.

Since the GD5480 is built into the motherboard, you have to disable it
before you can use a PCI video card.

For the Intel BIOS, there should be a switch somewhere in BIOS setup
typically.  If it's an older motherboard, there is probably a jumper.

For linuxbios/freebios, simply avoiding the Cirrus video BIOS init
should be sufficient I would think.  (though make sure to disable the
Cirrus's PCI MMIO and I/O regions)

Jeff

[fb-d] closer ...

[Ronald G Minnich]

On Wed, 3 May 2000, Jeff Garzik wrote:
> For linuxbios/freebios, simply avoiding the Cirrus video BIOS init
> should be sufficient I would think.  (though make sure to disable the
> Cirrus's PCI MMIO and I/O regions)

hmmm, I may disable the bios from probing that slot.

This will soon be of no concern, since I am just about ready to turn the
Intel bios off again ...

ron

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[fb-d] closer ...

[Jeff Garzik]

Ronald G Minnich wrote:
> On Wed, 3 May 2000, Jeff Garzik wrote:
> > For linuxbios/freebios, simply avoiding the Cirrus video BIOS init
> > should be sufficient I would think.  (though make sure to disable the
> > Cirrus's PCI MMIO and I/O regions)
>
> hmmm, I may disable the bios from probing that slot.
>
> This will soon be of no concern, since I am just about ready to turn the
> Intel bios off again ...

Various bits of advice:

* Video may be a red herring.  It seems more simple to me to disable ALL
video, and get serial console working.

* From reading the PCI spec, it seems like two passes are needed over
each PCI bus and device.  The first pass disables all devices, while at
the same time reading their address space requirements.  The second pass
enables each device, with the correct I/O and MMIO region settings. 
Note special cases like two VGA devices on the PCI bus need to be
handled by disabled the non-primary VGA device.

* If you run the video BIOS, everything gets easier!  You can simply use
vgacon and forget about other special consoles like sercon or fbdev.  It
is not a daunting as it seems, to run the video BIOS.  The procedure is
simple, and clearly detailed in the PCI spec I sent you.  I can help
too.  We eventually need to do this anyway.

* If you haven't already done so, run the Intel BIOS, get a fully copy
of the PCI config registers for -every- device, and then compare with
the results after running LinuxBIOS.  There may be something obvious you
are not setting up.  In my experience, comparing register dumps between
known good and devel code outputs are invaluable.

Jeff