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Re: Subject: Re: [Qemu-devel] VGA BIOS source code
From: |
Derek Fawcus |
Subject: |
Re: Subject: Re: [Qemu-devel] VGA BIOS source code |
Date: |
Tue, 1 Jun 2004 12:44:18 +0100 |
On Tue, Jun 01, 2004 at 07:48:38AM +0200, Bartosz Fabianowski wrote:
> That seems like a good idea. Though if you are pretending to be some
> particular chip set, you should be prepared to emulate the most weird
> register settings that drivers could set for that chip set. So if the
> goal is to reach close to 100% compatibility, I fear a substantial
> subset of the entire spec for the chosen subset will have to be implemented.
and that's the reason to try and pick a simple chip... The good thing about
the Cirrus chips, is that (ignoring the Laguna family - '62/'64/'65) the
TrueColour ('2x) and Alpine ('3x/'4x/'80) are all basically variations on
a theme.
So one should be able to take the work provided for the non PCI version
(a '2x or '30 I guess), and update it to be a simple PCI version. Then
(if desired) one could morph it into later chips (video windows etc).
>From a quick glance at the datasheets and tech refs, it looks as if
the '34 or '36 is the one to target - being early PCI supporting versions
and supporting 4M of video memory (i.e. 1024x768 @ 24 bit). They do contain
a BitBLT, but it's a relatively simple 2 operand (16 operations) version,
and may actually be the same op's as supported by X/Windows - need to check.
I'm not sure, but I guess the '36 is the one to target, as removing the
ISA and VL-bus of the '34 may make things simpler. But the '36 BitBLT is
slightly more capable (more support at 24/32 bpp, and seems to hang off
a FIFO). But it may be that the '34 canonly to 1024x768 @ 16bpp.
Mind the other complexity (some may think it an advantage) is that the '36
has byte swapping PCI windows (think PPC support).
> Since my main interest is in running Windows inside QEMU, I could also
> envision adding another driver later, similar to what is done in VMWare.
Well the VMware 'chip' interface is documented, you could implement it,
however I doubt they'd be happy for you to use their drivers.
DF
- Re: Subject: Re: [Qemu-devel] VGA BIOS source code, Kyle Hayes, 2004/06/01
- Re: Subject: Re: [Qemu-devel] VGA BIOS source code, Bartosz Fabianowski, 2004/06/01
- Re: Subject: Re: [Qemu-devel] VGA BIOS source code, Fabrice Bellard, 2004/06/01
- Re: Subject: Re: [Qemu-devel] VGA BIOS source code,
Derek Fawcus <=
- Re: Subject: Re: [Qemu-devel] VGA BIOS source code, Hetz Ben Hamo, 2004/06/01
- Re: Subject: Re: [Qemu-devel] VGA BIOS source code, Jan Fabianowski, 2004/06/01
- Re: Subject: Re: [Qemu-devel] VGA BIOS source code, Johannes Schindelin, 2004/06/02
- Re: Subject: Re: [Qemu-devel] VGA BIOS source code, Bartosz Fabianowski, 2004/06/02
- Re: Subject: Re: [Qemu-devel] VGA BIOS source code, Daniel Serpell, 2004/06/01
- Re: Subject: Re: [Qemu-devel] VGA BIOS source code, Derek Fawcus, 2004/06/01
- Re: Subject: Re: [Qemu-devel] VGA BIOS source code, Daniel Serpell, 2004/06/01