Subject: Re: Radeon framebuffer (the story continues)
To: Vincent <>
From: Michael Lorenz <>
List: tech-kern
Date: 12/27/2006 16:50:42
Hash: SHA1


On Dec 27, 2006, at 16:31, Vincent wrote:

>> Ah, so it /did/ find the video BIOS but can't make sense of it.
>> Any chance to update your BIOS ( and hope that would also update the 
>> DFP table ) ?
> None whatsoever. I guess nobody cares about a piece of silicium 5 
> years old (read: heap of crap) that only knows about NetBSD! :)

Well, you obviously do and that's good enough I guess :p

>> Another way would be to look at the radeon driver in xorg or xfree 
>> and see if/how they make sense of such a table - with some luck it's 
>> not too different from version 3 and can be added to radeonfb.
> I've done that. To no avail. DFT table prior to revision 3 do not seem 
> to hold the necessary info. Or nobody managed to get the right 
> information about it. I went ahead reading some code of the xorg 
> radeon driver written by the Gatos project. I understand the code, but 
> little of what is underlying it. I can't get anything solid on the 
> Radeon BIOS structure or registers besides lines of code with 
> hard-coded offset and absconse structure.

Does Linux do The Right Thing on your laptop? Maybe they have something 
readable in the kernel.

> Nothing out on Internet. That's a pain.

Trust me, I know. I wrote the mach64 acceleration code from reading 
xfree driver source. No way to get any halfway decent documentation on 
any ATI part it seems, at least if you're not some big corporation.
I applied for a developer registration with my NetBSD address a while 
ago, didn't even get an answer. Maybe I should try again now that 
they're part of AMD.

> I don't like to cut/copy verbatim pieces of software that I don't 
> understand.

Nobody asked you to.

> I can't figure out why datasheets explaining all that stuff is not 
> available, either.

Because ATI seems to think those are trade secrets or something.

> There seems to be a bunch of (Windows closed source) Radeon BIOS 
> twickers around, made up God knows with what documentation, since 
> nothing seems to be released . I can't see the point of ATI or nVIDIA 
> in  denying wide-access to their specs. That's way beyond the grasp of 
> my small intellect.

They apparently think that giving away the specs means to allow others 
to copy their designs.
I really don't understand why ATI doesn't even publish specs for older 
chips ( like all the mach64 variants, rage128 or older radeons ) - even 
Intel does that, docs for many C&T chips are freely available from

have fun
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