Subject: Re: Radeon framebuffer (the story continues)
To: Michael Lorenz <macallan@netbsd.org>
From: Vincent <10.50@free.fr>
List: tech-kern
Date: 12/28/2006 10:58:31
Michael,

>> 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

Remember: the needs of the many outweight the needs of the few... or the 
one. ;)

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

I've tried to find the Linux' radeonfb.c file. If I have stumbled upon 
the right one, it doesn't seem to read anything from the BIOS, just 
defaulting to typical cases. It is of no real use. But I may have erred.

> 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.

They don't seem to have evolved the slightest bit thereon... (see later)

>> I don't like to cut/copy verbatim pieces of software that I don't 
>> understand. 
> Nobody asked you to.

No, that's right. But eventually, if you don't own any other reliable 
source, you have to. At least you have to copy it to some degree. That 
means two things: first, you have to trust the code you imitate, and, if 
there is a bug, you can't even figure it out and fix it; second, I am 
unsure whether such a code can be licenced BSD if it is drawn out a GPL 
or LGPL'ed software.

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

Well, Intel® seems to have a natural position: the best you know a 
circuit, the more likely you are to use it. I've never bought a 
nVidia-based laptop, and I'm unlikely to buy an ATI-based one again if I 
can't manage to get some docs on their chips. I will go Intel® because 
at least the 945GM chipset spec is fully available. I wish anybody in 
the Open Source world do the same. That would probably make nVidia and 
ATI aware of their shortsighted and petty politics.

Vincent