Re: PCI amiga's..

[Michel <dae...@st...>]

Michael Schmitz wrote:

> > In  free86-4.0.1/build-tree/xc/programs/Xserver/hw/xfree86/os-support/bus
> > some *Pci.c files for several arches exist, but none for m68k. The files
> > say, they need kernel 2.2 for /proc/bus/pci, I am running 2.2.10, but I
> > only have /proc/bus/zorro, but not pci... so maybe it would not make sense
> > to add m68k to the Imakefile?
> 
> No, that would not make sense unless we add code in the kernel to
> masquerade the m68k builtin framebuffer devices as PCI devices of some
> sort (and I don't just mean support for /proc/bus/pci).

I have implemented something like this for the Permedia2 based boards in the
APUS tree. But I don't think it's feasible for all graphics hardware.


> Now how does XFree86 4.x deal with legacy Intel hardware with just ISA or
> EISA but no PCI bus? Does this still work, at all??

Yes. There's similar code for (E)ISA.


> > However, without pci, I have some problems to get xfree4.0 to build, see
> > error messages above. I think (anybody with a clue correct me please) that
> > XF4.0 requires some pci functions, or some major rework in the
> > (I)Makefiles and whatnot. So if somebody has a proposal (dummy, or maybe
> > some "real" pci functions for m68k) or maybe even a patch, I'd be happy to
> > hear about it.
> 
> There should be a way (in site.def, perhaps) to say 'there's no PCI on
> this architecture, use other access methods like VGA or fbdev'. If that's
> not possible, dummy PCI functions could be implemented that just return
> -ENODEV for anything if /proc/bus/pci isn't present, hoping XFree does
> what it is supposed to in this case: fall back on fbdev to map and access
> the hardware.

Just look at the PPC PCI code, that works fine without /proc/pci - tested on
APUS.


> If even that isn't possible, the design of XFree86 4.0 is badly broken (not
> that I'd be surprised; in my eyes the way XFree messes with PCI resources
> bypassing the kernel is a big design flaw and just asking for trouble).

Many people have complained about that, but they forget that XFree86 runs on a
lot more OSs than just Linux which may not have such a convenient API for PCI.
And even the older Linux kernels don't.


Michel


-- 
Earthling Michel Dänzer (MrCooper)  \  CS student and free software enthusiast
Debian GNU/Linux (powerpc,i386) user \   member of XFree86 and The DRI Project