christophe leroy wrote:
>
> >
> > The Linux kernel includes full PCI setup code (BIOS if you will).
> > I originally wrote it for the Alpha and it was then taken, expanded
> > etc. It is very functional, I believe that it runs/works on the ebsa-285
> > at system start up. I am assuming that this is the case 'cos I have
> > another PCI based ARM system that I'm about to turn PCI on for. Right now
> > I'm at the 'loading a RAMdisk stage'...
> >
>
> Is it the layout_? functions in bios32.c ?
> You find them in alpha and m68k arch, not in all arch, not in arm.
> I'd a look at it and I think i'll try to port it to arm.
>
> Could you please sum up how it works ? (I mean what function is
> doing what) And what I can discard as there is a lone PCI bus on
> EBSA285 board
>
> Christophe
> unsubscribe: body of `unsubscribe linux-arm' to [EMAIL PROTECTED]
I'm sure I'll be corrected if I'm wrong, but, I think the PCI bus scanning
and setup works correctly on ebsa285; the PCI subsystem has located all devices
on the bus. The problem lies in fact that some pre-OS
entity, BIOS for lack of a better term, did not allocate IO, MEM, and interupts
to the various devices. If you look at arch/arm/kernel/hw-ebsa285.c you'll see
where pcibios_fixup_ebsa285() assigns some interrupt values, maps some devices
to IO for some architectures, .....
For me, since the ebsa285 is a transitional platform, I added a hard coded
function
that assigns the IO and such; this looks like:
...
....
/* sort out the irq mapping for this device */
switch (machine_type) {
case MACH_TYPE_EBSA285:
dev->irq = ebsa_irqval(dev);
/* Turn on bus mastering - boot loader doesn't
* - perhaps it should! - dag
*/
#if 0
pci_set_cmd(dev, 0, PCI_COMMAND_MASTER);
#else
inet_pci_bios_fixup(dev);
#endif
break;
...
...
The function inet_pci_bios_fixup() simply looks for the devices I know I
have (a 3com ethernet) and assigns an IO address and sets the command register.
A more elegant and generic solution will have wait.
--
Dave Baukus
Inet Technologies Inc. - R & D
[EMAIL PROTECTED]
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