[coreboot] PCI IO Address space over 0xffff

Myles Watson mylesgw at gmail.com
Fri May 21 22:28:41 CEST 2010


> > If you send the log to the list we might be able to help.
> 
> Hi Myles,
> I've solved this one, kind of.  It is PCI IO Space
> overflow, we are going over 0xffff which apparently is
> a hard limit.  I image this is there so that inb, outw,
> etc instructions can be used to reference these devices.
> 
> But if one doesn't use such instructions (instead using
> memory mapped PCI IO space), I see no reason why Linux
> and coreboot couldn't work with PCI IO Space addresses
> > 0xffff.

The resource allocator doesn't care.  Just find the places where the I/O
flag is checked and the limit is set to 0xffff and try setting it larger.  I
would look in src/devices/pci_device.c and
src/northbridge/your_northbridge/northbridge.c first.

I'm not sure what will break, but we should be able to fix it pretty easily.

Thanks,
Myles






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