[coreboot] PCI IO Address space over 0xffff

Myles Watson mylesgw at gmail.com
Sat May 22 17:55:52 CEST 2010


>> I'm interested in how you want to map port IO space to memory.
>> Please explain.
>>
>> AFAIK PCI register space is totally independent of port IO space which
>> is totally independent of memory space. You can access PCI register
>> space via CF8/CFC port IO and via MMCONFIG memory, but I'm unaware of
>> any mechanisms to map IO ports to memory or the other way round.
>
> Well, all I know at this point is that the Linux kernel
> sources have code that maps inb etc either to the
> instructions or to a memory dereference, and the .config
> for that chooses memory dereference for x86.
>
> It's gonna be fun seeing if high-IO-address space can be
> made to work..

We should be able to support any mapping that you can make work in
Linux.  It will be fun to see.

Thanks,
Myles




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