Re: Linux 2.6.27-rc5: System boot regression caused by commit a2bd7274b47124d2fc4dfdb8c0591f545ba749dd

Linus Torvalds
2008-08-30T19:42:15Z

On Sat, 30 Aug 2008, Yinghai Lu wrote:
>
> AMD CPU/NB (quad core aka fam 10h later) has MSR to state MMCONFIG, and
> the ATI bridge BAR that have same address for MMCONFIG not even have
> chance to decode that, because NB intercept that already.

Ok, so it's similar to the local APIC in that respect (and presumably IO
APIC too, I haven't checked).

But that still just implies that the BAR probably means something else
totally, and the fact that it happens to have the same value as the MCFG
is just random luck.

> it seems ATI chipset doesn't have public version of doc...like reg
> info and BIOS/Kernel porting guide.

Yeah, I'm not finding anything either. The 690G databook that Rafael
pointed to does mention the config registers in passing, but it's really
just about electricals (pin setup etc). No BIOS writers guide indeed..

Linus