Re: [Qemu-devel] [edk2] [PATCH] OvmfPkg/PlatformPei: Initialise RCBA (B0:D31:F0 0xf0) register

[Jordan Justen]

On 2015-06-08 02:06:40, Laszlo Ersek wrote:
> On 06/06/15 21:10, Paulo Alcantara wrote:
> > diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
> > index 4cb70dc..a6586f3 100644
> > --- a/OvmfPkg/OvmfPkg.dec
> > +++ b/OvmfPkg/OvmfPkg.dec
> > @@ -78,6 +78,10 @@
> >    #  to PIIX4 function 3 offset 0x40-0x43 bits [15:6].
> >    gUefiOvmfPkgTokenSpaceGuid.PcdAcpiPmBaseAddress|0xB000|UINT16|5
> >  
> > +  ## This flag determines the Root Complex Register Block BAR, written to 
> > Q35
> > +  #  function 31 offset 0xf0-0xf3 bits [31:14]
> > +  
> > gUefiOvmfPkgTokenSpaceGuid.PcdRootComplexBaseAddress|0xfed1c000|UINT32|0x1e
> > +
> 
> I understand Jordan doesn't like the new PCD here, and proposes a
> fixed macro for the same purpose, but I don't understand why we
> should follow a different avenue for this base address when we opted
> for a PCD with the PMBA.

I'm not sure there is a good reason for the PMBA PCD at this point.

Do you remember why we decided to add a PCD? It doesn't actually
change values. I wonder if we were only half committed to the 0x400 =>
0xb000 value change at that point? :)

I could also see adding a PCD if it looks better for some 'common'
code to key off of the PCD, rather than including a chipset specific
include file.

-Jordan