[SeaBIOS] Graphics card pass-through working with two pass pci-initialization

[Gerd Hoffmann]

   Hi,

> 0xE0000000 is hard-coded in the DSDT for both piix and q35 as below.
> If the range is determined dynamically, the area also needs to be
> updated somehow dynamically.
>
> ...
>              Name (_CRS, ResourceTemplate ()
> ...
>                  DWordMemory (ResourceProducer, PosDecode, MinFixed, MaxFixed, NonCacheable, ReadWrite,
>                      0x00000000,         // Address Space Granularity
>                      0xE0000000,         // Address Range Minimum
>                      0xFEBFFFFF,         // Address Range Maximum
>                      0x00000000,         // Address Translation Offset
>                      0x1EC00000,         // Address Length
>                      ,, , AddressRangeMemory, TypeStatic)

Uhm, indeed.  I know next to nothing about ACPI though.  Ideas anyone 
how this could be done?

cheers,
   Gerd