[SeaBIOS] Re: Large 32 bit BAR's

[Gerd Hoffmann]

Hi,
> I'm running a x86 QEMU with Ubuntu. On this system we want to emulate
> a PCIe device which contains a large 32-bit BAR (2 GiB). This is not
> working and I get following error:

Why a 32-bit bar, not a 64-bit bar?

A 2G 32-bit bar simply can't be mapped anywhere on x86.  It must be
below 4G, and it must be 2G-aligned.  Which leaves exactly two options:
0G -> 2G or 2G -> 4G.  Both overlap with resources critical for x86
boot, the former with the real mode address space (0-1M) and the latter
with lapic, ioapic, hpet, tpm etc just below 4G.

take care,
  Gerd