>
> Question is if Radeon has BAR0 matching VRAM size because in that case if
> Rage128 has fixed 64MB and Radeon has size of VRAM for BAR0 then
> CONFIG_APER_SIZE can be half of BAR0 which would work for both. But if
> Radeon also has a fixed size BAR0 larger than actual VRAM (mathching max
> supported VRAM instead then current calculation is needed using VRAM size
> for radeon according to the FCode ROM I've tested. Changing
> CONFIG_APER_SIZE only for Rage128 should not break anything as I did not
> see anything using that so that would also work if we can't find out what
> Radeon has.
>
Card VRAM PCI BAR0 CONFIG_MEMSIZE
CONFIG_APER_SIZE AGP_APER_OFFSET
----------------------- ---- -------- --------------
---------------- ---------------
Rage 128 Pro Ultra TF 32MB 64MB 0x02000000 0x02000000
0x02000000
Rage 128 RF/SG AGP 16MB 64MB 0x01000000 0x02000000
0x02000000
Radeon R100 QD [Radeon 7200] 64MB 128MB 0x04000000 0x04000000
N/A
Looking at the linux source it appears the R100 doesn't have an
AGP_APER_OFFSET register. The register at that offset according to the
linux driver is something else entirely. This suggests that
the R100 doesn't map AGP memory space into BAR0 in the way that the
Rage 128 does. It makes sense that the R128's BAR0 would be twice the
max memory for the architecture given that it also has to do this AGP
mapping. But if the R100 _doesn't_ then it wouldn't need to make room
for AGP and it may just be that the BAR0 is the size of the max memory.
I don't have documentation for the R100 though so it's tough to know for sure.
But to answer your question about the BAR0 matching VRAM on the R100.
At least for this card it does not. The VRAM is half of the BAR0. I have a
32MB Radeon arriving soon so I'll be able to test that to see if it also
follows that pattern or if BAR0 is still 128MB. From what I'm seeing there
may have been some 128MB R100's, it's not entirely clear to me. So it's
possible that the 128MB is the max VRAM.
