[coreboot] Some questions about Intel 815EG GMCH

[ali hagigat]

I wonder if you can introduce some active forums or mailing lists to
discuss Intel chips in details technically except the Intel forums
because they are virtually inactive and no question is answered i have
tried it out before.
I have questions about Intel 82815EG north bridge(it is connected to
Pentium III). It has a display cache interface and up to 4 MB memory
can be plugged into its AGP port. I wonder if anybody knows how can i
map this 4 mega bytes memory above my main RAM physical memory because
I want to see and check the content of that local memory.
Also the manual of the chip talks about 32/64MB memory(and also
another 512K) configurable by some config registers. The display cache
memory can be configured to reside inside this 64 MB? What is this
64M, is it the display cache virtually or it is a different memory?
Also the manual says:
"GMCH does not support VGA on local memory"
What does it mean?