Support for more than 4GB on x86 platform

[Rick Wagner]

Hi,

I have seen reference to kernel support for up to 32GB on 32 bit x86 
platforms, with supporting hardware (some versions of Xeon?).

Perhaps I used the wrong search terms, but I could not locate much detailed 
information on the subject with Google.  Specifically, I was told that the 
kernel could map the memory virtually, but the I/O sub-system could not 
handle physical I/O to address over 32 bits, thus I/O to high memory was done 
via bounce buffers (i.e., DMA to low memory, then CPU copy to high).

Can anyone point to some documentation on the large memory implementation I 
can use to confirm or refute what I was told?

Thanks,
	--rick