Re: Using >1GB RAM

MOLNAR Ingo (mingo@chiara.csoma.elte.hu)
Tue, 13 Jan 1998 21:09:02 +0100 (CET)


On Tue, 13 Jan 1998, Albert D. Cahalan wrote:

> Perhaps a new architecture, p6big. Mostly it would have symbolic
> links into the i386 code. The page tables would use the weird
> 36-bit Pentium Pro features (64 GB physical memory). Segments
> would be used everywhere. All the old segment registers get used
> as originally intended, but to go past 4 GB in 1998.
>
> For really big processes, gcc needs to learn about 48-bit far pointers.

no, the PPro 'bigphys' feature extends physical memory space to 64G
(actually extends it to 64 bits, but i guess the CPU itself is 64G
limited), but logical address space will stay pure 32 bits.

hm, is such 'above 4G' memory PCI DMA-able? it's pretty much useless if it
doesnt integrate well into PCI.

-- mingo