Large mmio resources and 4G+ of RAM...

YhLu YhLu at
Tue Jun 1 11:53:01 CEST 2004


There is something called Memory lifting or memory remapping for Opteron.
For example if 2G for one Opteron and two ways system.

Then the CPU 0 will use [0,2G), and CPU 1 will use [4G, 6G).

If the RAM for CPU is above 4G, then We must lost 1/2G for MMIO range, the
reason is Opteron only has two reg for RAM LOW and HIGH limit. And there is
no other regs to record the memory hole. But it seems Intel CPU has more
regs to remember the memory hole.



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