[coreboot] [PATCH] Streamline CPU_ADDR_BITS usage

Scott Duplichan scott at notabs.org
Mon Oct 4 16:02:01 CEST 2010

]Are there processors where that CPU_ADDR_BITS_MASK cannot be reliably
]retrieved from CPUID? What is the harm in using a value that is too
]small for the CAR setup? In other words could we use the least common
]value for any CPU instead of having a different setting on each
]different chip?

My recent experience is with AMD processors. There are no known problems
with the AMD cpuid reporting of max physical address size for families
0Fh and beyond.

In my experience, using too few bits is workable. I once hard-coded
a 36-bit mask for a BIOS that boots both family 12h and family 14h.
Certainly coreboot should use the correct mask though. 



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