RE: [X86] Fix up silly i1586 boot message.

From: Jan Engelhardt
Date: Wed Oct 28 2009 - 04:30:40 EST



On Wednesday 2009-10-28 04:08, Yuhong Bao wrote:
> <Pine.LNX.4.55.0805290102340.29522@xxxxxxxxxxxxxxxxxxx>
>
>> Intel started it first with picking up a ridiculous number for the family
>> ID for the P4 line. There is no technical justification for not keeping
>> these numbers consecutive.

Once one knows that there are 4 bits for the family field, 15 is not
such a strange value - it is the last value, one could take it as
"reserved, and look elsewhere".

>[...] Intel has assigned family 7 for the original Itanium processor
>[...] there was a bug in original NT 4 truncating family IDs
>returned by CPUID [...]

That would explain why Intel still shows an oldfashioned family=6 on
many contemporary processors (e.g. core i7). BUT, AMD64 processors
have family=15 "almost throughout", and so seem to have at least some
Intel models. So that tells us that either NT4 works, or nobody uses
NT4 on fam15s.
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