On 11/23/2012 07:49 PM, Yuhong Bao wrote:
>> + * Specifically, cr4 exists if and only if CPUID exists,
>> + * which in turn exists if and only if EFLAGS.ID exists.
> This may be true for *Intel* 486 CPUs as VME was implemented at the same time as CPUID, but I am not sure that it is true for AMD 486 CPUs.
>
> Yuhong Bao 		 	   		

That is the architecture; if you know of a counterexample speak up.  "I 
am not sure" doesn't count.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.