The pre-B0 step Pentium does not support multiple CPUID levels: no matter
what input value you supply in EAX, all CPUID does on those processors is
load the family/model/stepping values into bits 11-8/7-4/3-0 of EAX.

So if you execute CPUID with EAX=0, and get EAX=0000_05xxh, then you know
it's a pre-B0 step Pentium.

You will have to "assume" 0000_00FFh for the standard feature flags: this
puppy supported FPU/VME/DE/PSE/TSC/MSR/PAE/MCE/CX8. (Yes, though somewhat
broken, it did have PAE support.)

| are the values returned by standard level 2 (cache) really standard for
| amd/intel or should i use standard level 2 for intel only (to retrieve the
| l1/l2 cache) and extended level 5/6 (to retrieve the l1/l2 cache) for amd?

The descriptors returned by level 0000_0002h are vendor-specific. (If you
check the sandpile.org's CPUID page, then you'll notice that (a) only In-
tel and Cyrix processors support them, (b) they are mostly for Intel pro-
cessors, and (c) Cyrix' descriptors collide with Intel's.)

By contrast levels 8000_0005h and 8000_0006h are more flexible -- various
AMD, Centaur, and Transmeta processors support them.

So far there is no processor which supports both.

| is that correct?
| - amd-k6-2+ = l2 cache 128kb and amd-k6-III+ = l2 cache 256kb?

Yes.

| - family 15, model 0 = pentium 4 (willamette)? no other models?

If the family is Fh, then you must check the new extended family field.
If the extended family is 00h, then it's a Pentium 4.

Does anyone have access to a Foster (ie. P4 Xeon)? If so, then please let
us know its model (0h or 1h?) and its extended family (01h?). :-)