Yes, it tries without the mask, i.e for 681 - 68f it tries 680. Then, if that does not match, it dies with "Unknown CPU". There is no failsafe nor fallback involved. What makes you think there is? It just means adding 1 entry to the table instead of 16.
Ok, if it is not a _fail_safe_ or _fall_back_ why don't we just always do this as a default?
My understanding is that barring errata, the stepping shouldn't matter. Just in case it does, we check it. If there isn't a specific entry for the stepping, we go to the "normal" case of using the ops without the stepping information.
Why print out a "generic" message?
I think it just means "not-stepping-specific"
Thanks, Myles