Re: [RFC, Announce] Unified x86 architecture, arch/x86

H. Peter Anvin
2007-07-21T00:10:41Z

Alan Cox wrote:
> On Fri, 20 Jul 2007 18:38:39 -0400
> Jeff Garzik <jeff@garzik.org> wrote:
>
>> I agree with Andi... it's quite nice to be able to leave some arch/i386
>> stuff, and not carry it over to arch/x86-64.
>
> Its easy enough to push that stuff into arch/x86/legacy and have one
> subdirectory of stuff to pull in for ancient systems.

The other thing is that "legacy" in this context is fungible. No IOMMU
was legacy until the Intel x86-64 chips came out, and I can promise you
that some legacy code will be necessary once we start seeing VIA and
others come out with embedded x86-64.

On the other hand, it's pretty bloody safe to assume that we'll never
see an x86-64 chip without CPUID, CMOV, FXSAVE, SSE-2, CMPXCHG, etc.

-hpa