John Baldwin jhb at FreeBSD.org
Thu Jul 31 09:31:25 PDT 2003

On 31-Jul-2003 Terry Lambert wrote:
> It wasn't clear to me at the time whether the discussion was
> geared toward having both APIC and xAPIC support, or only xAPIC
> support.

Both, the xAPIC is mostly backwards compatible.  The extension of
the ID field just uses bits that are reserved (and hard-wired to 0)
on the older APICs.  Thus, if one uses 0xFF to address all CPU's
(the only real difference), then it will work on both types of

> I'm not happy with my Circa 1996 dual P90 box.  It's not
> inconceivable that non-xAPIC processors might get deprecated
> in the rush to more than 16 CPU's, like my ASUS dual P90
> box seems to have been.

The P90 breakage isn't related to any APIC changes AFAICT.  Do
you have any more details of the exact breakage on the P90?
I've forgotten the details. :(

> Also, the recent change to make SSE instructions the build
> default also bit me on one of my machines without SSE support.

Humm, is this in the kernel?


John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve!"  -  http://www.FreeBSD.org/

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