Re: apic in 2.3.99-pre6

From: Frank Mehnert (
Date: Thu Apr 27 2000 - 08:59:51 EST

On Thu, 27 Apr 2000, Gerard Sharp wrote:

> I get the impression I don't really have an APIC (not surprising since it's a
> uniprocessor board :) )
> but then, on boot, it pretty clearly states
> Apr 28 01:42:50 midnight kernel: mapped APIC to ffffe000 (01242000)

As far as I know the APIC is disabled on most Uniprocessor Boards.
I have an Athlon 700 MHz Model 2 on a K7M Mainboard, which have an
APIC (see docs), but cat /proc/cpuinfo does not show this feature.

The APIC can be enabled by writing a machine status register (MSR 0x1B
bit 0xb). After enabling the APIC, it emulates an i8259 and has to
be programmed correct to get interrupts.


Frank Mehnert
## Dept. of Computer Science, Dresden University of Technology, Germany ##
## E-Mail: ##

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