Re: [Trion-kernel-dev] Compatibility patch

[Daniel R. <cos...@gm...>]

> Description                M/U #  LAPIC    ID Ver Red
>
> AMD Sempron 2800+           M  1  000f0d00  2  03  17
> AMD Athlon 2200+            U  1            1  11  17
> AMD dual-core Opteron 165   M  2  000f0d00  0  11  17
> Intel Celeron               M  1  000f0000  0  11  0f
> Intel P4                    M  1  000f12a0  1  20  17

Hi Stephen,
thanks for having taken the time for a test-run ! It's good to see that  
the new local apic reactivation code doesn't only work on my computer but  
also on you uniprocessor Athlon. From the results it also looks as if the  
I/O APIC was much more common on modern computers than I've expected. The  
only thing that causes me some headach is the version number returned by  
your Sempron 2800+, which  should actually be something in between 0x10  
and 0x20 for an internal APIC. The two other values (ID and Red) seem to  
be perfectly sensible though..
Luckily the machine's BIOS however does support the multiprocessor table  
and will thus report if there's an I/O APIC. For uniprocessor systems that  
don't provide any multiprocessor tables we could fall back to a probing  
mechanism. I would propose that we simply try to read-out the I/O APIC's  
version number to make some sanity checks on it. If the number is between  
0x10 and 0x20 we assume that it really is an I/O APIC, otherwise we'll  
have to retreat to the ISA PIC. It guess it should be unlikely enough that  
the bus-noise returned if there's no I/O APIC happens to be a valid  
version number ?

Description                M/U # ID Ver Red

AMD Athlon 2600+            M  1  2  11  17
Intel Pentium 3 700         U  1  f  ff  ff
Intel P4 2800               M  1  2  20  17

regards,
cosmo86