SMP only detects one CPU - help?

Chuck Swiger cswiger at
Fri Apr 20 16:58:33 UTC 2007

On Apr 20, 2007, at 9:14 AM, Adam J Richardson wrote:
> Finally, mptable shows what's really going on:
> "MP Config Base Table Entries:
> --
> Processors: APIC ID Version State        Family Model Step Flags
>              3       0x11    BSP, usable  6      8     3    0x387fbff
>              0       0x11    AP, unusable 6      8     3    0x387fbff"
> Apparently the "application processor" is "unusable", whatever that  
> means. I am now stuck.
> Is there a software fix for this, or do I have a broken CPU,  
> unlikely as it seems? Any help is appreciated.
> Does it seem likely that upgrading both CPUs to the highest Pentium- 
> IIIs I can find, which I was thinking about doing anyway, would fix  
> the problem?

It's more likely that updating the system BIOS and trying to tweak  
any settings related to SMP or ACPI might help.  You might also try  
enabling or toggling the "PnP OS installed", to avoid having the BIOS  
configure stuff it doesn't need to boot, and leaving FreeBSD to  
assign IRQs itself...

If that doesn't help, I believe there's a freebsd-acpi list which  
contain people who can look at the dump of your BIOS and fix the  
broken IRQ assignments it is doing.


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