Problems with AMD64 and 8 GB RAM?

John Baldwin jhb at
Thu Mar 31 05:39:16 PST 2005

On Mar 30, 2005, at 11:08 PM, Greg 'groggy' Lehey wrote:

> On Wednesday, 30 March 2005 at 23:01:03 -0500, John Baldwin wrote:
>> On Mar 30, 2005, at 8:54 PM, Greg 'groggy' Lehey wrote:
>>>> lapic0: LINT1 trigger: edge
>>>> lapic0: LINT1 polarity: high
>>>> lapic1: Routing NMI -> LINT1
>>>> lapic1: LINT1 trigger: edge
>>>> lapic1: LINT1 polarity: high
>>>> -ioapic0 <Version 0.3> irqs 0-23 on motherboard
>>>> +ioapic0 <Version 0.0> irqs 0-23 on motherboard
>>>> cpu0 BSP:
>>>>      ID: 0x00000000   VER: 0x00040010 LDR: 0x01000000 DFR: 
>>>> 0x0fffffff
>>>>   lint0: 0x00010700 lint1: 0x00000400 TPR: 0x00000000 SVR: 
>>>> 0x000001ff
>> This shows that in the - case the APIC is broken somehow (0.0 isn't a
>> valid I/O APIC version).
> You mean the + case, I suppose.  Yes, that's what I suspected.
>> It would seem that the system has mapped RAM over top of the I/O
>> APIC perhaps?
> That's what I suspected too, but imp doesn't think so.

Actually, if the full version register were zero, it would not have had 
24 IRQs (irqs 0-23 part), so I'm not sure what it is doing.  0.3 isn't 
really a valid APIC version AFAIK either, though I'm more familiar with 
the versions used in Intel APICs (usually 1.1, 1.2, or 2.0).

>> It would be interesting to see the contents of your MADT to see if
>> it's trying to use a 64-bit PA for your APIC.
> Any suggestions about how to do so?

Boot with 4g or boot an i386 version and get acpidump -t output.


John Baldwin <jhb at>  <><
"Power Users Use the Power to Serve"  =

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