enabling IOAPIC on C3 processor?

[jerome lacoste <jerome.lacoste@gmail.com>]

I have a VIA Epia M10000 board that crashes very badly (and pretty
often, especially when using DMA). I want to fix that.

Serial console + magic SysRQ didn't help so I am going the nmi
watchdog way. But in order to have nmi watchdog I need APIC, right?

The C3 processor seems to support IOAPIC.
(http://www.via.com.tw/en/products/processors/c3/specs.jsp)

But:
- I don't see anything in the BIOS related to APIC. 
- grep APIC /lib/modules/`uname -r`/build/.config shows me that all
APIC options are 'y'.
- dmesg | grep APIC tells me "no local APIC present or hardware disabled".
- adding lapic kernel parameter doesn't change that. 
- and of course, nmi_watchdog=1 or 2 gives me NMI count 0 in /proc/interrupts.

Did I miss something when it comes to enabling IOAPIC support on C3 processor?

Note: I also see a lot an increasing ERR count in /proc/interrupts,
especially when I put my box in conditions that make it also more
unstable (i.e. sending files on the network while using the PVR-350
using mythtv). Not sure if it is related.

Jerome

medios@medios:~$ dmesg | grep APIC
No local APIC present or hardware disabled
mapped APIC to ffffd000 (013c1000)

medios@medios:~$ grep APIC /lib/modules/`uname -r`/build/.config 
CONFIG_X86_UP_APIC=y
CONFIG_X86_UP_IOAPIC=y
CONFIG_X86_LOCAL_APIC=y
CONFIG_X86_IO_APIC=y

Grub options
[...]
kernel          /vmlinuz-2.6.11-medios1 root=/dev/hda1 ro 
console=ttyS0,57600n8 console=tty0 nmi_watchdog=1 lapic
[...]