extern char ioapic_Product_ID[];
extern char ioapic_OEM_ID[];
ASUS P/I-P65UP5 (dual P166, ASUS SC875 SCSI, S3 based PCI VGA) works
fine with pirq=0 but alas no OEM/PROD data so cannot whitelist.
Intel MultiProcessor Specification v1.1
Virtual Wire compatibility mode.
OEM ID: OEM00000 Product ID: PROD00000000 APIC at: 0xFEE00000
Processor #0 Pentium(tm) APIC version 16
Processor #1 Pentium(tm) APIC version 16
I/O APIC #2 Version 17 at 0xFEC00000.