Yes. I think that after power on, IOAPIC works on PIC mode or virtual wire mode by default. But no device use interrupts in both coreboot and FILO, keyboard, vga, serial port all polling. I check the mptable.c, some people set the IOAPIC in PIC mode via c00h/c01h, now that no device uses it, why they set it? Maybe at the very beginning of OS, PIC mode is applied before IOAPIC is enabled. My understanding is correct or not? Thank you.
Best Regards
??? Feng Libo @ AMD Ext: 20906 Mobile Phone: 13683249071 Office Phone: 0086-010-62801406
-----Original Message----- From: Rudolf Marek [mailto:r.marek@assembler.cz] Sent: Wednesday, March 05, 2008 4:11 PM To: Feng, Libo Cc: coreboot@coreboot.org Subject: Re: [coreboot] PIC, APIC, XAPIC and XIOAPIC
Hello,
You need to put at least SB IOAPICs in virtualwire mode. Thats what BIOS should do. CHeck the Multiprocessor Specs 1.4 for details. (or VIA 8237 code in southbridge/)
http://www.intel.com/design/intarch/MANUALS/242016.htm
Rudolf