Hi all,
1) we should provide at least the MP-Table. There is a still lot of OS without ACPI support (various homebrew OS, RTOS etc) which don't want to carry the ACPICA just to get idea how to route IRQs...
2) if we want to setup the PCI for PIC we need to do:
a) setup the PCI router (just couple of regs in the SB) This is done by: pirq_assign_irqs() b) setup the ELCR (0x4d0/0x4d1) set IRQs to level, this is done by: i8259_configure_irq_trigger() c) setup the 0x3c values in the PCI regs this is done by: pirq_route_irqs() which does the job if CONFIG_PIRQ_ROUTE
Oh yes coreboot knows how to do that if PIR table is present in quite generic way. Setting this up should not break things, except that AMD SB700 or similar needs to disable the IRQ routing to PIC in ASL code in _PIC method. I don't know if this necessary.
Thanks Rudolf