[coreboot] [AMD family16h] What need to be done in coreboot to support the Virtual Wire mode

Rudolf Marek r.marek at assembler.cz
Tue Oct 23 10:36:06 CEST 2018


Dne 23. 10. 18 v 1:57 Marc Jones napsal(a):
> Does VxWorks use the ACPI tables for IRQ routing? You might need that.

Yes good question. Usually OS uses ACPI, or MPTable or what BIOS provided in
the PCI device itself.

It seems because you are asking for the virtual wire mode IOAPIC is not supported and legacy PIC mode
maybe needed?

Does this OS configure LINT0 for ExtINT on at least one CPU? (this is how virtual wire can be implemented)

Or second way to do that, is to program IO-APIC 0 or 2 depending on chipset to ExtInt. This will cause PIC interrupts 
to be delivered to the CPU.

Please note that for PCI devices you also need to program PCI IRQ router and ELCR register if you are going to use the PIC mode,


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