- What is PIC and what is it for?
- What is APIC and what is it for? What is the purpose of LAPIC and I/O APIC?
- What are the differences between APIC, xAPIC, and x2APIC?
- What is MSI? What are the differences between MSI and MSI-X?
- What is the role of the $PIR, MPtable, and ACPI tables?
If you want to know the answer for one of these questions, or if you simply want to know about interrupt controller evolution, please, welcome.