Legacy8259

Field	Value
Index	0023
Module	Legacy8259
Size	4,608 bytes (PE32+)
Phase	DXE

Overview

UEFI DXE driver for the Intel 8259A Programmable Interrupt Controller (PIC). Manages legacy 8259 PIC hardware by providing an EFI_LEGACY_8259_PROTOCOL interface. Handles PIC initialization (ICW1-ICW4), interrupt masking via IMR, mode switching (legacy vs. virtual wire), IRQ-to-vector translation, and EOI signaling. Source: PcAtChipsetPkg/8259InterruptControllerDxe.

Key Functions

_ModuleEntryPoint -- PIC hardware init and protocol installation
Interrupt masking, mode switching, EOI signaling
IRQ-to-vector translation

Protocols/Dependencies

EFI_LEGACY_8259_PROTOCOL
EFI_DEBUG_OUTPUT_PROTOCOL
PCAT Compatibility Protocol
Hardware: Master PIC (Cmd=0x20, Data=0x21), Slave PIC (Cmd=0xA0, Data=0xA1)

Platform

HR650X Purley (PcAtChipsetPkg)