; vi:filetype=nasm ts=8 sts=8 sw=8:
	section .text

%include "intr.inc"

	global init_intr
init_intr:
	call init_pic
	ret

	global set_intr
set_intr:
	ret

PIC1_CMD equ 20h
PIC1_DATA equ 21h
PIC2_CMD equ 0a0h
PIC2_DATA equ 0a1h

; PIC initialization command word 1 bits
ICW1_ICW4_NEEDED	equ 01h
ICW1_SINGLE		equ 02h
ICW1_INTERVAL4		equ 04h
ICW1_LEVEL		equ 08h
ICW1_INIT		equ 10h
; PIC initialization command word 4 bits
ICW4_8086		equ 01h
ICW4_AUTO_EOI		equ 02h
ICW4_BUF_SLAVE		equ 08h
ICW4_BUF_MASTER		equ 0ch
ICW4_SPECIAL		equ 10h
; PIC operation command word 2 bits
OCW2_EOI		equ 20h

init_pic:
	; send ICW1 saying we'll follow with ICW4 later on
	mov al, ICW1_INIT | ICW1_ICW4_NEEDED
	out PIC1_CMD, al
	out PIC2_CMD, al
	; send ICW2 with IRQ remapping
	mov al, IRQ_OFFSET
	out PIC1_DATA, al
	add al, 8
	out PIC2_DATA, al
	; send ICW3 to setup the master/slave relationship
	; ... set bit3 = 3rd interrupt input has a slave
	mov al, 4
	out PIC1_DATA, al
	; ... set slave ID to 2
	mov al, 2
	out PIC2_DATA, al
	; send ICW4 to set 8086 mode (no calls generated)
	mov al, ICW4_8086
	out PIC1_DATA, al
	out PIC2_DATA, al
	; done, reset the data port to 0
	xor al, al
	out PIC1_DATA, al
	out PIC2_DATA, al
	ret