src/pic.c

#include "pic.h"
#include "log.h"
#include "io.h"

#define ICW1_ICW4	0x01		/* ICW4 (not) needed */
#define ICW1_SINGLE	0x02		/* Single (cascade) mode */
#define ICW1_INTERVAL4	0x04		/* Call address interval 4 (8) */
#define ICW1_LEVEL	0x08		/* Level triggered (edge) mode */
#define ICW1_INIT	0x10		/* Initialization - required! */
 
#define ICW4_8086	0x01		/* 8086/88 (MCS-80/85) mode */
#define ICW4_AUTO	0x02		/* Auto (normal) EOI */
#define ICW4_BUF_SLAVE	0x08		/* Buffered mode/slave */
#define ICW4_BUF_MASTER	0x0C		/* Buffered mode/master */
#define ICW4_SFNM	0x10		/* Special fully nested (not) */


void (* interrupt_handlers[256])(struct registers);

void pic_send_eoi(uchar interrupt)
{
	if (interrupt >= IRQ_TO_INT(8))
		outb(PIC2_COMMAND, PIC_EOI);

	outb(PIC1_COMMAND, PIC_EOI);
}

void irq_handler(struct registers regs)
{
	pic_send_eoi(regs.interrupt_number);

	kprintf("irq_handler called with interrupt %d\n", regs.interrupt_number);

	if (interrupt_handlers[regs.interrupt_number])
		interrupt_handlers[regs.interrupt_number](regs);
}

void add_interrupt_handler(uchar interrupt, void (* handler)(struct registers))
{
	interrupt_handlers[interrupt] = handler;
}

void pic_remap()
{
    outb(0x20, 0x11);
    outb(0xA0, 0x11);
    outb(0x21, 0x20);
    outb(0xA1, 0x28);
    outb(0x21, 0x04);
    outb(0xA1, 0x02);
    outb(0x21, 0x01);
    outb(0xA1, 0x01);
    outb(0x21, 0x0);
    outb(0xA1, 0x0);

	return;
}