pic.c

/* ** por compatibilidad se omiten tildes **
================================================================================
 TRABAJO PRACTICO 3 - System Programming - ORGANIZACION DE COMPUTADOR II - FCEN
================================================================================
  funciones del controlador de interrupciones
*/

#include "pic.h"

#define PIC1_PORT 0x20
#define PIC2_PORT 0xA0

static __inline __attribute__((always_inline)) void outb(int port, unsigned char data) {
    __asm __volatile("outb %0,%w1" : : "a" (data), "d" (port));
}
void fin_intr_pic1(void) { outb(0x20, 0x20); }
void fin_intr_pic2(void) { outb(0x20, 0x20); outb(0xA0, 0x20); }

void resetear_pic() {
    outb(PIC1_PORT+0, 0x11); /* IRQs activas x flanco, cascada, y ICW4 */
    outb(PIC1_PORT+1, 0x20); /* Addr */
    outb(PIC1_PORT+1, 0x04); /* PIC1 Master, Slave ingresa Int.x IRQ2 */
    outb(PIC1_PORT+1, 0x01); /* Modo 8086 */
    outb(PIC1_PORT+1, 0xFF); /* Enmasca todas! */

    outb(PIC2_PORT+0, 0x11); /* IRQs activas x flanco, cascada, y ICW4 */
    outb(PIC2_PORT+1, 0x28); /* Addr */
    outb(PIC2_PORT+1, 0x02); /* PIC2 Slave, ingresa Int x IRQ2 */
    outb(PIC2_PORT+1, 0x01); /* Modo 8086 */
    outb(PIC2_PORT+1, 0xFF); /* Enmasca todas! */
}

void habilitar_pic() {
    outb(PIC1_PORT+1, 0x00);
    outb(PIC2_PORT+1, 0x00);
}

void deshabilitar_pic() {
    outb(PIC1_PORT+1, 0xFF);
    outb(PIC2_PORT+1, 0xFF);
}