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Mon 14 Oct 23:06:38 CEST 2024

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sbosse 2024-10-14 23:07:23 +02:00
parent 782bf139a7
commit ba42a747e0
1 changed files with 75 additions and 0 deletions
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kernel/pic.c Normal file
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/*
Copyright (C) 2015-2019 The University of Notre Dame
This software is distributed under the GNU General Public License.
See the file LICENSE for details.
*/
#include "ioports.h"
#include "kernel/types.h"
#include "console.h"
#define PIC_ICW1 0x11
#define PIC_ICW4_MASTER 0x01
#define PIC_ICW4_SLAVE 0x05
#define PIC_ACK_SPECIFIC 0x60
static uint8_t pic_control[2] = { 0x20, 0xa0 };
static uint8_t pic_data[2] = { 0x21, 0xa1 };
void pic_init(int pic0base, int pic1base)
{
outb(PIC_ICW1, pic_control[0]);
outb(pic0base, pic_data[0]);
outb(1 << 2, pic_data[0]);
outb(PIC_ICW4_MASTER, pic_data[0]);
outb(~(1 << 2), pic_data[0]);
outb(PIC_ICW1, pic_control[1]);
outb(pic1base, pic_data[1]);
outb(2, pic_data[1]);
outb(PIC_ICW4_SLAVE, pic_data[1]);
outb(~0, pic_data[1]);
printf("pic: ready\n");
}
void pic_enable(uint8_t irq)
{
uint8_t mask;
if(irq < 8) {
mask = inb(pic_data[0]);
mask = mask & ~(1 << irq);
outb(mask, pic_data[0]);
} else {
irq -= 8;
mask = inb(pic_data[1]);
mask = mask & ~(1 << irq);
outb(mask, pic_data[1]);
pic_enable(2);
}
}
void pic_disable(uint8_t irq)
{
uint8_t mask;
if(irq < 8) {
mask = inb(pic_data[0]);
mask = mask | (1 << irq);
outb(mask, pic_data[0]);
} else {
irq -= 8;
mask = inb(pic_data[1]);
mask = mask | (1 << irq);
outb(mask, pic_data[1]);
}
}
void pic_acknowledge(uint8_t irq)
{
if(irq >= 8) {
outb(PIC_ACK_SPECIFIC + (irq - 8), pic_control[1]);
outb(PIC_ACK_SPECIFIC + (2), pic_control[0]);
} else {
outb(PIC_ACK_SPECIFIC + irq, pic_control[0]);
}
}