76 lines
1.5 KiB
C
76 lines
1.5 KiB
C
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/*
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Copyright (C) 2015-2019 The University of Notre Dame
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This software is distributed under the GNU General Public License.
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See the file LICENSE for details.
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*/
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#include "ioports.h"
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#include "kernel/types.h"
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#include "console.h"
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#define PIC_ICW1 0x11
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#define PIC_ICW4_MASTER 0x01
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#define PIC_ICW4_SLAVE 0x05
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#define PIC_ACK_SPECIFIC 0x60
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static uint8_t pic_control[2] = { 0x20, 0xa0 };
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static uint8_t pic_data[2] = { 0x21, 0xa1 };
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void pic_init(int pic0base, int pic1base)
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{
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outb(PIC_ICW1, pic_control[0]);
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outb(pic0base, pic_data[0]);
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outb(1 << 2, pic_data[0]);
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outb(PIC_ICW4_MASTER, pic_data[0]);
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outb(~(1 << 2), pic_data[0]);
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outb(PIC_ICW1, pic_control[1]);
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outb(pic1base, pic_data[1]);
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outb(2, pic_data[1]);
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outb(PIC_ICW4_SLAVE, pic_data[1]);
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outb(~0, pic_data[1]);
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printf("pic: ready\n");
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}
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void pic_enable(uint8_t irq)
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{
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uint8_t mask;
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if(irq < 8) {
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mask = inb(pic_data[0]);
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mask = mask & ~(1 << irq);
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outb(mask, pic_data[0]);
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} else {
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irq -= 8;
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mask = inb(pic_data[1]);
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mask = mask & ~(1 << irq);
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outb(mask, pic_data[1]);
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pic_enable(2);
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}
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}
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void pic_disable(uint8_t irq)
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{
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uint8_t mask;
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if(irq < 8) {
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mask = inb(pic_data[0]);
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mask = mask | (1 << irq);
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outb(mask, pic_data[0]);
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} else {
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irq -= 8;
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mask = inb(pic_data[1]);
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mask = mask | (1 << irq);
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outb(mask, pic_data[1]);
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}
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}
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void pic_acknowledge(uint8_t irq)
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{
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if(irq >= 8) {
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outb(PIC_ACK_SPECIFIC + (irq - 8), pic_control[1]);
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outb(PIC_ACK_SPECIFIC + (2), pic_control[0]);
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} else {
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outb(PIC_ACK_SPECIFIC + irq, pic_control[0]);
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}
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}
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