61 lines
1.8 KiB
C
61 lines
1.8 KiB
C
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/*
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File: irq.C
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Author: R. Bettati
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Department of Computer Science
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Texas A&M University
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Date : 09/03/05
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This code borrows heavily from Brandon Friesen's the code in Brandon
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Friesen's OS Development Tutorial.
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*/
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/*--------------------------------------------------------------------------*/
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/* DEFINES */
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/*--------------------------------------------------------------------------*/
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#define IRQ_BASE 32
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/*--------------------------------------------------------------------------*/
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/* INCLUDES */
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/*--------------------------------------------------------------------------*/
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#include "machine.H"
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#include "irq.H"
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/*--------------------------------------------------------------------------*/
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/* LOCAL FUNCTIONS . */
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/*--------------------------------------------------------------------------*/
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/* Normally, IRQs 0 to 7 are mapped to IDT entries 8 to 15.
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For a variety of reasons it is a good idea to re-map these
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IRQs to different locations
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We send a sequence of commands to the PICs - 8259's - in order
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to have IRQ0 to IRQ15 be remapped to IDT entries 32 to 47.
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*/
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static void irq_remap()
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{
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Machine::outportb(0x20, 0x11);
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Machine::outportb(0xA0, 0x11);
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Machine::outportb(0x21, 0x20);
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Machine::outportb(0xA1, 0x28);
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Machine::outportb(0x21, 0x04);
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Machine::outportb(0xA1, 0x02);
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Machine::outportb(0x21, 0x01);
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Machine::outportb(0xA1, 0x01);
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Machine::outportb(0x21, 0x0);
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Machine::outportb(0xA1, 0x0);
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}
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/*--------------------------------------------------------------------------*/
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/* EXPORTED FUNCTIONS . */
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/*--------------------------------------------------------------------------*/
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void IRQ::init() {
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irq_remap();
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}
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