forked from PoliEcho-holding-org/kern
44 lines
917 B
C
44 lines
917 B
C
#ifndef TIMER_H
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#define TIMER_H
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#include "stdint.h"
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#include "idt.h"
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#include "irq.h"
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#include "system.h"
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#include "screen.h"
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#define INPUT_CLK 1193180
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uint32_t timerTicks = 0;
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void timerHandler() {
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timerTicks++;
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// TODO: Improve the cursor rendering
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if (timerTicks % 500 == 0) putcAt(127, cursor.x, cursor.y);
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else if (timerTicks % 250 == 0) putcAt(' ', cursor.x, cursor.y);
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}
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void setupTimer() {
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installIrqHandler(0, timerHandler);
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}
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// Source: https://en.wikibooks.org/wiki/X86_Assembly/Programmable_Interval_Timer
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void timerPhase(uint32_t hz) {
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uint16_t div = INPUT_CLK / hz;
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outb(0x43, 0x36); // Tell PIT that we're setting channel 0
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outb(0x40, div & 0xff); // Low byte
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outb(0x40, div >> 8); // High byte
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}
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void sleep(uint32_t ticks) {
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uint32_t eticks = ticks + timerTicks;
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while (timerTicks != eticks); // Should ignore overflows unlike '<'
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}
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#endif
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