16 lines
471 B
C++
16 lines
471 B
C++
#include "arch/Timer.h"
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#include "arch/x86_64/IO.h"
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#define PIT_CHANNEL_0 0x40
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const u64 base_frequency = 1193182;
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const usize ARCH_TIMER_FREQ = 5;
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void Timer::arch_init()
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{
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constexpr u16 divisor = (u16)(base_frequency / (ARCH_TIMER_FREQ * 1000));
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static_assert(divisor >= 100, "ARCH_TIMER_FREQ is too high");
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IO::outb(PIT_CHANNEL_0, (u8)(divisor & 0xFF));
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IO::outb(0x80, 0); // short delay
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IO::outb(PIT_CHANNEL_0, (u8)((divisor & 0xFF00) >> 8));
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} |