#include <inttypes.h>
#include <round.h>
#include <stdio.h>
+#include "devices/pit.h"
#include "threads/interrupt.h"
-#include "threads/io.h"
#include "threads/synch.h"
#include "threads/thread.h"
static void real_time_sleep (int64_t num, int32_t denom);
static void real_time_delay (int64_t num, int32_t denom);
-/* Sets up the 8254 Programmable Interval Timer (PIT) to
- interrupt PIT_FREQ times per second, and registers the
- corresponding interrupt. */
+/* Sets up the timer to interrupt TIMER_FREQ times per second,
+ and registers the corresponding interrupt. */
void
timer_init (void)
{
- /* 8254 input frequency divided by TIMER_FREQ, rounded to
- nearest. */
- uint16_t count = (1193180 + TIMER_FREQ / 2) / TIMER_FREQ;
-
- outb (0x43, 0x34); /* CW: counter 0, LSB then MSB, mode 2, binary. */
- outb (0x40, count & 0xff);
- outb (0x40, count >> 8);
-
+ pit_configure_channel (0, 2, TIMER_FREQ);
intr_register_ext (0x20, timer_interrupt, "8254 Timer");
}
/* Refine the next 8 bits of loops_per_tick. */
high_bit = loops_per_tick;
for (test_bit = high_bit >> 1; test_bit != high_bit >> 10; test_bit >>= 1)
- if (!too_many_loops (high_bit | test_bit))
+ if (!too_many_loops (loops_per_tick | test_bit))
loops_per_tick |= test_bit;
printf ("%'"PRIu64" loops/s.\n", (uint64_t) loops_per_tick * TIMER_FREQ);
enum intr_level old_level = intr_disable ();
int64_t t = ticks;
intr_set_level (old_level);
- barrier ();
return t;
}