DOS/timer.c at main · PythonCoders45/DOS · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
#include"types.h"

volatileuint32_ttimer_ticks=0;

/**
 * @brief Called whenever the hardware PIT timer fires (IRQ0)
 */
voidtimer_handler(void) {
timer_ticks++;
}

/**
 * @brief Sleeps execution for a specified number of milliseconds
 */
voidsleep(uint32_tms) {
uint32_tstart_ticks=timer_ticks;
// Assuming PIT is configured to 100 Hz (1 tick = 10 ms)
uint32_tticks_to_wait=ms / 10;
while ((timer_ticks-start_ticks) <ticks_to_wait) {
 __asm__ __volatile__("hlt"); // Sleep CPU until next timer interrupt
 }
}