#define ALLOC_MAIN
#include <hlib.h>

#define PIT_A 0x40
#define PIT_CONTROL 0x43

#define PIT_MASK 0xFF
#define PIT_SCALE 1193180
#define PIT_SET 0x36

#define CMD_BINARY 0x00

#define CMD_MODE0 0x00
#define CMD_MODE1 0x02
#define CMD_MODE2 0x04
#define CMD_MODE3 0x06
#define CMD_MODE4 0x08
#define CMD_MODE5 0x0a

#define CMD_RW_BOTH 0x30

#define CMD_COUNTER0 0x00
#define CMD_COUNTER2 0x80

uint32_t systemTime = 0;

void interruptHandler() {
    systemTime++;
    if (!(systemTime % 100)) {
        printf("system time: %is\n", systemTime / 100);
    }
}

int32_t main() {
    uint32_t service = getService("pic");
    uint32_t event = getEvent(service, "irq0");
    subscribeEvent(service, event, interruptHandler);
    uint32_t hz = 100;
    int divisor = PIT_SCALE / hz;
    ioOut(PIT_CONTROL, CMD_BINARY | CMD_MODE3 | CMD_RW_BOTH | CMD_COUNTER0, 1);
    ioOut(PIT_A, (uint8_t)divisor, 1);
    ioOut(PIT_A, (uint8_t)(divisor >> 8), 1);
    printf("timer handler installed\n");
}