#include <asm/io.h>
#include <asm/msr.h>

#define JS_PORT 0x200
#define CPU_HZ 1462904000

void  trigger(void)
{
    outb(0x0, JS_PORT);
}

main()
{
    unsigned int low1, high1, low2, high2;
    iopl(3);
    trigger();
    rdtsc(low1, high1);
    while(inb(JS_PORT) & 1);
    rdtsc(low2, high2);
    printf("low1=%u, high1=%u, low2=%u, high2=%u\n", low1, high1, low2, high2);
    printf("low2 - low1 = %u\n", low2 - low1);
    printf("in ms = %f\n", (((double)(low2-low1))/CPU_HZ)*1000);
}