cpuid.c

#include <stdio.h>

static void cpuid(int op1, int op2, int *data) {
    asm("cpuid" 
        : "=a" (data[0]), "=b" (data[1]), "=c" (data[2]), "=d" (data[3])
        : "a"(op1), "c"(op2));
}

int main (int argc, const char * argv[]) {
    int values[4];
    int level_type = 0;
    int i = 0;

    while (1) {
      cpuid(0xB, i++, values);
    
      level_type = values[2] >> 8 & 0xFF;
      if (level_type == 0) break;

      printf("Shift: %d, Count: : %d, Level Id: %d, Level Type: %d, x2APIC: %d, Group: %d\n",
             values[0] & 0xF, values[1] & 0xFFFF, 
             values[2] & 0xFF, level_type, 
             values[3], values[3] >> (values[0] & 0xF));
    }
}