#include  <stdio.h>

inline void cpuid(unsigned int op, unsigned int *eax, unsigned int
*ebx, unsigned int *ecx, unsigned int *edx)
{
   __asm__("cpuid"
   : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx)
   : "a" (op)
   : "cc");
}

int main(void)
{
   unsigned int eax,ebx,ecx,edx;
   unsigned int i=0;
   char array[17];
   char *cp=array;

   cpuid(0x8fffffff, &eax,&ebx,&ecx,&edx);

   for (i = 0; i < 4; i++)
       *cp++ = eax >> (8 * i);
   for (i = 0; i < 4; i++)
       *cp++ = ebx >> (8 * i);
   for (i = 0; i < 4; i++)
       *cp++ = ecx >> (8 * i);
   for (i = 0; i < 4; i++)
       *cp++ = edx >> (8 * i);
   *cp = 0;

   printf ("%s\n", array);
}

$ /usr/sfw/bin/gcc -o opteron opteron.c