cpuid.c

cpuid.c (text/plain), 882 bytes, created by SpanKY on 2011-09-22 23:05:39 UTC

#include <stdio.h>
static inline void cpuid (unsigned int info, unsigned int *eax, unsigned int *ebx,
                          unsigned int *ecx, unsigned int *edx)
{
    unsigned int _eax = info, _ebx, _ecx, _edx;
    asm volatile ("mov %%ebx, %%edi;" // save ebx (for PIC)
                  "cpuid;"
                  "mov %%ebx, %%esi;" // pass to caller
                  "mov %%edi, %%ebx;" // restore ebx
                  :"+a" (_eax), "=S" (_ebx), "=c" (_ecx), "=d" (_edx)
                  :      /* inputs: eax is handled above */
                  :"edi" /* clobbers: we hit edi directly */);
    if (eax) *eax = _eax;
    if (ebx) *ebx = _ebx;
    if (ecx) *ecx = _ecx;
    if (edx) *edx = _edx;
}
foo(int i) {
unsigned int a,b,c,d;
cpuid(i, &a,&b,&c,&d);
printf("%#x: %#x %#x %#x %#x\n", i, a,b,c,d);
}
main() {foo(1);foo(0x80000000);foo(0x80000001);foo(0x80000002);}