ports/sysutils/cpuid/files/cpuid.c

87 lines
2.6 KiB
C

/*
* Copyright (c) 2016 Philip Guenther <guenther@openbsd.org>
* Copyright (c) 2016 Stuart Henderson <sthen@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
static inline void
showreg(const char *reg, unsigned value, int show_ascii)
{
unsigned char c;
printf("%s = 0x%08x % 10u", reg, value, value);
if (show_ascii) {
fputs(" \"", stdout);
c = value & 0xff; putchar(isprint(c) ? c : '?');
c = (value >> 8) & 0xff; putchar(isprint(c) ? c : '?');
c = (value >> 16) & 0xff; putchar(isprint(c) ? c : '?');
c = (value >> 24) & 0xff; putchar(isprint(c) ? c : '?');
putchar('"');
}
putchar('\n');
}
int
main(int argc, char **argv)
{
unsigned long code, leaf;
unsigned int a, b, c, d;
leaf = 0;
switch (argc) {
case 3:
errno = 0;
/* strtoul() to both dec and hex input */
leaf = strtoul(argv[2], NULL, 0);
if (leaf == ULONG_MAX && errno == ERANGE || leaf > UINT_MAX)
errx(1, "cpuid leaf out of range: %s", argv[2]);
/* FALLTHROUGH */
case 2:
errno = 0;
code = strtoul(argv[1], NULL, 0);
if (code == ULONG_MAX && errno == ERANGE || code > UINT_MAX)
errx(1, "cpuid code out of range: %s", argv[1]);
break;
default:
printf("usage: cpuid code [leaf]\n");
exit(1);
}
/*
* The dance here with %ebx is to work around a gcc bug on i386,
* where gcc uses %ebx for PIC/PIE code but fail to save/reload
* it around __asm() blocks that use %ebx. Oddly, if you declare
* that the __asm() *clobbers* ebx, gcc complains.
* Anyway, this dance is unnecessary but harmless on amd64.
*/
__asm volatile("mov %%ebx, %%esi; cpuid; xchg %%esi, %%ebx"
: "=a" (a), "=S" (b), "=c" (c), "=d" (d)
: "a" (code), "c" (leaf));
showreg("eax", a, 1);
showreg("ebx", b, 1);
showreg("ecx", c, 1);
showreg("edx", d, 1);
//getc(stdin);
return 0;
}