arch/x86/boot/cpu.c

   1 /* -*- linux-c -*- ------------------------------------------------------- *
   2  *
   3  *   Copyright (C) 1991, 1992 Linus Torvalds
   4  *   Copyright 2007 rPath, Inc. - All Rights Reserved
   5  *
   6  *   This file is part of the Linux kernel, and is made available under
   7  *   the terms of the GNU General Public License version 2.
   8  *
   9  * ----------------------------------------------------------------------- */
  10
  11 /*
  12  * arch/i386/boot/cpu.c
  13  *
  14  * Check for obligatory CPU features and abort if the features are not
  15  * present.
  16  */
  17
  18 #include "boot.h"
  19 #include "bitops.h"
  20 #include <asm/cpufeature.h>
  21
  22 static char *cpu_name(int level)
  23 {
  24         static char buf[6];
  25
  26         if (level == 64) {
  27                 return "x86-64";
  28         } else {
  29                 sprintf(buf, "i%d86", level);
  30                 return buf;
  31         }
  32 }
  33
  34 int validate_cpu(void)
  35 {
  36         u32 *err_flags;
  37         int cpu_level, req_level;
  38
  39         check_cpu(&cpu_level, &req_level, &err_flags);
  40
  41         if (cpu_level < req_level) {
  42                 printf("This kernel requires an %s CPU, ",
  43                        cpu_name(req_level));
  44                 printf("but only detected an %s CPU.\n",
  45                        cpu_name(cpu_level));
  46                 return -1;
  47         }
  48
  49         if (err_flags) {
  50                 int i, j;
  51                 puts("This kernel requires the following features "
  52                      "not present on the CPU:\n");
  53
  54                 for (i = 0; i < NCAPINTS; i++) {
  55                         u32 e = err_flags[i];
  56
  57                         for (j = 0; j < 32; j++) {
  58                                 if (e & 1)
  59                                         printf("%d:%d ", i, j);
  60
  61                                 e >>= 1;
  62                         }
  63                 }
  64                 putchar('\n');
  65                 return -1;
  66         } else {
  67                 return 0;
  68         }
  69 }