arch/x86/boot/cpu.c

   1 /* -*- linux-c -*- ------------------------------------------------------- *
   2  *
   3  *   Copyright (C) 1991, 1992 Linus Torvalds
   4  *   Copyright 2007-2008 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/x86/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 #include "cpustr.h"
  23
  24 static char *cpu_name(int level)
  25 {
  26         static char buf[6];
  27
  28         if (level == 64) {
  29                 return "x86-64";
  30         } else {
  31                 sprintf(buf, "i%d86", level);
  32                 return buf;
  33         }
  34 }
  35
  36 int validate_cpu(void)
  37 {
  38         u32 *err_flags;
  39         int cpu_level, req_level;
  40         const unsigned char *msg_strs;
  41
  42         check_cpu(&cpu_level, &req_level, &err_flags);
  43
  44         if (cpu_level < req_level) {
  45                 printf("This kernel requires an %s CPU, ",
  46                        cpu_name(req_level));
  47                 printf("but only detected an %s CPU.\n",
  48                        cpu_name(cpu_level));
  49                 return -1;
  50         }
  51
  52         if (err_flags) {
  53                 int i, j;
  54                 puts("This kernel requires the following features "
  55                      "not present on the CPU:\n");
  56
  57                 msg_strs = (const unsigned char *)x86_cap_strs;
  58
  59                 for (i = 0; i < NCAPINTS; i++) {
  60                         u32 e = err_flags[i];
  61
  62                         for (j = 0; j < 32; j++) {
  63                                 int n = (i << 5)+j;
  64                                 if (*msg_strs < n) {
  65                                         /* Skip to the next string */
  66                                         do {
  67                                                 msg_strs++;
  68                                         } while (*msg_strs);
  69                                         msg_strs++;
  70                                 }
  71                                 if (e & 1) {
  72                                         if (*msg_strs == n && msg_strs[1])
  73                                                 printf("%s ", msg_strs+1);
  74                                         else
  75                                                 printf("%d:%d ", i, j);
  76                                 }
  77                                 e >>= 1;
  78                         }
  79                 }
  80                 putchar('\n');
  81                 return -1;
  82         } else {
  83                 return 0;
  84         }
  85 }