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                 if (level == 15)
  32                         level = 6;
  33                 sprintf(buf, "i%d86", level);
  34                 return buf;
  35         }
  36 }
  37
  38 int validate_cpu(void)
  39 {
  40         u32 *err_flags;
  41         int cpu_level, req_level;
  42         const unsigned char *msg_strs;
  43
  44         check_cpu(&cpu_level, &req_level, &err_flags);
  45
  46         if (cpu_level < req_level) {
  47                 printf("This kernel requires an %s CPU, ",
  48                        cpu_name(req_level));
  49                 printf("but only detected an %s CPU.\n",
  50                        cpu_name(cpu_level));
  51                 return -1;
  52         }
  53
  54         if (err_flags) {
  55                 int i, j;
  56                 puts("This kernel requires the following features "
  57                      "not present on the CPU:\n");
  58
  59                 msg_strs = (const unsigned char *)x86_cap_strs;
  60
  61                 for (i = 0; i < NCAPINTS; i++) {
  62                         u32 e = err_flags[i];
  63
  64                         for (j = 0; j < 32; j++) {
  65                                 int n = (i << 5)+j;
  66                                 if (*msg_strs < n) {
  67                                         /* Skip to the next string */
  68                                         do {
  69                                                 msg_strs++;
  70                                         } while (*msg_strs);
  71                                         msg_strs++;
  72                                 }
  73                                 if (e & 1) {
  74                                         if (*msg_strs == n && msg_strs[1])
  75                                                 printf("%s ", msg_strs+1);
  76                                         else
  77                                                 printf("%d:%d ", i, j);
  78                                 }
  79                                 e >>= 1;
  80                         }
  81                 }
  82                 putchar('\n');
  83                 return -1;
  84         } else {
  85                 return 0;
  86         }
  87 }