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 "cpustr.h"
  20
  21 static char *cpu_name(int level)
  22 {
  23         static char buf[6];
  24
  25         if (level == 64) {
  26                 return "x86-64";
  27         } else {
  28                 if (level == 15)
  29                         level = 6;
  30                 sprintf(buf, "i%d86", level);
  31                 return buf;
  32         }
  33 }
  34
  35 int validate_cpu(void)
  36 {
  37         u32 *err_flags;
  38         int cpu_level, req_level;
  39         const unsigned char *msg_strs;
  40
  41         check_cpu(&cpu_level, &req_level, &err_flags);
  42
  43         if (cpu_level < req_level) {
  44                 printf("This kernel requires an %s CPU, ",
  45                        cpu_name(req_level));
  46                 printf("but only detected an %s CPU.\n",
  47                        cpu_name(cpu_level));
  48                 return -1;
  49         }
  50
  51         if (err_flags) {
  52                 int i, j;
  53                 puts("This kernel requires the following features "
  54                      "not present on the CPU:\n");
  55
  56                 msg_strs = (const unsigned char *)x86_cap_strs;
  57
  58                 for (i = 0; i < NCAPINTS; i++) {
  59                         u32 e = err_flags[i];
  60
  61                         for (j = 0; j < 32; j++) {
  62                                 int n = (i << 5)+j;
  63                                 if (*msg_strs < n) {
  64                                         /* Skip to the next string */
  65                                         do {
  66                                                 msg_strs++;
  67                                         } while (*msg_strs);
  68                                         msg_strs++;
  69                                 }
  70                                 if (e & 1) {
  71                                         if (*msg_strs == n && msg_strs[1])
  72                                                 printf("%s ", msg_strs+1);
  73                                         else
  74                                                 printf("%d:%d ", i, j);
  75                                 }
  76                                 e >>= 1;
  77                         }
  78                 }
  79                 putchar('\n');
  80                 return -1;
  81         } else {
  82                 return 0;
  83         }
  84 }