LXR linux/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
  21static 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
  35int 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                                if (msg_strs[0] < i ||
  63                                    (msg_strs[0] == i && msg_strs[1] < j)) {
  64                                        /* Skip to the next string */
  65                                        msg_strs += 2;
  66                                        while (*msg_strs++)
  67                                                ;
  68                                }
  69                                if (e & 1) {
  70                                        if (msg_strs[0] == i &&
  71                                            msg_strs[1] == j &&
  72                                            msg_strs[2])
  73                                                printf("%s ", msg_strs+2);
  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}
  86