cpu.c

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/* -*- linux-c -*- ------------------------------------------------------- *
 *
 *   Copyright (C) 1991, 1992 Linus Torvalds
 *   Copyright 2007-2008 rPath, Inc. - All Rights Reserved
 *
 *   This file is part of the Linux kernel, and is made available under
 *   the terms of the GNU General Public License version 2.
 *
 * ----------------------------------------------------------------------- */

/*
 * arch/x86/boot/cpu.c
 *
 * Check for obligatory CPU features and abort if the features are not
 * present.
 */

#include "boot.h"
#include "cpustr.h"

static char *cpu_name(int level)
{
    static char buf[6];

    if (level == 64) {
        return "x86-64";
    } else {
        if (level == 15)
            level = 6;
        sprintf(buf, "i%d86", level);
        return buf;
    }
}

int validate_cpu(void)
{
    u32 *err_flags;
    int cpu_level, req_level;
    const unsigned char *msg_strs;

    check_cpu(&cpu_level, &req_level, &err_flags);

    if (cpu_level < req_level) {
        printf("This kernel requires an %s CPU, ",
               cpu_name(req_level));
        printf("but only detected an %s CPU.\n",
               cpu_name(cpu_level));
        return -1;
    }

    if (err_flags) {
        int i, j;
        puts("This kernel requires the following features "
             "not present on the CPU:\n");

        msg_strs = (const unsigned char *)x86_cap_strs;

        for (i = 0; i < NCAPINTS; i++) {
            u32 e = err_flags[i];

            for (j = 0; j < 32; j++) {
                if (msg_strs[0] < i ||
                    (msg_strs[0] == i && msg_strs[1] < j)) {
                    /* Skip to the next string */
                    msg_strs += 2;
                    while (*msg_strs++)
                        ;
                }
                if (e & 1) {
                    if (msg_strs[0] == i &&
                        msg_strs[1] == j &&
                        msg_strs[2])
                        printf("%s ", msg_strs+2);
                    else
                        printf("%d:%d ", i, j);
                }
                e >>= 1;
            }
        }
        putchar('\n');
        return -1;
    } else {
        return 0;
    }
}