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#ifdef CONFIG_X86_FEATURE_NAMES
20#include "cpustr.h"
21#endif
22
23static char *cpu_name(int level)
24{
25	static char buf[6];
26
27	if (level == 64) {
28		return "x86-64";
29	} else {
30		if (level == 15)
31			level = 6;
32		sprintf(buf, "i%d86", level);
33		return buf;
34	}
35}
36
37static void show_cap_strs(u32 *err_flags)
38{
39	int i, j;
40#ifdef CONFIG_X86_FEATURE_NAMES
41	const unsigned char *msg_strs = (const unsigned char *)x86_cap_strs;
42	for (i = 0; i < NCAPINTS; i++) {
43		u32 e = err_flags[i];
44		for (j = 0; j < 32; j++) {
45			if (msg_strs[0] < i ||
46			    (msg_strs[0] == i && msg_strs[1] < j)) {
47				/* Skip to the next string */
48				msg_strs += 2;
49				while (*msg_strs++)
50					;
51			}
52			if (e & 1) {
53				if (msg_strs[0] == i &&
54				    msg_strs[1] == j &&
55				    msg_strs[2])
56					printf("%s ", msg_strs+2);
57				else
58					printf("%d:%d ", i, j);
59			}
60			e >>= 1;
61		}
62	}
63#else
64	for (i = 0; i < NCAPINTS; i++) {
65		u32 e = err_flags[i];
66		for (j = 0; j < 32; j++) {
67			if (e & 1)
68				printf("%d:%d ", i, j);
69			e >>= 1;
70		}
71	}
72#endif
73}
74
75int validate_cpu(void)
76{
77	u32 *err_flags;
78	int cpu_level, req_level;
79
80	check_cpu(&cpu_level, &req_level, &err_flags);
81
82	if (cpu_level < req_level) {
83		printf("This kernel requires an %s CPU, ",
84		       cpu_name(req_level));
85		printf("but only detected an %s CPU.\n",
86		       cpu_name(cpu_level));
87		return -1;
88	}
89
90	if (err_flags) {
91		puts("This kernel requires the following features "
92		     "not present on the CPU:\n");
93		show_cap_strs(err_flags);
94		putchar('\n');
95		return -1;
96	} else {
97		return 0;
98	}
99}
100