xref: /linux/arch/x86/boot/cpu.c (revision 40d3057ac036f2501c1930728a6179be4fca577b)
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 }
85