aboutsummaryrefslogtreecommitdiffstats
path: root/core/dmi.c
blob: 550b63e2d881679b5a3e8c6d9702a3d0bf723e1e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2011 Intel Corporation; author: H. Peter Anvin
 *
 *   Permission is hereby granted, free of charge, to any person
 *   obtaining a copy of this software and associated documentation
 *   files (the "Software"), to deal in the Software without
 *   restriction, including without limitation the rights to use,
 *   copy, modify, merge, publish, distribute, sublicense, and/or
 *   sell copies of the Software, and to permit persons to whom
 *   the Software is furnished to do so, subject to the following
 *   conditions:
 *
 *   The above copyright notice and this permission notice shall
 *   be included in all copies or substantial portions of the Software.
 *
 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 *   OTHER DEALINGS IN THE SOFTWARE.
 *
 * ----------------------------------------------------------------------- */

/*
 * Search DMI information for specific data or strings
 */

#include <string.h>
#include <stdio.h>
#include <sys/bitops.h>
#include <x86/cpu.h>
#include <syslinux/sysappend.h>
#include "core.h"

struct dmi_table {
    uint8_t type;
    uint8_t length;
    uint16_t handle;
};

struct dmi_header {
    char signature[5];
    uint8_t csum;
    uint16_t tbllen;
    uint32_t tbladdr;
    uint16_t nstruc;
    uint8_t revision;
    uint8_t reserved;
};

struct smbios_header {
    char signature[4];
    uint8_t csum;
    uint8_t len;
    uint8_t major;
    uint8_t minor;
    uint16_t maxsize;
    uint8_t revision;
    uint8_t fmt[5];

    struct dmi_header dmi;
};

static const struct dmi_header *dmi;

static uint8_t checksum(const void *buf, size_t len)
{
    const uint8_t *p = buf;
    uint8_t csum = 0;

    while (len--)
	csum += *p++;

    return csum;
}

static bool is_old_dmi(size_t dptr)
{
    const struct dmi_header *dmi = (void *)dptr;

    return !memcmp(dmi->signature, "_DMI_", 5) &&
	!checksum(dmi, 0x0f);
    return false;
}

static bool is_smbios(size_t dptr)
{
    const struct smbios_header *smb = (void *)dptr;

    return !memcmp(smb->signature, "_SM_", 4) &&
	!checksum(smb, smb->len) &&
	is_old_dmi(dptr+16);
}

/*
 * Find the root structure
 */
static void dmi_find_header(void)
{
    size_t dptr;

    /* Search for _SM_ or _DMI_ structure */
    for (dptr = 0xf0000 ; dptr < 0x100000 ; dptr += 16) {
	if (is_smbios(dptr)) {
	    dmi = (const struct dmi_header *)(dptr + 16);
	    break;
	} else if (is_old_dmi(dptr)) {
	    dmi = (const struct dmi_header *)dptr;
	    break;
	}
    }
}

/*
 * Return a specific data element in a specific table, and verify
 * that it is within the bounds of the table.
 */
static const void *dmi_find_data(uint8_t type, uint8_t base, uint8_t length)
{
    const struct dmi_table *table;
    size_t offset, end;
    unsigned int tblcount;

    if (!dmi)
	return NULL;

    if (base < 2)
	return NULL;

    end = base+length;

    offset = 0;
    tblcount = dmi->nstruc;

    while (offset+6 <= dmi->tbllen && tblcount--) {
	table = (const struct dmi_table *)(dmi->tbladdr + offset);

	if (table->type == 127)	/* End of table */
	    break;
	
	if (table->length < sizeof *table)
	    break;		/* Invalid length */

	offset += table->length;

	if (table->type == type && end <= table->length)
	    return (const char *)table + base;

	/* Search for a double NUL terminating the string table */
	while (offset+2 <= dmi->tbllen &&
	       *(const uint16_t *)(dmi->tbladdr + offset) != 0)
	    offset++;

	offset += 2;
    }

    return NULL;
}

/*
 * Return a specific string in a specific table.
 */
static const char *dmi_find_string(uint8_t type, uint8_t base)
{
    const struct dmi_table *table;
    size_t offset;
    unsigned int tblcount;

    if (!dmi)
	return NULL;

    if (base < 2)
	return NULL;

    offset = 0;
    tblcount = dmi->nstruc;

    while (offset+6 <= dmi->tbllen && tblcount--) {
	table = (const struct dmi_table *)(dmi->tbladdr + offset);

	if (table->type == 127)	/* End of table */
	    break;
	
	if (table->length < sizeof *table)
	    break;		/* Invalid length */

	offset += table->length;

	if (table->type == type && base < table->length) {
	    uint8_t index = ((const uint8_t *)table)[base];
	    const char *p = (const char *)table + table->length;
	    const char *str;
	    char c;

	    if (!index)
		return NULL;	/* String not present */

	    while (--index) {
		if (!*p)
		    return NULL;

		do {
		    if (offset++ >= dmi->tbllen)
			return NULL;
		    c = *p++;
		} while (c);
	    }

	    /* Make sure the string is null-terminated */
	    str = p;
	    do {
		if (offset++ >= dmi->tbllen)
		    return NULL;
		c = *p++;
	    } while (c);
	    return str;
	}

	/* Search for a double NUL terminating the string table */
	while (offset+2 <= dmi->tbllen &&
	       *(const uint16_t *)(dmi->tbladdr + offset) != 0)
	    offset++;

	offset += 2;
    }

    return NULL;
}

struct sysappend_dmi_strings {
    const char *prefix;
    enum syslinux_sysappend sa;
    uint8_t index;
    uint8_t offset;
};

static const struct sysappend_dmi_strings dmi_strings[] = {
    { "SYSVENDOR=",   SYSAPPEND_SYSVENDOR,   1, 0x04 },
    { "SYSPRODUCT=",  SYSAPPEND_SYSPRODUCT,  1, 0x05 },
    { "SYSVERSION=",  SYSAPPEND_SYSVERSION,  1, 0x06 },
    { "SYSSERIAL=",   SYSAPPEND_SYSSERIAL,   1, 0x07 },
    { "SYSSKU=",      SYSAPPEND_SYSSKU,      1, 0x19 },
    { "SYSFAMILY=",   SYSAPPEND_SYSFAMILY,   1, 0x1a },
    { "MBVENDOR=",    SYSAPPEND_MBVENDOR,    2, 0x04 },
    { "MBPRODUCT=",   SYSAPPEND_MBPRODUCT,   2, 0x05 },
    { "MBVERSION=",   SYSAPPEND_MBVERSION,   2, 0x06 },
    { "MBSERIAL=",    SYSAPPEND_MBSERIAL,    2, 0x07 },
    { "MBASSET=",     SYSAPPEND_MBASSET,     2, 0x08 },
    { "BIOSVENDOR=",  SYSAPPEND_BIOSVENDOR,  0, 0x04 },
    { "BIOSVERSION=", SYSAPPEND_BIOSVERSION, 0, 0x05 },
    { NULL, 0, 0, 0 }
};

/*
 * Install the string in the string table, if nonempty, after
 * removing leading and trailing whitespace.
 */
static bool is_ctl_or_whitespace(char c)
{
    return (c <= ' ' || c == '\x7f');
}

static const char *dmi_install_string(const char *pfx, const char *str)
{
    const char *p, *ep;
    size_t pfxlen;
    char *nstr, *q;

    if (!str)
	return NULL;

    while (*str && is_ctl_or_whitespace(*str))
	str++;

    if (!*str)
	return NULL;

    ep = p = str;
    while (*p) {
	if (!is_ctl_or_whitespace(*p))
	    ep = p+1;
	p++;
    }

    pfxlen = strlen(pfx);
    q = nstr = malloc(pfxlen + (ep-str) + 1);
    if (!nstr)
	return NULL;
    memcpy(q, pfx, pfxlen);
    q += pfxlen;
    memcpy(q, str, ep-str);
    q += (ep-str);
    *q = '\0';

    return nstr;
}

static void sysappend_set_sysff(const uint8_t *type)
{
    static char sysff_str[] = "SYSFF=000";

    if (!type || !*type)
	return;
    
    sprintf(sysff_str+6, "%u", *type & 0x7f);
    sysappend_strings[SYSAPPEND_SYSFF] = sysff_str;
}

struct cpuflag {
    uint8_t bit;
    char flag;
};

static void sysappend_set_cpu(void)
{
    static char cpu_str[6+6] = "CPU=";
    char *p = cpu_str + 4;
    static const struct cpuflag cpuflags[] = {
	{ 0*32+ 6, 'P' }, /* PAE */
	{ 1*32+ 5, 'V' }, /* VMX */
	{ 1*32+ 6, 'T' }, /* SMX (TXT) */
	{ 2*32+20, 'X' }, /* XD/NX */
	{ 2*32+29, 'L' }, /* Long mode (x86-64) */
	{ 3*32+ 2, 'S' }, /* SVM */
	{ 0, 0 }
    };
    const struct cpuflag *cf;

    /* Not technically from DMI, but it fit here... */

    if (!cpu_has_eflag(EFLAGS_ID)) {
	/* No CPUID */
	*p++ = cpu_has_eflag(EFLAGS_AC) ? '4' : '3';
    } else {
	uint32_t flags[4], eax, ebx, family;
	uint32_t ext_level;

	cpuid(1, &eax, &ebx, &flags[1], &flags[0]);
	family = (eax & 0x0ff00f00) >> 8;
	*p++ = family >= 6 ? '6' : family + '0';
	
	ext_level = cpuid_eax(0x80000000);
	if (ext_level >= 0x80000001 && ext_level <= 0x8000ffff) {
	    cpuid(0x80000001, &eax, &ebx, &flags[3], &flags[2]);
	} else {
	    flags[2] = flags[3] = 0;
	}

	for (cf = cpuflags; cf->flag; cf++) {
	    if (test_bit(cf->bit, flags))
		*p++ = cf->flag;
	}
    }

    *p = '\0';

    sysappend_strings[SYSAPPEND_CPU] = cpu_str;
}

void dmi_init(void)
{
    const struct sysappend_dmi_strings *ds;

    sysappend_set_cpu();

    dmi_find_header();
    if (!dmi)
	return;

    sysappend_set_uuid(dmi_find_data(1, 0x08, 16));
    sysappend_set_sysff(dmi_find_data(3, 0x05, 1));

    for (ds = dmi_strings; ds->prefix; ds++) {
	if (!sysappend_strings[ds->sa]) {
	    const char *str = dmi_find_string(ds->index, ds->offset);
	    sysappend_strings[ds->sa] = dmi_install_string(ds->prefix, str);
	}
    }
}