summaryrefslogtreecommitdiff
path: root/src/lib/cbfs.c
blob: 4bc6962562ba2fdaa27629812b9400b9a940744d (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
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
/* SPDX-License-Identifier: GPL-2.0-only */

#include <assert.h>
#include <boot_device.h>
#include <cbfs.h>
#include <cbfs_private.h>
#include <cbmem.h>
#include <commonlib/bsd/compression.h>
#include <commonlib/endian.h>
#include <console/console.h>
#include <fmap.h>
#include <lib.h>
#include <metadata_hash.h>
#include <security/tpm/tspi/crtm.h>
#include <security/vboot/vboot_common.h>
#include <stdlib.h>
#include <string.h>
#include <symbols.h>
#include <timestamp.h>

cb_err_t cbfs_boot_lookup(const char *name, bool force_ro,
			  union cbfs_mdata *mdata, struct region_device *rdev)
{
	const struct cbfs_boot_device *cbd = cbfs_get_boot_device(force_ro);
	if (!cbd)
		return CB_ERR;

	size_t data_offset;
	cb_err_t err = CB_CBFS_CACHE_FULL;
	if (!CONFIG(NO_CBFS_MCACHE) && !ENV_SMM && cbd->mcache_size)
		err = cbfs_mcache_lookup(cbd->mcache, cbd->mcache_size,
					  name, mdata, &data_offset);
	if (err == CB_CBFS_CACHE_FULL) {
		struct vb2_hash *metadata_hash = NULL;
		if (CONFIG(TOCTOU_SAFETY)) {
			if (ENV_SMM)  /* Cannot provide TOCTOU safety for SMM */
				dead_code();
			if (!cbd->mcache_size)
				die("Cannot access CBFS TOCTOU-safely in " ENV_STRING " before CBMEM init!\n");
			/* We can only reach this for the RW CBFS -- an mcache
			   overflow in the RO CBFS would have been caught when
			   building the mcache in cbfs_get_boot_device().
			   (Note that TOCTOU_SAFETY implies !NO_CBFS_MCACHE.) */
			assert(cbd == vboot_get_cbfs_boot_device());
			/* TODO: set metadata_hash to RW metadata hash here. */
		}
		err = cbfs_lookup(&cbd->rdev, name, mdata, &data_offset,
				  metadata_hash);
	}

	if (CONFIG(VBOOT_ENABLE_CBFS_FALLBACK) && !force_ro &&
	    err == CB_CBFS_NOT_FOUND) {
		printk(BIOS_INFO, "CBFS: Fall back to RO region for %s\n",
		       name);
		return cbfs_boot_lookup(name, true, mdata, rdev);
	}
	if (err) {
		if (err == CB_CBFS_NOT_FOUND)
			printk(BIOS_WARNING, "CBFS: '%s' not found.\n", name);
		else if (err == CB_CBFS_HASH_MISMATCH)
			printk(BIOS_ERR, "CBFS ERROR: metadata hash mismatch!\n");
		else
			printk(BIOS_ERR,
			       "CBFS ERROR: error %d when looking up '%s'\n",
			       err, name);
		return err;
	}

	if (rdev_chain(rdev, &cbd->rdev, data_offset, be32toh(mdata->h.len)))
		return CB_ERR;

	if (tspi_measure_cbfs_hook(rdev, name, be32toh(mdata->h.type))) {
		printk(BIOS_ERR, "CBFS ERROR: error when measuring '%s'\n", name);
	}

	return CB_SUCCESS;
}

int cbfs_boot_locate(struct cbfsf *fh, const char *name, uint32_t *type)
{
	if (cbfs_boot_lookup(name, false, &fh->mdata, &fh->data))
		return -1;

	size_t msize = be32toh(fh->mdata.h.offset);
	if (rdev_chain(&fh->metadata, &addrspace_32bit.rdev,
		       (uintptr_t)&fh->mdata, msize))
		return -1;

	if (type) {
		if (!*type)
			*type = be32toh(fh->mdata.h.type);
		else if (*type != be32toh(fh->mdata.h.type))
			return -1;
	}

	return 0;
}

static void *_cbfs_map(const char *name, size_t *size_out, bool force_ro)
{
	struct region_device rdev;
	union cbfs_mdata mdata;

	if (cbfs_boot_lookup(name, force_ro, &mdata, &rdev))
		return NULL;

	if (size_out != NULL)
		*size_out = region_device_sz(&rdev);

	return rdev_mmap_full(&rdev);
}

void *cbfs_map(const char *name, size_t *size_out)
{
	return _cbfs_map(name, size_out, false);
}

void *cbfs_ro_map(const char *name, size_t *size_out)
{
	return _cbfs_map(name, size_out, true);
}

int cbfs_unmap(void *mapping)
{
	/* This works because munmap() only works on the root rdev and never
	   cares about which chained subregion something was mapped from. */
	return rdev_munmap(boot_device_ro(), mapping);
}

int cbfs_locate_file_in_region(struct cbfsf *fh, const char *region_name,
			       const char *name, uint32_t *type)
{
	struct region_device rdev;
	int ret = 0;
	if (fmap_locate_area_as_rdev(region_name, &rdev)) {
		LOG("%s region not found while looking for %s\n",
		    region_name, name);
		return -1;
	}

	uint32_t dummy_type = 0;
	if (!type)
		type = &dummy_type;

	ret = cbfs_locate(fh, &rdev, name, type);
	if (!ret)
		if (tspi_measure_cbfs_hook(&rdev, name, *type))
			LOG("error measuring %s in region %s\n", name, region_name);
	return ret;
}

static inline bool fsps_env(void)
{
	/* FSP-S is assumed to be loaded in ramstage. */
	if (ENV_RAMSTAGE)
		return true;
	return false;
}

static inline bool fspm_env(void)
{
	/* FSP-M is assumed to be loaded in romstage. */
	if (ENV_ROMSTAGE)
		return true;
	return false;
}

static inline bool cbfs_lz4_enabled(void)
{
	if (fsps_env() && CONFIG(FSP_COMPRESS_FSP_S_LZ4))
		return true;
	if (fspm_env() && CONFIG(FSP_COMPRESS_FSP_M_LZ4))
		return true;

	if ((ENV_BOOTBLOCK || ENV_SEPARATE_VERSTAGE) && !CONFIG(COMPRESS_PRERAM_STAGES))
		return false;

	return true;
}

static inline bool cbfs_lzma_enabled(void)
{
	if (fsps_env() && CONFIG(FSP_COMPRESS_FSP_S_LZMA))
		return true;
	if (fspm_env() && CONFIG(FSP_COMPRESS_FSP_M_LZMA))
		return true;
	/* We assume here romstage and postcar are never compressed. */
	if (ENV_BOOTBLOCK || ENV_SEPARATE_VERSTAGE)
		return false;
	if (ENV_ROMSTAGE && CONFIG(POSTCAR_STAGE))
		return false;
	if ((ENV_ROMSTAGE || ENV_POSTCAR)
	    && !CONFIG(COMPRESS_RAMSTAGE))
		return false;
	return true;
}

size_t cbfs_load_and_decompress(const struct region_device *rdev, size_t offset,
	size_t in_size, void *buffer, size_t buffer_size, uint32_t compression)
{
	size_t out_size;
	void *map;

	switch (compression) {
	case CBFS_COMPRESS_NONE:
		if (buffer_size < in_size)
			return 0;
		if (rdev_readat(rdev, buffer, offset, in_size) != in_size)
			return 0;
		return in_size;

	case CBFS_COMPRESS_LZ4:
		if (!cbfs_lz4_enabled())
			return 0;

		/* cbfs_stage_load_and_decompress() takes care of in-place
		   lz4 decompression by setting up the rdev to be in memory. */
		map = rdev_mmap(rdev, offset, in_size);
		if (map == NULL)
			return 0;

		timestamp_add_now(TS_START_ULZ4F);
		out_size = ulz4fn(map, in_size, buffer, buffer_size);
		timestamp_add_now(TS_END_ULZ4F);

		rdev_munmap(rdev, map);

		return out_size;

	case CBFS_COMPRESS_LZMA:
		if (!cbfs_lzma_enabled())
			return 0;
		map = rdev_mmap(rdev, offset, in_size);
		if (map == NULL)
			return 0;

		/* Note: timestamp not useful for memory-mapped media (x86) */
		timestamp_add_now(TS_START_ULZMA);
		out_size = ulzman(map, in_size, buffer, buffer_size);
		timestamp_add_now(TS_END_ULZMA);

		rdev_munmap(rdev, map);

		return out_size;

	default:
		return 0;
	}
}

static size_t cbfs_stage_load_and_decompress(const struct region_device *rdev,
		size_t offset, size_t in_size, void *buffer, size_t buffer_size,
		uint32_t compression)
{
	struct region_device rdev_src;

	if (compression == CBFS_COMPRESS_LZ4) {
		if (!cbfs_lz4_enabled())
			return 0;
		/* Load the compressed image to the end of the available memory
		 * area for in-place decompression. It is the responsibility of
		 * the caller to ensure that buffer_size is large enough
		 * (see compression.h, guaranteed by cbfstool for stages). */
		void *compr_start = buffer + buffer_size - in_size;
		if (rdev_readat(rdev, compr_start, offset, in_size) != in_size)
			return 0;
		/* Create a region device backed by memory. */
		rdev_chain(&rdev_src, &addrspace_32bit.rdev,
				(uintptr_t)compr_start, in_size);

		return cbfs_load_and_decompress(&rdev_src, 0, in_size, buffer,
					buffer_size, compression);
	}

	/* All other algorithms can use the generic implementation. */
	return cbfs_load_and_decompress(rdev, offset, in_size, buffer,
					buffer_size, compression);
}

static inline int tohex4(unsigned int c)
{
	return (c <= 9) ? (c + '0') : (c - 10 + 'a');
}

static void tohex8(unsigned int val, char *dest)
{
	dest[0] = tohex4((val >> 4) & 0xf);
	dest[1] = tohex4(val & 0xf);
}

static void tohex16(unsigned int val, char *dest)
{
	dest[0] = tohex4(val >> 12);
	dest[1] = tohex4((val >> 8) & 0xf);
	dest[2] = tohex4((val >> 4) & 0xf);
	dest[3] = tohex4(val & 0xf);
}

void *cbfs_boot_map_optionrom(uint16_t vendor, uint16_t device)
{
	char name[17] = "pciXXXX,XXXX.rom";

	tohex16(vendor, name + 3);
	tohex16(device, name + 8);

	return cbfs_map(name, NULL);
}

void *cbfs_boot_map_optionrom_revision(uint16_t vendor, uint16_t device, uint8_t rev)
{
	char name[20] = "pciXXXX,XXXX,XX.rom";

	tohex16(vendor, name + 3);
	tohex16(device, name + 8);
	tohex8(rev, name + 13);

	return cbfs_map(name, NULL);
}

static size_t _cbfs_load(const char *name, void *buf, size_t buf_size,
			 bool force_ro)
{
	struct region_device rdev;
	union cbfs_mdata mdata;

	if (cbfs_boot_lookup(name, force_ro, &mdata, &rdev))
		return 0;

	uint32_t compression = CBFS_COMPRESS_NONE;
	const struct cbfs_file_attr_compression *attr = cbfs_find_attr(&mdata,
				CBFS_FILE_ATTR_TAG_COMPRESSION, sizeof(*attr));
	if (attr) {
		compression = be32toh(attr->compression);
		if (buf_size < be32toh(attr->decompressed_size))
			return 0;
	}

	return cbfs_load_and_decompress(&rdev, 0, region_device_sz(&rdev),
					buf, buf_size, compression);
}

size_t cbfs_load(const char *name, void *buf, size_t buf_size)
{
	return _cbfs_load(name, buf, buf_size, false);
}

size_t cbfs_ro_load(const char *name, void *buf, size_t buf_size)
{
	return _cbfs_load(name, buf, buf_size, true);
}

int cbfs_prog_stage_load(struct prog *pstage)
{
	struct cbfs_stage stage;
	uint8_t *load;
	void *entry;
	size_t fsize;
	size_t foffset;
	const struct region_device *fh = prog_rdev(pstage);

	if (rdev_readat(fh, &stage, 0, sizeof(stage)) != sizeof(stage))
		return -1;

	fsize = region_device_sz(fh);
	fsize -= sizeof(stage);
	foffset = 0;
	foffset += sizeof(stage);

	/* cbfs_stage fields are written in little endian despite the other
	   cbfs data types being encoded in big endian. */
	stage.compression = read_le32(&stage.compression);
	stage.entry = read_le64(&stage.entry);
	stage.load = read_le64(&stage.load);
	stage.len = read_le32(&stage.len);
	stage.memlen = read_le32(&stage.memlen);

	assert(fsize == stage.len);

	load = (void *)(uintptr_t)stage.load;
	entry = (void *)(uintptr_t)stage.entry;

	/* Hacky way to not load programs over read only media. The stages
	 * that would hit this path initialize themselves. */
	if ((ENV_BOOTBLOCK || ENV_SEPARATE_VERSTAGE) &&
	    !CONFIG(NO_XIP_EARLY_STAGES) && CONFIG(BOOT_DEVICE_MEMORY_MAPPED)) {
		void *mapping = rdev_mmap(fh, foffset, fsize);
		rdev_munmap(fh, mapping);
		if (mapping == load)
			goto out;
	}

	fsize = cbfs_stage_load_and_decompress(fh, foffset, fsize, load,
					 stage.memlen, stage.compression);
	if (!fsize)
		return -1;

	/* Clear area not covered by file. */
	memset(&load[fsize], 0, stage.memlen - fsize);

	prog_segment_loaded((uintptr_t)load, stage.memlen, SEG_FINAL);

out:
	prog_set_area(pstage, load, stage.memlen);
	prog_set_entry(pstage, entry, NULL);

	return 0;
}

void cbfs_boot_device_find_mcache(struct cbfs_boot_device *cbd, uint32_t id)
{
	if (CONFIG(NO_CBFS_MCACHE) || ENV_SMM)
		return;

	if (cbd->mcache_size)
		return;

	const struct cbmem_entry *entry;
	if (cbmem_possibly_online() &&
	    (entry = cbmem_entry_find(id))) {
		cbd->mcache = cbmem_entry_start(entry);
		cbd->mcache_size = cbmem_entry_size(entry);
	} else if (ENV_ROMSTAGE_OR_BEFORE) {
		u8 *boundary = _ecbfs_mcache - REGION_SIZE(cbfs_mcache) *
			CONFIG_CBFS_MCACHE_RW_PERCENTAGE / 100;
		boundary = (u8 *)ALIGN_DOWN((uintptr_t)boundary,
					    CBFS_MCACHE_ALIGNMENT);
		if (id == CBMEM_ID_CBFS_RO_MCACHE) {
			cbd->mcache = _cbfs_mcache;
			cbd->mcache_size = boundary - _cbfs_mcache;
		} else if (id == CBMEM_ID_CBFS_RW_MCACHE) {
			cbd->mcache = boundary;
			cbd->mcache_size = _ecbfs_mcache - boundary;
		}
	}
}

cb_err_t cbfs_init_boot_device(const struct cbfs_boot_device *cbd,
			       struct vb2_hash *metadata_hash)
{
	/* If we have an mcache, mcache_build() will also check mdata hash. */
	if (!CONFIG(NO_CBFS_MCACHE) && !ENV_SMM && cbd->mcache_size > 0)
		return cbfs_mcache_build(&cbd->rdev, cbd->mcache,
					 cbd->mcache_size, metadata_hash);

	/* No mcache and no verification means we have nothing special to do. */
	if (!CONFIG(CBFS_VERIFICATION) || !metadata_hash)
		return CB_SUCCESS;

	/* Verification only: use cbfs_walk() without a walker() function to
	   just run through the CBFS once, will return NOT_FOUND by default. */
	cb_err_t err = cbfs_walk(&cbd->rdev, NULL, NULL, metadata_hash, 0);
	if (err == CB_CBFS_NOT_FOUND)
		err = CB_SUCCESS;
	return err;
}

const struct cbfs_boot_device *cbfs_get_boot_device(bool force_ro)
{
	static struct cbfs_boot_device ro;

	/* Ensure we always init RO mcache, even if first file is from RW.
	   Otherwise it may not be available when needed in later stages. */
	if (ENV_INITIAL_STAGE && !force_ro && !region_device_sz(&ro.rdev))
		cbfs_get_boot_device(true);

	if (!force_ro) {
		const struct cbfs_boot_device *rw = vboot_get_cbfs_boot_device();
		/* This will return NULL if vboot isn't enabled, didn't run yet
		   or decided to boot into recovery mode. */
		if (rw)
			return rw;
	}

	/* In rare cases post-RAM stages may run this before cbmem_initialize(),
	   so we can't lock in the result of find_mcache() on the first try and
	   should keep trying every time until an mcache is found. */
	cbfs_boot_device_find_mcache(&ro, CBMEM_ID_CBFS_RO_MCACHE);

	if (region_device_sz(&ro.rdev))
		return &ro;

	if (fmap_locate_area_as_rdev("COREBOOT", &ro.rdev))
		die("Cannot locate primary CBFS");

	if (ENV_INITIAL_STAGE) {
		cb_err_t err = cbfs_init_boot_device(&ro, metadata_hash_get());
		if (err == CB_CBFS_HASH_MISMATCH)
			die("RO CBFS metadata hash verification failure");
		else if (CONFIG(TOCTOU_SAFETY) && err == CB_CBFS_CACHE_FULL)
			die("RO mcache overflow breaks TOCTOU safety!\n");
		else if (err && err != CB_CBFS_CACHE_FULL)
			die("RO CBFS initialization error: %d", err);
	}

	return &ro;
}

#if !CONFIG(NO_CBFS_MCACHE)
static void mcache_to_cbmem(const struct cbfs_boot_device *cbd, u32 cbmem_id)
{
	if (!cbd)
		return;

	size_t real_size = cbfs_mcache_real_size(cbd->mcache, cbd->mcache_size);
	void *cbmem_mcache = cbmem_add(cbmem_id, real_size);
	if (!cbmem_mcache) {
		printk(BIOS_ERR, "ERROR: Cannot allocate CBMEM mcache %#x (%#zx bytes)!\n",
		       cbmem_id, real_size);
		return;
	}
	memcpy(cbmem_mcache, cbd->mcache, real_size);
}

static void cbfs_mcache_migrate(int unused)
{
	mcache_to_cbmem(vboot_get_cbfs_boot_device(), CBMEM_ID_CBFS_RW_MCACHE);
	mcache_to_cbmem(cbfs_get_boot_device(true), CBMEM_ID_CBFS_RO_MCACHE);
}
ROMSTAGE_CBMEM_INIT_HOOK(cbfs_mcache_migrate)
#endif