summaryrefslogtreecommitdiff
path: root/util/cbfstool/cbfs_image.c
blob: 7d6239ac864bad422f44ae2baa872fa31876aa17 (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
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
/*
 * CBFS Image Manipulation
 *
 * Copyright (C) 2013 The Chromium OS Authors. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc.
 */

#include <inttypes.h>
#include <libgen.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>

#include "common.h"
#include "cbfs_image.h"

/* Even though the file-adding functions---cbfs_add_entry() and
 * cbfs_add_entry_at()---perform their sizing checks against the beginning of
 * the subsequent section rather than a stable recorded value such as an empty
 * file header's len field, it's possible to prove two interesting properties
 * about their behavior:
 *  - Placing a new file within an empty entry located below an existing file
 *    entry will never leave an aligned flash address containing neither the
 *    beginning of a file header nor part of a file.
 *  - Placing a new file in an empty entry at the very end of the image such
 *    that it fits, but leaves no room for a final header, is guaranteed not to
 *    change the total amount of space for entries, even if that new file is
 *    later removed from the CBFS.
 * These properties are somewhat nonobvious from the implementation, so the
 * reader is encouraged to blame this comment and examine the full proofs
 * in the commit message before making significant changes that would risk
 * removing said guarantees.
 */

/* The file name align is not defined in CBFS spec -- only a preference by
 * (old) cbfstool. */
#define CBFS_FILENAME_ALIGN	(16)

/* Type and format */

struct typedesc_t {
	uint32_t type;
	const char *name;
};

static const struct typedesc_t types_cbfs_entry[] = {
	{CBFS_COMPONENT_STAGE, "stage"},
	{CBFS_COMPONENT_PAYLOAD, "payload"},
	{CBFS_COMPONENT_OPTIONROM, "optionrom"},
	{CBFS_COMPONENT_BOOTSPLASH, "bootsplash"},
	{CBFS_COMPONENT_RAW, "raw"},
	{CBFS_COMPONENT_VSA, "vsa"},
	{CBFS_COMPONENT_MBI, "mbi"},
	{CBFS_COMPONENT_MICROCODE, "microcode"},
	{CBFS_COMPONENT_FSP, "fsp"},
	{CBFS_COMPONENT_MRC, "mrc"},
	{CBFS_COMPONENT_CMOS_DEFAULT, "cmos_default"},
	{CBFS_COMPONENT_CMOS_LAYOUT, "cmos_layout"},
	{CBFS_COMPONENT_SPD, "spd"},
	{CBFS_COMPONENT_MRC_CACHE, "mrc_cache"},
	{CBFS_COMPONENT_DELETED, "deleted"},
	{CBFS_COMPONENT_NULL, "null"},
	{0, NULL}
};

static const struct typedesc_t types_cbfs_compression[] = {
	{CBFS_COMPRESS_NONE, "none"},
	{CBFS_COMPRESS_LZMA, "LZMA"},
	{0, NULL}
};

static const char *lookup_name_by_type(const struct typedesc_t *desc, uint32_t type,
				const char *default_value)
{
	int i;
	for (i = 0; desc[i].name; i++)
		if (desc[i].type == type)
			return desc[i].name;
	return default_value;
}

static int lookup_type_by_name(const struct typedesc_t *desc, const char *name)
{
	int i;
	for (i = 0; desc[i].name && strcasecmp(name, desc[i].name); ++i);
	return desc[i].name ? (int)desc[i].type : -1;
}

static const char *get_cbfs_entry_type_name(uint32_t type)
{
	return lookup_name_by_type(types_cbfs_entry, type, "(unknown)");
}

int cbfs_parse_comp_algo(const char *name)
{
	return lookup_type_by_name(types_cbfs_compression, name);
}

/* CBFS image */

size_t cbfs_calculate_file_header_size(const char *name)
{
	return (sizeof(struct cbfs_file) +
		align_up(strlen(name) + 1, CBFS_FILENAME_ALIGN));
}

/* Only call on legacy CBFSes possessing a master header. */
static int cbfs_fix_legacy_size(struct cbfs_image *image, char *hdr_loc)
{
	assert(image);
	assert(cbfs_is_legacy_cbfs(image));
	// A bug in old cbfstool may produce extra few bytes (by alignment) and
	// cause cbfstool to overwrite things after free space -- which is
	// usually CBFS header on x86. We need to workaround that.

	struct cbfs_file *entry, *first = NULL, *last = NULL;
	for (first = entry = cbfs_find_first_entry(image);
	     entry && cbfs_is_valid_entry(image, entry);
	     entry = cbfs_find_next_entry(image, entry)) {
		last = entry;
	}
	if ((char *)first < (char *)hdr_loc &&
	    (char *)entry > (char *)hdr_loc) {
		WARN("CBFS image was created with old cbfstool with size bug. "
		     "Fixing size in last entry...\n");
		last->len = htonl(ntohl(last->len) - image->header.align);
		DEBUG("Last entry has been changed from 0x%x to 0x%x.\n",
		      cbfs_get_entry_addr(image, entry),
		      cbfs_get_entry_addr(image,
					  cbfs_find_next_entry(image, last)));
	}
	return 0;
}

void cbfs_put_header(void *dest, const struct cbfs_header *header)
{
	struct buffer outheader;

	outheader.data = dest;
	outheader.size = 0;

	xdr_be.put32(&outheader, header->magic);
	xdr_be.put32(&outheader, header->version);
	xdr_be.put32(&outheader, header->romsize);
	xdr_be.put32(&outheader, header->bootblocksize);
	xdr_be.put32(&outheader, header->align);
	xdr_be.put32(&outheader, header->offset);
	xdr_be.put32(&outheader, header->architecture);
}

static void cbfs_decode_payload_segment(struct cbfs_payload_segment *output,
					struct cbfs_payload_segment *input)
{
	struct buffer seg = {
		.data = (void *)input,
		.size = sizeof(*input),
	};
	output->type = xdr_be.get32(&seg);
	output->compression = xdr_be.get32(&seg);
	output->offset = xdr_be.get32(&seg);
	output->load_addr = xdr_be.get64(&seg);
	output->len = xdr_be.get32(&seg);
	output->mem_len = xdr_be.get32(&seg);
	assert(seg.size == 0);
}

void cbfs_get_header(struct cbfs_header *header, void *src)
{
	struct buffer outheader;

	outheader.data = src;	/* We're not modifying the data */
	outheader.size = 0;

	header->magic = xdr_be.get32(&outheader);
	header->version = xdr_be.get32(&outheader);
	header->romsize = xdr_be.get32(&outheader);
	header->bootblocksize = xdr_be.get32(&outheader);
	header->align = xdr_be.get32(&outheader);
	header->offset = xdr_be.get32(&outheader);
	header->architecture = xdr_be.get32(&outheader);
}

int cbfs_image_create(struct cbfs_image *image, size_t entries_size)
{
	assert(image);
	assert(image->buffer.data);

	size_t empty_header_len = cbfs_calculate_file_header_size("");
	uint32_t entries_offset = 0;
	uint32_t align = CBFS_ENTRY_ALIGNMENT;
	if (image->has_header) {
		entries_offset = image->header.offset;

		if (entries_offset > image->buffer.size) {
			ERROR("CBFS file entries are located outside CBFS itself\n");
			return -1;
		}

		align = image->header.align;
	}

	// This attribute must be given in order to prove that this module
	// correctly preserves certain CBFS properties. See the block comment
	// near the top of this file (and the associated commit message).
	if (align < empty_header_len) {
		ERROR("CBFS must be aligned to at least %zu bytes\n",
							empty_header_len);
		return -1;
	}

	if (entries_size > image->buffer.size - entries_offset) {
		ERROR("CBFS doesn't have enough space to fit its file entries\n");
		return -1;
	}

	if (empty_header_len > entries_size) {
		ERROR("CBFS is too small to fit any header\n");
		return -1;
	}
	struct cbfs_file *entry_header =
		(struct cbfs_file *)(image->buffer.data + entries_offset);
	// This alignment is necessary in order to prove that this module
	// correctly preserves certain CBFS properties. See the block comment
	// near the top of this file (and the associated commit message).
	entries_size -= entries_size % align;

	size_t capacity = entries_size - empty_header_len;
	LOG("Created CBFS (capacity = %zu bytes)\n", capacity);
	return cbfs_create_empty_entry(entry_header, CBFS_COMPONENT_NULL,
		capacity, "");
}

int cbfs_legacy_image_create(struct cbfs_image *image,
			     uint32_t architecture,
			     uint32_t align,
			     struct buffer *bootblock,
			     uint32_t bootblock_offset,
			     uint32_t header_offset,
			     uint32_t entries_offset)
{
	assert(image);
	assert(image->buffer.data);
	assert(bootblock);

	int32_t *rel_offset;
	uint32_t cbfs_len;
	void *header_loc;
	size_t size = image->buffer.size;

	DEBUG("cbfs_image_create: bootblock=0x%x+0x%zx, "
	      "header=0x%x+0x%zx, entries_offset=0x%x\n",
	      bootblock_offset, bootblock->size, header_offset,
	      sizeof(image->header), entries_offset);

	// Adjust legacy top-aligned address to ROM offset.
	if (IS_TOP_ALIGNED_ADDRESS(entries_offset))
		entries_offset = size + (int32_t)entries_offset;
	if (IS_TOP_ALIGNED_ADDRESS(bootblock_offset))
		bootblock_offset = size + (int32_t)bootblock_offset;
	if (IS_TOP_ALIGNED_ADDRESS(header_offset))
		header_offset = size + (int32_t)header_offset;

	DEBUG("cbfs_create_image: (real offset) bootblock=0x%x, "
	      "header=0x%x, entries_offset=0x%x\n",
	      bootblock_offset, header_offset, entries_offset);

	// Prepare bootblock
	if (bootblock_offset + bootblock->size > size) {
		ERROR("Bootblock (0x%x+0x%zx) exceed ROM size (0x%zx)\n",
		      bootblock_offset, bootblock->size, size);
		return -1;
	}
	if (entries_offset > bootblock_offset &&
	    entries_offset < bootblock->size) {
		ERROR("Bootblock (0x%x+0x%zx) overlap CBFS data (0x%x)\n",
		      bootblock_offset, bootblock->size, entries_offset);
		return -1;
	}
	memcpy(image->buffer.data + bootblock_offset, bootblock->data,
	       bootblock->size);

	// Prepare header
	if (header_offset + sizeof(image->header) > size - sizeof(int32_t)) {
		ERROR("Header (0x%x+0x%zx) exceed ROM size (0x%zx)\n",
		      header_offset, sizeof(image->header), size);
		return -1;
	}
	image->header.magic = CBFS_HEADER_MAGIC;
	image->header.version = CBFS_HEADER_VERSION;
	image->header.romsize = size;
	image->header.bootblocksize = bootblock->size;
	image->header.align = align;
	image->header.offset = entries_offset;
	image->header.architecture = architecture;

	header_loc = (image->buffer.data + header_offset);
	cbfs_put_header(header_loc, &image->header);
	image->has_header = true;

	// The last 4 byte of the image contain the relative offset from the end
	// of the image to the master header as a 32-bit signed integer. x86
	// relies on this also being its (memory-mapped, top-aligned) absolute
	// 32-bit address by virtue of how two's complement numbers work.
	assert(size % sizeof(int32_t) == 0);
	rel_offset = (int32_t *)(image->buffer.data + size - sizeof(int32_t));
	*rel_offset = header_offset - size;

	// Prepare entries
	if (align_up(entries_offset, align) != entries_offset) {
		ERROR("Offset (0x%x) must be aligned to 0x%x.\n",
		      entries_offset, align);
		return -1;
	}
	// To calculate available length, find
	//   e = min(bootblock, header, rel_offset) where e > entries_offset.
	cbfs_len = size - sizeof(int32_t);
	if (bootblock_offset > entries_offset && bootblock_offset < cbfs_len)
		cbfs_len = bootblock_offset;
	if (header_offset > entries_offset && header_offset < cbfs_len)
		cbfs_len = header_offset;

	if (cbfs_image_create(image, cbfs_len - entries_offset))
		return -1;
	return 0;
}

int cbfs_image_from_buffer(struct cbfs_image *out, struct buffer *in,
			   uint32_t offset)
{
	assert(out);
	assert(in);
	assert(in->data);

	buffer_clone(&out->buffer, in);
	out->has_header = false;

	void *header_loc = cbfs_find_header(in->data, in->size, offset);
	if (header_loc) {
		cbfs_get_header(&out->header, header_loc);
		out->has_header = true;
		cbfs_fix_legacy_size(out, header_loc);
	} else if (offset != ~0u) {
		ERROR("The -H switch is only valid on legacy images having CBFS master headers.\n");
		return 1;
	} else if (!cbfs_is_valid_cbfs(out)) {
		ERROR("Selected image region is not a valid CBFS.\n");
		return 1;
	}

	return 0;
}

int cbfs_copy_instance(struct cbfs_image *image, size_t copy_offset,
			size_t copy_size)
{
	assert(image);
	if (!cbfs_is_legacy_cbfs(image))
		return -1;

	struct cbfs_file *src_entry, *dst_entry;
	struct cbfs_header *copy_header;
	size_t align, entry_offset;
	ssize_t last_entry_size;

	size_t cbfs_offset, cbfs_end;
	size_t copy_end = copy_offset + copy_size;

	align = image->header.align;

	cbfs_offset = image->header.offset;
	cbfs_end = image->header.romsize;

	if (copy_end > image->buffer.size) {
		ERROR("Copy offset out of range: [%zx:%zx)\n",
			copy_offset, copy_end);
		return 1;
	}

	/* Range check requested copy region with source cbfs. */
	if ((copy_offset >= cbfs_offset && copy_offset < cbfs_end) ||
	    (copy_end >= cbfs_offset && copy_end <= cbfs_end)) {
		ERROR("New image would overlap old one.\n");
		return 1;
	}

	/* This will work, let's create a copy. */
	copy_header = (struct cbfs_header *)(image->buffer.data + copy_offset);
	cbfs_put_header(copy_header, &image->header);

	copy_header->bootblocksize = 0;
	/* Romsize is a misnomer. It's the absolute limit of cbfs content.*/
	copy_header->romsize = htonl(copy_end);
	entry_offset = align_up(copy_offset + sizeof(*copy_header), align);
	copy_header->offset = htonl(entry_offset);
	dst_entry = (struct cbfs_file *)(image->buffer.data + entry_offset);

	/* Copy non-empty files */
	for (src_entry = cbfs_find_first_entry(image);
	     src_entry && cbfs_is_valid_entry(image, src_entry);
	     src_entry = cbfs_find_next_entry(image, src_entry)) {
		size_t entry_size;

		if ((src_entry->type == htonl(CBFS_COMPONENT_NULL)) ||
		    (src_entry->type == htonl(CBFS_COMPONENT_DELETED)))
			continue;

		entry_size = htonl(src_entry->len) + htonl(src_entry->offset);
		memcpy(dst_entry, src_entry, entry_size);
		dst_entry = (struct cbfs_file *)(
			(uintptr_t)dst_entry + align_up(entry_size, align));

		if ((size_t)((char *)dst_entry - image->buffer.data) >=
								copy_end) {
			ERROR("Ran out of room in copy region.\n");
			return 1;
		}
	}

	/* Last entry size is all the room above it. */
	last_entry_size = copy_end - ((char *)dst_entry - image->buffer.data)
		- cbfs_calculate_file_header_size("");

	if (last_entry_size < 0)
		WARN("No room to create the last entry!\n")
	else
		cbfs_create_empty_entry(dst_entry, CBFS_COMPONENT_NULL,
			last_entry_size, "");

	return 0;
}

int cbfs_image_delete(struct cbfs_image *image)
{
	if (image == NULL)
		return 0;

	buffer_delete(&image->buffer);
	return 0;
}

/* Tries to add an entry with its data (CBFS_SUBHEADER) at given offset. */
static int cbfs_add_entry_at(struct cbfs_image *image,
			     struct cbfs_file *entry,
			     uint32_t size,
			     const char *name,
			     uint32_t type,
			     const void *data,
			     uint32_t content_offset,
			     uint32_t header_size)
{
	struct cbfs_file *next = cbfs_find_next_entry(image, entry);
	uint32_t addr = cbfs_get_entry_addr(image, entry),
		 addr_next = cbfs_get_entry_addr(image, next);
	uint32_t min_entry_size = cbfs_calculate_file_header_size("");
	uint32_t len, target;
	uint32_t align = image->has_header ? image->header.align :
							CBFS_ENTRY_ALIGNMENT;

	target = content_offset - header_size;
	if (target % align)
		target -= target % align;
	if (target < addr) {
		ERROR("No space to hold cbfs_file header.");
		return -1;
	}

	// Process buffer BEFORE content_offset.
	if (target - addr > min_entry_size) {
		DEBUG("|min|...|header|content|... <create new entry>\n");
		len = target - addr - min_entry_size;
		cbfs_create_empty_entry(entry, CBFS_COMPONENT_NULL, len, "");
		if (verbose > 1) cbfs_print_entry_info(image, entry, stderr);
		entry = cbfs_find_next_entry(image, entry);
		addr = cbfs_get_entry_addr(image, entry);
	}

	len = size + (content_offset - addr - header_size);
	cbfs_create_empty_entry(entry, type, len, name);
	if (len != size) {
		DEBUG("|..|header|content|... <use offset to create entry>\n");
		DEBUG("before: offset=0x%x, len=0x%x\n",
		      ntohl(entry->offset), ntohl(entry->len));
		// TODO reset expanded name buffer to 0xFF.
		entry->offset = htonl(ntohl(entry->offset) + (len - size));
		entry->len = htonl(size);
		DEBUG("after: offset=0x%x, len=0x%x\n",
		      ntohl(entry->offset), ntohl(entry->len));
	}

	// Ready to fill data into entry.
	assert(ntohl(entry->len) == size);
	DEBUG("content_offset: 0x%x, entry location: %x\n",
	      content_offset, (int)((char*)CBFS_SUBHEADER(entry) -
				    image->buffer.data));
	assert((char*)CBFS_SUBHEADER(entry) - image->buffer.data ==
	       (ptrdiff_t)content_offset);
	memcpy(CBFS_SUBHEADER(entry), data, size);
	if (verbose > 1) cbfs_print_entry_info(image, entry, stderr);

	// Process buffer AFTER entry.
	entry = cbfs_find_next_entry(image, entry);
	addr = cbfs_get_entry_addr(image, entry);
	if (addr == addr_next)
		return 0;

	assert(addr < addr_next);
	if (addr_next - addr < min_entry_size) {
		DEBUG("No need for new \"empty\" entry\n");
		/* No need to increase the size of the just
		 * stored file to extend to next file. Alignment
		 * of next file takes care of this.
		 */
		return 0;
	}

	len = addr_next - addr - min_entry_size;
	cbfs_create_empty_entry(entry, CBFS_COMPONENT_NULL, len, "");
	if (verbose > 1) cbfs_print_entry_info(image, entry, stderr);
	return 0;
}

int cbfs_add_entry(struct cbfs_image *image, struct buffer *buffer,
		   const char *name, uint32_t type, uint32_t content_offset,
		   uint32_t header_size)
{
	assert(image);
	assert(buffer);
	assert(buffer->data);
	assert(name);
	assert(!IS_TOP_ALIGNED_ADDRESS(content_offset));

	uint32_t entry_type;
	uint32_t addr, addr_next;
	struct cbfs_file *entry, *next;
	uint32_t need_size;

	if (header_size == 0)
		header_size = cbfs_calculate_file_header_size(name);

	need_size = header_size + buffer->size;
	DEBUG("cbfs_add_entry('%s'@0x%x) => need_size = %u+%zu=%u\n",
	      name, content_offset, header_size, buffer->size, need_size);

	// Merge empty entries.
	DEBUG("(trying to merge empty entries...)\n");
	cbfs_walk(image, cbfs_merge_empty_entry, NULL);

	for (entry = cbfs_find_first_entry(image);
	     entry && cbfs_is_valid_entry(image, entry);
	     entry = cbfs_find_next_entry(image, entry)) {

		entry_type = ntohl(entry->type);
		if (entry_type != CBFS_COMPONENT_NULL)
			continue;

		addr = cbfs_get_entry_addr(image, entry);
		next = cbfs_find_next_entry(image, entry);
		addr_next = cbfs_get_entry_addr(image, next);

		DEBUG("cbfs_add_entry: space at 0x%x+0x%x(%d) bytes\n",
		      addr, addr_next - addr, addr_next - addr);

		/* Will the file fit? Don't yet worry if we have space for a new
		 * "empty" entry. We take care of that later.
		 */
		if (addr + need_size > addr_next)
			continue;

		// Test for complicated cases
		if (content_offset > 0) {
			if (addr_next < content_offset) {
				DEBUG("Not for specified offset yet");
				continue;
			} else if (addr > content_offset) {
				DEBUG("Exceed specified content_offset.");
				break;
			} else if (addr + header_size > content_offset) {
				ERROR("Not enough space for header.\n");
				break;
			} else if (content_offset + buffer->size > addr_next) {
				ERROR("Not enough space for content.\n");
				break;
			}
		}

		// TODO there are more few tricky cases that we may
		// want to fit by altering offset.

		if (content_offset == 0) {
			// we tested every condition earlier under which
			// placing the file there might fail
			content_offset = addr + header_size;
		}

		DEBUG("section 0x%x+0x%x for content_offset 0x%x.\n",
		      addr, addr_next - addr, content_offset);

		if (cbfs_add_entry_at(image, entry, buffer->size, name, type,
				      buffer->data, content_offset,
				      header_size) == 0) {
			return 0;
		}
		break;
	}

	ERROR("Could not add [%s, %zd bytes (%zd KB)@0x%x]; too big?\n",
	      buffer->name, buffer->size, buffer->size / 1024, content_offset);
	return -1;
}

struct cbfs_file *cbfs_get_entry(struct cbfs_image *image, const char *name)
{
	struct cbfs_file *entry;
	for (entry = cbfs_find_first_entry(image);
	     entry && cbfs_is_valid_entry(image, entry);
	     entry = cbfs_find_next_entry(image, entry)) {
		if (strcasecmp(entry->filename, name) == 0) {
			DEBUG("cbfs_get_entry: found %s\n", name);
			return entry;
		}
	}
	return NULL;
}

int cbfs_export_entry(struct cbfs_image *image, const char *entry_name,
		      const char *filename)
{
	struct cbfs_file *entry = cbfs_get_entry(image, entry_name);
	struct buffer buffer;
	if (!entry) {
		ERROR("File not found: %s\n", entry_name);
		return -1;
	}
	LOG("Found file %.30s at 0x%x, type %.12s, size %d\n",
	    entry_name, cbfs_get_entry_addr(image, entry),
	    get_cbfs_entry_type_name(ntohl(entry->type)), ntohl(entry->len));

	if (ntohl(entry->type) != CBFS_COMPONENT_RAW) {
		WARN("Only 'raw' files are safe to extract.\n");
	}

	buffer.data = CBFS_SUBHEADER(entry);
	buffer.size = ntohl(entry->len);
	buffer.name = strdup("(cbfs_export_entry)");
	if (buffer_write_file(&buffer, filename) != 0) {
		ERROR("Failed to write %s into %s.\n",
		      entry_name, filename);
		free(buffer.name);
		return -1;
	}
	free(buffer.name);
	INFO("Successfully dumped the file to: %s\n", filename);
	return 0;
}

int cbfs_remove_entry(struct cbfs_image *image, const char *name)
{
	struct cbfs_file *entry;
	entry = cbfs_get_entry(image, name);
	if (!entry) {
		ERROR("CBFS file %s not found.\n", name);
		return -1;
	}
	DEBUG("cbfs_remove_entry: Removed %s @ 0x%x\n",
	      entry->filename, cbfs_get_entry_addr(image, entry));
	entry->type = htonl(CBFS_COMPONENT_DELETED);
	cbfs_walk(image, cbfs_merge_empty_entry, NULL);
	return 0;
}

int cbfs_print_header_info(struct cbfs_image *image)
{
	char *name = strdup(image->buffer.name);
	assert(image);
	printf("%s: %zd kB, bootblocksize %d, romsize %d, offset 0x%x\n"
	       "alignment: %d bytes, architecture: %s\n\n",
	       basename(name),
	       image->buffer.size / 1024,
	       image->header.bootblocksize,
	       image->header.romsize,
	       image->header.offset,
	       image->header.align,
	       arch_to_string(image->header.architecture));
	free(name);
	return 0;
}

static int cbfs_print_stage_info(struct cbfs_stage *stage, FILE* fp)
{
	fprintf(fp,
		"    %s compression, entry: 0x%" PRIx64 ", load: 0x%" PRIx64 ", "
		"length: %d/%d\n",
		lookup_name_by_type(types_cbfs_compression,
				    stage->compression, "(unknown)"),
		stage->entry,
		stage->load,
		stage->len,
		stage->memlen);
	return 0;
}

static int cbfs_print_decoded_payload_segment_info(
		struct cbfs_payload_segment *seg, FILE *fp)
{
	/* The input (seg) must be already decoded by
	 * cbfs_decode_payload_segment.
	 */
	switch (seg->type) {
		case PAYLOAD_SEGMENT_CODE:
		case PAYLOAD_SEGMENT_DATA:
			fprintf(fp, "    %s (%s compression, offset: 0x%x, "
				"load: 0x%" PRIx64 ", length: %d/%d)\n",
				(seg->type == PAYLOAD_SEGMENT_CODE ?
				 "code " : "data"),
				lookup_name_by_type(types_cbfs_compression,
						    seg->compression,
						    "(unknown)"),
				seg->offset, seg->load_addr, seg->len,
				seg->mem_len);
			break;

		case PAYLOAD_SEGMENT_ENTRY:
			fprintf(fp, "    entry (0x%" PRIx64 ")\n",
				seg->load_addr);
			break;

		case PAYLOAD_SEGMENT_BSS:
			fprintf(fp, "    BSS (address 0x%016" PRIx64 ", "
				"length 0x%x)\n",
				seg->load_addr, seg->len);
			break;

		case PAYLOAD_SEGMENT_PARAMS:
			fprintf(fp, "    parameters\n");
			break;

		default:
			fprintf(fp, "   0x%x (%s compression, offset: 0x%x, "
				"load: 0x%" PRIx64 ", length: %d/%d\n",
				seg->type,
				lookup_name_by_type(types_cbfs_compression,
						    seg->compression,
						    "(unknown)"),
				seg->offset, seg->load_addr, seg->len,
				seg->mem_len);
			break;
	}
	return 0;
}

int cbfs_print_entry_info(struct cbfs_image *image, struct cbfs_file *entry,
			  void *arg)
{
	const char *name = entry->filename;
	struct cbfs_payload_segment *payload;
	FILE *fp = (FILE *)arg;

	if (!cbfs_is_valid_entry(image, entry)) {
		ERROR("cbfs_print_entry_info: Invalid entry at 0x%x\n",
		      cbfs_get_entry_addr(image, entry));
		return -1;
	}
	if (!fp)
		fp = stdout;

	fprintf(fp, "%-30s 0x%-8x %-12s %d\n",
		*name ? name : "(empty)",
		cbfs_get_entry_addr(image, entry),
		get_cbfs_entry_type_name(ntohl(entry->type)),
		ntohl(entry->len));

	if (!verbose)
		return 0;

	DEBUG(" cbfs_file=0x%x, offset=0x%x, content_address=0x%x+0x%x\n",
	      cbfs_get_entry_addr(image, entry), ntohl(entry->offset),
	      cbfs_get_entry_addr(image, entry) + ntohl(entry->offset),
	      ntohl(entry->len));

	/* note the components of the subheader may be in host order ... */
	switch (ntohl(entry->type)) {
		case CBFS_COMPONENT_STAGE:
			cbfs_print_stage_info((struct cbfs_stage *)
					      CBFS_SUBHEADER(entry), fp);
			break;

		case CBFS_COMPONENT_PAYLOAD:
			payload  = (struct cbfs_payload_segment *)
					CBFS_SUBHEADER(entry);
			while (payload) {
				struct cbfs_payload_segment seg;
				cbfs_decode_payload_segment(&seg, payload);
				cbfs_print_decoded_payload_segment_info(
						&seg, fp);
				if (seg.type == PAYLOAD_SEGMENT_ENTRY)
					break;
				else
				payload ++;
			}
			break;
		default:
			break;
	}
	return 0;
}

int cbfs_print_directory(struct cbfs_image *image)
{
	if (cbfs_is_legacy_cbfs(image))
		cbfs_print_header_info(image);
	printf("%-30s %-10s %-12s Size\n", "Name", "Offset", "Type");
	cbfs_walk(image, cbfs_print_entry_info, NULL);
	return 0;
}

int cbfs_merge_empty_entry(struct cbfs_image *image, struct cbfs_file *entry,
			   unused void *arg)
{
	struct cbfs_file *next;
	uint32_t type, addr, last_addr;

	type = ntohl(entry->type);
	if (type == CBFS_COMPONENT_DELETED) {
		// Ready to be recycled.
		type = CBFS_COMPONENT_NULL;
		entry->type = htonl(type);
	}
	if (type != CBFS_COMPONENT_NULL)
		return 0;

	next = cbfs_find_next_entry(image, entry);

	while (next && cbfs_is_valid_entry(image, next)) {
		type = ntohl(next->type);
		if (type == CBFS_COMPONENT_DELETED) {
			type = CBFS_COMPONENT_NULL;
			next->type = htonl(type);
		}
		if (type != CBFS_COMPONENT_NULL)
			return 0;

		addr = cbfs_get_entry_addr(image, entry);
		last_addr = cbfs_get_entry_addr(
				image, cbfs_find_next_entry(image, next));

		// Now, we find two deleted/empty entries; try to merge now.
		DEBUG("join_empty_entry: combine 0x%x+0x%x and 0x%x+0x%x.\n",
		      cbfs_get_entry_addr(image, entry), ntohl(entry->len),
		      cbfs_get_entry_addr(image, next), ntohl(next->len));
		cbfs_create_empty_entry(entry, CBFS_COMPONENT_NULL,
					(last_addr - addr -
					 cbfs_calculate_file_header_size("")),
					"");
		DEBUG("new empty entry: length=0x%x\n", ntohl(entry->len));
		next = cbfs_find_next_entry(image, entry);
	}
	return 0;
}

int cbfs_walk(struct cbfs_image *image, cbfs_entry_callback callback,
	      void *arg)
{
	int count = 0;
	struct cbfs_file *entry;
	for (entry = cbfs_find_first_entry(image);
	     entry && cbfs_is_valid_entry(image, entry);
	     entry = cbfs_find_next_entry(image, entry)) {
		count ++;
		if (callback(image, entry, arg) != 0)
			break;
	}
	return count;
}

static int cbfs_header_valid(struct cbfs_header *header, size_t size)
{
	if ((ntohl(header->magic) == CBFS_HEADER_MAGIC) &&
	    ((ntohl(header->version) == CBFS_HEADER_VERSION1) ||
	     (ntohl(header->version) == CBFS_HEADER_VERSION2)) &&
	    (ntohl(header->romsize) <= size) &&
	    (ntohl(header->offset) < ntohl(header->romsize)))
		return 1;
	return 0;
}

struct cbfs_header *cbfs_find_header(char *data, size_t size,
				     uint32_t forced_offset)
{
	size_t offset;
	int found = 0;
	int32_t rel_offset;
	struct cbfs_header *header, *result = NULL;

	if (forced_offset < (size - sizeof(struct cbfs_header))) {
		/* Check if the forced header is valid. */
		header = (struct cbfs_header *)(data + forced_offset);
		if (cbfs_header_valid(header, size))
			return header;
		return NULL;
	}

	// Try finding relative offset of master header at end of file first.
	rel_offset = *(int32_t *)(data + size - sizeof(int32_t));
	offset = size + rel_offset;
	DEBUG("relative offset: %#zx(-%#zx), offset: %#zx\n",
	      (size_t)rel_offset, (size_t)-rel_offset, offset);

	if (offset >= size - sizeof(*header) ||
	    !cbfs_header_valid((struct cbfs_header *)(data + offset), size)) {
		// Some use cases append non-CBFS data to the end of the ROM.
		DEBUG("relative offset seems wrong, scanning whole image...\n");
		offset = 0;
	}

	for (; offset + sizeof(*header) < size; offset++) {
		header = (struct cbfs_header *)(data + offset);
		if (!cbfs_header_valid(header, size))
			continue;
		if (!found++)
			result = header;
	}
	if (found > 1)
		// Top-aligned images usually have a working relative offset
		// field, so this is more likely to happen on bottom-aligned
		// ones (where the first header is the "outermost" one)
		WARN("Multiple (%d) CBFS headers found, using the first one.\n",
		       found);
	return result;
}


struct cbfs_file *cbfs_find_first_entry(struct cbfs_image *image)
{
	assert(image);
	return image->has_header ? (struct cbfs_file *)(image->buffer.data +
						   image->header.offset) :
				   (struct cbfs_file *)image->buffer.data;
}

struct cbfs_file *cbfs_find_next_entry(struct cbfs_image *image,
				       struct cbfs_file *entry)
{
	uint32_t addr = cbfs_get_entry_addr(image, entry);
	int align = image->has_header ? image->header.align :
							CBFS_ENTRY_ALIGNMENT;
	assert(entry && cbfs_is_valid_entry(image, entry));
	addr += ntohl(entry->offset) + ntohl(entry->len);
	addr = align_up(addr, align);
	return (struct cbfs_file *)(image->buffer.data + addr);
}

uint32_t cbfs_get_entry_addr(struct cbfs_image *image, struct cbfs_file *entry)
{
	assert(image && image->buffer.data && entry);
	return (int32_t)((char *)entry - image->buffer.data);
}

int cbfs_is_valid_cbfs(struct cbfs_image *image)
{
	return buffer_check_magic(&image->buffer, CBFS_FILE_MAGIC,
						strlen(CBFS_FILE_MAGIC));
}

int cbfs_is_legacy_cbfs(struct cbfs_image *image)
{
	return image->has_header;
}

int cbfs_is_valid_entry(struct cbfs_image *image, struct cbfs_file *entry)
{
	uint32_t offset = cbfs_get_entry_addr(image, entry);

	if (offset >= image->buffer.size)
		return 0;

	struct buffer entry_data;
	buffer_clone(&entry_data, &image->buffer);
	buffer_seek(&entry_data, offset);
	return buffer_check_magic(&entry_data, CBFS_FILE_MAGIC,
						strlen(CBFS_FILE_MAGIC));
}

struct cbfs_file *cbfs_create_file_header(int type,
			    size_t len, const char *name)
{
	// assume that there won't be file names of ~1000 bytes
	const int bufsize = 1024;

	struct cbfs_file *entry = malloc(bufsize);
	memset(entry, CBFS_CONTENT_DEFAULT_VALUE, bufsize);
	memcpy(entry->magic, CBFS_FILE_MAGIC, sizeof(entry->magic));
	entry->type = htonl(type);
	entry->len = htonl(len);
	entry->attributes_offset = 0;
	entry->offset = htonl(cbfs_calculate_file_header_size(name));
	memset(entry->filename, 0, ntohl(entry->offset) - sizeof(*entry));
	strcpy(entry->filename, name);
	return entry;
}

int cbfs_create_empty_entry(struct cbfs_file *entry, int type,
			    size_t len, const char *name)
{
	struct cbfs_file *tmp = cbfs_create_file_header(type, len, name);
	memcpy(entry, tmp, ntohl(tmp->offset));
	free(tmp);
	memset(CBFS_SUBHEADER(entry), CBFS_CONTENT_DEFAULT_VALUE, len);
	return 0;
}

/* Finds a place to hold whole data in same memory page. */
static int is_in_same_page(uint32_t start, uint32_t size, uint32_t page)
{
	if (!page)
		return 1;
	return (start / page) == (start + size - 1) / page;
}

/* Tests if data can fit in a range by given offset:
 *  start ->| header_len | offset (+ size) |<- end
 */
static int is_in_range(uint32_t start, uint32_t end, uint32_t header_len,
		       uint32_t offset, uint32_t size)
{
	return (offset >= start + header_len && offset + size <= end);
}

int32_t cbfs_locate_entry(struct cbfs_image *image, const char *name,
			  uint32_t size, uint32_t page_size, uint32_t align)
{
	struct cbfs_file *entry;
	size_t need_len;
	uint32_t addr, addr_next, addr2, addr3, offset, header_len;

	/* Default values: allow fitting anywhere in ROM. */
	if (!page_size)
		page_size = image->has_header ? image->header.romsize :
							image->buffer.size;
	if (!align)
		align = 1;

	if (size > page_size)
		ERROR("Input file size (%d) greater than page size (%d).\n",
		      size, page_size);

	uint32_t image_align = image->has_header ? image->header.align :
							CBFS_ENTRY_ALIGNMENT;
	if (page_size % image_align)
		WARN("%s: Page size (%#x) not aligned with CBFS image (%#x).\n",
		     __func__, page_size, image_align);

	/* TODO Old cbfstool always assume input is a stage file (and adding
	 * sizeof(cbfs_stage) for header. We should fix that by adding "-t"
	 * (type) param in future. For right now, we assume cbfs_stage is the
	 * largest structure and add it into header size. */
	assert(sizeof(struct cbfs_stage) >= sizeof(struct cbfs_payload));
	header_len = (cbfs_calculate_file_header_size(name) +
		      sizeof(struct cbfs_stage));
	need_len = header_len + size;

	// Merge empty entries to build get max available space.
	cbfs_walk(image, cbfs_merge_empty_entry, NULL);

	/* Three cases of content location on memory page:
	 * case 1.
	 *          |  PAGE 1  |   PAGE 2  |
	 *          |     <header><content>| Fit. Return start of content.
	 *
	 * case 2.
	 *          |  PAGE 1  |   PAGE 2  |
	 *          | <header><content>    | Fits when we shift content to align
	 *  shift-> |  <header>|<content>  | at starting of PAGE 2.
	 *
	 * case 3. (large content filling whole page)
	 *  | PAGE 1 |  PAGE 2  | PAGE 3 |
	 *  |  <header>< content >       | Can't fit. If we shift content to
	 *  |trial-> <header>< content > | PAGE 2, header can't fit in free
	 *  |  shift->  <header><content> space, so we must use PAGE 3.
	 *
	 * The returned address can be then used as "base-address" (-b) in add-*
	 * commands (will be re-calculated and positioned by cbfs_add_entry_at).
	 * For stage targets, the address is also used to re-link stage before
	 * being added into CBFS.
	 */
	for (entry = cbfs_find_first_entry(image);
	     entry && cbfs_is_valid_entry(image, entry);
	     entry = cbfs_find_next_entry(image, entry)) {

		uint32_t type = ntohl(entry->type);
		if (type != CBFS_COMPONENT_NULL)
			continue;

		addr = cbfs_get_entry_addr(image, entry);
		addr_next = cbfs_get_entry_addr(image, cbfs_find_next_entry(
				image, entry));
		if (addr_next - addr < need_len)
			continue;

		offset = align_up(addr + header_len, align);
		if (is_in_same_page(offset, size, page_size) &&
		    is_in_range(addr, addr_next, header_len, offset, size)) {
			DEBUG("cbfs_locate_entry: FIT (PAGE1).");
			return offset;
		}

		addr2 = align_up(addr, page_size);
		offset = align_up(addr2, align);
		if (is_in_range(addr, addr_next, header_len, offset, size)) {
			DEBUG("cbfs_locate_entry: OVERLAP (PAGE2).");
			return offset;
		}

		/* Assume page_size >= header_len so adding one page will
		 * definitely provide the space for header. */
		assert(page_size >= header_len);
		addr3 = addr2 + page_size;
		offset = align_up(addr3, align);
		if (is_in_range(addr, addr_next, header_len, offset, size)) {
			DEBUG("cbfs_locate_entry: OVERLAP+ (PAGE3).");
			return offset;
		}
	}
	return -1;
}