2 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
4 * Copyright (C) 2002-2007 Aleph One Ltd.
5 * for Toby Churchill Ltd and Brightstar Engineering
7 * Created by Charles Manning <charles@aleph1.co.uk>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
17 #include "yaffs_packedtags2.h"
19 #include "yaffs_tagsvalidity.h"
21 /* This code packs a set of extended tags into a binary structure for
25 /* Some of the information is "extra" struff which can be packed in to
27 * This is defined by having the EXTRA_HEADER_INFO_FLAG set.
30 /* Extra flags applied to chunkId */
32 #define EXTRA_HEADER_INFO_FLAG 0x80000000
33 #define EXTRA_SHRINK_FLAG 0x40000000
34 #define EXTRA_SHADOWS_FLAG 0x20000000
35 #define EXTRA_SPARE_FLAGS 0x10000000
37 #define ALL_EXTRA_FLAGS 0xF0000000
39 /* Also, the top 4 bits of the object Id are set to the object type. */
40 #define EXTRA_OBJECT_TYPE_SHIFT (28)
41 #define EXTRA_OBJECT_TYPE_MASK ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT)
43 static void yaffs_DumpPackedTags2(const yaffs_PackedTags2 * pt)
46 (TSTR("packed tags obj %d chunk %d byte %d seq %d" TENDSTR),
47 pt->t.objectId, pt->t.chunkId, pt->t.byteCount,
48 pt->t.sequenceNumber));
51 static void yaffs_DumpTags2(const yaffs_ExtendedTags * t)
55 ("ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte "
56 "%d del %d ser %d seq %d"
57 TENDSTR), t->eccResult, t->blockBad, t->chunkUsed, t->objectId,
58 t->chunkId, t->byteCount, t->chunkDeleted, t->serialNumber,
63 void yaffs_PackTags2(yaffs_PackedTags2 * pt, const yaffs_ExtendedTags * t)
65 pt->t.chunkId = t->chunkId;
66 pt->t.sequenceNumber = t->sequenceNumber;
67 pt->t.byteCount = t->byteCount;
68 pt->t.objectId = t->objectId;
70 if (t->chunkId == 0 && t->extraHeaderInfoAvailable) {
71 /* Store the extra header info instead */
72 /* We save the parent object in the chunkId */
73 pt->t.chunkId = EXTRA_HEADER_INFO_FLAG
74 | t->extraParentObjectId;
75 if (t->extraIsShrinkHeader) {
76 pt->t.chunkId |= EXTRA_SHRINK_FLAG;
78 if (t->extraShadows) {
79 pt->t.chunkId |= EXTRA_SHADOWS_FLAG;
82 pt->t.objectId &= ~EXTRA_OBJECT_TYPE_MASK;
84 (t->extraObjectType << EXTRA_OBJECT_TYPE_SHIFT);
86 if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
87 pt->t.byteCount = t->extraEquivalentObjectId;
88 } else if (t->extraObjectType == YAFFS_OBJECT_TYPE_FILE) {
89 pt->t.byteCount = t->extraFileLength;
95 yaffs_DumpPackedTags2(pt);
98 #ifndef YAFFS_IGNORE_TAGS_ECC
100 yaffs_ECCCalculateOther((unsigned char *)&pt->t,
101 sizeof(yaffs_PackedTags2TagsPart),
107 void yaffs_UnpackTags2(yaffs_ExtendedTags * t, yaffs_PackedTags2 * pt)
110 memset(t, 0, sizeof(yaffs_ExtendedTags));
112 yaffs_InitialiseTags(t);
114 if (pt->t.sequenceNumber != 0xFFFFFFFF) {
116 #ifdef YAFFS_IGNORE_TAGS_ECC
118 t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
124 yaffs_ECCCalculateOther((unsigned char *)&pt->t,
126 (yaffs_PackedTags2TagsPart),
129 yaffs_ECCCorrectOther((unsigned char *)&pt->t,
131 (yaffs_PackedTags2TagsPart),
135 t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
138 t->eccResult = YAFFS_ECC_RESULT_FIXED;
141 t->eccResult = YAFFS_ECC_RESULT_UNFIXED;
144 t->eccResult = YAFFS_ECC_RESULT_UNKNOWN;
150 t->objectId = pt->t.objectId;
151 t->chunkId = pt->t.chunkId;
152 t->byteCount = pt->t.byteCount;
155 t->sequenceNumber = pt->t.sequenceNumber;
157 /* Do extra header info stuff */
159 if (pt->t.chunkId & EXTRA_HEADER_INFO_FLAG) {
163 t->extraHeaderInfoAvailable = 1;
164 t->extraParentObjectId =
165 pt->t.chunkId & (~(ALL_EXTRA_FLAGS));
166 t->extraIsShrinkHeader =
167 (pt->t.chunkId & EXTRA_SHRINK_FLAG) ? 1 : 0;
169 (pt->t.chunkId & EXTRA_SHADOWS_FLAG) ? 1 : 0;
171 pt->t.objectId >> EXTRA_OBJECT_TYPE_SHIFT;
172 t->objectId &= ~EXTRA_OBJECT_TYPE_MASK;
174 if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
175 t->extraEquivalentObjectId = pt->t.byteCount;
177 t->extraFileLength = pt->t.byteCount;
182 yaffs_DumpPackedTags2(pt);