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.
15 #include "yaffs_packedtags2.h"
17 #include "yaffs_tagsvalidity.h"
19 /* This code packs a set of extended tags into a binary structure for
23 /* Some of the information is "extra" struff which can be packed in to
25 * This is defined by having the EXTRA_HEADER_INFO_FLAG set.
28 /* Extra flags applied to chunkId */
30 #define EXTRA_HEADER_INFO_FLAG 0x80000000
31 #define EXTRA_SHRINK_FLAG 0x40000000
32 #define EXTRA_SHADOWS_FLAG 0x20000000
33 #define EXTRA_SPARE_FLAGS 0x10000000
35 #define ALL_EXTRA_FLAGS 0xF0000000
37 /* Also, the top 4 bits of the object Id are set to the object type. */
38 #define EXTRA_OBJECT_TYPE_SHIFT (28)
39 #define EXTRA_OBJECT_TYPE_MASK ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT)
41 static void yaffs_DumpPackedTags2(const yaffs_PackedTags2 * pt)
44 (TSTR("packed tags obj %d chunk %d byte %d seq %d" TENDSTR),
45 pt->t.objectId, pt->t.chunkId, pt->t.byteCount,
46 pt->t.sequenceNumber));
49 static void yaffs_DumpTags2(const yaffs_ExtendedTags * t)
53 ("ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte "
54 "%d del %d ser %d seq %d"
55 TENDSTR), t->eccResult, t->blockBad, t->chunkUsed, t->objectId,
56 t->chunkId, t->byteCount, t->chunkDeleted, t->serialNumber,
61 void yaffs_PackTags2(yaffs_PackedTags2 * pt, const yaffs_ExtendedTags * t)
63 pt->t.chunkId = t->chunkId;
64 pt->t.sequenceNumber = t->sequenceNumber;
65 pt->t.byteCount = t->byteCount;
66 pt->t.objectId = t->objectId;
68 if (t->chunkId == 0 && t->extraHeaderInfoAvailable) {
69 /* Store the extra header info instead */
70 /* We save the parent object in the chunkId */
71 pt->t.chunkId = EXTRA_HEADER_INFO_FLAG
72 | t->extraParentObjectId;
73 if (t->extraIsShrinkHeader) {
74 pt->t.chunkId |= EXTRA_SHRINK_FLAG;
76 if (t->extraShadows) {
77 pt->t.chunkId |= EXTRA_SHADOWS_FLAG;
80 pt->t.objectId &= ~EXTRA_OBJECT_TYPE_MASK;
82 (t->extraObjectType << EXTRA_OBJECT_TYPE_SHIFT);
84 if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
85 pt->t.byteCount = t->extraEquivalentObjectId;
86 } else if (t->extraObjectType == YAFFS_OBJECT_TYPE_FILE) {
87 pt->t.byteCount = t->extraFileLength;
93 yaffs_DumpPackedTags2(pt);
96 #ifndef YAFFS_IGNORE_TAGS_ECC
98 yaffs_ECCCalculateOther((unsigned char *)&pt->t,
99 sizeof(yaffs_PackedTags2TagsPart),
105 void yaffs_UnpackTags2(yaffs_ExtendedTags * t, yaffs_PackedTags2 * pt)
108 memset(t, 0, sizeof(yaffs_ExtendedTags));
110 yaffs_InitialiseTags(t);
112 if (pt->t.sequenceNumber != 0xFFFFFFFF) {
114 #ifdef YAFFS_IGNORE_TAGS_ECC
116 t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
122 yaffs_ECCCalculateOther((unsigned char *)&pt->t,
124 (yaffs_PackedTags2TagsPart),
127 yaffs_ECCCorrectOther((unsigned char *)&pt->t,
129 (yaffs_PackedTags2TagsPart),
133 t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
136 t->eccResult = YAFFS_ECC_RESULT_FIXED;
139 t->eccResult = YAFFS_ECC_RESULT_UNFIXED;
142 t->eccResult = YAFFS_ECC_RESULT_UNKNOWN;
148 t->objectId = pt->t.objectId;
149 t->chunkId = pt->t.chunkId;
150 t->byteCount = pt->t.byteCount;
153 t->sequenceNumber = pt->t.sequenceNumber;
155 /* Do extra header info stuff */
157 if (pt->t.chunkId & EXTRA_HEADER_INFO_FLAG) {
161 t->extraHeaderInfoAvailable = 1;
162 t->extraParentObjectId =
163 pt->t.chunkId & (~(ALL_EXTRA_FLAGS));
164 t->extraIsShrinkHeader =
165 (pt->t.chunkId & EXTRA_SHRINK_FLAG) ? 1 : 0;
167 (pt->t.chunkId & EXTRA_SHADOWS_FLAG) ? 1 : 0;
169 pt->t.objectId >> EXTRA_OBJECT_TYPE_SHIFT;
170 t->objectId &= ~EXTRA_OBJECT_TYPE_MASK;
172 if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
173 t->extraEquivalentObjectId = pt->t.byteCount;
175 t->extraFileLength = pt->t.byteCount;
180 yaffs_DumpPackedTags2(pt);