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.
14 #include "yaffs_packedtags2.h"
16 #include "yaffs_tagsvalidity.h"
18 /* This code packs a set of extended tags into a binary structure for
22 /* Some of the information is "extra" struff which can be packed in to
24 * This is defined by having the EXTRA_HEADER_INFO_FLAG set.
27 /* Extra flags applied to chunkId */
29 #define EXTRA_HEADER_INFO_FLAG 0x80000000
30 #define EXTRA_SHRINK_FLAG 0x40000000
31 #define EXTRA_SHADOWS_FLAG 0x20000000
32 #define EXTRA_SPARE_FLAGS 0x10000000
34 #define ALL_EXTRA_FLAGS 0xF0000000
36 /* Also, the top 4 bits of the object Id are set to the object type. */
37 #define EXTRA_OBJECT_TYPE_SHIFT (28)
38 #define EXTRA_OBJECT_TYPE_MASK ((0x0F) << EXTRA_OBJECT_TYPE_SHIFT)
40 static void yaffs_DumpPackedTags2(const yaffs_PackedTags2 * pt)
43 (TSTR("packed tags obj %d chunk %d byte %d seq %d" TENDSTR),
44 pt->t.objectId, pt->t.chunkId, pt->t.byteCount,
45 pt->t.sequenceNumber));
48 static void yaffs_DumpTags2(const yaffs_ExtendedTags * t)
52 ("ext.tags eccres %d blkbad %d chused %d obj %d chunk%d byte "
53 "%d del %d ser %d seq %d"
54 TENDSTR), t->eccResult, t->blockBad, t->chunkUsed, t->objectId,
55 t->chunkId, t->byteCount, t->chunkDeleted, t->serialNumber,
60 void yaffs_PackTags2(yaffs_PackedTags2 * pt, const yaffs_ExtendedTags * t)
62 pt->t.chunkId = t->chunkId;
63 pt->t.sequenceNumber = t->sequenceNumber;
64 pt->t.byteCount = t->byteCount;
65 pt->t.objectId = t->objectId;
67 if (t->chunkId == 0 && t->extraHeaderInfoAvailable) {
68 /* Store the extra header info instead */
69 /* We save the parent object in the chunkId */
70 pt->t.chunkId = EXTRA_HEADER_INFO_FLAG
71 | t->extraParentObjectId;
72 if (t->extraIsShrinkHeader) {
73 pt->t.chunkId |= EXTRA_SHRINK_FLAG;
75 if (t->extraShadows) {
76 pt->t.chunkId |= EXTRA_SHADOWS_FLAG;
79 pt->t.objectId &= ~EXTRA_OBJECT_TYPE_MASK;
81 (t->extraObjectType << EXTRA_OBJECT_TYPE_SHIFT);
83 if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
84 pt->t.byteCount = t->extraEquivalentObjectId;
85 } else if (t->extraObjectType == YAFFS_OBJECT_TYPE_FILE) {
86 pt->t.byteCount = t->extraFileLength;
92 yaffs_DumpPackedTags2(pt);
95 #ifndef YAFFS_IGNORE_TAGS_ECC
97 yaffs_ECCCalculateOther((unsigned char *)&pt->t,
98 sizeof(yaffs_PackedTags2TagsPart),
104 void yaffs_UnpackTags2(yaffs_ExtendedTags * t, yaffs_PackedTags2 * pt)
107 memset(t, 0, sizeof(yaffs_ExtendedTags));
109 yaffs_InitialiseTags(t);
111 if (pt->t.sequenceNumber != 0xFFFFFFFF) {
113 #ifdef YAFFS_IGNORE_TAGS_ECC
115 t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
121 yaffs_ECCCalculateOther((unsigned char *)&pt->t,
123 (yaffs_PackedTags2TagsPart),
126 yaffs_ECCCorrectOther((unsigned char *)&pt->t,
128 (yaffs_PackedTags2TagsPart),
132 t->eccResult = YAFFS_ECC_RESULT_NO_ERROR;
135 t->eccResult = YAFFS_ECC_RESULT_FIXED;
138 t->eccResult = YAFFS_ECC_RESULT_UNFIXED;
141 t->eccResult = YAFFS_ECC_RESULT_UNKNOWN;
147 t->objectId = pt->t.objectId;
148 t->chunkId = pt->t.chunkId;
149 t->byteCount = pt->t.byteCount;
152 t->sequenceNumber = pt->t.sequenceNumber;
154 /* Do extra header info stuff */
156 if (pt->t.chunkId & EXTRA_HEADER_INFO_FLAG) {
160 t->extraHeaderInfoAvailable = 1;
161 t->extraParentObjectId =
162 pt->t.chunkId & (~(ALL_EXTRA_FLAGS));
163 t->extraIsShrinkHeader =
164 (pt->t.chunkId & EXTRA_SHRINK_FLAG) ? 1 : 0;
166 (pt->t.chunkId & EXTRA_SHADOWS_FLAG) ? 1 : 0;
168 pt->t.objectId >> EXTRA_OBJECT_TYPE_SHIFT;
169 t->objectId &= ~EXTRA_OBJECT_TYPE_MASK;
171 if (t->extraObjectType == YAFFS_OBJECT_TYPE_HARDLINK) {
172 t->extraEquivalentObjectId = pt->t.byteCount;
174 t->extraFileLength = pt->t.byteCount;
179 yaffs_DumpPackedTags2(pt);