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Diffstat (limited to 'include/mtd/ubi-header.h')
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diff --git a/include/mtd/ubi-header.h b/include/mtd/ubi-header.h deleted file mode 100644 index 292f916ea564..000000000000 --- a/include/mtd/ubi-header.h +++ /dev/null | |||
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1 | /* | ||
2 | * Copyright (c) International Business Machines Corp., 2006 | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or modify | ||
5 | * it under the terms of the GNU General Public License as published by | ||
6 | * the Free Software Foundation; either version 2 of the License, or | ||
7 | * (at your option) any later version. | ||
8 | * | ||
9 | * This program is distributed in the hope that it will be useful, | ||
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See | ||
12 | * the GNU General Public License for more details. | ||
13 | * | ||
14 | * You should have received a copy of the GNU General Public License | ||
15 | * along with this program; if not, write to the Free Software | ||
16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
17 | * | ||
18 | * Authors: Artem Bityutskiy (Битюцкий Артём) | ||
19 | * Thomas Gleixner | ||
20 | * Frank Haverkamp | ||
21 | * Oliver Lohmann | ||
22 | * Andreas Arnez | ||
23 | */ | ||
24 | |||
25 | /* | ||
26 | * This file defines the layout of UBI headers and all the other UBI on-flash | ||
27 | * data structures. May be included by user-space. | ||
28 | */ | ||
29 | |||
30 | #ifndef __UBI_HEADER_H__ | ||
31 | #define __UBI_HEADER_H__ | ||
32 | |||
33 | #include <asm/byteorder.h> | ||
34 | |||
35 | /* The version of UBI images supported by this implementation */ | ||
36 | #define UBI_VERSION 1 | ||
37 | |||
38 | /* The highest erase counter value supported by this implementation */ | ||
39 | #define UBI_MAX_ERASECOUNTER 0x7FFFFFFF | ||
40 | |||
41 | /* The initial CRC32 value used when calculating CRC checksums */ | ||
42 | #define UBI_CRC32_INIT 0xFFFFFFFFU | ||
43 | |||
44 | /* Erase counter header magic number (ASCII "UBI#") */ | ||
45 | #define UBI_EC_HDR_MAGIC 0x55424923 | ||
46 | /* Volume identifier header magic number (ASCII "UBI!") */ | ||
47 | #define UBI_VID_HDR_MAGIC 0x55424921 | ||
48 | |||
49 | /* | ||
50 | * Volume type constants used in the volume identifier header. | ||
51 | * | ||
52 | * @UBI_VID_DYNAMIC: dynamic volume | ||
53 | * @UBI_VID_STATIC: static volume | ||
54 | */ | ||
55 | enum { | ||
56 | UBI_VID_DYNAMIC = 1, | ||
57 | UBI_VID_STATIC = 2 | ||
58 | }; | ||
59 | |||
60 | /* | ||
61 | * Volume flags used in the volume table record. | ||
62 | * | ||
63 | * @UBI_VTBL_AUTORESIZE_FLG: auto-resize this volume | ||
64 | * | ||
65 | * %UBI_VTBL_AUTORESIZE_FLG flag can be set only for one volume in the volume | ||
66 | * table. UBI automatically re-sizes the volume which has this flag and makes | ||
67 | * the volume to be of largest possible size. This means that if after the | ||
68 | * initialization UBI finds out that there are available physical eraseblocks | ||
69 | * present on the device, it automatically appends all of them to the volume | ||
70 | * (the physical eraseblocks reserved for bad eraseblocks handling and other | ||
71 | * reserved physical eraseblocks are not taken). So, if there is a volume with | ||
72 | * the %UBI_VTBL_AUTORESIZE_FLG flag set, the amount of available logical | ||
73 | * eraseblocks will be zero after UBI is loaded, because all of them will be | ||
74 | * reserved for this volume. Note, the %UBI_VTBL_AUTORESIZE_FLG bit is cleared | ||
75 | * after the volume had been initialized. | ||
76 | * | ||
77 | * The auto-resize feature is useful for device production purposes. For | ||
78 | * example, different NAND flash chips may have different amount of initial bad | ||
79 | * eraseblocks, depending of particular chip instance. Manufacturers of NAND | ||
80 | * chips usually guarantee that the amount of initial bad eraseblocks does not | ||
81 | * exceed certain percent, e.g. 2%. When one creates an UBI image which will be | ||
82 | * flashed to the end devices in production, he does not know the exact amount | ||
83 | * of good physical eraseblocks the NAND chip on the device will have, but this | ||
84 | * number is required to calculate the volume sized and put them to the volume | ||
85 | * table of the UBI image. In this case, one of the volumes (e.g., the one | ||
86 | * which will store the root file system) is marked as "auto-resizable", and | ||
87 | * UBI will adjust its size on the first boot if needed. | ||
88 | * | ||
89 | * Note, first UBI reserves some amount of physical eraseblocks for bad | ||
90 | * eraseblock handling, and then re-sizes the volume, not vice-versa. This | ||
91 | * means that the pool of reserved physical eraseblocks will always be present. | ||
92 | */ | ||
93 | enum { | ||
94 | UBI_VTBL_AUTORESIZE_FLG = 0x01, | ||
95 | }; | ||
96 | |||
97 | /* | ||
98 | * Compatibility constants used by internal volumes. | ||
99 | * | ||
100 | * @UBI_COMPAT_DELETE: delete this internal volume before anything is written | ||
101 | * to the flash | ||
102 | * @UBI_COMPAT_RO: attach this device in read-only mode | ||
103 | * @UBI_COMPAT_PRESERVE: preserve this internal volume - do not touch its | ||
104 | * physical eraseblocks, don't allow the wear-leveling unit to move them | ||
105 | * @UBI_COMPAT_REJECT: reject this UBI image | ||
106 | */ | ||
107 | enum { | ||
108 | UBI_COMPAT_DELETE = 1, | ||
109 | UBI_COMPAT_RO = 2, | ||
110 | UBI_COMPAT_PRESERVE = 4, | ||
111 | UBI_COMPAT_REJECT = 5 | ||
112 | }; | ||
113 | |||
114 | /* Sizes of UBI headers */ | ||
115 | #define UBI_EC_HDR_SIZE sizeof(struct ubi_ec_hdr) | ||
116 | #define UBI_VID_HDR_SIZE sizeof(struct ubi_vid_hdr) | ||
117 | |||
118 | /* Sizes of UBI headers without the ending CRC */ | ||
119 | #define UBI_EC_HDR_SIZE_CRC (UBI_EC_HDR_SIZE - sizeof(__be32)) | ||
120 | #define UBI_VID_HDR_SIZE_CRC (UBI_VID_HDR_SIZE - sizeof(__be32)) | ||
121 | |||
122 | /** | ||
123 | * struct ubi_ec_hdr - UBI erase counter header. | ||
124 | * @magic: erase counter header magic number (%UBI_EC_HDR_MAGIC) | ||
125 | * @version: version of UBI implementation which is supposed to accept this | ||
126 | * UBI image | ||
127 | * @padding1: reserved for future, zeroes | ||
128 | * @ec: the erase counter | ||
129 | * @vid_hdr_offset: where the VID header starts | ||
130 | * @data_offset: where the user data start | ||
131 | * @padding2: reserved for future, zeroes | ||
132 | * @hdr_crc: erase counter header CRC checksum | ||
133 | * | ||
134 | * The erase counter header takes 64 bytes and has a plenty of unused space for | ||
135 | * future usage. The unused fields are zeroed. The @version field is used to | ||
136 | * indicate the version of UBI implementation which is supposed to be able to | ||
137 | * work with this UBI image. If @version is greater then the current UBI | ||
138 | * version, the image is rejected. This may be useful in future if something | ||
139 | * is changed radically. This field is duplicated in the volume identifier | ||
140 | * header. | ||
141 | * | ||
142 | * The @vid_hdr_offset and @data_offset fields contain the offset of the the | ||
143 | * volume identifier header and user data, relative to the beginning of the | ||
144 | * physical eraseblock. These values have to be the same for all physical | ||
145 | * eraseblocks. | ||
146 | */ | ||
147 | struct ubi_ec_hdr { | ||
148 | __be32 magic; | ||
149 | __u8 version; | ||
150 | __u8 padding1[3]; | ||
151 | __be64 ec; /* Warning: the current limit is 31-bit anyway! */ | ||
152 | __be32 vid_hdr_offset; | ||
153 | __be32 data_offset; | ||
154 | __u8 padding2[36]; | ||
155 | __be32 hdr_crc; | ||
156 | } __attribute__ ((packed)); | ||
157 | |||
158 | /** | ||
159 | * struct ubi_vid_hdr - on-flash UBI volume identifier header. | ||
160 | * @magic: volume identifier header magic number (%UBI_VID_HDR_MAGIC) | ||
161 | * @version: UBI implementation version which is supposed to accept this UBI | ||
162 | * image (%UBI_VERSION) | ||
163 | * @vol_type: volume type (%UBI_VID_DYNAMIC or %UBI_VID_STATIC) | ||
164 | * @copy_flag: if this logical eraseblock was copied from another physical | ||
165 | * eraseblock (for wear-leveling reasons) | ||
166 | * @compat: compatibility of this volume (%0, %UBI_COMPAT_DELETE, | ||
167 | * %UBI_COMPAT_IGNORE, %UBI_COMPAT_PRESERVE, or %UBI_COMPAT_REJECT) | ||
168 | * @vol_id: ID of this volume | ||
169 | * @lnum: logical eraseblock number | ||
170 | * @leb_ver: version of this logical eraseblock (IMPORTANT: obsolete, to be | ||
171 | * removed, kept only for not breaking older UBI users) | ||
172 | * @data_size: how many bytes of data this logical eraseblock contains | ||
173 | * @used_ebs: total number of used logical eraseblocks in this volume | ||
174 | * @data_pad: how many bytes at the end of this physical eraseblock are not | ||
175 | * used | ||
176 | * @data_crc: CRC checksum of the data stored in this logical eraseblock | ||
177 | * @padding1: reserved for future, zeroes | ||
178 | * @sqnum: sequence number | ||
179 | * @padding2: reserved for future, zeroes | ||
180 | * @hdr_crc: volume identifier header CRC checksum | ||
181 | * | ||
182 | * The @sqnum is the value of the global sequence counter at the time when this | ||
183 | * VID header was created. The global sequence counter is incremented each time | ||
184 | * UBI writes a new VID header to the flash, i.e. when it maps a logical | ||
185 | * eraseblock to a new physical eraseblock. The global sequence counter is an | ||
186 | * unsigned 64-bit integer and we assume it never overflows. The @sqnum | ||
187 | * (sequence number) is used to distinguish between older and newer versions of | ||
188 | * logical eraseblocks. | ||
189 | * | ||
190 | * There are 2 situations when there may be more then one physical eraseblock | ||
191 | * corresponding to the same logical eraseblock, i.e., having the same @vol_id | ||
192 | * and @lnum values in the volume identifier header. Suppose we have a logical | ||
193 | * eraseblock L and it is mapped to the physical eraseblock P. | ||
194 | * | ||
195 | * 1. Because UBI may erase physical eraseblocks asynchronously, the following | ||
196 | * situation is possible: L is asynchronously erased, so P is scheduled for | ||
197 | * erasure, then L is written to,i.e. mapped to another physical eraseblock P1, | ||
198 | * so P1 is written to, then an unclean reboot happens. Result - there are 2 | ||
199 | * physical eraseblocks P and P1 corresponding to the same logical eraseblock | ||
200 | * L. But P1 has greater sequence number, so UBI picks P1 when it attaches the | ||
201 | * flash. | ||
202 | * | ||
203 | * 2. From time to time UBI moves logical eraseblocks to other physical | ||
204 | * eraseblocks for wear-leveling reasons. If, for example, UBI moves L from P | ||
205 | * to P1, and an unclean reboot happens before P is physically erased, there | ||
206 | * are two physical eraseblocks P and P1 corresponding to L and UBI has to | ||
207 | * select one of them when the flash is attached. The @sqnum field says which | ||
208 | * PEB is the original (obviously P will have lower @sqnum) and the copy. But | ||
209 | * it is not enough to select the physical eraseblock with the higher sequence | ||
210 | * number, because the unclean reboot could have happen in the middle of the | ||
211 | * copying process, so the data in P is corrupted. It is also not enough to | ||
212 | * just select the physical eraseblock with lower sequence number, because the | ||
213 | * data there may be old (consider a case if more data was added to P1 after | ||
214 | * the copying). Moreover, the unclean reboot may happen when the erasure of P | ||
215 | * was just started, so it result in unstable P, which is "mostly" OK, but | ||
216 | * still has unstable bits. | ||
217 | * | ||
218 | * UBI uses the @copy_flag field to indicate that this logical eraseblock is a | ||
219 | * copy. UBI also calculates data CRC when the data is moved and stores it at | ||
220 | * the @data_crc field of the copy (P1). So when UBI needs to pick one physical | ||
221 | * eraseblock of two (P or P1), the @copy_flag of the newer one (P1) is | ||
222 | * examined. If it is cleared, the situation* is simple and the newer one is | ||
223 | * picked. If it is set, the data CRC of the copy (P1) is examined. If the CRC | ||
224 | * checksum is correct, this physical eraseblock is selected (P1). Otherwise | ||
225 | * the older one (P) is selected. | ||
226 | * | ||
227 | * Note, there is an obsolete @leb_ver field which was used instead of @sqnum | ||
228 | * in the past. But it is not used anymore and we keep it in order to be able | ||
229 | * to deal with old UBI images. It will be removed at some point. | ||
230 | * | ||
231 | * There are 2 sorts of volumes in UBI: user volumes and internal volumes. | ||
232 | * Internal volumes are not seen from outside and are used for various internal | ||
233 | * UBI purposes. In this implementation there is only one internal volume - the | ||
234 | * layout volume. Internal volumes are the main mechanism of UBI extensions. | ||
235 | * For example, in future one may introduce a journal internal volume. Internal | ||
236 | * volumes have their own reserved range of IDs. | ||
237 | * | ||
238 | * The @compat field is only used for internal volumes and contains the "degree | ||
239 | * of their compatibility". It is always zero for user volumes. This field | ||
240 | * provides a mechanism to introduce UBI extensions and to be still compatible | ||
241 | * with older UBI binaries. For example, if someone introduced a journal in | ||
242 | * future, he would probably use %UBI_COMPAT_DELETE compatibility for the | ||
243 | * journal volume. And in this case, older UBI binaries, which know nothing | ||
244 | * about the journal volume, would just delete this volume and work perfectly | ||
245 | * fine. This is similar to what Ext2fs does when it is fed by an Ext3fs image | ||
246 | * - it just ignores the Ext3fs journal. | ||
247 | * | ||
248 | * The @data_crc field contains the CRC checksum of the contents of the logical | ||
249 | * eraseblock if this is a static volume. In case of dynamic volumes, it does | ||
250 | * not contain the CRC checksum as a rule. The only exception is when the | ||
251 | * data of the physical eraseblock was moved by the wear-leveling unit, then | ||
252 | * the wear-leveling unit calculates the data CRC and stores it in the | ||
253 | * @data_crc field. And of course, the @copy_flag is %in this case. | ||
254 | * | ||
255 | * The @data_size field is used only for static volumes because UBI has to know | ||
256 | * how many bytes of data are stored in this eraseblock. For dynamic volumes, | ||
257 | * this field usually contains zero. The only exception is when the data of the | ||
258 | * physical eraseblock was moved to another physical eraseblock for | ||
259 | * wear-leveling reasons. In this case, UBI calculates CRC checksum of the | ||
260 | * contents and uses both @data_crc and @data_size fields. In this case, the | ||
261 | * @data_size field contains data size. | ||
262 | * | ||
263 | * The @used_ebs field is used only for static volumes and indicates how many | ||
264 | * eraseblocks the data of the volume takes. For dynamic volumes this field is | ||
265 | * not used and always contains zero. | ||
266 | * | ||
267 | * The @data_pad is calculated when volumes are created using the alignment | ||
268 | * parameter. So, effectively, the @data_pad field reduces the size of logical | ||
269 | * eraseblocks of this volume. This is very handy when one uses block-oriented | ||
270 | * software (say, cramfs) on top of the UBI volume. | ||
271 | */ | ||
272 | struct ubi_vid_hdr { | ||
273 | __be32 magic; | ||
274 | __u8 version; | ||
275 | __u8 vol_type; | ||
276 | __u8 copy_flag; | ||
277 | __u8 compat; | ||
278 | __be32 vol_id; | ||
279 | __be32 lnum; | ||
280 | __be32 leb_ver; /* obsolete, to be removed, don't use */ | ||
281 | __be32 data_size; | ||
282 | __be32 used_ebs; | ||
283 | __be32 data_pad; | ||
284 | __be32 data_crc; | ||
285 | __u8 padding1[4]; | ||
286 | __be64 sqnum; | ||
287 | __u8 padding2[12]; | ||
288 | __be32 hdr_crc; | ||
289 | } __attribute__ ((packed)); | ||
290 | |||
291 | /* Internal UBI volumes count */ | ||
292 | #define UBI_INT_VOL_COUNT 1 | ||
293 | |||
294 | /* | ||
295 | * Starting ID of internal volumes. There is reserved room for 4096 internal | ||
296 | * volumes. | ||
297 | */ | ||
298 | #define UBI_INTERNAL_VOL_START (0x7FFFFFFF - 4096) | ||
299 | |||
300 | /* The layout volume contains the volume table */ | ||
301 | |||
302 | #define UBI_LAYOUT_VOLUME_ID UBI_INTERNAL_VOL_START | ||
303 | #define UBI_LAYOUT_VOLUME_TYPE UBI_VID_DYNAMIC | ||
304 | #define UBI_LAYOUT_VOLUME_ALIGN 1 | ||
305 | #define UBI_LAYOUT_VOLUME_EBS 2 | ||
306 | #define UBI_LAYOUT_VOLUME_NAME "layout volume" | ||
307 | #define UBI_LAYOUT_VOLUME_COMPAT UBI_COMPAT_REJECT | ||
308 | |||
309 | /* The maximum number of volumes per one UBI device */ | ||
310 | #define UBI_MAX_VOLUMES 128 | ||
311 | |||
312 | /* The maximum volume name length */ | ||
313 | #define UBI_VOL_NAME_MAX 127 | ||
314 | |||
315 | /* Size of the volume table record */ | ||
316 | #define UBI_VTBL_RECORD_SIZE sizeof(struct ubi_vtbl_record) | ||
317 | |||
318 | /* Size of the volume table record without the ending CRC */ | ||
319 | #define UBI_VTBL_RECORD_SIZE_CRC (UBI_VTBL_RECORD_SIZE - sizeof(__be32)) | ||
320 | |||
321 | /** | ||
322 | * struct ubi_vtbl_record - a record in the volume table. | ||
323 | * @reserved_pebs: how many physical eraseblocks are reserved for this volume | ||
324 | * @alignment: volume alignment | ||
325 | * @data_pad: how many bytes are unused at the end of the each physical | ||
326 | * eraseblock to satisfy the requested alignment | ||
327 | * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) | ||
328 | * @upd_marker: if volume update was started but not finished | ||
329 | * @name_len: volume name length | ||
330 | * @name: the volume name | ||
331 | * @flags: volume flags (%UBI_VTBL_AUTORESIZE_FLG) | ||
332 | * @padding: reserved, zeroes | ||
333 | * @crc: a CRC32 checksum of the record | ||
334 | * | ||
335 | * The volume table records are stored in the volume table, which is stored in | ||
336 | * the layout volume. The layout volume consists of 2 logical eraseblock, each | ||
337 | * of which contains a copy of the volume table (i.e., the volume table is | ||
338 | * duplicated). The volume table is an array of &struct ubi_vtbl_record | ||
339 | * objects indexed by the volume ID. | ||
340 | * | ||
341 | * If the size of the logical eraseblock is large enough to fit | ||
342 | * %UBI_MAX_VOLUMES records, the volume table contains %UBI_MAX_VOLUMES | ||
343 | * records. Otherwise, it contains as many records as it can fit (i.e., size of | ||
344 | * logical eraseblock divided by sizeof(struct ubi_vtbl_record)). | ||
345 | * | ||
346 | * The @upd_marker flag is used to implement volume update. It is set to %1 | ||
347 | * before update and set to %0 after the update. So if the update operation was | ||
348 | * interrupted, UBI knows that the volume is corrupted. | ||
349 | * | ||
350 | * The @alignment field is specified when the volume is created and cannot be | ||
351 | * later changed. It may be useful, for example, when a block-oriented file | ||
352 | * system works on top of UBI. The @data_pad field is calculated using the | ||
353 | * logical eraseblock size and @alignment. The alignment must be multiple to the | ||
354 | * minimal flash I/O unit. If @alignment is 1, all the available space of | ||
355 | * the physical eraseblocks is used. | ||
356 | * | ||
357 | * Empty records contain all zeroes and the CRC checksum of those zeroes. | ||
358 | */ | ||
359 | struct ubi_vtbl_record { | ||
360 | __be32 reserved_pebs; | ||
361 | __be32 alignment; | ||
362 | __be32 data_pad; | ||
363 | __u8 vol_type; | ||
364 | __u8 upd_marker; | ||
365 | __be16 name_len; | ||
366 | __u8 name[UBI_VOL_NAME_MAX+1]; | ||
367 | __u8 flags; | ||
368 | __u8 padding[23]; | ||
369 | __be32 crc; | ||
370 | } __attribute__ ((packed)); | ||
371 | |||
372 | #endif /* !__UBI_HEADER_H__ */ | ||