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2 * Copyright (c) International Business Machines Corp., 2006
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.
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.
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
18 * Author: Artem Bityutskiy (Битюцкий Артём)
21 #ifndef __UBI_USER_H__
22 #define __UBI_USER_H__
25 * UBI device creation (the same as MTD device attachment)
26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
28 * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI
29 * control device. The caller has to properly fill and pass
30 * &struct ubi_attach_req object - UBI will attach the MTD device specified in
31 * the request and return the newly created UBI device number as the ioctl
34 * UBI device deletion (the same as MTD device detachment)
35 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
37 * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI
43 * UBI volumes are created via the %UBI_IOCMKVOL IOCTL command of UBI character
44 * device. A &struct ubi_mkvol_req object has to be properly filled and a
45 * pointer to it has to be passed to the IOCTL.
50 * To delete a volume, the %UBI_IOCRMVOL IOCTL command of the UBI character
51 * device should be used. A pointer to the 32-bit volume ID hast to be passed
57 * To re-size a volume, the %UBI_IOCRSVOL IOCTL command of the UBI character
58 * device should be used. A &struct ubi_rsvol_req object has to be properly
59 * filled and a pointer to it has to be passed to the IOCTL.
64 * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command
65 * of the UBI character device should be used. A &struct ubi_rnvol_req object
66 * has to be properly filled and a pointer to it has to be passed to the IOCTL.
71 * Volume update should be done via the %UBI_IOCVOLUP IOCTL command of the
72 * corresponding UBI volume character device. A pointer to a 64-bit update
73 * size should be passed to the IOCTL. After this, UBI expects user to write
74 * this number of bytes to the volume character device. The update is finished
75 * when the claimed number of bytes is passed. So, the volume update sequence
78 * fd = open("/dev/my_volume");
79 * ioctl(fd, UBI_IOCVOLUP, &image_size);
80 * write(fd, buf, image_size);
83 * Atomic eraseblock change
84 * ~~~~~~~~~~~~~~~~~~~~~~~~
86 * Atomic eraseblock change operation is done via the %UBI_IOCEBCH IOCTL
87 * command of the corresponding UBI volume character device. A pointer to
88 * &struct ubi_leb_change_req has to be passed to the IOCTL. Then the user is
89 * expected to write the requested amount of bytes. This is similar to the
90 * "volume update" IOCTL.
94 * When a new UBI volume or UBI device is created, users may either specify the
95 * volume/device number they want to create or to let UBI automatically assign
96 * the number using these constants.
98 #define UBI_VOL_NUM_AUTO (-1)
99 #define UBI_DEV_NUM_AUTO (-1)
101 /* Maximum volume name length */
102 #define UBI_MAX_VOLUME_NAME 127
104 /* IOCTL commands of UBI character devices */
106 #define UBI_IOC_MAGIC 'o'
108 /* Create an UBI volume */
109 #define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req)
110 /* Remove an UBI volume */
111 #define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, int32_t)
112 /* Re-size an UBI volume */
113 #define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req)
114 /* Re-name volumes */
115 #define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req)
117 /* IOCTL commands of the UBI control character device */
119 #define UBI_CTRL_IOC_MAGIC 'o'
121 /* Attach an MTD device */
122 #define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req)
123 /* Detach an MTD device */
124 #define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, int32_t)
126 /* IOCTL commands of UBI volume character devices */
128 #define UBI_VOL_IOC_MAGIC 'O'
130 /* Start UBI volume update */
131 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, int64_t)
132 /* An eraseblock erasure command, used for debugging, disabled by default */
133 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, int32_t)
134 /* An atomic eraseblock change command */
135 #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, int32_t)
137 /* Maximum MTD device name length supported by UBI */
138 #define MAX_UBI_MTD_NAME_LEN 127
140 /* Maximum amount of UBI volumes that can be re-named at one go */
141 #define UBI_MAX_RNVOL 32
144 * UBI data type hint constants.
146 * UBI_LONGTERM: long-term data
147 * UBI_SHORTTERM: short-term data
148 * UBI_UNKNOWN: data persistence is unknown
150 * These constants are used when data is written to UBI volumes in order to
151 * help the UBI wear-leveling unit to find more appropriate physical
161 * UBI volume type constants.
163 * @UBI_DYNAMIC_VOLUME: dynamic volume
164 * @UBI_STATIC_VOLUME: static volume
167 UBI_DYNAMIC_VOLUME
= 3,
168 UBI_STATIC_VOLUME
= 4,
172 * struct ubi_attach_req - attach MTD device request.
173 * @ubi_num: UBI device number to create
174 * @mtd_num: MTD device number to attach
175 * @vid_hdr_offset: VID header offset (use defaults if %0)
176 * @padding: reserved for future, not used, has to be zeroed
178 * This data structure is used to specify MTD device UBI has to attach and the
179 * parameters it has to use. The number which should be assigned to the new UBI
180 * device is passed in @ubi_num. UBI may automatically assign the number if
181 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in
184 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default
185 * offset of the VID header within physical eraseblocks. The default offset is
186 * the next min. I/O unit after the EC header. For example, it will be offset
187 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or
188 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages.
190 * But in rare cases, if this optimizes things, the VID header may be placed to
191 * a different offset. For example, the boot-loader might do things faster if
192 * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages.
193 * As the boot-loader would not normally need to read EC headers (unless it
194 * needs UBI in RW mode), it might be faster to calculate ECC. This is weird
195 * example, but it real-life example. So, in this example, @vid_hdr_offer would
196 * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes
197 * aligned, which is OK, as UBI is clever enough to realize this is 4th
198 * sub-page of the first page and add needed padding.
200 struct ubi_attach_req
{
203 int32_t vid_hdr_offset
;
208 * struct ubi_mkvol_req - volume description data structure used in
209 * volume creation requests.
210 * @vol_id: volume number
211 * @alignment: volume alignment
212 * @bytes: volume size in bytes
213 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
214 * @padding1: reserved for future, not used, has to be zeroed
215 * @name_len: volume name length
216 * @padding2: reserved for future, not used, has to be zeroed
219 * This structure is used by user-space programs when creating new volumes. The
220 * @used_bytes field is only necessary when creating static volumes.
222 * The @alignment field specifies the required alignment of the volume logical
223 * eraseblock. This means, that the size of logical eraseblocks will be aligned
224 * to this number, i.e.,
225 * (UBI device logical eraseblock size) mod (@alignment) = 0.
227 * To put it differently, the logical eraseblock of this volume may be slightly
228 * shortened in order to make it properly aligned. The alignment has to be
229 * multiple of the flash minimal input/output unit, or %1 to utilize the entire
230 * available space of logical eraseblocks.
232 * The @alignment field may be useful, for example, when one wants to maintain
233 * a block device on top of an UBI volume. In this case, it is desirable to fit
234 * an integer number of blocks in logical eraseblocks of this UBI volume. With
235 * alignment it is possible to update this volume using plane UBI volume image
236 * BLOBs, without caring about how to properly align them.
238 struct ubi_mkvol_req
{
246 char name
[UBI_MAX_VOLUME_NAME
+ 1];
247 } __attribute__ ((packed
));
250 * struct ubi_rsvol_req - a data structure used in volume re-size requests.
251 * @vol_id: ID of the volume to re-size
252 * @bytes: new size of the volume in bytes
254 * Re-sizing is possible for both dynamic and static volumes. But while dynamic
255 * volumes may be re-sized arbitrarily, static volumes cannot be made to be
256 * smaller then the number of bytes they bear. To arbitrarily shrink a static
257 * volume, it must be wiped out first (by means of volume update operation with
258 * zero number of bytes).
260 struct ubi_rsvol_req
{
263 } __attribute__ ((packed
));
266 * struct ubi_rnvol_req - volumes re-name request.
267 * @count: count of volumes to re-name
268 * @padding1: reserved for future, not used, has to be zeroed
269 * @vol_id: ID of the volume to re-name
270 * @name_len: name length
271 * @padding2: reserved for future, not used, has to be zeroed
272 * @name: new volume name
274 * UBI allows to re-name up to %32 volumes at one go. The count of volumes to
275 * re-name is specified in the @count field. The ID of the volumes to re-name
276 * and the new names are specified in the @vol_id and @name fields.
278 * The UBI volume re-name operation is atomic, which means that should power cut
279 * happen, the volumes will have either old name or new name. So the possible
280 * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes
281 * A and B one may create temporary volumes %A1 and %B1 with the new contents,
282 * then atomically re-name A1->A and B1->B, in which case old %A and %B will
285 * If it is not desirable to remove old A and B, the re-name request has to
286 * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1
287 * become A and B, and old A and B will become A1 and B1.
289 * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1
290 * and B1 become A and B, and old A and B become X and Y.
292 * In other words, in case of re-naming into an existing volume name, the
293 * existing volume is removed, unless it is re-named as well at the same
296 struct ubi_rnvol_req
{
303 char name
[UBI_MAX_VOLUME_NAME
+ 1];
304 } ents
[UBI_MAX_RNVOL
];
305 } __attribute__ ((packed
));
308 * struct ubi_leb_change_req - a data structure used in atomic logical
309 * eraseblock change requests.
310 * @lnum: logical eraseblock number to change
311 * @bytes: how many bytes will be written to the logical eraseblock
312 * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
313 * @padding: reserved for future, not used, has to be zeroed
315 struct ubi_leb_change_req
{
320 } __attribute__ ((packed
));
322 #endif /* __UBI_USER_H__ */