2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) 2006-2017 The strace developers.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * Author: Artem Bityutskiy (Битюцкий Артём)
22 #ifndef __UBI_USER_H__
23 #define __UBI_USER_H__
25 #include <linux/types.h>
28 * UBI device creation (the same as MTD device attachment)
29 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
31 * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI
32 * control device. The caller has to properly fill and pass
33 * &struct ubi_attach_req object - UBI will attach the MTD device specified in
34 * the request and return the newly created UBI device number as the ioctl
37 * UBI device deletion (the same as MTD device detachment)
38 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
40 * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI
46 * UBI volumes are created via the %UBI_IOCMKVOL ioctl command of UBI character
47 * device. A &struct ubi_mkvol_req object has to be properly filled and a
48 * pointer to it has to be passed to the ioctl.
53 * To delete a volume, the %UBI_IOCRMVOL ioctl command of the UBI character
54 * device should be used. A pointer to the 32-bit volume ID hast to be passed
60 * To re-size a volume, the %UBI_IOCRSVOL ioctl command of the UBI character
61 * device should be used. A &struct ubi_rsvol_req object has to be properly
62 * filled and a pointer to it has to be passed to the ioctl.
67 * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command
68 * of the UBI character device should be used. A &struct ubi_rnvol_req object
69 * has to be properly filled and a pointer to it has to be passed to the ioctl.
74 * Volume update should be done via the %UBI_IOCVOLUP ioctl command of the
75 * corresponding UBI volume character device. A pointer to a 64-bit update
76 * size should be passed to the ioctl. After this, UBI expects user to write
77 * this number of bytes to the volume character device. The update is finished
78 * when the claimed number of bytes is passed. So, the volume update sequence
81 * fd = open("/dev/my_volume");
82 * ioctl(fd, UBI_IOCVOLUP, &image_size);
83 * write(fd, buf, image_size);
86 * Logical eraseblock erase
87 * ~~~~~~~~~~~~~~~~~~~~~~~~
89 * To erase a logical eraseblock, the %UBI_IOCEBER ioctl command of the
90 * corresponding UBI volume character device should be used. This command
91 * unmaps the requested logical eraseblock, makes sure the corresponding
92 * physical eraseblock is successfully erased, and returns.
94 * Atomic logical eraseblock change
95 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
97 * Atomic logical eraseblock change operation is called using the %UBI_IOCEBCH
98 * ioctl command of the corresponding UBI volume character device. A pointer to
99 * a &struct ubi_leb_change_req object has to be passed to the ioctl. Then the
100 * user is expected to write the requested amount of bytes (similarly to what
101 * should be done in case of the "volume update" ioctl).
103 * Logical eraseblock map
104 * ~~~~~~~~~~~~~~~~~~~~~
106 * To map a logical eraseblock to a physical eraseblock, the %UBI_IOCEBMAP
107 * ioctl command should be used. A pointer to a &struct ubi_map_req object is
108 * expected to be passed. The ioctl maps the requested logical eraseblock to
109 * a physical eraseblock and returns. Only non-mapped logical eraseblocks can
110 * be mapped. If the logical eraseblock specified in the request is already
111 * mapped to a physical eraseblock, the ioctl fails and returns error.
113 * Logical eraseblock unmap
114 * ~~~~~~~~~~~~~~~~~~~~~~~~
116 * To unmap a logical eraseblock to a physical eraseblock, the %UBI_IOCEBUNMAP
117 * ioctl command should be used. The ioctl unmaps the logical eraseblocks,
118 * schedules corresponding physical eraseblock for erasure, and returns. Unlike
119 * the "LEB erase" command, it does not wait for the physical eraseblock being
120 * erased. Note, the side effect of this is that if an unclean reboot happens
121 * after the unmap ioctl returns, you may find the LEB mapped again to the same
122 * physical eraseblock after the UBI is run again.
124 * Check if logical eraseblock is mapped
125 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
127 * To check if a logical eraseblock is mapped to a physical eraseblock, the
128 * %UBI_IOCEBISMAP ioctl command should be used. It returns %0 if the LEB is
129 * not mapped, and %1 if it is mapped.
131 * Set an UBI volume property
132 * ~~~~~~~~~~~~~~~~~~~~~~~~~
134 * To set an UBI volume property the %UBI_IOCSETPROP ioctl command should be
135 * used. A pointer to a &struct ubi_set_vol_prop_req object is expected to be
136 * passed. The object describes which property should be set, and to which value
141 * When a new UBI volume or UBI device is created, users may either specify the
142 * volume/device number they want to create or to let UBI automatically assign
143 * the number using these constants.
145 #define UBI_VOL_NUM_AUTO (-1)
146 #define UBI_DEV_NUM_AUTO (-1)
148 /* Maximum volume name length */
149 #define UBI_MAX_VOLUME_NAME 127
151 /* ioctl commands of UBI character devices */
153 #define UBI_IOC_MAGIC 'o'
155 /* Create an UBI volume */
156 #define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req)
157 /* Remove an UBI volume */
158 #define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, __s32)
159 /* Re-size an UBI volume */
160 #define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req)
161 /* Re-name volumes */
162 #define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req)
164 /* ioctl commands of the UBI control character device */
166 #define UBI_CTRL_IOC_MAGIC 'o'
168 /* Attach an MTD device */
169 #define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req)
170 /* Detach an MTD device */
171 #define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, __s32)
173 /* ioctl commands of UBI volume character devices */
175 #define UBI_VOL_IOC_MAGIC 'O'
177 /* Start UBI volume update */
178 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, __s64)
179 /* LEB erasure command, used for debugging, disabled by default */
180 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, __s32)
181 /* Atomic LEB change command */
182 #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, __s32)
183 /* Map LEB command */
184 #define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req)
185 /* Unmap LEB command */
186 #define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, __s32)
187 /* Check if LEB is mapped command */
188 #define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, __s32)
189 /* Set an UBI volume property */
190 #define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \
191 struct ubi_set_vol_prop_req)
193 /* Maximum MTD device name length supported by UBI */
194 #define MAX_UBI_MTD_NAME_LEN 127
196 /* Maximum amount of UBI volumes that can be re-named at one go */
197 #define UBI_MAX_RNVOL 32
200 * UBI volume type constants.
202 * @UBI_DYNAMIC_VOLUME: dynamic volume
203 * @UBI_STATIC_VOLUME: static volume
206 UBI_DYNAMIC_VOLUME = 3,
207 UBI_STATIC_VOLUME = 4,
211 * UBI set volume property ioctl constants.
213 * @UBI_VOL_PROP_DIRECT_WRITE: allow (any non-zero value) or disallow (value 0)
214 * user to directly write and erase individual
215 * eraseblocks on dynamic volumes
218 UBI_VOL_PROP_DIRECT_WRITE = 1,
222 * struct ubi_attach_req - attach MTD device request.
223 * @ubi_num: UBI device number to create
224 * @mtd_num: MTD device number to attach
225 * @vid_hdr_offset: VID header offset (use defaults if %0)
226 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
227 * @padding: reserved for future, not used, has to be zeroed
229 * This data structure is used to specify MTD device UBI has to attach and the
230 * parameters it has to use. The number which should be assigned to the new UBI
231 * device is passed in @ubi_num. UBI may automatically assign the number if
232 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in
235 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default
236 * offset of the VID header within physical eraseblocks. The default offset is
237 * the next min. I/O unit after the EC header. For example, it will be offset
238 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or
239 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages.
241 * But in rare cases, if this optimizes things, the VID header may be placed to
242 * a different offset. For example, the boot-loader might do things faster if
243 * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages.
244 * As the boot-loader would not normally need to read EC headers (unless it
245 * needs UBI in RW mode), it might be faster to calculate ECC. This is weird
246 * example, but it real-life example. So, in this example, @vid_hdr_offer would
247 * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes
248 * aligned, which is OK, as UBI is clever enough to realize this is 4th
249 * sub-page of the first page and add needed padding.
251 * The @max_beb_per1024 is the maximum amount of bad PEBs UBI expects on the
252 * UBI device per 1024 eraseblocks. This value is often given in an other form
253 * in the NAND datasheet (min NVB i.e. minimal number of valid blocks). The
254 * maximum expected bad eraseblocks per 1024 is then:
255 * 1024 * (1 - MinNVB / MaxNVB)
256 * Which gives 20 for most NAND devices. This limit is used in order to derive
257 * amount of eraseblock UBI reserves for handling new bad blocks. If the device
258 * has more bad eraseblocks than this limit, UBI does not reserve any physical
259 * eraseblocks for new bad eraseblocks, but attempts to use available
260 * eraseblocks (if any). The accepted range is 0-768. If 0 is given, the
261 * default kernel value of %CONFIG_MTD_UBI_BEB_LIMIT will be used.
263 struct ubi_attach_req {
266 __s32 vid_hdr_offset;
267 __s16 max_beb_per1024;
272 * struct ubi_mkvol_req - volume description data structure used in
273 * volume creation requests.
274 * @vol_id: volume number
275 * @alignment: volume alignment
276 * @bytes: volume size in bytes
277 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
278 * @padding1: reserved for future, not used, has to be zeroed
279 * @name_len: volume name length
280 * @padding2: reserved for future, not used, has to be zeroed
283 * This structure is used by user-space programs when creating new volumes. The
284 * @used_bytes field is only necessary when creating static volumes.
286 * The @alignment field specifies the required alignment of the volume logical
287 * eraseblock. This means, that the size of logical eraseblocks will be aligned
288 * to this number, i.e.,
289 * (UBI device logical eraseblock size) mod (@alignment) = 0.
291 * To put it differently, the logical eraseblock of this volume may be slightly
292 * shortened in order to make it properly aligned. The alignment has to be
293 * multiple of the flash minimal input/output unit, or %1 to utilize the entire
294 * available space of logical eraseblocks.
296 * The @alignment field may be useful, for example, when one wants to maintain
297 * a block device on top of an UBI volume. In this case, it is desirable to fit
298 * an integer number of blocks in logical eraseblocks of this UBI volume. With
299 * alignment it is possible to update this volume using plane UBI volume image
300 * BLOBs, without caring about how to properly align them.
302 struct ubi_mkvol_req {
310 char name[UBI_MAX_VOLUME_NAME + 1];
314 * struct ubi_rsvol_req - a data structure used in volume re-size requests.
315 * @vol_id: ID of the volume to re-size
316 * @bytes: new size of the volume in bytes
318 * Re-sizing is possible for both dynamic and static volumes. But while dynamic
319 * volumes may be re-sized arbitrarily, static volumes cannot be made to be
320 * smaller than the number of bytes they bear. To arbitrarily shrink a static
321 * volume, it must be wiped out first (by means of volume update operation with
322 * zero number of bytes).
324 struct ubi_rsvol_req {
330 * struct ubi_rnvol_req - volumes re-name request.
331 * @count: count of volumes to re-name
332 * @padding1: reserved for future, not used, has to be zeroed
333 * @vol_id: ID of the volume to re-name
334 * @name_len: name length
335 * @padding2: reserved for future, not used, has to be zeroed
336 * @name: new volume name
338 * UBI allows to re-name up to %32 volumes at one go. The count of volumes to
339 * re-name is specified in the @count field. The ID of the volumes to re-name
340 * and the new names are specified in the @vol_id and @name fields.
342 * The UBI volume re-name operation is atomic, which means that should power cut
343 * happen, the volumes will have either old name or new name. So the possible
344 * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes
345 * A and B one may create temporary volumes %A1 and %B1 with the new contents,
346 * then atomically re-name A1->A and B1->B, in which case old %A and %B will
349 * If it is not desirable to remove old A and B, the re-name request has to
350 * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1
351 * become A and B, and old A and B will become A1 and B1.
353 * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1
354 * and B1 become A and B, and old A and B become X and Y.
356 * In other words, in case of re-naming into an existing volume name, the
357 * existing volume is removed, unless it is re-named as well at the same
360 struct ubi_rnvol_req {
367 char name[UBI_MAX_VOLUME_NAME + 1];
368 } ents[UBI_MAX_RNVOL];
372 * struct ubi_leb_change_req - a data structure used in atomic LEB change
374 * @lnum: logical eraseblock number to change
375 * @bytes: how many bytes will be written to the logical eraseblock
376 * @dtype: pass "3" for better compatibility with old kernels
377 * @padding: reserved for future, not used, has to be zeroed
379 * The @dtype field used to inform UBI about what kind of data will be written
380 * to the LEB: long term (value 1), short term (value 2), unknown (value 3).
381 * UBI tried to pick a PEB with lower erase counter for short term data and a
382 * PEB with higher erase counter for long term data. But this was not really
383 * used because users usually do not know this and could easily mislead UBI. We
384 * removed this feature in May 2012. UBI currently just ignores the @dtype
385 * field. But for better compatibility with older kernels it is recommended to
386 * set @dtype to 3 (unknown).
388 struct ubi_leb_change_req {
391 __s8 dtype; /* obsolete, do not use! */
396 * struct ubi_map_req - a data structure used in map LEB requests.
397 * @dtype: pass "3" for better compatibility with old kernels
398 * @lnum: logical eraseblock number to unmap
399 * @padding: reserved for future, not used, has to be zeroed
403 __s8 dtype; /* obsolete, do not use! */
409 * struct ubi_set_vol_prop_req - a data structure used to set an UBI volume
411 * @property: property to set (%UBI_VOL_PROP_DIRECT_WRITE)
412 * @padding: reserved for future, not used, has to be zeroed
413 * @value: value to set
415 struct ubi_set_vol_prop_req {
421 #endif /* __UBI_USER_H__ */