2 * Copyright © 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__
24 #include <linux/types.h>
27 * UBI device creation (the same as MTD device attachment)
28 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
30 * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI
31 * control device. The caller has to properly fill and pass
32 * &struct ubi_attach_req object - UBI will attach the MTD device specified in
33 * the request and return the newly created UBI device number as the ioctl
36 * UBI device deletion (the same as MTD device detachment)
37 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
39 * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI
45 * UBI volumes are created via the %UBI_IOCMKVOL ioctl command of UBI character
46 * device. A &struct ubi_mkvol_req object has to be properly filled and a
47 * pointer to it has to be passed to the ioctl.
52 * To delete a volume, the %UBI_IOCRMVOL ioctl command of the UBI character
53 * device should be used. A pointer to the 32-bit volume ID hast to be passed
59 * To re-size a volume, the %UBI_IOCRSVOL ioctl command of the UBI character
60 * device should be used. A &struct ubi_rsvol_req object has to be properly
61 * filled and a pointer to it has to be passed to the ioctl.
66 * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command
67 * of the UBI character device should be used. A &struct ubi_rnvol_req object
68 * has to be properly filled and a pointer to it has to be passed to the ioctl.
73 * Volume update should be done via the %UBI_IOCVOLUP ioctl command of the
74 * corresponding UBI volume character device. A pointer to a 64-bit update
75 * size should be passed to the ioctl. After this, UBI expects user to write
76 * this number of bytes to the volume character device. The update is finished
77 * when the claimed number of bytes is passed. So, the volume update sequence
80 * fd = open("/dev/my_volume");
81 * ioctl(fd, UBI_IOCVOLUP, &image_size);
82 * write(fd, buf, image_size);
85 * Logical eraseblock erase
86 * ~~~~~~~~~~~~~~~~~~~~~~~~
88 * To erase a logical eraseblock, the %UBI_IOCEBER ioctl command of the
89 * corresponding UBI volume character device should be used. This command
90 * unmaps the requested logical eraseblock, makes sure the corresponding
91 * physical eraseblock is successfully erased, and returns.
93 * Atomic logical eraseblock change
94 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
96 * Atomic logical eraseblock change operation is called using the %UBI_IOCEBCH
97 * ioctl command of the corresponding UBI volume character device. A pointer to
98 * a &struct ubi_leb_change_req object has to be passed to the ioctl. Then the
99 * user is expected to write the requested amount of bytes (similarly to what
100 * should be done in case of the "volume update" ioctl).
102 * Logical eraseblock map
103 * ~~~~~~~~~~~~~~~~~~~~~
105 * To map a logical eraseblock to a physical eraseblock, the %UBI_IOCEBMAP
106 * ioctl command should be used. A pointer to a &struct ubi_map_req object is
107 * expected to be passed. The ioctl maps the requested logical eraseblock to
108 * a physical eraseblock and returns. Only non-mapped logical eraseblocks can
109 * be mapped. If the logical eraseblock specified in the request is already
110 * mapped to a physical eraseblock, the ioctl fails and returns error.
112 * Logical eraseblock unmap
113 * ~~~~~~~~~~~~~~~~~~~~~~~~
115 * To unmap a logical eraseblock to a physical eraseblock, the %UBI_IOCEBUNMAP
116 * ioctl command should be used. The ioctl unmaps the logical eraseblocks,
117 * schedules corresponding physical eraseblock for erasure, and returns. Unlike
118 * the "LEB erase" command, it does not wait for the physical eraseblock being
119 * erased. Note, the side effect of this is that if an unclean reboot happens
120 * after the unmap ioctl returns, you may find the LEB mapped again to the same
121 * physical eraseblock after the UBI is run again.
123 * Check if logical eraseblock is mapped
124 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
126 * To check if a logical eraseblock is mapped to a physical eraseblock, the
127 * %UBI_IOCEBISMAP ioctl command should be used. It returns %0 if the LEB is
128 * not mapped, and %1 if it is mapped.
130 * Set an UBI volume property
131 * ~~~~~~~~~~~~~~~~~~~~~~~~~
133 * To set an UBI volume property the %UBI_IOCSETPROP ioctl command should be
134 * used. A pointer to a &struct ubi_set_vol_prop_req object is expected to be
135 * passed. The object describes which property should be set, and to which value
140 * When a new UBI volume or UBI device is created, users may either specify the
141 * volume/device number they want to create or to let UBI automatically assign
142 * the number using these constants.
144 #define UBI_VOL_NUM_AUTO (-1)
145 #define UBI_DEV_NUM_AUTO (-1)
147 /* Maximum volume name length */
148 #define UBI_MAX_VOLUME_NAME 127
150 /* ioctl commands of UBI character devices */
152 #define UBI_IOC_MAGIC 'o'
154 /* Create an UBI volume */
155 #define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req)
156 /* Remove an UBI volume */
157 #define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, __s32)
158 /* Re-size an UBI volume */
159 #define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req)
160 /* Re-name volumes */
161 #define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req)
163 /* ioctl commands of the UBI control character device */
165 #define UBI_CTRL_IOC_MAGIC 'o'
167 /* Attach an MTD device */
168 #define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req)
169 /* Detach an MTD device */
170 #define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, __s32)
172 /* ioctl commands of UBI volume character devices */
174 #define UBI_VOL_IOC_MAGIC 'O'
176 /* Start UBI volume update */
177 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, __s64)
178 /* LEB erasure command, used for debugging, disabled by default */
179 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, __s32)
180 /* Atomic LEB change command */
181 #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, __s32)
182 /* Map LEB command */
183 #define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req)
184 /* Unmap LEB command */
185 #define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, __s32)
186 /* Check if LEB is mapped command */
187 #define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, __s32)
188 /* Set an UBI volume property */
189 #define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \
190 struct ubi_set_vol_prop_req)
192 /* Maximum MTD device name length supported by UBI */
193 #define MAX_UBI_MTD_NAME_LEN 127
195 /* Maximum amount of UBI volumes that can be re-named at one go */
196 #define UBI_MAX_RNVOL 32
199 * UBI volume type constants.
201 * @UBI_DYNAMIC_VOLUME: dynamic volume
202 * @UBI_STATIC_VOLUME: static volume
205 UBI_DYNAMIC_VOLUME
= 3,
206 UBI_STATIC_VOLUME
= 4,
210 * UBI set volume property ioctl constants.
212 * @UBI_VOL_PROP_DIRECT_WRITE: allow (any non-zero value) or disallow (value 0)
213 * user to directly write and erase individual
214 * eraseblocks on dynamic volumes
217 UBI_VOL_PROP_DIRECT_WRITE
= 1,
221 * struct ubi_attach_req - attach MTD device request.
222 * @ubi_num: UBI device number to create
223 * @mtd_num: MTD device number to attach
224 * @vid_hdr_offset: VID header offset (use defaults if %0)
225 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
226 * @padding: reserved for future, not used, has to be zeroed
228 * This data structure is used to specify MTD device UBI has to attach and the
229 * parameters it has to use. The number which should be assigned to the new UBI
230 * device is passed in @ubi_num. UBI may automatically assign the number if
231 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in
234 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default
235 * offset of the VID header within physical eraseblocks. The default offset is
236 * the next min. I/O unit after the EC header. For example, it will be offset
237 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or
238 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages.
240 * But in rare cases, if this optimizes things, the VID header may be placed to
241 * a different offset. For example, the boot-loader might do things faster if
242 * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages.
243 * As the boot-loader would not normally need to read EC headers (unless it
244 * needs UBI in RW mode), it might be faster to calculate ECC. This is weird
245 * example, but it real-life example. So, in this example, @vid_hdr_offer would
246 * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes
247 * aligned, which is OK, as UBI is clever enough to realize this is 4th
248 * sub-page of the first page and add needed padding.
250 * The @max_beb_per1024 is the maximum amount of bad PEBs UBI expects on the
251 * UBI device per 1024 eraseblocks. This value is often given in an other form
252 * in the NAND datasheet (min NVB i.e. minimal number of valid blocks). The
253 * maximum expected bad eraseblocks per 1024 is then:
254 * 1024 * (1 - MinNVB / MaxNVB)
255 * Which gives 20 for most NAND devices. This limit is used in order to derive
256 * amount of eraseblock UBI reserves for handling new bad blocks. If the device
257 * has more bad eraseblocks than this limit, UBI does not reserve any physical
258 * eraseblocks for new bad eraseblocks, but attempts to use available
259 * eraseblocks (if any). The accepted range is 0-768. If 0 is given, the
260 * default kernel value of %CONFIG_MTD_UBI_BEB_LIMIT will be used.
262 struct ubi_attach_req
{
265 __s32 vid_hdr_offset
;
266 __s16 max_beb_per1024
;
271 * struct ubi_mkvol_req - volume description data structure used in
272 * volume creation requests.
273 * @vol_id: volume number
274 * @alignment: volume alignment
275 * @bytes: volume size in bytes
276 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
277 * @padding1: reserved for future, not used, has to be zeroed
278 * @name_len: volume name length
279 * @padding2: reserved for future, not used, has to be zeroed
282 * This structure is used by user-space programs when creating new volumes. The
283 * @used_bytes field is only necessary when creating static volumes.
285 * The @alignment field specifies the required alignment of the volume logical
286 * eraseblock. This means, that the size of logical eraseblocks will be aligned
287 * to this number, i.e.,
288 * (UBI device logical eraseblock size) mod (@alignment) = 0.
290 * To put it differently, the logical eraseblock of this volume may be slightly
291 * shortened in order to make it properly aligned. The alignment has to be
292 * multiple of the flash minimal input/output unit, or %1 to utilize the entire
293 * available space of logical eraseblocks.
295 * The @alignment field may be useful, for example, when one wants to maintain
296 * a block device on top of an UBI volume. In this case, it is desirable to fit
297 * an integer number of blocks in logical eraseblocks of this UBI volume. With
298 * alignment it is possible to update this volume using plane UBI volume image
299 * BLOBs, without caring about how to properly align them.
301 struct ubi_mkvol_req
{
309 char name
[UBI_MAX_VOLUME_NAME
+ 1];
313 * struct ubi_rsvol_req - a data structure used in volume re-size requests.
314 * @vol_id: ID of the volume to re-size
315 * @bytes: new size of the volume in bytes
317 * Re-sizing is possible for both dynamic and static volumes. But while dynamic
318 * volumes may be re-sized arbitrarily, static volumes cannot be made to be
319 * smaller than the number of bytes they bear. To arbitrarily shrink a static
320 * volume, it must be wiped out first (by means of volume update operation with
321 * zero number of bytes).
323 struct ubi_rsvol_req
{
329 * struct ubi_rnvol_req - volumes re-name request.
330 * @count: count of volumes to re-name
331 * @padding1: reserved for future, not used, has to be zeroed
332 * @vol_id: ID of the volume to re-name
333 * @name_len: name length
334 * @padding2: reserved for future, not used, has to be zeroed
335 * @name: new volume name
337 * UBI allows to re-name up to %32 volumes at one go. The count of volumes to
338 * re-name is specified in the @count field. The ID of the volumes to re-name
339 * and the new names are specified in the @vol_id and @name fields.
341 * The UBI volume re-name operation is atomic, which means that should power cut
342 * happen, the volumes will have either old name or new name. So the possible
343 * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes
344 * A and B one may create temporary volumes %A1 and %B1 with the new contents,
345 * then atomically re-name A1->A and B1->B, in which case old %A and %B will
348 * If it is not desirable to remove old A and B, the re-name request has to
349 * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1
350 * become A and B, and old A and B will become A1 and B1.
352 * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1
353 * and B1 become A and B, and old A and B become X and Y.
355 * In other words, in case of re-naming into an existing volume name, the
356 * existing volume is removed, unless it is re-named as well at the same
359 struct ubi_rnvol_req
{
366 char name
[UBI_MAX_VOLUME_NAME
+ 1];
367 } ents
[UBI_MAX_RNVOL
];
371 * struct ubi_leb_change_req - a data structure used in atomic LEB change
373 * @lnum: logical eraseblock number to change
374 * @bytes: how many bytes will be written to the logical eraseblock
375 * @dtype: pass "3" for better compatibility with old kernels
376 * @padding: reserved for future, not used, has to be zeroed
378 * The @dtype field used to inform UBI about what kind of data will be written
379 * to the LEB: long term (value 1), short term (value 2), unknown (value 3).
380 * UBI tried to pick a PEB with lower erase counter for short term data and a
381 * PEB with higher erase counter for long term data. But this was not really
382 * used because users usually do not know this and could easily mislead UBI. We
383 * removed this feature in May 2012. UBI currently just ignores the @dtype
384 * field. But for better compatibility with older kernels it is recommended to
385 * set @dtype to 3 (unknown).
387 struct ubi_leb_change_req
{
390 __s8 dtype
; /* obsolete, do not use! */
395 * struct ubi_map_req - a data structure used in map LEB requests.
396 * @dtype: pass "3" for better compatibility with old kernels
397 * @lnum: logical eraseblock number to unmap
398 * @padding: reserved for future, not used, has to be zeroed
402 __s8 dtype
; /* obsolete, do not use! */
408 * struct ubi_set_vol_prop_req - a data structure used to set an UBI volume
410 * @property: property to set (%UBI_VOL_PROP_DIRECT_WRITE)
411 * @padding: reserved for future, not used, has to be zeroed
412 * @value: value to set
414 struct ubi_set_vol_prop_req
{
420 #endif /* __UBI_USER_H__ */