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Artem B. Bityutskiy801c1352006-06-27 12:22:22 +04001/*
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 * Author: Artem Bityutskiy (Битюцкий Артём)
19 */
20
21#ifndef __UBI_USER_H__
22#define __UBI_USER_H__
23
24/*
25 * UBI volume creation
26 * ~~~~~~~~~~~~~~~~~~~
27 *
28 * UBI volumes are created via the %UBI_IOCMKVOL IOCTL command of UBI character
29 * device. A &struct ubi_mkvol_req object has to be properly filled and a
30 * pointer to it has to be passed to the IOCTL.
31 *
32 * UBI volume deletion
33 * ~~~~~~~~~~~~~~~~~~~
34 *
35 * To delete a volume, the %UBI_IOCRMVOL IOCTL command of the UBI character
36 * device should be used. A pointer to the 32-bit volume ID hast to be passed
37 * to the IOCTL.
38 *
39 * UBI volume re-size
40 * ~~~~~~~~~~~~~~~~~~
41 *
42 * To re-size a volume, the %UBI_IOCRSVOL IOCTL command of the UBI character
43 * device should be used. A &struct ubi_rsvol_req object has to be properly
44 * filled and a pointer to it has to be passed to the IOCTL.
45 *
46 * UBI volume update
47 * ~~~~~~~~~~~~~~~~~
48 *
49 * Volume update should be done via the %UBI_IOCVOLUP IOCTL command of the
50 * corresponding UBI volume character device. A pointer to a 64-bit update
51 * size should be passed to the IOCTL. After then, UBI expects user to write
52 * this number of bytes to the volume character device. The update is finished
53 * when the claimed number of bytes is passed. So, the volume update sequence
54 * is something like:
55 *
56 * fd = open("/dev/my_volume");
57 * ioctl(fd, UBI_IOCVOLUP, &image_size);
58 * write(fd, buf, image_size);
59 * close(fd);
60 */
61
62/*
63 * When a new volume is created, users may either specify the volume number they
64 * want to create or to let UBI automatically assign a volume number using this
65 * constant.
66 */
67#define UBI_VOL_NUM_AUTO (-1)
68
69/* Maximum volume name length */
70#define UBI_MAX_VOLUME_NAME 127
71
72/* IOCTL commands of UBI character devices */
73
74#define UBI_IOC_MAGIC 'o'
75
76/* Create an UBI volume */
77#define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req)
78/* Remove an UBI volume */
79#define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, int32_t)
80/* Re-size an UBI volume */
81#define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req)
82
83/* IOCTL commands of UBI volume character devices */
84
85#define UBI_VOL_IOC_MAGIC 'O'
86
87/* Start UBI volume update */
88#define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, int64_t)
89/* An eraseblock erasure command, used for debugging, disabled by default */
90#define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, int32_t)
91
92/*
93 * UBI volume type constants.
94 *
95 * @UBI_DYNAMIC_VOLUME: dynamic volume
96 * @UBI_STATIC_VOLUME: static volume
97 */
98enum {
99 UBI_DYNAMIC_VOLUME = 3,
100 UBI_STATIC_VOLUME = 4
101};
102
103/**
104 * struct ubi_mkvol_req - volume description data structure used in
105 * volume creation requests.
106 * @vol_id: volume number
107 * @alignment: volume alignment
108 * @bytes: volume size in bytes
109 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
110 * @padding1: reserved for future, not used
111 * @name_len: volume name length
112 * @padding2: reserved for future, not used
113 * @name: volume name
114 *
115 * This structure is used by userspace programs when creating new volumes. The
116 * @used_bytes field is only necessary when creating static volumes.
117 *
118 * The @alignment field specifies the required alignment of the volume logical
119 * eraseblock. This means, that the size of logical eraseblocks will be aligned
120 * to this number, i.e.,
121 * (UBI device logical eraseblock size) mod (@alignment) = 0.
122 *
123 * To put it differently, the logical eraseblock of this volume may be slightly
124 * shortened in order to make it properly aligned. The alignment has to be
125 * multiple of the flash minimal input/output unit, or %1 to utilize the entire
126 * available space of logical eraseblocks.
127 *
128 * The @alignment field may be useful, for example, when one wants to maintain
129 * a block device on top of an UBI volume. In this case, it is desirable to fit
130 * an integer number of blocks in logical eraseblocks of this UBI volume. With
131 * alignment it is possible to update this volume using plane UBI volume image
132 * BLOBs, without caring about how to properly align them.
133 */
134struct ubi_mkvol_req {
135 int32_t vol_id;
136 int32_t alignment;
137 int64_t bytes;
138 int8_t vol_type;
139 int8_t padding1;
140 int16_t name_len;
141 int8_t padding2[4];
142 char name[UBI_MAX_VOLUME_NAME+1];
143} __attribute__ ((packed));
144
145/**
146 * struct ubi_rsvol_req - a data structure used in volume re-size requests.
147 * @vol_id: ID of the volume to re-size
148 * @bytes: new size of the volume in bytes
149 *
150 * Re-sizing is possible for both dynamic and static volumes. But while dynamic
151 * volumes may be re-sized arbitrarily, static volumes cannot be made to be
152 * smaller then the number of bytes they bear. To arbitrarily shrink a static
153 * volume, it must be wiped out first (by means of volume update operation with
154 * zero number of bytes).
155 */
156struct ubi_rsvol_req {
157 int64_t bytes;
158 int32_t vol_id;
159} __attribute__ ((packed));
160
161#endif /* __UBI_USER_H__ */