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 * Author: Artem Bityutskiy (Битюцкий Артём) 19 */ 20 21 #ifndef __UBI_USER_H__ 22 #define __UBI_USER_H__ 23 24 /* 25 * UBI device creation (the same as MTD device attachment) 26 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 27 * 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 32 * return value. 33 * 34 * UBI device deletion (the same as MTD device detachment) 35 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 36 * 37 * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI 38 * control device. 39 * 40 * UBI volume creation 41 * ~~~~~~~~~~~~~~~~~~~ 42 * 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. 46 * 47 * UBI volume deletion 48 * ~~~~~~~~~~~~~~~~~~~ 49 * 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 52 * to the IOCTL. 53 * 54 * UBI volume re-size 55 * ~~~~~~~~~~~~~~~~~~ 56 * 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. 60 * 61 * UBI volume update 62 * ~~~~~~~~~~~~~~~~~ 63 * 64 * Volume update should be done via the %UBI_IOCVOLUP IOCTL command of the 65 * corresponding UBI volume character device. A pointer to a 64-bit update 66 * size should be passed to the IOCTL. After this, UBI expects user to write 67 * this number of bytes to the volume character device. The update is finished 68 * when the claimed number of bytes is passed. So, the volume update sequence 69 * is something like: 70 * 71 * fd = open("/dev/my_volume"); 72 * ioctl(fd, UBI_IOCVOLUP, &image_size); 73 * write(fd, buf, image_size); 74 * close(fd); 75 * 76 * Atomic eraseblock change 77 * ~~~~~~~~~~~~~~~~~~~~~~~~ 78 * 79 * Atomic eraseblock change operation is done via the %UBI_IOCEBCH IOCTL 80 * command of the corresponding UBI volume character device. A pointer to 81 * &struct ubi_leb_change_req has to be passed to the IOCTL. Then the user is 82 * expected to write the requested amount of bytes. This is similar to the 83 * "volume update" IOCTL. 84 */ 85 86 /* 87 * When a new UBI volume or UBI device is created, users may either specify the 88 * volume/device number they want to create or to let UBI automatically assign 89 * the number using these constants. 90 */ 91 #define UBI_VOL_NUM_AUTO (-1) 92 #define UBI_DEV_NUM_AUTO (-1) 93 94 /* Maximum volume name length */ 95 #define UBI_MAX_VOLUME_NAME 127 96 97 /* IOCTL commands of UBI character devices */ 98 99 #define UBI_IOC_MAGIC 'o' 100 101 /* Create an UBI volume */ 102 #define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req) 103 /* Remove an UBI volume */ 104 #define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, int32_t) 105 /* Re-size an UBI volume */ 106 #define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req) 107 108 /* IOCTL commands of the UBI control character device */ 109 110 #define UBI_CTRL_IOC_MAGIC 'o' 111 112 /* Attach an MTD device */ 113 #define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req) 114 /* Detach an MTD device */ 115 #define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, int32_t) 116 117 /* IOCTL commands of UBI volume character devices */ 118 119 #define UBI_VOL_IOC_MAGIC 'O' 120 121 /* Start UBI volume update */ 122 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, int64_t) 123 /* An eraseblock erasure command, used for debugging, disabled by default */ 124 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, int32_t) 125 /* An atomic eraseblock change command */ 126 #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, int32_t) 127 128 /* Maximum MTD device name length supported by UBI */ 129 #define MAX_UBI_MTD_NAME_LEN 127 130 131 /* 132 * UBI data type hint constants. 133 * 134 * UBI_LONGTERM: long-term data 135 * UBI_SHORTTERM: short-term data 136 * UBI_UNKNOWN: data persistence is unknown 137 * 138 * These constants are used when data is written to UBI volumes in order to 139 * help the UBI wear-leveling unit to find more appropriate physical 140 * eraseblocks. 141 */ 142 enum { 143 UBI_LONGTERM = 1, 144 UBI_SHORTTERM = 2, 145 UBI_UNKNOWN = 3, 146 }; 147 148 /* 149 * UBI volume type constants. 150 * 151 * @UBI_DYNAMIC_VOLUME: dynamic volume 152 * @UBI_STATIC_VOLUME: static volume 153 */ 154 enum { 155 UBI_DYNAMIC_VOLUME = 3, 156 UBI_STATIC_VOLUME = 4, 157 }; 158 159 /** 160 * struct ubi_attach_req - attach MTD device request. 161 * @ubi_num: UBI device number to create 162 * @mtd_num: MTD device number to attach 163 * @vid_hdr_offset: VID header offset (use defaults if %0) 164 * @padding: reserved for future, not used, has to be zeroed 165 * 166 * This data structure is used to specify MTD device UBI has to attach and the 167 * parameters it has to use. The number which should be assigned to the new UBI 168 * device is passed in @ubi_num. UBI may automatically assign the number if 169 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in 170 * @ubi_num. 171 * 172 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default 173 * offset of the VID header within physical eraseblocks. The default offset is 174 * the next min. I/O unit after the EC header. For example, it will be offset 175 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or 176 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages. 177 * 178 * But in rare cases, if this optimizes things, the VID header may be placed to 179 * a different offset. For example, the boot-loader might do things faster if the 180 * VID header sits at the end of the first 2KiB NAND page with 4 sub-pages. As 181 * the boot-loader would not normally need to read EC headers (unless it needs 182 * UBI in RW mode), it might be faster to calculate ECC. This is weird example, 183 * but it real-life example. So, in this example, @vid_hdr_offer would be 184 * 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes 185 * aligned, which is OK, as UBI is clever enough to realize this is 4th sub-page 186 * of the first page and add needed padding. 187 */ 188 struct ubi_attach_req { 189 int32_t ubi_num; 190 int32_t mtd_num; 191 int32_t vid_hdr_offset; 192 uint8_t padding[12]; 193 }; 194 195 /** 196 * struct ubi_mkvol_req - volume description data structure used in 197 * volume creation requests. 198 * @vol_id: volume number 199 * @alignment: volume alignment 200 * @bytes: volume size in bytes 201 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) 202 * @padding1: reserved for future, not used, has to be zeroed 203 * @name_len: volume name length 204 * @padding2: reserved for future, not used, has to be zeroed 205 * @name: volume name 206 * 207 * This structure is used by user-space programs when creating new volumes. The 208 * @used_bytes field is only necessary when creating static volumes. 209 * 210 * The @alignment field specifies the required alignment of the volume logical 211 * eraseblock. This means, that the size of logical eraseblocks will be aligned 212 * to this number, i.e., 213 * (UBI device logical eraseblock size) mod (@alignment) = 0. 214 * 215 * To put it differently, the logical eraseblock of this volume may be slightly 216 * shortened in order to make it properly aligned. The alignment has to be 217 * multiple of the flash minimal input/output unit, or %1 to utilize the entire 218 * available space of logical eraseblocks. 219 * 220 * The @alignment field may be useful, for example, when one wants to maintain 221 * a block device on top of an UBI volume. In this case, it is desirable to fit 222 * an integer number of blocks in logical eraseblocks of this UBI volume. With 223 * alignment it is possible to update this volume using plane UBI volume image 224 * BLOBs, without caring about how to properly align them. 225 */ 226 struct ubi_mkvol_req { 227 int32_t vol_id; 228 int32_t alignment; 229 int64_t bytes; 230 int8_t vol_type; 231 int8_t padding1; 232 int16_t name_len; 233 int8_t padding2[4]; 234 char name[UBI_MAX_VOLUME_NAME + 1]; 235 } __attribute__ ((packed)); 236 237 /** 238 * struct ubi_rsvol_req - a data structure used in volume re-size requests. 239 * @vol_id: ID of the volume to re-size 240 * @bytes: new size of the volume in bytes 241 * 242 * Re-sizing is possible for both dynamic and static volumes. But while dynamic 243 * volumes may be re-sized arbitrarily, static volumes cannot be made to be 244 * smaller then the number of bytes they bear. To arbitrarily shrink a static 245 * volume, it must be wiped out first (by means of volume update operation with 246 * zero number of bytes). 247 */ 248 struct ubi_rsvol_req { 249 int64_t bytes; 250 int32_t vol_id; 251 } __attribute__ ((packed)); 252 253 /** 254 * struct ubi_leb_change_req - a data structure used in atomic logical 255 * eraseblock change requests. 256 * @lnum: logical eraseblock number to change 257 * @bytes: how many bytes will be written to the logical eraseblock 258 * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN) 259 * @padding: reserved for future, not used, has to be zeroed 260 */ 261 struct ubi_leb_change_req { 262 int32_t lnum; 263 int32_t bytes; 264 uint8_t dtype; 265 uint8_t padding[7]; 266 } __attribute__ ((packed)); 267 268 #endif /* __UBI_USER_H__ */ 269