1 /* 2 * Copyright (c) International Business Machines Corp., 2006 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 * 6 * Author: Artem Bityutskiy (Битюцкий Артём) 7 */ 8 9 #ifndef __UBI_USER_H__ 10 #define __UBI_USER_H__ 11 12 /* 13 * UBI device creation (the same as MTD device attachment) 14 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 15 * 16 * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI 17 * control device. The caller has to properly fill and pass 18 * &struct ubi_attach_req object - UBI will attach the MTD device specified in 19 * the request and return the newly created UBI device number as the ioctl 20 * return value. 21 * 22 * UBI device deletion (the same as MTD device detachment) 23 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 24 * 25 * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI 26 * control device. 27 * 28 * UBI volume creation 29 * ~~~~~~~~~~~~~~~~~~~ 30 * 31 * UBI volumes are created via the %UBI_IOCMKVOL IOCTL command of UBI character 32 * device. A &struct ubi_mkvol_req object has to be properly filled and a 33 * pointer to it has to be passed to the IOCTL. 34 * 35 * UBI volume deletion 36 * ~~~~~~~~~~~~~~~~~~~ 37 * 38 * To delete a volume, the %UBI_IOCRMVOL IOCTL command of the UBI character 39 * device should be used. A pointer to the 32-bit volume ID hast to be passed 40 * to the IOCTL. 41 * 42 * UBI volume re-size 43 * ~~~~~~~~~~~~~~~~~~ 44 * 45 * To re-size a volume, the %UBI_IOCRSVOL IOCTL command of the UBI character 46 * device should be used. A &struct ubi_rsvol_req object has to be properly 47 * filled and a pointer to it has to be passed to the IOCTL. 48 * 49 * UBI volume update 50 * ~~~~~~~~~~~~~~~~~ 51 * 52 * Volume update should be done via the %UBI_IOCVOLUP IOCTL command of the 53 * corresponding UBI volume character device. A pointer to a 64-bit update 54 * size should be passed to the IOCTL. After this, UBI expects user to write 55 * this number of bytes to the volume character device. The update is finished 56 * when the claimed number of bytes is passed. So, the volume update sequence 57 * is something like: 58 * 59 * fd = open("/dev/my_volume"); 60 * ioctl(fd, UBI_IOCVOLUP, &image_size); 61 * write(fd, buf, image_size); 62 * close(fd); 63 * 64 * Atomic eraseblock change 65 * ~~~~~~~~~~~~~~~~~~~~~~~~ 66 * 67 * Atomic eraseblock change operation is done via the %UBI_IOCEBCH IOCTL 68 * command of the corresponding UBI volume character device. A pointer to 69 * &struct ubi_leb_change_req has to be passed to the IOCTL. Then the user is 70 * expected to write the requested amount of bytes. This is similar to the 71 * "volume update" IOCTL. 72 */ 73 74 /* 75 * When a new UBI volume or UBI device is created, users may either specify the 76 * volume/device number they want to create or to let UBI automatically assign 77 * the number using these constants. 78 */ 79 #define UBI_VOL_NUM_AUTO (-1) 80 #define UBI_DEV_NUM_AUTO (-1) 81 82 /* Maximum volume name length */ 83 #define UBI_MAX_VOLUME_NAME 127 84 85 /* IOCTL commands of UBI character devices */ 86 87 #define UBI_IOC_MAGIC 'o' 88 89 /* Create an UBI volume */ 90 #define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req) 91 /* Remove an UBI volume */ 92 #define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, int32_t) 93 /* Re-size an UBI volume */ 94 #define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req) 95 96 /* IOCTL commands of the UBI control character device */ 97 98 #define UBI_CTRL_IOC_MAGIC 'o' 99 100 /* Attach an MTD device */ 101 #define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req) 102 /* Detach an MTD device */ 103 #define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, int32_t) 104 105 /* IOCTL commands of UBI volume character devices */ 106 107 #define UBI_VOL_IOC_MAGIC 'O' 108 109 /* Start UBI volume update */ 110 #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, int64_t) 111 /* An eraseblock erasure command, used for debugging, disabled by default */ 112 #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, int32_t) 113 /* An atomic eraseblock change command */ 114 #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, int32_t) 115 116 /* Maximum MTD device name length supported by UBI */ 117 #define MAX_UBI_MTD_NAME_LEN 127 118 119 /* 120 * UBI data type hint constants. 121 * 122 * UBI_LONGTERM: long-term data 123 * UBI_SHORTTERM: short-term data 124 * UBI_UNKNOWN: data persistence is unknown 125 * 126 * These constants are used when data is written to UBI volumes in order to 127 * help the UBI wear-leveling unit to find more appropriate physical 128 * eraseblocks. 129 */ 130 enum { 131 UBI_LONGTERM = 1, 132 UBI_SHORTTERM = 2, 133 UBI_UNKNOWN = 3, 134 }; 135 136 /* 137 * UBI volume type constants. 138 * 139 * @UBI_DYNAMIC_VOLUME: dynamic volume 140 * @UBI_STATIC_VOLUME: static volume 141 */ 142 enum { 143 UBI_DYNAMIC_VOLUME = 3, 144 UBI_STATIC_VOLUME = 4, 145 }; 146 147 /** 148 * struct ubi_attach_req - attach MTD device request. 149 * @ubi_num: UBI device number to create 150 * @mtd_num: MTD device number to attach 151 * @vid_hdr_offset: VID header offset (use defaults if %0) 152 * @padding: reserved for future, not used, has to be zeroed 153 * 154 * This data structure is used to specify MTD device UBI has to attach and the 155 * parameters it has to use. The number which should be assigned to the new UBI 156 * device is passed in @ubi_num. UBI may automatically assign the number if 157 * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in 158 * @ubi_num. 159 * 160 * Most applications should pass %0 in @vid_hdr_offset to make UBI use default 161 * offset of the VID header within physical eraseblocks. The default offset is 162 * the next min. I/O unit after the EC header. For example, it will be offset 163 * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or 164 * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages. 165 * 166 * But in rare cases, if this optimizes things, the VID header may be placed to 167 * a different offset. For example, the boot-loader might do things faster if the 168 * VID header sits at the end of the first 2KiB NAND page with 4 sub-pages. As 169 * the boot-loader would not normally need to read EC headers (unless it needs 170 * UBI in RW mode), it might be faster to calculate ECC. This is weird example, 171 * but it real-life example. So, in this example, @vid_hdr_offer would be 172 * 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes 173 * aligned, which is OK, as UBI is clever enough to realize this is 4th sub-page 174 * of the first page and add needed padding. 175 */ 176 struct ubi_attach_req { 177 int32_t ubi_num; 178 int32_t mtd_num; 179 int32_t vid_hdr_offset; 180 uint8_t padding[12]; 181 }; 182 183 /** 184 * struct ubi_mkvol_req - volume description data structure used in 185 * volume creation requests. 186 * @vol_id: volume number 187 * @alignment: volume alignment 188 * @bytes: volume size in bytes 189 * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) 190 * @padding1: reserved for future, not used, has to be zeroed 191 * @name_len: volume name length 192 * @padding2: reserved for future, not used, has to be zeroed 193 * @name: volume name 194 * 195 * This structure is used by user-space programs when creating new volumes. The 196 * @used_bytes field is only necessary when creating static volumes. 197 * 198 * The @alignment field specifies the required alignment of the volume logical 199 * eraseblock. This means, that the size of logical eraseblocks will be aligned 200 * to this number, i.e., 201 * (UBI device logical eraseblock size) mod (@alignment) = 0. 202 * 203 * To put it differently, the logical eraseblock of this volume may be slightly 204 * shortened in order to make it properly aligned. The alignment has to be 205 * multiple of the flash minimal input/output unit, or %1 to utilize the entire 206 * available space of logical eraseblocks. 207 * 208 * The @alignment field may be useful, for example, when one wants to maintain 209 * a block device on top of an UBI volume. In this case, it is desirable to fit 210 * an integer number of blocks in logical eraseblocks of this UBI volume. With 211 * alignment it is possible to update this volume using plane UBI volume image 212 * BLOBs, without caring about how to properly align them. 213 */ 214 struct ubi_mkvol_req { 215 int32_t vol_id; 216 int32_t alignment; 217 int64_t bytes; 218 int8_t vol_type; 219 int8_t padding1; 220 int16_t name_len; 221 int8_t padding2[4]; 222 char name[UBI_MAX_VOLUME_NAME + 1]; 223 } __attribute__ ((packed)); 224 225 /** 226 * struct ubi_rsvol_req - a data structure used in volume re-size requests. 227 * @vol_id: ID of the volume to re-size 228 * @bytes: new size of the volume in bytes 229 * 230 * Re-sizing is possible for both dynamic and static volumes. But while dynamic 231 * volumes may be re-sized arbitrarily, static volumes cannot be made to be 232 * smaller then the number of bytes they bear. To arbitrarily shrink a static 233 * volume, it must be wiped out first (by means of volume update operation with 234 * zero number of bytes). 235 */ 236 struct ubi_rsvol_req { 237 int64_t bytes; 238 int32_t vol_id; 239 } __attribute__ ((packed)); 240 241 /** 242 * struct ubi_leb_change_req - a data structure used in atomic logical 243 * eraseblock change requests. 244 * @lnum: logical eraseblock number to change 245 * @bytes: how many bytes will be written to the logical eraseblock 246 * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN) 247 * @padding: reserved for future, not used, has to be zeroed 248 */ 249 struct ubi_leb_change_req { 250 int32_t lnum; 251 int32_t bytes; 252 uint8_t dtype; 253 uint8_t padding[7]; 254 } __attribute__ ((packed)); 255 256 #endif /* __UBI_USER_H__ */ 257