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Diffstat (limited to 'include/mtd')
| -rw-r--r-- | include/mtd/ubi-user.h | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/include/mtd/ubi-user.h b/include/mtd/ubi-user.h new file mode 100644 index 0000000..a7421f1 --- /dev/null +++ b/include/mtd/ubi-user.h @@ -0,0 +1,268 @@ +/* + * Copyright (c) International Business Machines Corp., 2006 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Artem Bityutskiy (Битюцкий Артём) + */ + +#ifndef __UBI_USER_H__ +#define __UBI_USER_H__ + +/* + * UBI device creation (the same as MTD device attachment) + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI + * control device. The caller has to properly fill and pass + * &struct ubi_attach_req object - UBI will attach the MTD device specified in + * the request and return the newly created UBI device number as the ioctl + * return value. + * + * UBI device deletion (the same as MTD device detachment) + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI + * control device. + * + * UBI volume creation + * ~~~~~~~~~~~~~~~~~~~ + * + * UBI volumes are created via the %UBI_IOCMKVOL IOCTL command of UBI character + * device. A &struct ubi_mkvol_req object has to be properly filled and a + * pointer to it has to be passed to the IOCTL. + * + * UBI volume deletion + * ~~~~~~~~~~~~~~~~~~~ + * + * To delete a volume, the %UBI_IOCRMVOL IOCTL command of the UBI character + * device should be used. A pointer to the 32-bit volume ID hast to be passed + * to the IOCTL. + * + * UBI volume re-size + * ~~~~~~~~~~~~~~~~~~ + * + * To re-size a volume, the %UBI_IOCRSVOL IOCTL command of the UBI character + * device should be used. A &struct ubi_rsvol_req object has to be properly + * filled and a pointer to it has to be passed to the IOCTL. + * + * UBI volume update + * ~~~~~~~~~~~~~~~~~ + * + * Volume update should be done via the %UBI_IOCVOLUP IOCTL command of the + * corresponding UBI volume character device. A pointer to a 64-bit update + * size should be passed to the IOCTL. After this, UBI expects user to write + * this number of bytes to the volume character device. The update is finished + * when the claimed number of bytes is passed. So, the volume update sequence + * is something like: + * + * fd = open("/dev/my_volume"); + * ioctl(fd, UBI_IOCVOLUP, &image_size); + * write(fd, buf, image_size); + * close(fd); + * + * Atomic eraseblock change + * ~~~~~~~~~~~~~~~~~~~~~~~~ + * + * Atomic eraseblock change operation is done via the %UBI_IOCEBCH IOCTL + * command of the corresponding UBI volume character device. A pointer to + * &struct ubi_leb_change_req has to be passed to the IOCTL. Then the user is + * expected to write the requested amount of bytes. This is similar to the + * "volume update" IOCTL. + */ + +/* + * When a new UBI volume or UBI device is created, users may either specify the + * volume/device number they want to create or to let UBI automatically assign + * the number using these constants. + */ +#define UBI_VOL_NUM_AUTO (-1) +#define UBI_DEV_NUM_AUTO (-1) + +/* Maximum volume name length */ +#define UBI_MAX_VOLUME_NAME 127 + +/* IOCTL commands of UBI character devices */ + +#define UBI_IOC_MAGIC 'o' + +/* Create an UBI volume */ +#define UBI_IOCMKVOL _IOW(UBI_IOC_MAGIC, 0, struct ubi_mkvol_req) +/* Remove an UBI volume */ +#define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, int32_t) +/* Re-size an UBI volume */ +#define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req) + +/* IOCTL commands of the UBI control character device */ + +#define UBI_CTRL_IOC_MAGIC 'o' + +/* Attach an MTD device */ +#define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req) +/* Detach an MTD device */ +#define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, int32_t) + +/* IOCTL commands of UBI volume character devices */ + +#define UBI_VOL_IOC_MAGIC 'O' + +/* Start UBI volume update */ +#define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, int64_t) +/* An eraseblock erasure command, used for debugging, disabled by default */ +#define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, int32_t) +/* An atomic eraseblock change command */ +#define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, int32_t) + +/* Maximum MTD device name length supported by UBI */ +#define MAX_UBI_MTD_NAME_LEN 127 + +/* + * UBI data type hint constants. + * + * UBI_LONGTERM: long-term data + * UBI_SHORTTERM: short-term data + * UBI_UNKNOWN: data persistence is unknown + * + * These constants are used when data is written to UBI volumes in order to + * help the UBI wear-leveling unit to find more appropriate physical + * eraseblocks. + */ +enum { + UBI_LONGTERM = 1, + UBI_SHORTTERM = 2, + UBI_UNKNOWN = 3, +}; + +/* + * UBI volume type constants. + * + * @UBI_DYNAMIC_VOLUME: dynamic volume + * @UBI_STATIC_VOLUME: static volume + */ +enum { + UBI_DYNAMIC_VOLUME = 3, + UBI_STATIC_VOLUME = 4, +}; + +/** + * struct ubi_attach_req - attach MTD device request. + * @ubi_num: UBI device number to create + * @mtd_num: MTD device number to attach + * @vid_hdr_offset: VID header offset (use defaults if %0) + * @padding: reserved for future, not used, has to be zeroed + * + * This data structure is used to specify MTD device UBI has to attach and the + * parameters it has to use. The number which should be assigned to the new UBI + * device is passed in @ubi_num. UBI may automatically assign the number if + * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in + * @ubi_num. + * + * Most applications should pass %0 in @vid_hdr_offset to make UBI use default + * offset of the VID header within physical eraseblocks. The default offset is + * the next min. I/O unit after the EC header. For example, it will be offset + * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or + * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages. + * + * But in rare cases, if this optimizes things, the VID header may be placed to + * a different offset. For example, the boot-loader might do things faster if the + * VID header sits at the end of the first 2KiB NAND page with 4 sub-pages. As + * the boot-loader would not normally need to read EC headers (unless it needs + * UBI in RW mode), it might be faster to calculate ECC. This is weird example, + * but it real-life example. So, in this example, @vid_hdr_offer would be + * 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes + * aligned, which is OK, as UBI is clever enough to realize this is 4th sub-page + * of the first page and add needed padding. + */ +struct ubi_attach_req { + int32_t ubi_num; + int32_t mtd_num; + int32_t vid_hdr_offset; + uint8_t padding[12]; +}; + +/** + * struct ubi_mkvol_req - volume description data structure used in + * volume creation requests. + * @vol_id: volume number + * @alignment: volume alignment + * @bytes: volume size in bytes + * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME) + * @padding1: reserved for future, not used, has to be zeroed + * @name_len: volume name length + * @padding2: reserved for future, not used, has to be zeroed + * @name: volume name + * + * This structure is used by user-space programs when creating new volumes. The + * @used_bytes field is only necessary when creating static volumes. + * + * The @alignment field specifies the required alignment of the volume logical + * eraseblock. This means, that the size of logical eraseblocks will be aligned + * to this number, i.e., + * (UBI device logical eraseblock size) mod (@alignment) = 0. + * + * To put it differently, the logical eraseblock of this volume may be slightly + * shortened in order to make it properly aligned. The alignment has to be + * multiple of the flash minimal input/output unit, or %1 to utilize the entire + * available space of logical eraseblocks. + * + * The @alignment field may be useful, for example, when one wants to maintain + * a block device on top of an UBI volume. In this case, it is desirable to fit + * an integer number of blocks in logical eraseblocks of this UBI volume. With + * alignment it is possible to update this volume using plane UBI volume image + * BLOBs, without caring about how to properly align them. + */ +struct ubi_mkvol_req { + int32_t vol_id; + int32_t alignment; + int64_t bytes; + int8_t vol_type; + int8_t padding1; + int16_t name_len; + int8_t padding2[4]; + char name[UBI_MAX_VOLUME_NAME + 1]; +} __attribute__ ((packed)); + +/** + * struct ubi_rsvol_req - a data structure used in volume re-size requests. + * @vol_id: ID of the volume to re-size + * @bytes: new size of the volume in bytes + * + * Re-sizing is possible for both dynamic and static volumes. But while dynamic + * volumes may be re-sized arbitrarily, static volumes cannot be made to be + * smaller then the number of bytes they bear. To arbitrarily shrink a static + * volume, it must be wiped out first (by means of volume update operation with + * zero number of bytes). + */ +struct ubi_rsvol_req { + int64_t bytes; + int32_t vol_id; +} __attribute__ ((packed)); + +/** + * struct ubi_leb_change_req - a data structure used in atomic logical + * eraseblock change requests. + * @lnum: logical eraseblock number to change + * @bytes: how many bytes will be written to the logical eraseblock + * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN) + * @padding: reserved for future, not used, has to be zeroed + */ +struct ubi_leb_change_req { + int32_t lnum; + int32_t bytes; + uint8_t dtype; + uint8_t padding[7]; +} __attribute__ ((packed)); + +#endif /* __UBI_USER_H__ */ |