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Diffstat (limited to 'include/uapi/mtd/ubi-user.h')
| -rw-r--r-- | include/uapi/mtd/ubi-user.h | 420 |
1 files changed, 420 insertions, 0 deletions
diff --git a/include/uapi/mtd/ubi-user.h b/include/uapi/mtd/ubi-user.h new file mode 100644 index 000000000000..53cae1e11e57 --- /dev/null +++ b/include/uapi/mtd/ubi-user.h @@ -0,0 +1,420 @@ +/* + * Copyright © 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__ + +#include <linux/types.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 volumes re-name + * ~~~~~~~~~~~~~~~~~~~ + * + * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command + * of the UBI character device should be used. A &struct ubi_rnvol_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); + * + * Logical eraseblock erase + * ~~~~~~~~~~~~~~~~~~~~~~~~ + * + * To erase a logical eraseblock, the %UBI_IOCEBER ioctl command of the + * corresponding UBI volume character device should be used. This command + * unmaps the requested logical eraseblock, makes sure the corresponding + * physical eraseblock is successfully erased, and returns. + * + * Atomic logical eraseblock change + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * Atomic logical eraseblock change operation is called using the %UBI_IOCEBCH + * ioctl command of the corresponding UBI volume character device. A pointer to + * a &struct ubi_leb_change_req object has to be passed to the ioctl. Then the + * user is expected to write the requested amount of bytes (similarly to what + * should be done in case of the "volume update" ioctl). + * + * Logical eraseblock map + * ~~~~~~~~~~~~~~~~~~~~~ + * + * To map a logical eraseblock to a physical eraseblock, the %UBI_IOCEBMAP + * ioctl command should be used. A pointer to a &struct ubi_map_req object is + * expected to be passed. The ioctl maps the requested logical eraseblock to + * a physical eraseblock and returns. Only non-mapped logical eraseblocks can + * be mapped. If the logical eraseblock specified in the request is already + * mapped to a physical eraseblock, the ioctl fails and returns error. + * + * Logical eraseblock unmap + * ~~~~~~~~~~~~~~~~~~~~~~~~ + * + * To unmap a logical eraseblock to a physical eraseblock, the %UBI_IOCEBUNMAP + * ioctl command should be used. The ioctl unmaps the logical eraseblocks, + * schedules corresponding physical eraseblock for erasure, and returns. Unlike + * the "LEB erase" command, it does not wait for the physical eraseblock being + * erased. Note, the side effect of this is that if an unclean reboot happens + * after the unmap ioctl returns, you may find the LEB mapped again to the same + * physical eraseblock after the UBI is run again. + * + * Check if logical eraseblock is mapped + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * To check if a logical eraseblock is mapped to a physical eraseblock, the + * %UBI_IOCEBISMAP ioctl command should be used. It returns %0 if the LEB is + * not mapped, and %1 if it is mapped. + * + * Set an UBI volume property + * ~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * To set an UBI volume property the %UBI_IOCSETPROP ioctl command should be + * used. A pointer to a &struct ubi_set_vol_prop_req object is expected to be + * passed. The object describes which property should be set, and to which value + * it should be set. + */ + +/* + * 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, __s32) +/* Re-size an UBI volume */ +#define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req) +/* Re-name volumes */ +#define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_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, __s32) + +/* 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, __s64) +/* LEB erasure command, used for debugging, disabled by default */ +#define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, __s32) +/* Atomic LEB change command */ +#define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, __s32) +/* Map LEB command */ +#define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req) +/* Unmap LEB command */ +#define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, __s32) +/* Check if LEB is mapped command */ +#define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, __s32) +/* Set an UBI volume property */ +#define UBI_IOCSETVOLPROP _IOW(UBI_VOL_IOC_MAGIC, 6, \ + struct ubi_set_vol_prop_req) + +/* Maximum MTD device name length supported by UBI */ +#define MAX_UBI_MTD_NAME_LEN 127 + +/* Maximum amount of UBI volumes that can be re-named at one go */ +#define UBI_MAX_RNVOL 32 + +/* + * UBI volume type constants. + * + * @UBI_DYNAMIC_VOLUME: dynamic volume + * @UBI_STATIC_VOLUME: static volume + */ +enum { + UBI_DYNAMIC_VOLUME = 3, + UBI_STATIC_VOLUME = 4, +}; + +/* + * UBI set volume property ioctl constants. + * + * @UBI_VOL_PROP_DIRECT_WRITE: allow (any non-zero value) or disallow (value 0) + * user to directly write and erase individual + * eraseblocks on dynamic volumes + */ +enum { + UBI_VOL_PROP_DIRECT_WRITE = 1, +}; + +/** + * 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) + * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs + * @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. + * + * The @max_beb_per1024 is the maximum amount of bad PEBs UBI expects on the + * UBI device per 1024 eraseblocks. This value is often given in an other form + * in the NAND datasheet (min NVB i.e. minimal number of valid blocks). The + * maximum expected bad eraseblocks per 1024 is then: + * 1024 * (1 - MinNVB / MaxNVB) + * Which gives 20 for most NAND devices. This limit is used in order to derive + * amount of eraseblock UBI reserves for handling new bad blocks. If the device + * has more bad eraseblocks than this limit, UBI does not reserve any physical + * eraseblocks for new bad eraseblocks, but attempts to use available + * eraseblocks (if any). The accepted range is 0-768. If 0 is given, the + * default kernel value of %CONFIG_MTD_UBI_BEB_LIMIT will be used. + */ +struct ubi_attach_req { + __s32 ubi_num; + __s32 mtd_num; + __s32 vid_hdr_offset; + __s16 max_beb_per1024; + __s8 padding[10]; +}; + +/** + * 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 { + __s32 vol_id; + __s32 alignment; + __s64 bytes; + __s8 vol_type; + __s8 padding1; + __s16 name_len; + __s8 padding2[4]; + char name[UBI_MAX_VOLUME_NAME + 1]; +} __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 than 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 { + __s64 bytes; + __s32 vol_id; +} __packed; + +/** + * struct ubi_rnvol_req - volumes re-name request. + * @count: count of volumes to re-name + * @padding1: reserved for future, not used, has to be zeroed + * @vol_id: ID of the volume to re-name + * @name_len: name length + * @padding2: reserved for future, not used, has to be zeroed + * @name: new volume name + * + * UBI allows to re-name up to %32 volumes at one go. The count of volumes to + * re-name is specified in the @count field. The ID of the volumes to re-name + * and the new names are specified in the @vol_id and @name fields. + * + * The UBI volume re-name operation is atomic, which means that should power cut + * happen, the volumes will have either old name or new name. So the possible + * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes + * A and B one may create temporary volumes %A1 and %B1 with the new contents, + * then atomically re-name A1->A and B1->B, in which case old %A and %B will + * be removed. + * + * If it is not desirable to remove old A and B, the re-name request has to + * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1 + * become A and B, and old A and B will become A1 and B1. + * + * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1 + * and B1 become A and B, and old A and B become X and Y. + * + * In other words, in case of re-naming into an existing volume name, the + * existing volume is removed, unless it is re-named as well at the same + * re-name request. + */ +struct ubi_rnvol_req { + __s32 count; + __s8 padding1[12]; + struct { + __s32 vol_id; + __s16 name_len; + __s8 padding2[2]; + char name[UBI_MAX_VOLUME_NAME + 1]; + } ents[UBI_MAX_RNVOL]; +} __packed; + +/** + * struct ubi_leb_change_req - a data structure used in atomic LEB change + * requests. + * @lnum: logical eraseblock number to change + * @bytes: how many bytes will be written to the logical eraseblock + * @dtype: pass "3" for better compatibility with old kernels + * @padding: reserved for future, not used, has to be zeroed + * + * The @dtype field used to inform UBI about what kind of data will be written + * to the LEB: long term (value 1), short term (value 2), unknown (value 3). + * UBI tried to pick a PEB with lower erase counter for short term data and a + * PEB with higher erase counter for long term data. But this was not really + * used because users usually do not know this and could easily mislead UBI. We + * removed this feature in May 2012. UBI currently just ignores the @dtype + * field. But for better compatibility with older kernels it is recommended to + * set @dtype to 3 (unknown). + */ +struct ubi_leb_change_req { + __s32 lnum; + __s32 bytes; + __s8 dtype; /* obsolete, do not use! */ + __s8 padding[7]; +} __packed; + +/** + * struct ubi_map_req - a data structure used in map LEB requests. + * @dtype: pass "3" for better compatibility with old kernels + * @lnum: logical eraseblock number to unmap + * @padding: reserved for future, not used, has to be zeroed + */ +struct ubi_map_req { + __s32 lnum; + __s8 dtype; /* obsolete, do not use! */ + __s8 padding[3]; +} __packed; + + +/** + * struct ubi_set_vol_prop_req - a data structure used to set an UBI volume + * property. + * @property: property to set (%UBI_VOL_PROP_DIRECT_WRITE) + * @padding: reserved for future, not used, has to be zeroed + * @value: value to set + */ +struct ubi_set_vol_prop_req { + __u8 property; + __u8 padding[7]; + __u64 value; +} __packed; + +#endif /* __UBI_USER_H__ */ |
