linux-sg2042/include/mtd/ubi-user.h

162 lines
5.5 KiB
C

/*
* 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 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 then, 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);
*/
/*
* When a new volume is created, users may either specify the volume number they
* want to create or to let UBI automatically assign a volume number using this
* constant.
*/
#define UBI_VOL_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 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)
/*
* 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_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
* @name_len: volume name length
* @padding2: reserved for future, not used
* @name: volume name
*
* This structure is used by userspace 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));
#endif /* __UBI_USER_H__ */