diff options
Diffstat (limited to 'include/mtd/ubi-user.h')
| -rw-r--r-- | include/mtd/ubi-user.h | 127 |
1 files changed, 117 insertions, 10 deletions
diff --git a/include/mtd/ubi-user.h b/include/mtd/ubi-user.h index fe06ded0e6b8..a7421f130cc0 100644 --- a/include/mtd/ubi-user.h +++ b/include/mtd/ubi-user.h @@ -22,6 +22,21 @@ #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 * ~~~~~~~~~~~~~~~~~~~ * @@ -48,7 +63,7 @@ * * 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 + * 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: @@ -57,14 +72,24 @@ * 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 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. + * 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 @@ -80,6 +105,15 @@ /* 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' @@ -88,6 +122,28 @@ #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. @@ -97,22 +153,58 @@ */ enum { UBI_DYNAMIC_VOLUME = 3, - UBI_STATIC_VOLUME = 4 + 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. + * 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 + * @padding1: reserved for future, not used, has to be zeroed * @name_len: volume name length - * @padding2: reserved for future, not used + * @padding2: reserved for future, not used, has to be zeroed * @name: volume name * - * This structure is used by userspace programs when creating new volumes. The + * 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 @@ -139,7 +231,7 @@ struct ubi_mkvol_req { int8_t padding1; int16_t name_len; int8_t padding2[4]; - char name[UBI_MAX_VOLUME_NAME+1]; + char name[UBI_MAX_VOLUME_NAME + 1]; } __attribute__ ((packed)); /** @@ -158,4 +250,19 @@ struct ubi_rsvol_req { 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__ */ |