diff options
| -rw-r--r-- | include/mtd/ubi-user.h | 88 |
1 files changed, 62 insertions, 26 deletions
diff --git a/include/mtd/ubi-user.h b/include/mtd/ubi-user.h index 5828d7879199..82113e160a2c 100644 --- a/include/mtd/ubi-user.h +++ b/include/mtd/ubi-user.h @@ -40,37 +40,37 @@ * UBI volume creation * ~~~~~~~~~~~~~~~~~~~ * - * UBI volumes are created via the %UBI_IOCMKVOL IOCTL command of UBI character + * 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. + * 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 + * 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. + * to the ioctl. * * UBI volume re-size * ~~~~~~~~~~~~~~~~~~ * - * To re-size a volume, the %UBI_IOCRSVOL IOCTL command of the UBI character + * 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. + * 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. + * 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 + * 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 + * 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: @@ -80,14 +80,50 @@ * write(fd, buf, image_size); * close(fd); * - * Atomic eraseblock change + * Logical eraseblock erase * ~~~~~~~~~~~~~~~~~~~~~~~~ * - * 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. + * 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. */ /* @@ -101,7 +137,7 @@ /* Maximum volume name length */ #define UBI_MAX_VOLUME_NAME 127 -/* IOCTL commands of UBI character devices */ +/* ioctl commands of UBI character devices */ #define UBI_IOC_MAGIC 'o' @@ -114,7 +150,7 @@ /* Re-name volumes */ #define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req) -/* IOCTL commands of the UBI control character device */ +/* ioctl commands of the UBI control character device */ #define UBI_CTRL_IOC_MAGIC 'o' @@ -123,21 +159,21 @@ /* Detach an MTD device */ #define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, int32_t) -/* IOCTL commands of UBI volume character devices */ +/* 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 */ +/* LEB erasure command, used for debugging, disabled by default */ #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, int32_t) -/* An atomic eraseblock change command */ +/* Atomic LEB change command */ #define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, int32_t) -/* Map an eraseblock, used for debugging, disabled by default */ +/* Map LEB command */ #define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req) -/* Unmap an eraseblock, used for debugging, disabled by default */ +/* Unmap LEB command */ #define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, int32_t) -/* Check if an eraseblock is mapped, used for debugging, disabled by default */ +/* Check if LEB is mapped command */ #define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, int32_t) /* Maximum MTD device name length supported by UBI */ @@ -311,8 +347,8 @@ struct ubi_rnvol_req { } __attribute__ ((packed)); /** - * struct ubi_leb_change_req - a data structure used in atomic logical - * eraseblock change requests. + * 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: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN) @@ -326,7 +362,7 @@ struct ubi_leb_change_req { } __attribute__ ((packed)); /** - * struct ubi_map_req - a data structure used in map eraseblock requests. + * struct ubi_map_req - a data structure used in map LEB requests. * @lnum: logical eraseblock number to unmap * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN) * @padding: reserved for future, not used, has to be zeroed |