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-rw-r--r--include/mtd/ubi-header.h166
1 files changed, 84 insertions, 82 deletions
diff --git a/include/mtd/ubi-header.h b/include/mtd/ubi-header.h
index c003d98..69d5d7e 100644
--- a/include/mtd/ubi-header.h
+++ b/include/mtd/ubi-header.h
@@ -15,7 +15,7 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
- * Authors: Artem B. Bityutskiy
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
* Thomas Gleixner
* Frank Haverkamp
* Oliver Lohmann
@@ -58,6 +58,43 @@ enum {
};
/*
+ * Volume flags used in the volume table record.
+ *
+ * @UBI_VTBL_AUTORESIZE_FLG: auto-resize this volume
+ *
+ * %UBI_VTBL_AUTORESIZE_FLG flag can be set only for one volume in the volume
+ * table. UBI automatically re-sizes the volume which has this flag and makes
+ * the volume to be of largest possible size. This means that if after the
+ * initialization UBI finds out that there are available physical eraseblocks
+ * present on the device, it automatically appends all of them to the volume
+ * (the physical eraseblocks reserved for bad eraseblocks handling and other
+ * reserved physical eraseblocks are not taken). So, if there is a volume with
+ * the %UBI_VTBL_AUTORESIZE_FLG flag set, the amount of available logical
+ * eraseblocks will be zero after UBI is loaded, because all of them will be
+ * reserved for this volume. Note, the %UBI_VTBL_AUTORESIZE_FLG bit is cleared
+ * after the volume had been initialized.
+ *
+ * The auto-resize feature is useful for device production purposes. For
+ * example, different NAND flash chips may have different amount of initial bad
+ * eraseblocks, depending of particular chip instance. Manufacturers of NAND
+ * chips usually guarantee that the amount of initial bad eraseblocks does not
+ * exceed certain percent, e.g. 2%. When one creates an UBI image which will be
+ * flashed to the end devices in production, he does not know the exact amount
+ * of good physical eraseblocks the NAND chip on the device will have, but this
+ * number is required to calculate the volume sized and put them to the volume
+ * table of the UBI image. In this case, one of the volumes (e.g., the one
+ * which will store the root file system) is marked as "auto-resizable", and
+ * UBI will adjust its size on the first boot if needed.
+ *
+ * Note, first UBI reserves some amount of physical eraseblocks for bad
+ * eraseblock handling, and then re-sizes the volume, not vice-versa. This
+ * means that the pool of reserved physical eraseblocks will always be present.
+ */
+enum {
+ UBI_VTBL_AUTORESIZE_FLG = 0x01,
+};
+
+/*
* Compatibility constants used by internal volumes.
*
* @UBI_COMPAT_DELETE: delete this internal volume before anything is written
@@ -74,42 +111,13 @@ enum {
UBI_COMPAT_REJECT = 5
};
-/*
- * ubi16_t/ubi32_t/ubi64_t - 16, 32, and 64-bit integers used in UBI on-flash
- * data structures.
- */
-typedef struct {
- uint16_t int16;
-} __attribute__ ((packed)) ubi16_t;
-
-typedef struct {
- uint32_t int32;
-} __attribute__ ((packed)) ubi32_t;
-
-typedef struct {
- uint64_t int64;
-} __attribute__ ((packed)) ubi64_t;
-
-/*
- * In this implementation of UBI uses the big-endian format for on-flash
- * integers. The below are the corresponding conversion macros.
- */
-#define cpu_to_ubi16(x) ((ubi16_t){__cpu_to_be16(x)})
-#define ubi16_to_cpu(x) ((uint16_t)__be16_to_cpu((x).int16))
-
-#define cpu_to_ubi32(x) ((ubi32_t){__cpu_to_be32(x)})
-#define ubi32_to_cpu(x) ((uint32_t)__be32_to_cpu((x).int32))
-
-#define cpu_to_ubi64(x) ((ubi64_t){__cpu_to_be64(x)})
-#define ubi64_to_cpu(x) ((uint64_t)__be64_to_cpu((x).int64))
-
/* Sizes of UBI headers */
#define UBI_EC_HDR_SIZE sizeof(struct ubi_ec_hdr)
#define UBI_VID_HDR_SIZE sizeof(struct ubi_vid_hdr)
/* Sizes of UBI headers without the ending CRC */
-#define UBI_EC_HDR_SIZE_CRC (UBI_EC_HDR_SIZE - sizeof(ubi32_t))
-#define UBI_VID_HDR_SIZE_CRC (UBI_VID_HDR_SIZE - sizeof(ubi32_t))
+#define UBI_EC_HDR_SIZE_CRC (UBI_EC_HDR_SIZE - sizeof(__be32))
+#define UBI_VID_HDR_SIZE_CRC (UBI_VID_HDR_SIZE - sizeof(__be32))
/**
* struct ubi_ec_hdr - UBI erase counter header.
@@ -137,14 +145,14 @@ typedef struct {
* eraseblocks.
*/
struct ubi_ec_hdr {
- ubi32_t magic;
- uint8_t version;
- uint8_t padding1[3];
- ubi64_t ec; /* Warning: the current limit is 31-bit anyway! */
- ubi32_t vid_hdr_offset;
- ubi32_t data_offset;
- uint8_t padding2[36];
- ubi32_t hdr_crc;
+ __be32 magic;
+ __u8 version;
+ __u8 padding1[3];
+ __be64 ec; /* Warning: the current limit is 31-bit anyway! */
+ __be32 vid_hdr_offset;
+ __be32 data_offset;
+ __u8 padding2[36];
+ __be32 hdr_crc;
} __attribute__ ((packed));
/**
@@ -262,22 +270,22 @@ struct ubi_ec_hdr {
* software (say, cramfs) on top of the UBI volume.
*/
struct ubi_vid_hdr {
- ubi32_t magic;
- uint8_t version;
- uint8_t vol_type;
- uint8_t copy_flag;
- uint8_t compat;
- ubi32_t vol_id;
- ubi32_t lnum;
- ubi32_t leb_ver; /* obsolete, to be removed, don't use */
- ubi32_t data_size;
- ubi32_t used_ebs;
- ubi32_t data_pad;
- ubi32_t data_crc;
- uint8_t padding1[4];
- ubi64_t sqnum;
- uint8_t padding2[12];
- ubi32_t hdr_crc;
+ __be32 magic;
+ __u8 version;
+ __u8 vol_type;
+ __u8 copy_flag;
+ __u8 compat;
+ __be32 vol_id;
+ __be32 lnum;
+ __be32 leb_ver; /* obsolete, to be removed, don't use */
+ __be32 data_size;
+ __be32 used_ebs;
+ __be32 data_pad;
+ __be32 data_crc;
+ __u8 padding1[4];
+ __be64 sqnum;
+ __u8 padding2[12];
+ __be32 hdr_crc;
} __attribute__ ((packed));
/* Internal UBI volumes count */
@@ -289,19 +297,11 @@ struct ubi_vid_hdr {
*/
#define UBI_INTERNAL_VOL_START (0x7FFFFFFF - 4096)
-/*
- * IDs of internal UBI volumes.
- *
- * %UBI_LAYOUT_VOL_ID: layout volume ID
- */
-enum {
- UBI_LAYOUT_VOL_ID = UBI_INTERNAL_VOL_START,
-};
-
/* The layout volume contains the volume table */
+#define UBI_LAYOUT_VOL_ID UBI_INTERNAL_VOL_START
#define UBI_LAYOUT_VOLUME_EBS 2
-#define UBI_LAYOUT_VOLUME_NAME "The layout volume"
+#define UBI_LAYOUT_VOLUME_NAME "layout volume"
#define UBI_LAYOUT_VOLUME_COMPAT UBI_COMPAT_REJECT
/* The maximum number of volumes per one UBI device */
@@ -311,13 +311,13 @@ enum {
#define UBI_VOL_NAME_MAX 127
/* Size of the volume table record */
-#define UBI_VTBL_RECORD_SIZE sizeof(struct ubi_vol_tbl_record)
+#define UBI_VTBL_RECORD_SIZE sizeof(struct ubi_vtbl_record)
/* Size of the volume table record without the ending CRC */
-#define UBI_VTBL_RECORD_SIZE_CRC (UBI_VTBL_RECORD_SIZE - sizeof(ubi32_t))
+#define UBI_VTBL_RECORD_SIZE_CRC (UBI_VTBL_RECORD_SIZE - sizeof(__be32))
/**
- * struct ubi_vol_tbl_record - a record in the volume table.
+ * struct ubi_vtbl_record - a record in the volume table.
* @reserved_pebs: how many physical eraseblocks are reserved for this volume
* @alignment: volume alignment
* @data_pad: how many bytes are unused at the end of the each physical
@@ -326,19 +326,20 @@ enum {
* @upd_marker: if volume update was started but not finished
* @name_len: volume name length
* @name: the volume name
- * @padding2: reserved, zeroes
+ * @flags: volume flags (%UBI_VTBL_AUTORESIZE_FLG)
+ * @padding: reserved, zeroes
* @crc: a CRC32 checksum of the record
*
* The volume table records are stored in the volume table, which is stored in
* the layout volume. The layout volume consists of 2 logical eraseblock, each
* of which contains a copy of the volume table (i.e., the volume table is
- * duplicated). The volume table is an array of &struct ubi_vol_tbl_record
+ * duplicated). The volume table is an array of &struct ubi_vtbl_record
* objects indexed by the volume ID.
*
* If the size of the logical eraseblock is large enough to fit
* %UBI_MAX_VOLUMES records, the volume table contains %UBI_MAX_VOLUMES
* records. Otherwise, it contains as many records as it can fit (i.e., size of
- * logical eraseblock divided by sizeof(struct ubi_vol_tbl_record)).
+ * logical eraseblock divided by sizeof(struct ubi_vtbl_record)).
*
* The @upd_marker flag is used to implement volume update. It is set to %1
* before update and set to %0 after the update. So if the update operation was
@@ -353,16 +354,17 @@ enum {
*
* Empty records contain all zeroes and the CRC checksum of those zeroes.
*/
-struct ubi_vol_tbl_record {
- ubi32_t reserved_pebs;
- ubi32_t alignment;
- ubi32_t data_pad;
- uint8_t vol_type;
- uint8_t upd_marker;
- ubi16_t name_len;
- uint8_t name[UBI_VOL_NAME_MAX+1];
- uint8_t padding2[24];
- ubi32_t crc;
+struct ubi_vtbl_record {
+ __be32 reserved_pebs;
+ __be32 alignment;
+ __be32 data_pad;
+ __u8 vol_type;
+ __u8 upd_marker;
+ __be16 name_len;
+ __u8 name[UBI_VOL_NAME_MAX+1];
+ __u8 flags;
+ __u8 padding[23];
+ __be32 crc;
} __attribute__ ((packed));
#endif /* !__UBI_HEADER_H__ */