Needed for ubiformat, we are interested in image_seq especially.
Signed-off-by: Wolfram Sang <w.s...@pengutronix.de>
---
include/mtd/ubi-media.h | 55 ++++++++++++++++++++++++++---------------------
1 file changed, 30 insertions(+), 25 deletions(-)
diff --git a/include/mtd/ubi-media.h b/include/mtd/ubi-media.h
index cd1bd8e..d552db8 100644
--- a/include/mtd/ubi-media.h
+++ b/include/mtd/ubi-media.h
@@ -11,7 +11,6 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
- *
* Authors: Artem Bityutskiy (Битюцкий Артём)
* Thomas Gleixner
* Frank Haverkamp
@@ -95,10 +94,11 @@ enum {
* Compatibility constants used by internal volumes.
*
* @UBI_COMPAT_DELETE: delete this internal volume before anything is written
- * to the flash
+ * to the flash
* @UBI_COMPAT_RO: attach this device in read-only mode
* @UBI_COMPAT_PRESERVE: preserve this internal volume - do not touch its
- * physical eraseblocks, don't allow the wear-leveling unit to move them
+ * physical eraseblocks, don't allow the wear-leveling
+ * sub-system to move them
* @UBI_COMPAT_REJECT: reject this UBI image
*/
enum {
@@ -120,18 +120,19 @@ enum {
* struct ubi_ec_hdr - UBI erase counter header.
* @magic: erase counter header magic number (%UBI_EC_HDR_MAGIC)
* @version: version of UBI implementation which is supposed to accept this
- * UBI image
+ * UBI image
* @padding1: reserved for future, zeroes
* @ec: the erase counter
* @vid_hdr_offset: where the VID header starts
* @data_offset: where the user data start
+ * @image_seq: image sequence number
* @padding2: reserved for future, zeroes
* @hdr_crc: erase counter header CRC checksum
*
* The erase counter header takes 64 bytes and has a plenty of unused space for
* future usage. The unused fields are zeroed. The @version field is used to
* indicate the version of UBI implementation which is supposed to be able to
- * work with this UBI image. If @version is greater then the current UBI
+ * work with this UBI image. If @version is greater than the current UBI
* version, the image is rejected. This may be useful in future if something
* is changed radically. This field is duplicated in the volume identifier
* header.
@@ -140,6 +141,14 @@ enum {
* volume identifier header and user data, relative to the beginning of the
* physical eraseblock. These values have to be the same for all physical
* eraseblocks.
+ *
+ * The @image_seq field is used to validate a UBI image that has been prepared
+ * for a UBI device. The @image_seq value can be any value, but it must be the
+ * same on all eraseblocks. UBI will ensure that all new erase counter headers
+ * also contain this value, and will check the value when scanning at start-up.
+ * One way to make use of @image_seq is to increase its value by one every time
+ * an image is flashed over an existing image, then, if the flashing does not
+ * complete, UBI will detect the error when scanning.
*/
struct ubi_ec_hdr {
__be32 magic;
@@ -148,7 +157,8 @@ struct ubi_ec_hdr {
__be64 ec; /* Warning: the current limit is 31-bit anyway! */
__be32 vid_hdr_offset;
__be32 data_offset;
- __u8 padding2[36];
+ __be32 image_seq;
+ __u8 padding2[32];
__be32 hdr_crc;
} __attribute__ ((packed));
@@ -156,24 +166,23 @@ struct ubi_ec_hdr {
* struct ubi_vid_hdr - on-flash UBI volume identifier header.
* @magic: volume identifier header magic number (%UBI_VID_HDR_MAGIC)
* @version: UBI implementation version which is supposed to accept this UBI
- * image (%UBI_VERSION)
+ * image (%UBI_VERSION)
* @vol_type: volume type (%UBI_VID_DYNAMIC or %UBI_VID_STATIC)
* @copy_flag: if this logical eraseblock was copied from another physical
- * eraseblock (for wear-leveling reasons)
+ * eraseblock (for wear-leveling reasons)
* @compat: compatibility of this volume (%0, %UBI_COMPAT_DELETE,
- * %UBI_COMPAT_IGNORE, %UBI_COMPAT_PRESERVE, or %UBI_COMPAT_REJECT)
+ * %UBI_COMPAT_IGNORE, %UBI_COMPAT_PRESERVE, or %UBI_COMPAT_REJECT)
* @vol_id: ID of this volume
* @lnum: logical eraseblock number
- * @leb_ver: version of this logical eraseblock (IMPORTANT: obsolete, to be
- * removed, kept only for not breaking older UBI users)
+ * @padding1: reserved for future, zeroes
* @data_size: how many bytes of data this logical eraseblock contains
* @used_ebs: total number of used logical eraseblocks in this volume
* @data_pad: how many bytes at the end of this physical eraseblock are not
- * used
+ * used
* @data_crc: CRC checksum of the data stored in this logical eraseblock
- * @padding1: reserved for future, zeroes
- * @sqnum: sequence number
* @padding2: reserved for future, zeroes
+ * @sqnum: sequence number
+ * @padding3: reserved for future, zeroes
* @hdr_crc: volume identifier header CRC checksum
*
* The @sqnum is the value of the global sequence counter at the time when this
@@ -184,7 +193,7 @@ struct ubi_ec_hdr {
* (sequence number) is used to distinguish between older and newer versions of
* logical eraseblocks.
*
- * There are 2 situations when there may be more then one physical eraseblock
+ * There are 2 situations when there may be more than one physical eraseblock
* corresponding to the same logical eraseblock, i.e., having the same @vol_id
* and @lnum values in the volume identifier header. Suppose we have a logical
* eraseblock L and it is mapped to the physical eraseblock P.
@@ -221,10 +230,6 @@ struct ubi_ec_hdr {
* checksum is correct, this physical eraseblock is selected (P1). Otherwise
* the older one (P) is selected.
*
- * Note, there is an obsolete @leb_ver field which was used instead of @sqnum
- * in the past. But it is not used anymore and we keep it in order to be able
- * to deal with old UBI images. It will be removed at some point.
- *
* There are 2 sorts of volumes in UBI: user volumes and internal volumes.
* Internal volumes are not seen from outside and are used for various internal
* UBI purposes. In this implementation there is only one internal volume - the
@@ -245,9 +250,9 @@ struct ubi_ec_hdr {
* The @data_crc field contains the CRC checksum of the contents of the logical
* eraseblock if this is a static volume. In case of dynamic volumes, it does
* not contain the CRC checksum as a rule. The only exception is when the
- * data of the physical eraseblock was moved by the wear-leveling unit, then
- * the wear-leveling unit calculates the data CRC and stores it in the
- * @data_crc field. And of course, the @copy_flag is %in this case.
+ * data of the physical eraseblock was moved by the wear-leveling sub-system,
+ * then the wear-leveling sub-system calculates the data CRC and stores it in
+ * the @data_crc field. And of course, the @copy_flag is %in this case.
*
* The @data_size field is used only for static volumes because UBI has to know
* how many bytes of data are stored in this eraseblock. For dynamic volumes,
@@ -274,14 +279,14 @@ struct ubi_vid_hdr {
__u8 compat;
__be32 vol_id;
__be32 lnum;
- __be32 leb_ver; /* obsolete, to be removed, don't use */
+ __be32 leb_ver;
__be32 data_size;
__be32 used_ebs;
__be32 data_pad;
__be32 data_crc;
- __u8 padding1[4];
+ __u8 padding2[4];
__be64 sqnum;
- __u8 padding2[12];
+ __u8 padding3[12];
__be32 hdr_crc;
} __attribute__ ((packed));
--
1.7.10.4
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