Add UBI README
This patch adds a small README to describe the usage of the
U-Boot UBI commands.
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/doc/README.ubi b/doc/README.ubi
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+-------------------
+UBI usage in U-Boot
+-------------------
+
+Here the list of the currently implemented UBI commands:
+
+=> help ubi
+ubi - ubi commands
+
+Usage:
+ubi part [part] [offset]
+ - Show or set current partition (with optional VID header offset)
+ubi info [l[ayout]] - Display volume and ubi layout information
+ubi create[vol] volume [size] [type] - create volume name with size
+ubi write[vol] address volume size - Write volume from address with size
+ubi read[vol] address volume [size] - Read volume to address with size
+ubi remove[vol] volume - Remove volume
+[Legends]
+ volume: character name
+ size: specified in bytes
+ type: s[tatic] or d[ynamic] (default=dynamic)
+
+
+The first command that is needed to be issues is "ubi part" to connect
+one mtd partition to the UBI subsystem. This command will either create
+a new UBI device on the requested MTD partition. Or it will attach a
+previously created UBI device. The other UBI commands will only work
+when such a UBI device is attached (via "ubi part"). Here an example:
+
+=> mtdparts
+
+device nor0 <1fc000000.nor_flash>, # parts = 6
+ #: name size offset mask_flags
+ 0: kernel 0x00200000 0x00000000 0
+ 1: dtb 0x00040000 0x00200000 0
+ 2: root 0x00200000 0x00240000 0
+ 3: user 0x01ac0000 0x00440000 0
+ 4: env 0x00080000 0x01f00000 0
+ 5: u-boot 0x00080000 0x01f80000 0
+
+active partition: nor0,0 - (kernel) 0x00200000 @ 0x00000000
+
+defaults:
+mtdids : nor0=1fc000000.nor_flash
+mtdparts: mtdparts=1fc000000.nor_flash:2m(kernel),256k(dtb),2m(root),27392k(user),512k(env),512k(u-boot)
+
+=> ubi part root
+Creating 1 MTD partitions on "nor0":
+0x000000240000-0x000000440000 : "mtd=2"
+UBI: attaching mtd1 to ubi0
+UBI: physical eraseblock size: 262144 bytes (256 KiB)
+UBI: logical eraseblock size: 262016 bytes
+UBI: smallest flash I/O unit: 1
+UBI: VID header offset: 64 (aligned 64)
+UBI: data offset: 128
+UBI: attached mtd1 to ubi0
+UBI: MTD device name: "mtd=2"
+UBI: MTD device size: 2 MiB
+UBI: number of good PEBs: 8
+UBI: number of bad PEBs: 0
+UBI: max. allowed volumes: 128
+UBI: wear-leveling threshold: 4096
+UBI: number of internal volumes: 1
+UBI: number of user volumes: 1
+UBI: available PEBs: 0
+UBI: total number of reserved PEBs: 8
+UBI: number of PEBs reserved for bad PEB handling: 0
+UBI: max/mean erase counter: 2/1
+
+
+Now that the UBI device is attached, this device can be modified
+using the following commands:
+
+ubi info Display volume and ubi layout information
+ubi createvol Create UBI volume on UBI device
+ubi removevol Remove UBI volume from UBI device
+ubi read Read data from UBI volume to memory
+ubi write Write data from memory to UBI volume
+
+
+Here a few examples on the usage:
+
+=> ubi create testvol
+Creating dynamic volume testvol of size 1048064
+
+=> ubi info l
+UBI: volume information dump:
+UBI: vol_id 0
+UBI: reserved_pebs 4
+UBI: alignment 1
+UBI: data_pad 0
+UBI: vol_type 3
+UBI: name_len 7
+UBI: usable_leb_size 262016
+UBI: used_ebs 4
+UBI: used_bytes 1048064
+UBI: last_eb_bytes 262016
+UBI: corrupted 0
+UBI: upd_marker 0
+UBI: name testvol
+
+UBI: volume information dump:
+UBI: vol_id 2147479551
+UBI: reserved_pebs 2
+UBI: alignment 1
+UBI: data_pad 0
+UBI: vol_type 3
+UBI: name_len 13
+UBI: usable_leb_size 262016
+UBI: used_ebs 2
+UBI: used_bytes 524032
+UBI: last_eb_bytes 2
+UBI: corrupted 0
+UBI: upd_marker 0
+UBI: name layout volume
+
+=> ubi info
+UBI: MTD device name: "mtd=2"
+UBI: MTD device size: 2 MiB
+UBI: physical eraseblock size: 262144 bytes (256 KiB)
+UBI: logical eraseblock size: 262016 bytes
+UBI: number of good PEBs: 8
+UBI: number of bad PEBs: 0
+UBI: smallest flash I/O unit: 1
+UBI: VID header offset: 64 (aligned 64)
+UBI: data offset: 128
+UBI: max. allowed volumes: 128
+UBI: wear-leveling threshold: 4096
+UBI: number of internal volumes: 1
+UBI: number of user volumes: 1
+UBI: available PEBs: 0
+UBI: total number of reserved PEBs: 8
+UBI: number of PEBs reserved for bad PEB handling: 0
+UBI: max/mean erase counter: 4/1
+
+=> ubi write 800000 testvol 80000
+Volume "testvol" found at volume id 0
+
+=> ubi read 900000 testvol 80000
+Volume testvol found at volume id 0
+read 524288 bytes from volume 0 to 900000(buf address)
+
+=> cmp.b 800000 900000 80000
+Total of 524288 bytes were the same