Re: UBI and OneNAND

[Artem Bityutskiy <dedekind@infradead.org>]

Hi, few notes:

On Tue, 2006-11-07 at 10:20 +0000, John Smith wrote:
> UBI: data offset:                2048
> UBI: max. allowed volumes:       128
> UBI: wear-levelling threshold:   4096
> UBI: number of internal volumes: 2
> UBI: number of user volumes:     1
> UBI: available PEBs:             49
> UBI: total number of reserved PEBs: 126
> UBI: number of PEBs reserved for bad PEB handling: 1
Hmm, only one PEB is reserved, may be it makes sense to reserve more -
there is a corresponding option.

> 
> 
> ##
> ## Then with the busybox shell I can list the MTD partitions
> ##
> 
> / # cat /proc/mtd
> dev:    size   erasesize  name
> mtd0: 00c00000 00020000 "BootLoader"    <<< Nor Flash
> mtd1: 00400000 00020000 "OldCFE"        <<< Nor Flash
> mtd2: 00100000 00010000 "CFE"           <<< OneNAND Flash
> mtd3: 00400000 00010000 "Kernel"        <<< OneNAND Flash
> mtd4: 00af0000 00010000 "rootfs"        <<< OneNAND Flash
> mtd5: 00010000 00010000 "CFE-NVM"       <<< OneNAND Flash
> mtd6: 00753800 0000f800 "Kernel"        <<< UBI Partition on mtd4:
I would recommend you to use unique names for MTD partitions. You have
two "kernel" partitions.

> ##
> ## Look at existing devices
> ##
> / # ls -l /dev/mtdblock?
> brw-r-----    1 0        0         31,   0 Jan  1 00:00 /dev/mtdblock0
> brw-r-----    1 0        0         31,   1 Jan  1 00:00 /dev/mtdblock1
> brw-r-----    1 0        0         31,   2 Jan  1 00:00 /dev/mtdblock2
> brw-r-----    1 0        0         31,   3 Jan  1 00:00 /dev/mtdblock3
Yo do not need mtdblock devices to mount JFFS2 at all. JFFS2 anyway
works with MTD devices directly and this is just an old way to mount
JFFS2. /dev/mtdX are character devices and you cannot feed the mount
utility by character devices, so this is why fake block devices were
used. Nowadays there is device-less mount support and you may use:

mount mtd7 /mnt/nvm

-- 
Best regards,
Artem Bityutskiy (Битюцкий Артём)