[Yaffs] Re: yaffs2 on 2.6.17.6

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Author: Wookey
Date:  
To: yaffs
Subject: [Yaffs] Re: yaffs2 on 2.6.17.6
On 06-07-26 08:09 +0200, kim M wrote:
>    Hi all

>
>    I am considering switching from jffs2 to yaffs2 to improve  mount time.
>    Currently, I have aprox 30-60 sec mount time for a 22 MB partition + some
>    additional 60 sec while the garbage collection continues to run.

>
>    I have previously used YAFFS with success. Back then I was using the
>    direct interface though.

>
>    Currently I am on a  2.6.17.6 ARM kernel with a fresh YAFFS2 checkout and
>    up-to-date MTD utils from git. I create my Image with mkyaffs2image and
>    burn it using flash_eraseall + nandwrite -a -o. When mounted I get a
>    single "lost+found" dir which contains a lot files:

>
>    UCM]$ll /mnt/flash_fs/lost\+found/
>    Using fallback suid method
>    ?---------    1 root     root    535297448 Jan  1 00:06 obj100201
>    ?---------    1 root     root    127526295 Jan  1 00:06 obj100250
>    ?---------    1 root     root    382546882 Jan  1 00:06 obj1007
>    ?---------    1 root     root    534871804 Jan  1 00:06 obj1008
>    ?---------    1 root     root    511678771 Jan  1 00:06 obj1011
>    ?---------    1 root     root 380946853 Jan  1 00:06 obj101205
>    etc...

>
>    I have tried applying the mtd2if2.c patch and switching back and forth
>    between YAFFS and MTD ECC. Have I missed something here?


Well you are bang up to date on the code - more so than me right now.
You probably also want Vitaly's recent patch to make YAFFS2 match up
with latest MTD.
http://www.aleph1.co.uk/pipermail/yaffs/2006q3/002074.html

Also check that mkyaffs2image is laying out the OOB (tags and ECC) in
the same way that MTD is. That tool is ripe for improvement.

>    BTW: what is the correct way of forcing YAFFS2 to use ECC calculated by
>    MTD? I wan't to do this so I can burn the images from u-boot in the same
>    way as I burn JFFS2 images.


unset CONFIG_YAFFS_DOES_ECC

>    If I manage to get YAFFS2 running on my target, I want to enhance the
>    mkyaffs2image to support root+permission squash plus support
>    for device_table files. Is anyone else working on this?


That would be great. No, so far as I know, no-one else is working on
this - the device_table thing has been suggested as a Good Thing (TM)
before, and I am inclined to agree :-)

Wookey
-- 
Aleph One Ltd, Bottisham, CAMBRIDGE, CB5 9BA, UK  Tel +44 (0) 1223 811679
work: http://www.aleph1.co.uk/                 play: http://wookware.org/