I agree with Nick as to what the problem most likely is.

The original EEC layout is part of the SmartMedia specification. It seems 
though that the EEC in mtd (nand_ecc.c) generates the wrong byte ordering for 
the ECC bytes. 

If you're using the ECC in YAFFS (yaffs_ecc.c) then you can configure it to 
use the SmartMedia byte ordering (the "correct" one) or the mtd one (the 
"wrong" one).  To get the same result as mtd you must set 
CONFIG_YAFFS_ECC_WRONG_ORDER .


-- Charles

> > -----Original Message-----
> > From: zhengwei [mailto:jackzheng2002@sohu.com]
> > Sent: 14 November 2004 03:32
> > To: Nick Bane
> > Subject: Re: RE: yaffs problem ?
> >
> >
> >
> > Nick Bane,您好！
> >
> > 	Ok，Thank you ! Do you have charles's email. I will contact
> > him for advice...
> > It's urgent for me to solve the problem.
> >     Thank you so much!
> >
> > ======= 2004-11-12 10:27:00 您在来信中写道：=======
> >
> > >I think this may have to do with swapping or not the oob bytes
> >
> > for SmartMedia compatability. See the yaffs source.
> >
> > >There was a problem with #ifdef and #if in the file. I mentioned
> >
> > it to Charles and it is now ok in the current cvs
> >
> > >Nick
> > >
> > >> -----Original Message-----
> > >> From: jackzheng2002@sohu.com [mailto:jackzheng2002@sohu.com]
> > >> Sent: 12 November 2004 03:25
> > >> To: nick@cecomputing.co.uk
> > >> Subject: yaffs problem ?
> > >>
> > >>
> > >>
> > >>
> > >> Sir, Can you help me?
> > >> I don't use the MTD ECC, I use the yaffs itself ECC, and there
> > >> are some errors:
> > >> I don't know how to start? Thank you !!!!
> > >> Eager waiting for your response...
> > >>
> > >> Mounted devfs on /dev
> > >> Freeing init memory: 76K
> > >> zw: mount /etc as ramfs
> > >> zw: re-create the /etc/mtab entries
> > >> zw: /bin/mount -f -t cramfs -o remount,ro /dev/mtdblock/3 /
> > >> zw: /sbin/insmod -f /lib/yaffs.o
> > >> zw: /bin/mount -t yaffs /dev/mtdblock/4 /usr
> > >> yaffs: dev is 7940 name is "1f:04"
> > >> ecc_code : c3 ff 33 30 f3 3f
> > >> ecc_calc : ff c3 33 f3 30 3f
> > >> oob : 0 0 d0 ff ff ff 4 1 c3 ff 33 5c c1 30 f3 3f
> > >> nand_read_ecc: Failed ECC read, page 0x00002020
> > >> nand_read_ecc: Failed ECC read, page 0x00002020
> > >> ecc_code : c3 ff 33 30 f3 3f
> > >> ecc_calc : ff c3 33 f3 30 3f
> > >> oob : 0 0 e0 ff ff ff 4 1 c3 ff 33 50 c1 30 f3 3f
> > >> nand_read_ecc: Failed ECC read, page 0x00002022
> > >> nand_read_ecc: Failed ECC read, page 0x00002022
> > >> ecc_code : cc ff 3f 95 a6 ab
> > >> ecc_calc : ff cc 3f a6 95 ab
> > >> oob : 0 0 d0 ff ff ff 5 1 cc ff 3f d8 c1 95 a6 ab
> > >> nand_read_ecc: Failed ECC read, page 0x00002023
> > >> nand_read_ecc: Failed ECC read, page 0x00002023
> > >> ecc_code : cc ff 3f 96 a6 67
> > >> ecc_calc : ff cc 3f a6 96 67
> > >> oob : 0 0 e0 ff ff ff 5 1 cc ff 3f d4 c1 96 a6 67
> > >> nand_read_ecc: Failed ECC read, page 0x00002026
> > >> nand_read_ecc: Failed ECC read, page 0x00002026
> > >> ecc_code : c3 ff 33 65 aa 5b
> > >> ecc_calc : ff c3 33 aa 65 5b
> > >> oob : 0 0 d0 ff ff ff 4 1 c3 ff 33 5c c1 65 aa 5b
> > >> nand_read_ecc: Failed ECC read, page 0x00002027
> > >> nand_read_ecc: Failed ECC read, page 0x00002027
> > >> ecc_code : c3 ff 33 a5 a5 97
> > >> ecc_calc : ff c3 33 a5 a5 97
> > >> oob : 0 0 e0 ff ff ff 4 1 c3 ff 33 50 c1 a5 a5 97
> > >> nand_read_ecc: Failed ECC read, page 0x00002029
> > >> ecc_code : a9 aa 67 96 a6 67
> > >> ecc_calc : aa a9 67 a6 96 67
> > >> oob : 0 0 f0 ff ff ff 5 1 a9 aa 67 80 c1 96 a6 67
> > >> nand_read_ecc: Failed ECC read, page 0x0000202a
> > >> nand_read_ecc: Failed ECC read, page 0x0000202a
> > >> zw: exec /sbin/init
> > >> console=/dev/co?ole
> > >> init started:  BusyBox v0.60.3 (2002.05.13-08:36+0000) multi-c?l
> > >> binary Starting pid 22, console /dev/console: '/etc/init.d/rcS'
> > >> exec: /usr/etc/rc.local: No such file or dire?ory
> > >> Waiting for enter to start '/bin/sh' (pid 25, terminal /dev/console)
> > >>
> > >>
> > >> Please press Enter to activate this console.
> >
> > = = = = = = = = = = = = = = = = = = = =
> >
> >
> > 　　　　　　　　致
> > 礼！
> >
> >
> > 　　　　　　　　zhengwei
> > 　　　　　　　　jackzheng2002@sohu.com
> > 　　　　　　　　　　2004-11-12