Re: [Yaffs] yaffs2 on 2.4 vs yaffs2 on 2.6

On Sunday 11 April 2010 06:51:43 yaffs@piments.com wrote:
> Re:
>
>
>
> Author: yaffs@piments.com
> Date: 2010-04-05 21:41 +200
> To: YAFFS ML
> Subject: [Yaffs] yaffs2 on 2.4 vs yaffs2 on 2.6
> Hi,
>
> I am in the porcess of updating an older yaffs2 partition on a 2.4
> kernel to a recent 2.6 kernel build with the following yaffs code.
>
> # cat /proc/mtd
> dev: size erasesize name
> mtd0: 00020000 00020000 "TS-BOOTROM"
> mtd1: 07d00000 00020000 "Linux"
> mtd2: 002e0000 00020000 "RedBoot"
> # cat /proc/yaffs
> YAFFS built:Aug 16 2009 21:32:17
> $Id: yaffs_fs.c,v 1.79 2009/03/17 01:12:00 wookey Exp $
> $Id: yaffs_guts.c,v 1.82 2009/03/09 04:24:17 charles Exp $
>
>
> If I mount /dev/mtdblock1 under a nfs boot of the 2.6 kernel and fsystem
> I get rubbish. Some files seem to be interpreted as directories and the
> result is chaos.

First off, I'd suggest you try to remove variables. Try doing this without nfs
first.

I expect the difference is in changes in the mtd layer. The yaffs<-->VFS
connection should be fine.


>
> Fortunately it did not hose the fs.
>
> I was able to make a tarball of the fs by nfs boot to 2.4 and an fs
> image close to that in flash. Here mount /dev/mtdblock/1 is OK.
>
> The earlier version is signed:
>
> $ cat /proc/yaffs
> YAFFS built:Jun 6 2006 14:14:22
> $Id: yaffs_fs.c,v 1.2 2006/02/14 18:20:41 michael Exp $
> $Id: yaffs_guts.c,v 1.1 2006/02/09 21:08:29 michael Exp $
>
> $ cat /proc/mtd
> dev: size erasesize name
> mtd0: 00020000 00020000 "TS-BOOTROM"
> mtd1: 07d00000 00020000 "Linux"
> mtd2: 002e0000 00020000 "RedBoot"
>
> $ cat /proc/partitions
> major minor #blocks name
>
>
> 31 0 128 mtdblocka
> 31 1 128000 mtdblockb
> 31 2 2944 mtdblockc
>
> It seems the two versions have different nomenclatures for the block
> devices.
>
>
> Should it be possible to mount this partition with the 2.6 yaffs2 code?

Yes, so long as the mtd is good.

>
> What version of flash_erase should I use to clear the partition prior to
> installing the new fs image?

Use the one that matches the kernel you're using.

> Any comment on this issue please . I need to install the new fs image
> but do not want to run this risk of bricking the device with
> incompatible tools screwing up the flash structure.
>
> If hose the reboot partition through something going wrong I'll have a
> bill of $200 for a new board or an RMA and postage nearly as dear.
>
> Is there a known incompatibility between these two vintages of yaffs2
> code ? Is the name change a problem?

I would expect it to still boot, so long as the mtd in the new kernel matches
the old kernel.

>
> What tools should I use to clear the old partition? Before installing
> the new fs?

flash_eraseall.