transfer jffs2 rootFS to Nand flash

transfer jffs2 rootFS to Nand flash

[Saravanan Chanemouganandam]

Hi all,

I am fascing problem in mounting jffs2 root file system on the cm-x270 board
after flashing the jffs2 root file system image on to the MTD Nand partition
with the following steps....

1. boot cm-x270 with NAND, NOR and JFFS2 drivers built into kernel
2. mounted root file system via "nfs"
3. checked the partitions
        cm-debian:~# cat /proc/partitions
        major minor  #blocks  name
         254     0     513576 nand
          31     0       4096 mtdblock0            ( NOR)
          31     1     524288 mtdblock1          (NAND)
        cm-debian:~# cat /proc/mtd
        dev:    size   erasesize  name
        mtd0: 00400000 00010000 "phys_mapped_flash"
        mtd1: 20000000 00020000 "cmx270-0"
        cm-debian:~#

4. cm-debian:~#flash_eraseall -j /dev/mtd1          

5. on the host created jffs2 rootfs image using #mkfs.jffs2 -r cmrootfs -n -o
cmrootfs.img -e 0x20000 --pad=0x20000000

6. copied cmrootfs.img to the cm-x270 board

7. on the cm-x270, flashed rootfs image using mtd-utilities
        cm-debian:~# nandwrite /dev/mtdblock1 /mnt/net/cmrootfs.img
	.....
        Writing data to block 1ffe0000
	Data did not fit into device, due to bad blocks
	: Success
	cm-debian:~#

8. Tested the jffs2 rootFS using mount
        cm-debian:~# mount -t jffs2 /dev/mtdblock1 /mnt/test

	cm-debian:/mnt/net# ls /mnt/test
	bin   dev  home    lib         media  opt           proc  sbin  sys  usr
	boot  etc  initrd  lost+found  mnt    packages.txt  root  srv   tmp  var

After reboot, I am getting the kernel panic  with boot option for root as
root=/dev/mtdblock1 rootfstype=jffs2"

...
...
IP-Config: Complete:
      device=eth0, addr=192.168.6.202, mask=255.255.255.0, gw=192.168.6.1,
     host=cm-x270, domain=, nis-domain=(none),
     bootserver=192.168.6.1, rootserver=192.168.6.1, rootpath=
Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes
empty_blocks 0, bad_blocks 8, c->nr_blocks 4096
VFS: Cannot open root device "mtdblock1" or unknown-block(31,1)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on
unknown-block(31,1)

Could anyone please tell me where I am wrong ? and why is the JFFS doesn't
mount the file system?

Thanks
Sara

Re: transfer jffs2 rootFS to Nand flash

[Ricard Wanderlof]

On Wed, 29 Aug 2007, Saravanan Chanemouganandam wrote:

> 5. on the host created jffs2 rootfs image using #mkfs.jffs2 -r cmrootfs -n -o
> cmrootfs.img -e 0x20000 --pad=0x20000000
> ...
> 7. on the cm-x270, flashed rootfs image using mtd-utilities
>        cm-debian:~# nandwrite /dev/mtdblock1 /mnt/net/cmrootfs.img
> 	.....
>        Writing data to block 1ffe0000
> 	Data did not fit into device, due to bad blocks
> 	: Success
> 	cm-debian:~#

You shouldn't pad the image up to the size of the device (or partition, if 
you were using partitions) or you will get this error, if there are bad 
blocks in your flash (there usually are). However, your subsequent test 
mount seems to work, so you seem to have gotten all valid data into the 
flash anyway, so it still doesn't explain why it doesn't want to be 
mounted when 
the kernel boots.

/Ricard
--
Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
Phone +46 46 272 2016                           Fax +46 46 13 61 30

Re: transfer jffs2 rootFS to Nand flash

[Ricard Wanderlof]

On Thu, 30 Aug 2007, Saravanan Chanemouganandam wrote:

> Thanks to your analysis and answer. I have removed the --pad option in
> mkfs.jffs2 and then flashed the image using "nandwrite -p /dev/mtdblock1
> cmrootfs.img". This time theres no  "due to bad blocks" error.

Ok, well that's good anyway.

>
> The test on mounting jffs2 image was success once after flashing within the
> running linux as
>
> cm-debian:/mnt/net#mount -t jffs2 /dev/mtdblock1 /mnt/test
> cm-debian:/mnt/net# ls /mnt/test
>  bin   dev  home    lib         media  opt              proc  sbin  sys  usr
> boot  etc  initrd  lost+found  mnt    packages.txt  root  srv   tmp  var
>
> Indeed, the test of above jffs2 mount after reboot of the system got failed
> and its a strange.
>
> cm-debian:/mnt/net# mount -t jffs2 /dev/mtdblock1 /mnt/test
> Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes
> empty_blocks 0, bad_blocks 8, c->nr_blocks 4080
> mount: /dev/mtdblock1: can't read superblock

The "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 
nodes" indicates to me that what Linux thinks is /dev/mtdblock1 is in fact 
completely erased flash.

> I hope this may explain some hidden stuffs behind the failure of mounting when
> kernel boots. I think it could be the compatibility isseu of the compulab NAND driver and
> the JFFS2. any idea from this behaviour?

The only idea I have is that the device numbers (/dev/mtdblockN) get 
shifted around for some reason, i.e. you should use /dev/mtdblock0 or 2 or 
something. Can't understand why though.

/Ricard

Re: transfer jffs2 rootFS to Nand flash

[Ricard Wanderlof]

On Thu, 30 Aug 2007, Saravanan Chanemouganandam wrote:

> I have unconfigured the compulab NAND flash block driver which reinitialise
> (erases on reboot) each and everytime of reboot that conflicts with MTD nand
> driver.

That would definitely explain the symptoms you were seeing (no jffs2 nodes 
found when mounting the rootfs).

>
> This fixed my problem and I can be able to successfully mount the jffs2
> rootfs.
>
> IP-Config: Complete:
>      device=eth0, addr=192.168.6.202, mask=255.255.255.0, gw=192.168.6.1,
>     host=cm-x270, domain=, nis-domain=(none),
>     bootserver=192.168.6.1, rootserver=192.168.6.1, rootpath=
> VFS: Mounted root (jffs2 filesystem).
> Freeing init memory: 120K
> INIT: version 2.86 booting
>
> Thanks a lot for your comments and your valuable time.

Great!

/Ricard
--
Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
Phone +46 46 272 2016                           Fax +46 46 13 61 30

Re: transfer jffs2 rootFS to Nand flash

[Saravanan Chanemouganandam]

Hi all,

I got my problem fix up by gurus. The work around solution to transfer jffs2 
rootfs on the cm-x270 nand ( /dev/mtdblock1 ) is to have the following 
kernel configuration setup.

CONFIG_ARMCORE_FLASH is not set
CONFIG_ARMCORE_NAND is not set      
CONFIG_MTD_NAND_CM_X270 is set

The "compulab Nand flash" block driver CONFIG_ARMCORE_NAND initializes 
(erases) nand contents on each reboot that causes the jffs2 rootfs mounting 
failure. 

Unconfig CONFIG_ARMCORE_NAND fixs the problem and the jffs2 rootfs on the 
cm-x270 nand mounted succesfully.

IP-Config: Complete:
      device=eth0, addr=192.168.6.203, mask=255.255.255.0, gw=192.168.6.1,
     host=cm-x270, domain=, nis-domain=(none),
     bootserver=192.168.6.1, rootserver=192.168.6.1, rootpath=
VFS: Mounted root (jffs2 filesystem).
Freeing init memory: 120K

Regards,
Sara



Le Jeudi 30 Août 2007 17:09, vous avez écrit :
> On Thu, 30 Aug 2007, Saravanan Chanemouganandam wrote:
> > I have unconfigured the compulab NAND flash block driver which
> > reinitialise (erases on reboot) each and everytime of reboot that
> > conflicts with MTD nand driver.
>
> That would definitely explain the symptoms you were seeing (no jffs2 nodes
> found when mounting the rootfs).
>
> > This fixed my problem and I can be able to successfully mount the jffs2
> > rootfs.
> >
> > IP-Config: Complete:
> >      device=eth0, addr=192.168.6.202, mask=255.255.255.0, gw=192.168.6.1,
> >     host=cm-x270, domain=, nis-domain=(none),
> >     bootserver=192.168.6.1, rootserver=192.168.6.1, rootpath=
> > VFS: Mounted root (jffs2 filesystem).
> > Freeing init memory: 120K
> > INIT: version 2.86 booting
> >
> > Thanks a lot for your comments and your valuable time.
>
> Great!
>
> /Ricard
> --
> Ricard Wolf Wanderlöf                           ricardw(at)axis.com
> Axis Communications AB, Lund, Sweden            www.axis.com
> Phone +46 46 272 2016                           Fax +46 46 13 61 30
>
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