Problem booting from MTD partition of NAND device

[Demke Torsten-atd012]

Some additional info:

With both NOR and NAND flashes enabled, I tried to boot from a NOR
partition
e.g. (root=/dev/mtdblock9). The partition is detected correctly (but
fails later
because there is no jffs2 filesystem). 
...
VFS: Mount ROOT_DEV 32505865 - mtdblock9
jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00000000:
0x7436 instead
...
Cowardly refusing to erase blocks on filesystem with no valid JFFS2
nodes
empty_blocks 252, bad_blocks 0, c->nr_blocks 256
VFS: Cannot open root device "mtdblock9" or unknown-block(31,9)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on
unknown-block(31,9)
 <0>Rebooting in 180 seconds..


Regards,
Torsten
> -----Original Message-----
> From: Pete MacKay [mailto:linux at architechnical.net] 
> Sent: Donnerstag, 12. April 2007 02:37
> To: Demke Torsten-atd012
> Cc: linux-mtd at lists.infradead.org
> Subject: Problem booting from MTD partition of NAND device
> 
> Not sure if you've done this, but make sure you specify 
> "rootfstype=jffs2"
> in the kernel parameters.
> 
> Additionally, make sure the NOR driver doesn't specify the 
> root file system using code.  Look for "ROOT_DEV = 
> MKDEV(MTD_BLOCK_MAJOR, 0);", or the inclusion of "<linux/root_dev.h>".
> 
> Torsten Demke writes:
> 
> Hi all,
> 
> I have a PPC system that consists of several MTD partitions 
> on a mix of NOR and NAND flashes.
> MTD partition layout in my system:
> dev:    size   erasesize  name
> mtd0: 00020000 00020000 "enviroment-flash1"
> mtd1: 00500000 00020000 "kernel-flash1"
> mtd2: 01a60000 00020000 "empty-flash1"
> mtd3: 00080000 00020000 "uboot-flash1"
> mtd4: 02000000 00020000 "boot-flash1"
> mtd5: 00020000 00020000 "enviroment-flash2"
> mtd6: 00500000 00020000 "kernel-flash2"
> mtd7: 01a60000 00020000 "empty-flash2"
> mtd8: 00080000 00020000 "uboot-flash2"
> mtd9: 02000000 00020000 "boot-flash2"
> mtd10: 80000000 00020000 "NAND Flash"
> 
> Partition 4 is the merge of partitions 0..3 Partition 9 is 
> the merge of partition 5..8
> 0..4 and 5..9 are independent NOR flash devices (Intel 
> Strataflash) Partition 10 is located on a NAND flash device 
> and is formated with jffs2.
> 
> Whenever I try to boot from the NAND flash 
> (root=/dev/mtdblock10)  I get following error:
>   VFS: Mount ROOT_DEV 0 - mtdblock10		<< some additional debug
> output
>   Kernel panic - not syncing: VFS: Unable to mount root fs on
> unknown-block(0,0)
> 
> When I disable all NOR flashes in the kernel (2.6.14) I can boot
> (root=/dev/mtdblock0)
> my board without a problem.
> Any hints or comments?
> 
> Thanks for your help.
> Regards,
> Torsten
>