Rebuilding FS MDS 8349 BSP & JFFS2 integration

Kumar Gala galak at
Wed Apr 26 00:18:21 EST 2006

On Apr 24, 2006, at 4:30 PM, Krawczuk, Victor wrote:

> Hi,
> I am a newbie to Linux but not to embedded PPC. I was hoping  
> someone could point me to the direction here. I apologize in  
> advance if this is kindergarten stuff.
> I downloaded the MDS-8349 Linux BSP from FreeScale. I was able to  
> burn the default prebuilt images "uboot" and "jffs2.img" to my  
> MDS-8349 (PB) board and have uboot tftp the prebuilt "uImage" to my  
> PB. I used "tftpboot 200000 uImage" to download and "bootm" to  
> boot.  As per included instructions, I had "setenv bootargs root=/ 
> dev/mtdblock1 rootfstype=jffs2 rw console=ttyS0,115200" in uboot,  
> followed by a "saveenv". The prebuilt Linux (uImage) came up, no  
> problem.
> As I need to include USB Host support to the PPC kernel, I used the  
> ltib tool to reconfigure and rebuild Linux, as well as a matching  
> jffs2 (I would think). Ltib produced vmlinux.gz.uboot and  
> rootfs.jffs2 for me.  For some reason, rootfs.jffs2 was  
> significantly smaller than the prebuilt "jffs2.img" (2483184 bytes  
> vs. 4325376 bytes). I'm not sure why. I then did the following:
Questions regarding the Freescale BSP are best directed at Freescale  
as they have a custom kernel they are providing with their BSPs.
> bootargs is still set to "root=/dev/mtdblock1 rootfstype=jffs2 rw  
> console=ttyS0,115200"  in uboot:
> Using the same (prebuilt) uboot as before:
> - tftpboot 400000 rootfs.jffs2 (rebuilt jffs2)
> - erase fe020000 fe5fffff
> - cp.b 400000 fe020000 25e3f0
> - tftpboot 200000 vmlinux.gz.uboot (rebuilt Linux containing USB  
> Host stuff)
> - bootm
> Linux could not boot!  I got the following root FS error:
> [stuff deleted…]
> io scheduler deadline registered
> io scheduler cfq registered
> RAMDISK driver initialized: 16 RAM disks of 32768K size 1024 blocksize
> loop: loaded (max 8 devices)
> eth0: Gianfar Ethernet Controller Version 1.1, 00:04:9f:00:2d:b7
> eth0: Running with NAPI disabled
> eth0: 64/64 RX/TX BD ring size
> eth1: Gianfar Ethernet Controller Version 1.1, 00:04:9f:00:2d:b8
> eth1: Running with NAPI disabled
> eth1: 64/64 RX/TX BD ring size
> i2c /dev entries driver
> NET: Registered protocol family 2
> IP: routing cache hash table of 2048 buckets, 16Kbytes
> TCP established hash table entries: 16384 (order: 5, 131072 bytes)
> TCP bind hash table entries: 16384 (order: 4, 65536 bytes)
> TCP: Hash tables configured (established 16384 bind 16384)
> NET: Registered protocol family 1
> NET: Registered protocol family 17
> Root-NFS: No NFS server available, giving up.
> VFS: Unable to mount root fs via NFS, trying floppy.
> VFS: Cannot open root device "mtdblock1" or unknown-block(2,0)
> Please append a correct "root=" boot option
> Kernel panic - not syncing: VFS: Unable to mount root fs on unknown- 
> block(2,0)
>  <0>Rebooting in 180 seconds..
> Would anybody happen to know what is going wrong?  How am I  
> supposed to know the correct "root=" boot option for a rebuilt  
> jffs2 using LTIB, if that is my problem?
Where there any messages related to MTD or flash in the boot log?  If  
not that would seem to be the first place to look.

- kumar

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