mounting SD-root-Partition failed

I try to boot a linux-kernel from SD-Card and mount a second partition as
rootfs.

In my FriendlyARM.ini on the first partition I have the following entries:

Linux-Kernel = Linux/zImage_SD_2.6.28
Linux-CommandLine = root=/dev/mmcblk0p2 rootfstype=ext2 rootwait
console=ttySAC0,115200 init=/init


The kernel gets called correctly, but it seams not to be able to mount the
second partition. I get the following error-message:

mount: mounting /dev/mmcblk0p2 on /r failed: No such device


I added the /dev/mmcblk0p2 in the .cpio-file like described here:
http://www.friendlyarm.net/forum/topic/2385#18469

My device is the Mini6410
I tried the 2.6.28 and 2.6.38. The 2.6.38 is from the friendly-arm-DVD, the
2.6.28 from an other fileserver with mini6410-images/sources.


Any ideas? :)

first which boot loader u used ? 
 
second try to check this 

#################### Linux #####################
Linux-BootLoader = superboot-6410.bin
Linux-Kernel = Linux/zImage_n43
Linux-CommandLine = root=/dev/mtdblock2 rootfstype=yaffs2 init=/linuxrc
console=ttySAC0,115200
Linux-RootFs-InstallImage = Linux/rootfs_qtopia_qt4.img
Linux-RootFs-RunImage = Linux/rootfs_qtopia_qt4.ext3

1. I use u-boot_sd-ram256.bin from the current DVD

2. I can boot the available images (with rootwait added to the
commandline), so the SD-Card works well.
But that's not what I want :) I want to create my own Linux-System, and the
root-fs should be on the second partition, not in an image-file. :)

using superboot instead of u-boot doesn't change anything. Do I need a
bootloader at all? If I disable the Linux-BootLoader-Entry it works anyway
:) (well, at least until Linux should mount the SD-Card)

I'm confused… With an ext3-filesystem it works :D 

So, problem solved by using ext3 instead of ext2 :)

It appears to me that you're able to use u-boot_sd-ram256.bin successfully.

I failed to use it using sd-flasher via SD card !?!?

How you burned that file successfully ?

First i have to say that i still don't know how the boot-process really
works. :)
But at least I know what I did to boot Linux from SD-Card :D

First I created a bootable SD-Card like in the manual described (using the
SD-Flasher and superboot for my device)

Then I formated the SD-Card on Linux to the following scheme:
partition 1: 20MB FAT32
partition 2: ext3 - nearly to the max but with a buffer off ~200MB at the
end so that I didn't destroy the bootloader which SD-Flasher wrote there.

Now I can put the kernel, u-boot and the ini-file on the FAT-partition and
the root-fs can be build/copied to the second one.
And in the ini-file as the entry for Linux-BootLoader I wrote u-boot-*