Android file system problem on beagleboard

I've already ported the android kernel to beagleboard(2.6.22) with
full android kernel m5_rc20 patches,
and I can boot from android emulator with appropriate kernel config
(goldfish and qemu). I think this steps
will make sure the kernel is okay. But now, I have some problem with
android file system.

I do the following test (refer to "Android on OMAP" article):
1. boot from the startard file system(ext2) of beagle board and switch
the control to android system.
   I meet "segmemntation fault" while executing the "/init" command.

2. apply yaffs2 file system on /dev/mtdblock4, and copy the android's
stuff to it. After that,
   modify the boot argument (root=/dev/mtdblock4 rootfstype=yaffs2
init=/init ...), but the boot procedure
   stop at the following point.
... ...
<6>yaffs: dev is 32505860 name is "mtdblock4"
yaffs: dev is 32505860 name is "mtdblock4"
<6>yaffs: passed flags ""
yaffs: passed flags ""
yaffs: Attempting MTD mount on 31.4, "mtdblock4"
yaffs: Attempting MTD mount on 31.4, "mtdblock4"
VFS: Mounted root (yaffs2 filesystem).
VFS: Mounted root (yaffs2 filesystem).
<6>Freeing init memory: 132K
Freeing init memory: 132K

   it seems to be the "/init" issue as well. (I make sure that I can
beagleboard file system on yaffs2)
I have no idea about it, and i can't go on. any suggestion is
applicated.