Kernel panic - not syncing: No init found.

[hangtoo]

I try to make a new uRamdisk for my bubinga board(linux-2.6.14,PPC405EP).
actully I just copy the most of the files in the board,and compiled busybox with ppc tools.
but when I use the new uRamdisk for a try,it just showed up this errors(as follow),then reboot,back and forth...
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RAMDISK: incomplete write (-28 != 32768) 4194304

EXT2-fs warning: checktime reached, running e2fsck is recommended

VFS: Mounted root (ext2 filesystem).

Freeing unused kernel memory: 116k init

attempt to access beyond end of device  //this is where the error begins.

ram0: rw=0, want=10330, limit=8192

Buffer I/O error on device ram0, logical block 5164

attempt to access beyond end of device

ram0: rw=0, want=10330, limit=8192

Buffer I/O error on device ram0, logical block 5164

attempt to access beyond end of device

ram0: rw=0, want=10330, limit=8192

Buffer I/O error on device ram0, logical block 5164

attempt to access beyond end of device

ram0: rw=0, want=10330, limit=8192

Buffer I/O error on device ram0, logical block 5164

Kernel panic - not syncing: No init found.  Try passing init= option to kernel.
//according to this note,is there something I have to do with my kernel??
 <0>Rebooting in 1 seconds..
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Any help is appreciated.

regards
tony