Beagleboard C4 boot up problem

Hi,
   I have formatted and build Angstrom system on SD card as per steps
given in http://elinux.org/BeagleBoardBeginners. I am able to boot up
my board after giving following commands:

mmc init
mmc rescan 0
fatload mmc 0 82000000 MLO
nand unlock
nand ecc hw
nandecc hw
nand erase 0 80000
nand write 82000000 0 20000
nand write 82000000 20000 20000
nand write 82000000 40000 20000
nand write 82000000 60000 20000
fatload mmc 0 0x80200000 u-boot.bin
nand unlock
nand ecc sw
nandecc sw
nand erase 80000 170000
nand write 0x80200000 80000 170000

After that boot command is issued then Beagleboard boots up. After
restart board will not boot up. Again I have followed above procedure
for boot up.
Please give details about how to boot up Beagleboard automatically.

Thank you,
With regards,
Mr.S.S.Kendre

use this link:
http://code.google.com/p/beagleboard/wiki/BeagleboardRevC3Validation