[ELDK] How to Boot a New Kernal from TFTP Server

[camel joe]

Forgive me for my very basic questions, since I am a newbie and this
is my first time to learn using ELDK/U-Boot.

By following the DULG for Kilauea document, I was able to build the
kernel and to set up the TFTP server and U-boot parameters, as
follows:

Hit any key to stop autoboot:  0
=> setenv ipaddr 172.20.10.45
=> setenv serverip 172.20.10.34
=> tftpboot
Waiting for PHY auto negotiation to complete.. done
ENET Speed is 100 Mbps - FULL duplex connection (EMAC0)
Using ppc_4xx_eth0 device
TFTP from server 172.20.10.34; our IP address is 172.20.10.45
Filename 'kilauea/uImage'.
Load address: 0x100000
Loading: #################################################################
         ##################################################
done
Bytes transferred = 1680071 (19a2c7 hex)
=>

But I don't know exactly what to do next for booting up the board,
since when I use "reset" or "boot" commands, the board always is
running with the old existing kernel that comes with the manufactory.

Any help would be appreciated.

Thanks,

--Joe Chen