singh0601,
I do not have a DE2 eval board, so I cannot verify this.
If the character driver for the display is loaded in your kernel,
and you use the MSH shell which allows redirection from the echo command, you should be able to do something as simple as:
switch to the MSH shell:
/> msh
# echo "Hello World!" > /dev/lcd16207
You will need to have the MSH shell enabled in the kernel and the 'echo' command from busybox.
FYI
The following is a very good article describing uClinux, NIOS2, and device drivers on the DE2 board.
"Devicedrivers and Testapplication for a SOPC solution with a Nios II softcore processor and uClinux"
Author: Philipp Lutz
University of Applied Sciences, Augsburg
You can find this article on the web.
Good Huntin'
cb