Thank you for your response.
i was checked through getevent command but i didn't get any response .
after that i reloaded the system.img,persist.img , userdata.img and boot.img
it is working now. but i didn't get what was the problem.
can you please explain about all images except boot.img and how to build..?
and also trying to interface ov5645 camera module but i am new to this please help me.
Thanks and regards,