[U-Boot-Users] "How to erase the Flash used by u-boot"

Hi All, We are developing one walnut405 based embedded system with U-boot and Montavista linux.

Here customer is asking to give provision to erase U-boot from Kernel as well as from existing U-boot when there is any updated U-Boot.

Currently i am erasing U-Boot from U-Boot only. I do not know how to erase U-Boot from Kernel.

Here i have some fundamental doubts that , How to erase U-Boot from Kernel level? How to access Physical address directly in Linux Kernel?

Please help me out ..........

Thanks in Advance.

Nagi Reddy