[U-Boot] howto write uboot to nand

I thought I should ask before I screw this up. I have a new uboot that I load with kwboot. It works fine and I want to write it to nand. I see many references to write it after loading with tftp but not kwboot. Can I do this? How? This is to a Guruplug. Using tftp

tftp 0x6400000 u-boot.kwb nand erase 0x00000000 0x0100000 nand write 0x6400000 0x0000000 0x80000

Richard