[U-Boot] howto flash ubi rootfs image into nand flash with u-boot?

Hi everybody,

I wonder how I can flash a ubi rootfs image into my NAND flash by using u-boot to do this?

The doc inside u-boot doesn't show me some readme and also google doesn't have some interesting links for me. The online help of the ubi commands is "a bit crypted " - at least for me and the denx online manual has no entries about ubi commands :(

Please can someone point me into the right direction?

Thank you very much and have fun, Dieter