[U-Boot-Users] Invoke a U-boot session from a U-boot session...

I want to invoke Uboot from uboot! I have a stable uboot on flash. when it is up I would like to do something like:

ftp 100000 experimental_uboot.bin go 100000 .... something go terribly wrong .... [power off] [ power on] old stable uboot is up.

Any help will be appreciated

10x, Liberty