[U-Boot] How to program u-boot in eMMC/MMC on iMX

[Marco Cavallini]

Hello,

I'd like to know if exists a method to store in eMMC a bootolader
without kobs-ng, so without using linux, but simply running a command
from u-boot.
I booted my i.MX28 system (I have the same question for i.MX6 as well)
using the u-boot.sb (u-boot-2015.01 with SPL) file loaded with mxsldr
(or imx-bootlets).
Now I am trying to save it in eMMC with the following command
 loady    (load u-boot.sb with ymodem)
 mmc write ${loadaddr} 0 ${filesize}
but at reboot nothing happens.
Is it possible?

TIA
--
Marco