[U-Boot] imx6sx and u-boot - question

dear all,

i'm new in yocto!

i'm using *imx6sxsabresd* and i'm trying to port the u-boot for it.

(just to learn! in next step i will design my own board with iMX6 SoloX)

now i don't have *sf commands* in boot command prompt! even though i activated them in /configs/<mycostum name>_defconfig

what else should i do?

thanks a lot

vahid