Boot.cmd equivalent for U-boot v2011~

Hello,

I was finally able to boot Ubuntu using BPI-M2-bsp, which uses the old 2011 U-boot.

But, somehow the default bootargs is incorrect and is being set to root=${mmc_root}init=${init} i.e. without a space.

Currently, I have to interrupt autoboot and edit this manually everytime.

How can I make this change permanent?