Help using an Encrypted Root Partition with OLinuXino

[squirel89]

There's a very good guide for using an encrypted root partition with Raspbian at this site http://paxswill.com/

I don't think it would be hard doing the same thing with the OLinuXino image but my lack of experience prevents me from doing so. For instance, I would not know how to translate this into the A20 rootfs' language:

sudo BRANCH=next rpi-update

In Raspbian there's also a /pi_boot/cmdline.txt file that has to be modified:
"to tell the kernel what the new root partition is and how to access it. Change root=/dev/mmcblk0p2 to root=/dev/mapper/sdcard and add cryptdevice=/dev/mmcblk0p2:sdcard"

Where would you have to make these changes in the official OLinuXino's rootfs ?

I think that knowing just that would be enough for me to be able to do the rest on my own. However, if you can provide a more step-by-step guide it would be great. Thank you.