U-Boot / mmcblkXboot0

[Arwen]

I'm not sure why you are going on about this
Partitions don't matter, as long as the 1st (user) doesn't overlap ATF
The command line given by manjaro is correct, you do have to
replace the "X" with the right number
As long as idbloader, uboot, ATF are in the right place,
that is all that matters, partitions don't matter AT ALL
AND, you don't really have to do this, maybe the update
gives something "extra", this has not been stated
Now, if you are trying to write a BSP uboot for the
other sleep method, well that might be worthwhile,
I, as of yet, have heard no reports, pro or con

If the comment about partitions was directed at me, the answer is simple. With partitions in place, I know where things are and where the 1st user partition must start. It's nothing more than built in documentation. (Though it does ease copying or updates because I don't have to remember sector offsets.)