Pushed series as:

ae30bf6332fe42e146ae3f950fa88d6e48afcfda gnu: Add make-u-boot-rockchip-package procedure.
7edd5fdf23db4704d51f3f0b54175bed694e7e62 gnu: u-boot-rockpro64-rk3399: Remove obsolete substitute.
5196b49756ca2d21f16c2abd8ca8d91163c4b13e gnu: bootloader: u-boot: Add write-u-boot-image procedure.
498e0557c56d84a46065f61fef320478577e30fb gnu: bootloader: u-boot: Add u-boot-rockchip-bootloader.

And added one more further simplifying u-boot-rockpro64-rk3399:

c1ec9e8d53da209ba1d6f8466d03180d195d7334 gnu: u-boot-rockpro64-rk3399: Drop obsolete phase.

Marking as done.

live well,
  vagrant