My build environment was missing the device tree compiler...

sudo apt-get install device-tree-compiler

problem solved!

Attempting to build Linux kernel and U-Boot for NanoPi Fire3 target. Kernel builds successfully, U-Boot fails to build. Reference: http://wiki.friendlyarm.com/wiki/index.php/Template:S5P6818BuildFromSource Command History: git clone https://github.com/friendlyarm/prebuilts.git sudo mkdir -p /opt/Fri...