reproduce (this is a W=1 build):
        # https://github.com/frank-w/BPI-R2-4.14/commit/9ff7cf620a77384912985c98eb0369776932fba2
        git remote add frank-w-bpi-r2-4.14 https://github.com/frank-w/BPI-R2-4.14
        git fetch --no-tags frank-w-bpi-r2-4.14 7.2-dango
        git checkout 9ff7cf620a77384912985c98eb0369776932fba2

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash block/partitions/ drivers/net/phy/