reproduce (this is a W=1 build):
        # https://github.com/Xilinx/linux-xlnx/commit/6556503dd049e54cb7439aab65eedd719450cdaa
        git remote add xilinx-xlnx https://github.com/Xilinx/linux-xlnx
        git fetch --no-tags xilinx-xlnx master
        git checkout 6556503dd049e54cb7439aab65eedd719450cdaa

        # 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 drivers/net/ethernet/cadence/