reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        git checkout 062b3e4a1f880f104a8d4b90b767788786aa7b78
        b4 shazam https://lore.kernel.org/r/20250908-net-k1-emac-v10-2-90d807ccd469@iscas.ac.cn
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-15.1.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-15.1.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash drivers/net/ethernet/spacemit/