reproduce (this is a W=1 build):
        # https://github.com/norov/linux/commit/2a93ac837c4d184b40d46a2ed2a30313fd1984e1
        git remote add norov https://github.com/norov/linux
        git fetch --no-tags norov smp4
        git checkout 2a93ac837c4d184b40d46a2ed2a30313fd1984e1
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash kernel/