reproduce (this is a W=1 build):
        # https://github.com/avpatel/linux/commit/aff61774c9e2d4065e31290db5c04e3f190eac33
        git remote add avpatel https://github.com/avpatel/linux.git
        git fetch --no-tags avpatel riscv_sbi_sse_v3
        git checkout aff61774c9e2d4065e31290db5c04e3f190eac33
        # 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