reproduce (this is a W=1 build):
        # https://github.com/morimoto/linux/commit/b51f2331665d7a9a5f69fbac3022f2685f926904
        git remote add morimoto https://github.com/morimoto/linux
        git fetch --no-tags morimoto renesas-lts/v6.18-rc5-2025-11-10-sparrow-hawk
        git checkout b51f2331665d7a9a5f69fbac3022f2685f926904

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=um olddefconfig
        make W=1 O=build_dir ARCH=um SHELL=/bin/bash drivers/media/platform/dreamchip/rppx1/