bm1880-ai-demo-program get code: https://github.com/BM1880-BIRD/bm1880-ai-demo-program.git get tool chains: https://sophon-file.bitmain.com.cn/sophon-prod/drive/18/11/08/11/gcc-linaro-6.3.1-2017.05-x86_64_aarch64-linux-gnu.tar.xz.zip