由于很多国内源的arm内容并不全面，所以不推荐使用，而官方源服务器在国外速度非常缓慢。经常导致安装错误，清华的软件源arm较为全面，推荐给大家！
armbian版本为：debian
编辑sources.list
nano /etc/apt/sources.list注释掉原有内容或直接删除，将以下内容复制进去。
清华源：
deb [ arch=arm64,armhf ] https://mirrors.tuna.tsinghua.edu.cn/debian/ stretch main contrib non-free
#deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ stretch main contrib non-free
deb [ arch=arm64,armhf ] https://mirrors.tuna.tsinghua.edu.cn/debian/ stretch-updates main contrib non-free
#deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ stretch-updates main contrib non-free
deb [ arch=arm64,armhf ] https://mirrors.tuna.tsinghua.edu.cn/debian/ stretch-backports main contrib non-free
#deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ stretch-backports main contrib non-free
deb [ arch=arm64,armhf ] https://mirrors.tuna.tsinghua.edu.cn/debian-security/ stretch/updates main contrib non-free
#deb-src https://mirrors.tuna.tsinghua.edu.cn/debian-security/ stretch/updates main contrib non-free
#deb [ arch=arm64,armhf ] https://mirrors.tuna.tsinghua.edu.cn/debian/ sid main contrib non-free按Ctrl+x 按 y 后回车键退出
修改完成后更新下引索即可。
apt-get update
apt-get upgrade
