RK3588 ubuntu20.04 换源 aarch64源

备份sudo cp /etc/apt/sources.list /etc/apt/sources.list.backup
编辑 sudo vim /etc/apt/sources.list

拷贝一下：

deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ focal main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ focal main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ focal-updates main restricted universe multiverse
deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ focal-updates main restricted universe multiverse
 

更新源：

sudo apt update