NVIDIA Jetson TX2 or AGX Xavier apt 切换国内的源

日期可能稍稍有些久远导致不能用，但目前还可以用。

1. 首先备份下之前的 source.list

sudo cp /etc/apt/sources.list/etc/apt/sources.list.backup

2. 修改 source.list

换源需要换 ARM 的源，不要换成了 PC 平台的软件源。这里推荐的两个国内源为清华和中科大的源，将原来文件里面的内容全部替换成下面两个源之一就可以。并且由于 TX2 的系统是 16.04 (xenial) 的，Xavier 的系统是 18.04 (bionic), 所以两者的源还要换个系统版本.

Xavier 清华的:

deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/bionic-updates main restricted universe multiverse
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/bionic-updates main restricted universe multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/bionic-security main restricted universe multiverse
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/bionic-security main restricted universe multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/bionic-backports main restricted universe multiverse
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/bionic-backports main restricted universe multiverse
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/bionic main universe restricted
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/bionic main universe restricted
```Jetson TX2 清华的:```bash
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/xenial-updates main restricted universe multiverse  
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/xenial-updates main restricted universe multiverse   
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/xenial-security main restricted universe multiverse   
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/xenial-security main restricted universe multiverse   
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/xenial-backports main restricted universe multiverse   
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/xenial-backports main restricted universe multiverse   
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/xenial main universe restricted   
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/xenial main universe restricted 
```Xavier 中科大的:```bash
deb http://mirrors.ustc.edu.cn/ubuntu-ports/xenial-updates main restricted universe multiverse 
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/xenial-updates main restricted universe multiverse 
deb http://mirrors.ustc.edu.cn/ubuntu-ports/xenial-security main restricted universe multiverse 
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/xenial-security main restricted universe multiverse 
deb http://mirrors.ustc.edu.cn/ubuntu-ports/xenial-backports main restricted universe multiverse 
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/xenial-backports main restricted universe multiverse 
deb http://mirrors.ustc.edu.cn/ubuntu-ports/xenial main universe restricted 
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/xenial main universe restricted
```Jetson TX2 中科大的:```bash
deb http://mirrors.ustc.edu.cn/ubuntu-ports/xenial-updates main restricted universe multiverse 
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/xenial-updates main restricted universe multiverse 
deb http://mirrors.ustc.edu.cn/ubuntu-ports/xenial-security main restricted universe multiverse 
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/xenial-security main restricted universe multiverse 
deb http://mirrors.ustc.edu.cn/ubuntu-ports/xenial-backports main restricted universe multiverse 
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/xenial-backports main restricted universe multiverse 
deb http://mirrors.ustc.edu.cn/ubuntu-ports/xenial main universe restricted 
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/xenial main universe restricted
```修改完保存后`sudo apt update` 一些就 OK 了.