此次拿到的不知名板子已經有大佬移植了ubuntu16.04系統，dpkg --print-architecture時顯示的是arm64。
如果直接照搬桌面系統的軟件源進行更新，會出現如下的not found 問題。
/main/binary-arm64/Packages 404 Not Found
這時嘗試清華源、阿里源、東北大學源等都是一樣的。網上搜索的方法，提到的主要是針對Nvidia TX1的，就是在源中的deb後增加:
[arch=amd64,i386]
舉個例子：
deb [arch=amd64,i386] http://mirror.neu.edu.cn/ubuntu/ xenial main restricted
更具體的說明這裏不展開了，詳見參考鏈接1
然而這樣治標不治本！！！
這裏替換的源應當是樹莓派等開發板的源，於是我查看了下樹莓派的源和tx1的源，拷貝到了板子裏，更新下就OK了。
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.deb http://ports.ubuntu.com/ubuntu-ports/ xenial main restricted universe multiverse
deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial main restricted universe multiverse## Major bug fix updates produced after the final release of the
## distribution.
deb http://ports.ubuntu.com/ubuntu-ports/ xenial-updates main restricted universe multiverse
deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial-updates main restricted universe multiverse## Uncomment the following two lines to add software from the 'universe'
## repository.
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
# deb http://ports.ubuntu.com/ubuntu-ports/ xenial universe
# deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial universe
# deb http://ports.ubuntu.com/ubuntu-ports/ xenial-updates universe
# deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial-updates universe## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
# deb http://ports.ubuntu.com/ubuntu-ports/ xenial-backports main restricted
# deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial-backports main restricteddeb http://ports.ubuntu.com/ubuntu-ports/ xenial-security main restricted universe multiverse
deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial-security main restricted universe multiverse
# deb http://ports.ubuntu.com/ubuntu-ports/ xenial-security universe
# deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial-security universe
# deb http://ports.ubuntu.com/ubuntu-ports/ xenial-security multiverse
# deb-src http://ports.ubuntu.com/ubuntu-ports/ xenial-security multiverse
上述是tx1的源。
使用方法是打開/etc/apt/sources.list然後將源換成上面這個再更新就OK了。