默认云芯一号是ubuntu18.04的系统，都2020了，系统也可以升级一下啦。
首先，还是把当前版本升级到最新的
sudo apt udpate
sudo apt upgrade升级非常方便，安装update-manager-core
sudo apt install update-manager-core
sudo do-release-upgrade -m server -d将会看到如下log：
Checking for a new Ubuntu release
Get:1 Upgrade tool signature [1554 B]
Get:2 Upgrade tool [1348 kB]
Fetched 1350 kB in 6s (220 kB/s)
authenticate 'focal.tar.gz' against 'focal.tar.gz.gpg'
extracting 'focal.tar.gz'
Reading cache
Checking package manager
Continue running under SSH?
This session appears to be running under ssh. It is not recommended to perform a upgrade over ssh currently because in case of failure it is harder to recover.
If you continue, an additional ssh daemon will be started at port
'1022'.
Do you want to continue?
Continue [yN] y
Starting additional sshd
To make recovery in case of failure easier, an additional sshd will be started on port '1022'. If anything goes wrong with the running ssh you can still connect to the additional one.
If you run a firewall, you may need to temporarily open this port. As this is potentially dangerous it's not done automatically. You can open the port with e.g.:
'iptables -I INPUT -p tcp --dport 1022 -j ACCEPT'
To continue please press [ENTER]
更新当前的apt source list：
Reading package lists... Done
Building dependency tree
Reading state information... Done
Hit http://repo.huaweicloud.com/ubuntu-ports bionic InRelease
Hit http://repo.huaweicloud.com/ubuntu-ports bionic-security InRelease
Hit http://repo.huaweicloud.com/ubuntu-ports bionic-updates InRelease
Hit http://repo.huaweicloud.com/ubuntu-ports bionic-backports InRelease
Hit http://sdk.aijishu.com:90 bionic InRelease
Fetched 0 B in 0s (0 B/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done
Updating repository information
No valid mirror found
While scanning your repository information no mirror entry for the
upgrade was found. This can happen if you run an internal mirror or
if the mirror information is out of date.
Do you want to rewrite your 'sources.list' file anyway? If you choose
'Yes' here it will update all 'bionic' to 'focal' entries.
If you select 'No' the upgrade will cancel.
Continue [yN] y
Third party sources disabled
Some third party entries in your sources.list were disabled. You can
re-enable them after the upgrade with the 'software-properties' tool
or your package manager.
To continue please press [ENTER]获取20.04版本，也就是focal的source list：
Get:1 http://repo.huaweicloud.com/ubuntu-ports focal InRelease [265 kB]
Get:2 http://repo.huaweicloud.com/ubuntu-ports focal-security InRelease [107 kB]
Get:3 http://repo.huaweicloud.com/ubuntu-ports focal-updates InRelease [111 kB]
Get:4 http://repo.huaweicloud.com/ubuntu-ports focal-backports InRelease [98.3 kB]
Get:5 http://repo.huaweicloud.com/ubuntu-ports focal/main arm64 Packages [940 kB]
Get:6 http://repo.huaweicloud.com/ubuntu-ports focal/main Translation-en [506 kB]
Get:7 http://repo.huaweicloud.com/ubuntu-ports focal/restricted arm64 Packages [1300 B]
Get:8 http://repo.huaweicloud.com/ubuntu-ports focal/restricted Translation-en [6212 B]
Get:9 http://repo.huaweicloud.com/ubuntu-ports focal/universe arm64 Packages [8458 kB]
Get:10 http://repo.huaweicloud.com/ubuntu-ports focal/universe Translation-en [5124 kB]
Get:11 http://repo.huaweicloud.com/ubuntu-ports focal/multiverse arm64 Packages [114 kB]
Get:12 http://repo.huaweicloud.com/ubuntu-ports focal/multiverse Translation-en [104 kB]
Get:13 http://repo.huaweicloud.com/ubuntu-ports focal-security/main arm64 Packages [131 kB]
Get:14 http://repo.huaweicloud.com/ubuntu-ports focal-security/main Translation-en [59.8 kB]
Get:15 http://repo.huaweicloud.com/ubuntu-ports focal-security/restricted arm64 Packages [932 B]
Get:16 http://repo.huaweicloud.com/ubuntu-ports focal-security/restricted Translation-en [7732 B]
Get:17 http://repo.huaweicloud.com/ubuntu-ports focal-security/universe arm64 Packages [52.0 kB]
Get:18 http://repo.huaweicloud.com/ubuntu-ports focal-security/universe Translation-en [28.4 kB]
Get:19 http://repo.huaweicloud.com/ubuntu-ports focal-security/multiverse Translation-en [540 B]
Get:20 http://repo.huaweicloud.com/ubuntu-ports focal-updates/main arm64 Packages [298 kB]
Get:21 http://repo.huaweicloud.com/ubuntu-ports focal-updates/main Translation-en [127 kB]
Get:22 http://repo.huaweicloud.com/ubuntu-ports focal-updates/restricted arm64 Packages [932 B]
Get:23 http://repo.huaweicloud.com/ubuntu-ports focal-updates/restricted Translation-en [7768 B]
Get:24 http://repo.huaweicloud.com/ubuntu-ports focal-updates/universe arm64 Packages [157 kB]
Get:25 http://repo.huaweicloud.com/ubuntu-ports focal-updates/universe Translation-en [81.3 kB]
Get:26 http://repo.huaweicloud.com/ubuntu-ports focal-updates/multiverse arm64 Packages [2260 B]
Get:27 http://repo.huaweicloud.com/ubuntu-ports focal-updates/multiverse Translation-en [3892 B]
Get:28 http://repo.huaweicloud.com/ubuntu-ports focal-backports/universe arm64 Packages [3088 B]
Get:29 http://repo.huaweicloud.com/ubuntu-ports focal-backports/universe Translation-en [1448 B]
Fetched 16.8 MB in 6s (1327 kB/s)
Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating the changes
Calculating the changes
Do you want to start the upgrade?
5 installed packages are no longer supported by Canonical. You can
still get support from the community.
11 packages are going to be removed. 134 new packages are going to be
installed. 514 packages are going to be upgraded.
You have to download a total of 389 M. This download will take about
4 minutes with your connection.
Installing the upgrade can take several hours. Once the download has
finished, the process cannot be canceled.
Continue [yN] Details [d]y漫长的升级过程，时间取决于网速哈
Fetching
Get:1 http://repo.huaweicloud.com/ubuntu-ports focal/main arm64 gcc-10-base arm64 10-20200411-0ubuntu1 [19.0 kB]
......
升级完毕
Welcome to Ubuntu 20.04.1 LTS (GNU/Linux 4.4.194 aarch64)
* Documentation: https://help.ubuntu.com
* Management: https://landscape.canonical.com
* Support: https://ubuntu.com/advantage
