<p>'''https://mirrors.tuna.tsinghua.edu.cn/ubuntu-releases/22.04/ubuntu-22.04-desktop-amd64.iso'''</p>
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After installing Ubuntu 22.04 on the computer or virtual machine, please set the software source of Ubuntu 22.04 to Tsinghua source (or other domestic sources that you think is fast), otherwise it is easy to make mistakes due to network reasons when installing software later. The steps to replace Tsinghua source are as follows:
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<li>For the method of replacing Tsinghua source, please refer to the instructions on this web page.
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[https://mirrors.tuna.tsinghua.edu.cn/help/ubuntu/ '''https://mirrors.tuna.tsinghua.edu.cn/help/ubuntu/''']
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<li><p>Note that the Ubuntu version needs to be switched to 22.04.</p>
<p>[[File:zero3-img293.png]]</p></li>
<li><p>The content of the '''/etc/apt/sources.list''' file that needs to be replaced is:</p>
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<p>test@test:~$ '''sudo mv /etc/apt/sources.list cat /etc/apt/sources.list.bak'''</p>
<p>test@test:~$ '''sudo vim /etc/apt/sources.list'''</p>
<p># By default, the source image is commented to improve the speed of apt update, you can uncomment it yourself if necessary</p>
<p>deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy main restricted universe multiverse</p>
<p># deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy main restricted universe multiverse</p>
<p>deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-updates main restricted universe multiverse</p>
<p># deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-updates main restricted universe multiverse</p>
<p>deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-backports main restricted universe multiverse</p>
<p># deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-backports main restricted universe multiverse</p>
<p>deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-security main restricted universe multiverse</p>
<p># deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-security main restricted universe multiverse</p>
<p># Pre-release software source, not recommended to enable</p>
<p># deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-proposed main restricted universe multiverse</p>
<p># deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-proposed main restricted universe multiverse</p>
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</li>
<li><p>After the replacement, you need to update the download information and make sure that there is no error.</p>
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<p>test@test:~$ '''sudo apt-get update'''</p>
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<li><p>'''<span style="color:#FF0000">In addition, since the source codes such as the kernel and U-boot are stored on GitHub, it is very important to ensure that the computer can download codes from GitHub normally when compiling the image.</span>'''</p></li></ol>
<span id="get-the-source-code-of-linux-sdk"></span>
