Reference：

https://docs.nvidia.com/jetson/archives/r35.4.1/DeveloperGuide/text/SD/SoftwarePackagesAndTheUpdateMechanism.html#over-the-air-update

如何区分版本

JetPack版本与L4T Release是两个不同的版本概念，L4T（Linux for Tegra）是JetPack的子集，通常会一起更新。

它们之间的对应关系如下：

L4T的更新有三种，前两种基本可以无损升级，但第三种（跨大版本）不一定能无损升级，建议备份好后重刷系统：

• Point Release Update（点版本更新）：
  例如从35.1.0 到 35.1.1，通常是小型错误修复。

• Minor Release Update（小版本更新）：
  例如从35.5到35.6，通常会更新系统组件如CUDA、TensorRT等。

• Release Update（大版本更新）：
  例如从34.x(JP4/Ubuntu18)升级到35.x(JP5/Ubuntu20)，则必须要清空数据刷机才能进行。

更新之前

在执行任何更新之前，我都强烈建议你先安装好TimeShift并创建快照！以防更新后出现问题导致不得不重装系统。

这部分与其他普通Ubuntu系统一样，非常简单但能救命，可直接参考：

点版本更新

这种更新最简单，不需要修改任何文件，只需：

sudo apt update
sudo apt list --upgradable # 可选
sudo apt upgrade

小版本更新/大版本更新

注意：大版本更新流程与小版本更新基本一致，都需要修改软件源后执行dist-upgrade，可以直接参考。

当你发现一些工具包（例如CUDA或者TensorRT等）过旧的时候，就需要检查一下是否有小版本更新了。

检查是否有新版本

在这里可以看到当前的最新版本：

以我手头的Jetson Xavier NX为例，当前安装的版本是L4T 35.5（JP5.1.3），有新版本L4T 35.6（JP 5.1.4）可以更新。

查看已安装的JetPack版本：

sudo apt-cache show nvidia-jetpack

注意：此方式是查询软件源缓存来查看版本，可能不准确，建议使用jtop工具查看。

修改软件源

sudo nano /etc/apt/sources.list.d/nvidia-l4t-apt-source.list

将rXX.X改为当前最新的版本，例如我这里将r35.5改为r35.6。

然后使用apt更新：

sudo apt update
sudo apt dist-upgrade

然后就会看到有一大堆需要更新的东西：

jetson@patrick-jetson:~$ sudo apt update
Hit:1 http://mirrors.ustc.edu.cn/ubuntu-ports focal InRelease
Hit:2 http://mirrors.ustc.edu.cn/ubuntu-ports focal-updates InRelease
Hit:3 http://mirrors.ustc.edu.cn/ubuntu-ports focal-backports InRelease
Hit:4 http://mirrors.ustc.edu.cn/ubuntu-ports focal-security InRelease
Hit:5 http://ports.ubuntu.com/ubuntu-ports focal InRelease
Hit:6 http://packages.ros.org/ros2/ubuntu focal InRelease
Hit:8 https://packages.microsoft.com/repos/code stable InRelease
Hit:7 https://repo.download.nvidia.cn/jetson/common r35.6 InRelease
Hit:9 https://repo.download.nvidia.cn/jetson/t194 r35.6 InRelease
Hit:10 https://repo.download.nvidia.cn/jetson/ffmpeg r35.6 InRelease
Reading package lists... Done
Building dependency tree
Reading state information... Done
329 packages can be upgraded. Run 'apt list --upgradable' to see them.
jetson@patrick-jetson:~$ sudo apt dist-upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
  elementary-xfce-icon-theme exo-utils greybird-gtk-theme hddtemp libburn4 libexo-1-0 libexo-2-0 libexo-common
  libexo-helpers libgarcon-1-0 libgarcon-common libgarcon-gtk3-1-0 libgtksourceview-3.0-1
  libgtksourceview-3.0-common libisofs6 libjte2 libkeybinder-3.0-0 libqrencode4 libtagc0 libthunarx-3-0
  libxfce4panel-2.0-4 libxfce4ui-utils mousepad ristretto thunar thunar-archive-plugin thunar-data
  thunar-media-tags-plugin thunar-volman xarchiver xfburn xfdesktop4 xfdesktop4-data xiccd
Use 'sudo apt autoremove' to remove them.
Get more security updates through Ubuntu Pro with 'esm-apps' enabled:
  libavformat58 exo-utils libavfilter7 libpython3.9-minimal libswresample3
  libpython3.9-stdlib libzmq5 iperf3 python2.7-minimal libcgraph6 libpython2.7
  python2.7 python3-pip libavformat-dev python3.9 libzbar0 libexo-1-0
  libexo-2-0 libswresample-dev libpostproc55 liblab-gamut1 libavutil-dev
  libavcodec-dev libpmix2 python3.9-minimal libexo-common python-pkg-resources
  libcdt5 libavutil56 libpathplan4 libswscale5 libgvpr2 libopenexr24
  libsdl2-2.0-0 libmysofa1 libiperf0 libpython2.7-minimal libswscale-dev
  libgvc6 libpython2.7-stdlib python3-scipy graphviz python-pip-whl libde265-0
  libexo-helpers
Learn more about Ubuntu Pro at https://ubuntu.com/pro
The following NEW packages will be installed:
  python3-toml ubuntu-pro-client ubuntu-pro-client-l10n
The following packages will be upgraded:
  accountsservice apparmor base-files bind9-host bind9-libs binutils binutils-aarch64-linux-gnu binutils-common
  bluez bluez-obexd bsdutils bubblewrap busybox-initramfs ca-certificates code cpio cups cups-browsed cups-client
  cups-common cups-core-drivers cups-daemon cups-filters cups-filters-core-drivers cups-ipp-utils cups-ppdc
  cups-server-common curl distro-info-data dns-root-data dnsmasq-base e2fsprogs espeak-ng-data fdisk firefox
  fonts-opensymbol gdb gdbserver ghostscript ghostscript-x gir1.2-accountsservice-1.0 gir1.2-gdkpixbuf-2.0
  gir1.2-gst-plugins-base-1.0 gir1.2-gstreamer-1.0 gir1.2-gtk-3.0 gir1.2-nm-1.0 gir1.2-soup-2.4 gir1.2-vte-2.91
  git git-man gnome-shell gnome-shell-common gstreamer1.0-alsa gstreamer1.0-gl gstreamer1.0-plugins-base
  gstreamer1.0-plugins-base-apps gstreamer1.0-plugins-good gstreamer1.0-pulseaudio gstreamer1.0-tools
  gstreamer1.0-x gtk-update-icon-cache gtk2-engines-pixbuf iputils-ping jetson-gpio-common klibc-utils less
  libaccountsservice0 libapparmor1 libapr1 libarchive13 libbinutils libblkid-dev libblkid1 libbluetooth3 libc-bin
  libc-dev-bin libc6 libc6-dbg libc6-dev libcdio18 libcom-err2 libctf-nobfd0 libctf0 libcups2 libcupsfilters1
  libcupsimage2 libcurl3-gnutls libcurl4 libcurl4-openssl-dev libde265-0 libespeak-ng1 libexpat1 libexpat1-dev
  libext2fs2 libfdisk1 libfontembed1 libfreerdp-client2-2 libfreerdp2-2 libgail-common libgail18 libgd3
  libgdk-pixbuf2.0-0 libgdk-pixbuf2.0-common libgif7 libglib2.0-0 libglib2.0-bin libglib2.0-data libglib2.0-dev
  libglib2.0-dev-bin libglib2.0-doc libglib2.0-tests libgnutls30 libgpgme11 libgs9 libgs9-common libgsf-1-114
  libgsf-1-common libgssapi-krb5-2 libgstreamer-gl1.0-0 libgstreamer-plugins-base1.0-0
  libgstreamer-plugins-base1.0-dev libgstreamer-plugins-good1.0-0 libgstreamer-plugins-good1.0-dev
  libgstreamer1.0-0 libgstreamer1.0-0-dbg libgstreamer1.0-dev libgtk-3-0 libgtk-3-common libgtk2.0-0 libgtk2.0-bin
  libgtk2.0-common libk5crypto3 libklibc libkpathsea6 libkrb5-3 libkrb5support0 libldap-2.4-2 libldap-common
  libmount-dev libmount1 libmpg123-0 libmysqlclient21 libndp0 libnghttp2-14 libnm0 libnspr4 libnss-systemd libnss3
  libopenjp2-7 liborc-0.4-0 liborc-0.4-dev liborc-0.4-dev-bin libpam-modules libpam-modules-bin libpam-runtime
  libpam-systemd libpam0g libpcap0.8 libpython2.7 libpython2.7-minimal libpython2.7-stdlib libpython3.8
  libpython3.8-dev libpython3.8-minimal libpython3.8-stdlib librados2 librbd1 libsmartcols1 libsmbclient
  libsoup-gnome2.4-1 libsoup2.4-1 libss2 libssh-4 libssh-gcrypt-4 libsynctex2 libsystemd0 libtiff5 libtss2-esys0
  libudev1 libuuid1 libuv1 libvpx6 libvte-2.91-0 libvte-2.91-common libwbclient0 libwinpr2-2 libxml2 libxml2-dev
  linux-libc-dev locales login logsave mount nano nautilus-share network-manager
  network-manager-config-connectivity-ubuntu nfs-common nvidia-l4t-3d-core nvidia-l4t-apt-source
  nvidia-l4t-bootloader nvidia-l4t-camera nvidia-l4t-configs nvidia-l4t-core nvidia-l4t-cuda
  nvidia-l4t-display-kernel nvidia-l4t-firmware nvidia-l4t-gbm nvidia-l4t-graphics-demos nvidia-l4t-gstreamer
  nvidia-l4t-init nvidia-l4t-initrd nvidia-l4t-jetson-io nvidia-l4t-jetson-multimedia-api
  nvidia-l4t-jetsonpower-gui-tools nvidia-l4t-kernel nvidia-l4t-kernel-dtbs nvidia-l4t-kernel-headers
  nvidia-l4t-libvulkan nvidia-l4t-multimedia nvidia-l4t-multimedia-utils nvidia-l4t-nvfancontrol
  nvidia-l4t-nvpmodel nvidia-l4t-nvpmodel-gui-tools nvidia-l4t-nvsci nvidia-l4t-oem-config nvidia-l4t-openwfd
  nvidia-l4t-optee nvidia-l4t-pva nvidia-l4t-tools nvidia-l4t-vulkan-sc nvidia-l4t-vulkan-sc-dev
  nvidia-l4t-vulkan-sc-samples nvidia-l4t-vulkan-sc-sdk nvidia-l4t-wayland nvidia-l4t-weston nvidia-l4t-x11
  nvidia-l4t-xusb-firmware openssh-client openssh-server openssh-sftp-server openssl openvpn passwd
  python-jetson-gpio python-pip-whl python-zipp python2.7 python2.7-minimal python3-colcon-argcomplete
  python3-colcon-bash python3-colcon-cd python3-colcon-cmake python3-colcon-common-extensions python3-colcon-core
  python3-colcon-defaults python3-colcon-devtools python3-colcon-installed-package-information
  python3-colcon-library-path python3-colcon-metadata python3-colcon-mixin python3-colcon-notification
  python3-colcon-output python3-colcon-override-check python3-colcon-package-information
  python3-colcon-package-selection python3-colcon-parallel-executor python3-colcon-pkg-config
  python3-colcon-powershell python3-colcon-python-setup-py python3-colcon-recursive-crawl python3-colcon-ros
  python3-colcon-test-result python3-colcon-zsh python3-configobj python3-cryptography python3-idna
  python3-jetson-gpio python3-paramiko python3-pil python3-pip python3-pkg-resources python3-rosdistro
  python3-rosdistro-modules python3-setuptools python3-update-manager python3-urllib3 python3.8 python3.8-dev
  python3.8-minimal python3.8-venv remmina remmina-common remmina-plugin-rdp remmina-plugin-secret
  remmina-plugin-vnc rfkill samba-libs snapd systemd systemd-sysv systemd-timesyncd thunderbird
  thunderbird-gnome-support tracker-extract tracker-miner-fs tzdata ubuntu-advantage-desktop-daemon
  ubuntu-advantage-tools ubuntu-drivers-common udev unzip update-manager update-manager-core update-notifier
  update-notifier-common util-linux uuid-dev vim vim-common vim-runtime wget wpasupplicant xserver-common
  xserver-xephyr xserver-xorg-core xserver-xorg-legacy xwayland xxd
329 upgraded, 3 newly installed, 0 to remove and 0 not upgraded.
219 standard LTS security updates
Need to get 964 MB/968 MB of archives.
After this operation, 12.8 MB disk space will be freed.
Do you want to continue? [Y/n] Y

敲个Y回车，喝杯茶慢慢等吧~

偶尔得瞄两眼更新过程，有时可能有一些变更需要你确认，例如：

这里建议输入Y，虽然你已经把版本号改好了，但万一有什么其他变动呢…

注意：如果你正在从34.x升级到35.x(不是请忽略)

还需要执行：

sudo apt install nvidia-l4t-openwfd nvidia-l4t-vulkan-sc-dev nvidia-l4t-vulkan-sc-samples nvidia-l4t-vulkan-sc-sdk nvidia-l4t-vulkan-sc nvidia-l4t-jetsonpower-gui-tools

重启设备

更新完成，但别忘了jtop还需要更新一下：

sudo pip3 install -U jetson-stats

之后重启设备即可：

sudo reboot

如果发现启动之后出了问题，赶紧打开Timeshift准备Restore吧……