Create a custom Ubuntu Server preinstalled image

Prerequisites

  • Ubuntu-image is the tool used by Canonical to build official Ubuntu images. It must be installed on a build environment running Ubuntu 20.04 (Focal Fossa) or newer. It is recommended to use Ubuntu 24.04 (Noble Numbat).

sudo snap install --classic --channel latest/stable ubuntu-image

Create an image definition file

An image definition file, in YAML format, defines the various configurations required to build a custom Ubuntu image:

  • class: Defines the type of image, such as cloud, installer or preinstalled (Canonical certified Server images are preinstalled).

  • kernel: Specifies the preinstalled kernel in the image. The official Ubuntu kernel for Jetson is “linux-nvidia-tegra-jetson”, but it can be replaced with an alternative custom kernel, for instance hosted in a PPA for development purpose.

  • gadget: Boot assets of an image.

  • customization: Features such as particular snaps and packages that will come installed in the image.

  • artifacts: Artifacts to create, including (but not limited to) the actual images, and manifest files.

For more details about each field, refer to the image definition documentation.

Ubuntu certified Image definition files

The ubuntu-images repository serves as the official source for Canonical image definitions and scripts. It is used to build various Ubuntu versions and flavors. This includes optimized versions for Jetson Tegra hardware, currently supporting Ubuntu 22.04 (Jammy Jellyfish) for Jetson Orin platforms and 24.04 (Noble Numbat) for Jetson Thor devices.

The following commands allow to check the definition files used to generate the Ubuntu Server image certified by Canonical:

git clone -b jammy https://git.launchpad.net/ubuntu-images
cd ubuntu-images
cat ubuntu-server-tegra-jetson.yaml

Build the Classic Server image

Once the corresponding image definition file is created, the server image can be built through the following command.

sudo ubuntu-image classic <image_definition>.yaml --debug

In the example above, the –debug flag prints additional information about each step executed as part of the image build process, coming in handy to troubleshoot any issues.