Ubuntu Kernel plugin¶

The Ubuntu Kernel plugin builds signed Ubuntu kernels using official Debian build rules. It supports customized kernel packages that can target Ubuntu snap-based systems.

This plugin is separate from the Kernel plugin. The Kernel plugin builds a custom kernel from source using mainline Linux build scripts. The Ubuntu Kernel plugin builds an Ubuntu kernel using the Ubuntu debian/rules build scripts – the same scripts used to produce the official Ubuntu kernels.

The plugin supports building Ubuntu kernel snaps from existing Debian packages or from source. When building from source the optional source key may be used to provide a custom source repository URL. If not provided, the official Canonical Ubuntu kernel source repository will be used.

Currently, signed kernel snaps can only be built using the official Canonical kernel Debian packages.

Keys¶

ubuntu-kernel-flavor¶

Type string

Default “generic”

The Ubuntu kernel flavor to pack. Ubuntu kernels come in different flavors that may target different architectures and configurations.

ubuntu-kernel-dkms¶

Type list[string]

Note If provided, the key ubuntu-kernel-use-binary-package must be false.

List of dynamic kernel modules to include in the kernel pack. When not provided, the DKMS list will be the default list provided by the Ubuntu kernel source.

ubuntu-kernel-release-name¶

Type string

Note This key is mutually exclusive with the source key.

If provided, this key specifies the Ubuntu release name to build, e.g. Jammy, Noble. The release name dictates which kernel version will be built.

If not provided, a source key must be provided.

ubuntu-kernel-defconfig¶

Type path

Note If provided, the key ubuntu-kernel-use-binary-package must be false.

Path to a kernel defconfig file for custom kernel configuration.

ubuntu-kernel-config¶

Type list[string]

Note If provided, the key ubuntu-kernel-use-binary-package must be false.

List of kernel config options and values. Useful if only a few kernel configuration entries need to be modified.

ubuntu-kernel-image-target¶

Type string

Note If provided, the key ubuntu-kernel-use-binary-package must be false.

Specify the kernel image target type if different from the platform image type. The default target platform image type is defined as:

Target	Image
amd64	bzImage
arm64	Image.gz
armhf	zImage
i386	bzImage
powerpc	uImage
ppc64el	vmlinux.strip
riscv64	Image
s390x	bzImage

ubuntu-kernel-tools¶

Type list[string]

Note If provided, the key ubuntu-kernel-use-binary-package must be false.

List of kernel tools to package. Supported tools are: cpupower, perf, bpftool. If not provided, the default tools for the kernel flavor will be packaged.

ubuntu-kernel-use-binary-package¶

Type bool

If true, build the kernel snap using existing kernel Debian packages. The key ubuntu-kernel-release-name will define which Ubuntu kernel packages are used as the source.

Example¶

This example shows the minimal plugin part that builds a generic noble kernel from source.

name: kernel-noble
summary: Noble kernel snap package.
description: |
    Build a kernel snap package of the latest Noble release.
version: test
grade: devel
confinement: devmode
base: core24
platform:
    arm64:
        build-on: amd64
        build-for: arm64
parts:
    ubuntu-kernel:
        plugin: ubuntu-kernel
        ubuntu-kernel-release-name: noble

Example¶

This example part builds a noble kernel snap from an existing signed Ubuntu kernel apt package.

parts:
    ubuntu-kernel:
        plugin: ubuntu-kernel
        ubuntu-kernel-release-name: noble
        ubuntu-kernel-use-binary-package: true

Example¶

This part example shows how to build the noble kernel from source with additional dkms packages.

parts:
    ubuntu-kernel:
        plugin: ubuntu-kernel
        ubuntu-kernel-release-name: noble
        ubuntu-kernel-dkms: [
          "vpoll-dkms",
          "r8125-dkms"
        ]

Example¶

This part example builds an Ubuntu kernel from source. Any source can be used.

parts:
    ubuntu-kernel:
        plugin: ubuntu-kernel
        source: https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/noble
        source-type: git
        source-branch: master-next
        source-depth: 1