m1khal3v / focal-mainline-builder

Docker container to build Ubuntu Mainline kernels for use on 20.04 LTS

Builder for Ubuntu Mainline kernels

This container will build a mainline kernel from the Ubuntu source tree. By default the container will build binary packages which you can then install on your systems. You can optionally build a metapackage to track a build flavour, and major release of kernel (eg 5.12.x).

If you build the metapackage it will have a name like: linux-generic-5.12 and will depend on the version of 5.12.x you are building.

Alternatively it can build signed source packages for uploading to a PPA.

I upload my mainline kernels to these PPAs

Kernel Version	PPA Link	Packages
mainline/stable	lts-mainline PPA	lts-mainline Packages
longterm	lts-mainline-longterm PPA	lts-mainline-longterm Packages

Usage

1. Checkout the Mainline kernel from Ubuntu

sudo mkdir -p /usr/local/src/cod/
sudo chown $(whoami) /usr/local/src/cod

• Download the full source tree, if you want to be able to build any kernel (including previous releases)

git clone git://git.launchpad.net/~ubuntu-kernel-test/ubuntu/+source/linux/+git/mainline-crack \
  /usr/local/src/cod/mainline

• Download a specific kernel version if you only need to build this version. Eg v5.12.4:

git clone --depth=1 -b cod/mainline/v5.12.4 \
  git://git.launchpad.net/~ubuntu-kernel-test/ubuntu/+source/linux/+git/mainline-crack \
  /usr/local/src/cod/mainline

You should also pass --update=no when checking out only a single release.

2. Create a directory to receive the debian packages

mkdir /usr/local/src/cod/debs

3. Run the container

Launch the container with two volume mounts, one to the source code downloaded above, and the other for the deb packages to be copied into.

Binary debs

sudo docker run -ti -e kver=v5.12.1 -v /usr/local/src/cod/mainline:/home/source \
     -v /usr/local/src/cod/debs:/home/debs --rm tuxinvader/focal-mainline-builder:latest

Go and make a nice cup-of-tea while your kernel is built.

If you want to build a signed source package, you need to also provide your GPG keyring:

Signed Source package

sudo docker run -ti -e kver=v5.12.1 -v /usr/local/src/cod/mainline:/home/source \
     -v /usr/local/src/cod/debs:/home/debs -v ~/.gnupg:/root/keys \
     --rm tuxinvader/focal-mainline-builder:latest --btype=source --sign=<SECRET_KEY_ID> \
     --flavour=generic --exclude=cloud-tools,udebs --rename=yes

Build and sign metapackage

sudo docker run -ti -e kver=v5.12.1 -v /usr/local/src/cod/mainline:/home/source \
     -v /usr/local/src/cod/debs:/home/debs -v ~/.gnupg:/root/keys \
     --rm tuxinvader/focal-mainline-builder:latest --btype=source --sign=<SECRET_KEY_ID> \
     --flavour=generic --exclude=cloud-tools,udebs --rename=yes --buildmeta=yes \
     --maintainer="Zaphod <[email protected]>"

The linux source package builds some debs which are linked (by name) against the kernel and some which are common. Using --rename=yes allows us to store multiple kernels in the same PPA by changing the name of the source package and the linking all binaries (by name) to a specific kernel.

Notes

Set the kver variable to the version of the kernel you want to build (from here: https://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D)

The built packages or source files will be placed in the mounted volume at /home/debs, which is /usr/local/src/cod/debs if you've followed the example.

The container will do an update in the source code repository when it runs, if the tree is already up-to-date then you can append --update=no to the docker run command to skip that step.

Additional options

• Update: You can pass --update=[yes|no] to have the container perform a git pull before building the kernel. Default is yes

• Shell: You can pass --shell=[yes|no] to launch a bash shell before and after the build process. Default is no

• Build Type: You can pass --btype=[binary,source,any,all,full] to chose the type of build performed. Default is binary.

• Customize: You can pass --custom=[yes|no] to run make menuconfig before the the build process. Default is no

• Sign: You can pass --sign=<secret-key-id> to sign source packages ready for uploading to a PPA. Default is no. You'll also need to mount your GPG keys into the cotainer. Eg: -v ~/.gnupg:/root/keys and specify --btype=source

• Falvour: You can pass --flavour=[generic|lowlatency] if you want to limit the build to just one flavour. Default is none, and we build both.

• Exclude: You can pass --exclude=[cloud-tools,udebs] to exclude one or more packages. Default is none.

• Rename: You can pass --rename=[yes|no] to rename the source package to be kernel release specific. This enables hosting multple kernels in the same PPA. Use with --exclude=tools,udebs to stop duplicate packages being built. Default is no

• Series: You can pass --series=[focal|groovy|...] to set the ubuntu version you're building for. Default is focal

• Patch: You can pass a patch version to apply upstream patch to the ubuntu kernel. Eg --patch=v5.11.21 to patch v5.11.20 upto v5.11.21. Default is no

• Check bugs: You can pass --checkbugs=yes to work around any known bugs, currently this is required to build older 5.10.x and 5.11.x kernels see bug #4

• Build metapackage: You can pass --buildmeta=[yes|no] to build a metapackage named linux-<flavour>-<major version> that will depend on the kernel you are building. This makes it easy to track the latest release and auto-update using apt.

• Maintainer: If you want to sign the metapackage (for PPA upload), then you need to provide the details of your signing key by passing --maintainer="Me <[email protected]>"