[RFC PATCH 0/2] Yocto Gitlab CI support

[Bertrand Marquis <bertrand.marquis@xxxxxxx>]

This patch series is a first attempt to check if we could use Yocto in
gitlab ci to build and run xen on qemu for arm, arm64 and x86.

The first patch is creating a container with all elements required to
build Yocto, a checkout of the yocto layers required and an helper
script to build and run xen on qemu with yocto.

The second patch is creating containers with a first build of yocto done
so that susbsequent build with those containers would only rebuild what
was changed and take the rest from the cache.

This is is mainly for discussion and sharing as there are still some
issues/problem to solve:
- building the qemu* containers can take several hours depending on the
  network bandwith and computing power of the machine where those are
  created
- produced containers containing the cache have a size between 8 and
  12GB depending on the architecture. We might need to store the build
  cache somewhere else to reduce the size. If we choose to have one
  single image, the needed size is around 20GB and we need up to 40GB
  during the build, which is why I splitted them.
- during the build and run, we use a bit more then 20GB of disk which is
  over the allowed size in gitlab

Once all problems passed, this can be used to build and run dom0 on qemu
with a modified Xen on the 3 archs in less than 10 minutes.

Bertrand Marquis (2):
  automation: Add elements for Yocto test and run
  automation: Add yocto containers with cache

 automation/build/Makefile                     |   2 +
 automation/build/yocto/build-yocto.sh         | 322 ++++++++++++++++++
 .../build/yocto/kirkstone-qemuarm.dockerfile  |  28 ++
 .../yocto/kirkstone-qemuarm64.dockerfile      |  28 ++
 .../yocto/kirkstone-qemux86-64.dockerfile     |  28 ++
 automation/build/yocto/kirkstone.dockerfile   |  98 ++++++
 6 files changed, 506 insertions(+)
 create mode 100755 automation/build/yocto/build-yocto.sh
 create mode 100644 automation/build/yocto/kirkstone-qemuarm.dockerfile
 create mode 100644 automation/build/yocto/kirkstone-qemuarm64.dockerfile
 create mode 100644 automation/build/yocto/kirkstone-qemux86-64.dockerfile
 create mode 100644 automation/build/yocto/kirkstone.dockerfile

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2.25.1