Yocto Layers

The meta-ewaol repository provides three layers compatible with the Yocto Project, in the following sub-directories:

  • meta-ewaol-distro

    Yocto distribution layer providing top-level and general policies for the EWAOL distribution images.

  • meta-ewaol-tests

    Yocto software layer with recipes that include run-time tests to validate EWAOL functionalities.

  • meta-ewaol-bsp

    Yocto BSP layer with target platform specific extensions for particular EWAOL distribution images. Currently this layer extends the n1sdp machine definition from the meta-arm-bsp layer for EWAOL virtualization distribution images. The meta-ewaol-bsp layer contains an additional grub configuration file with Xen boot entry and a custom kickstart ewaol-virtualization-n1sdp-efidisk.wks.in file. There is also a xen-devicetree.bb recipe, to generate a devicetree with extra modules nodes required by Xen to start the Control VM (Dom0). In addition, the Xen devicetree together with a Xen efi binary are included into the final wic image in the boot partition.

Layer Dependency Overview

The following diagram illustrates the layers which are integrated by the EWAOL project, which are further expanded on below. The layer revisions are related to the EWAOL v1.0 release.

../_images/ewaol_layers_deps_diagram.png

EWAOL depends on the following layer dependency sources:

URL: https://git.yoctoproject.org/git/poky
layers: meta, meta-poky
branch: kirkstone
revision: 453be4d258f71855205f45599eea04589eb4a369

URL: https://git.openembedded.org/meta-openembedded
layers: meta-filesystems, meta-networking, meta-oe, meta-python
branch: kirkstone
revision: 166ef8dbb14ad98b2094a77fcf352f6c63d5abf2

URL: https://git.yoctoproject.org/git/meta-virtualization
layers: meta-virtualization
branch: kirkstone
revision: 2fae71cdf0e8c6f398f51219bdf31eac76c662ec

An additional layer dependency source is conditionally required, depending on the specific EWAOL distribution image being built. This layer dependency source is the meta-arm repository, which provides three Yocto layers:

URL: https://git.yoctoproject.org/git/meta-arm
layers: meta-arm, meta-arm-bsp, meta-arm-toolchain
branch: kirkstone
revision: fc09cc0e8db287600625e64905170a6de24f2686

The layers required from meta-arm depend on the EWAOL distribution image:

  • EWAOL SDK distribution images require meta-arm and meta-arm-toolchain, as the gator-daemon package is installed on the rootfs.

  • An EWAOL virtualization distribution image requires meta-arm and meta-arm-toolchain, as by default a bundled Guest VM image based on the generic-arm64 MACHINE is built.

  • An EWAOL distribution image built for the N1SDP hardware target platform requires meta-arm, meta-arm-bsp, and meta-arm-toolchain.

These layers are described as follows: