Yocto Layers

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

  • meta-cassini-bsp

    A Yocto layer which holds board-specific recipes or append files that either:

    • will not be upstreamed (Cassini specific modifications)

    • have not been upstreamed yet

    • For the N1SDP hardware target platform, this layer currently extends the n1sdp machine definition from the meta-arm-bsp layer with additional Trusted Services (crypto, storage, internal trusted storage, attestation)

  • meta-cassini-distro

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

  • meta-cassini-tests

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

Layer Dependency Overview

The following diagram illustrates the layers which are integrated by the Cassini project, which are further expanded on below. The layer revisions are related to the Cassini v0.9.0 release.


../_images/cassini_layers_deps.png

Cassini distribution depends on the following layer dependency sources:

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

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

URL: https://git.yoctoproject.org/git/meta-virtualization
layer: meta-virtualization
branch: langdale
revision: 2fae71cdf0e8c6f398f51219bdf31eac76c662ec

URL: https://git.yoctoproject.org/git/meta-security
layers: meta-parsec
branch: langdale
revision: c79262a30bd385f5dbb009ef8704a1a01644528e

An additional layer dependency source is conditionally required, depending on the specific Cassini 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: langdale
revision: fc09cc0e8db287600625e64905170a6de24f2686

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

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

  • A Cassini 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: