Setup tool for bitbake based projects

This tool provides an easy mechanism to setup bitbake based projects.

The OpenEmbedded tooling support starts at step 2 with bitbake. The downloading of sources and then configuration has to be done by hand. Usually, this is explained in a README. Instead kas is using a project configuration file and does the download and configuration phase.

Currently supported Yocto versions:

• 2.1 (Krogoth)
• 2.2 (Morty)

Dependencies

This projects depends on

• Python 3
• configparser

If you need Python 2 support consider sending patches. The most obvious place to start is to use the trollius package intead of asyncio.

Build Tool features

Key features provided by the build tool:

• clone and checkout bitbake layers
• create default bitbake settings (machine, arch, ...)
• automatically apply proxy settings in build environment (creates a minimal environment)
• initiate bitbake build process

Usage

There are three options for using kas:

• Install it via pip to get the kas command
• Use the docker image. In this case replace kas in the examples below with docker run -it <kas-image>
• Use the run-kas wrapper from this directory. In this case replace kas in the examples below with path/to/run-kas.

Start build:

$ kas build project/ebs.py

Note: In the docker case you have to bind-mount the config to the container first.

Alternatively, experienced bitbake users can do the usual oe-init-buildenv, bitbake steps, but then you need to take care about necessary proxy settings by yourself.

Use Cases

1. Initial build/setup

   $ mkdir $PROJECT_DIR
   $ cd $PROJECT_DIR
   $ git clone $PROJECT_URL meta-project
   $ kas build meta-project/kas-project.py
   

2. Update/rebuild

   $ cd $PROJECT_DIR/meta-project
   $ git pull
   $ kas build kas-project.py
   

Project Configuration

Two types of input formats supported. For an product image a the static configuration can be used. In case several different configuration should be supported the dynamic configuration file can be used.

Static project configuration

Currently there is supports for JSON and Yaml.

{
    "machine": "qemu",
    "distro": "poky",
    "repos": [
        { "url": "" },
        { "url": "https://git.yoctoproject.org/git/poky",
          "refspec": "krogoth",
          "sublayers": [ "meta", "meta-poky", "meta-yocto-bsp"]}
    ]
}

A minimal input file consist out of 'machine', 'distro', and 'repos'.

Additionally, you can add 'bblayers_conf_header' and 'local_conf_header' which are arrays of strings, e.g.

    "bblayers_conf_header": ["POKY_BBLAYERS_CONF_VERSION = \"2\"",
                             "BBPATH = \"${TOPDIR}\"",
                             "BBFILES ?= \"\""],
    "local_conf_header": ["PATCHRESOLVE = \"noop\"",
                          "CONF_VERSION = \"1\"",
                          "IMAGE_FSTYPES = \"tar\""]

Dynamic project configuration

The dynamic project configuration is plain Python with following mandatory functions which need to be provided:

def get_machine(config):
    return 'qemu'


def get_distro(config):
    return 'poky'


def get_repos(target):
    repos = []

    repos.append(Repo(
        url='URL',
        refspec='REFSPEC'))

    repos.append(Repo(
        url='https://git.yoctoproject.org/git/poky',
        refspec='krogoth',
        sublayers=['meta', 'meta-poky', 'meta-yocto-bsp'])))

    return repos

Additionally, get_bblayers_conf_header(), get_local_conf_header() can be added.

def get_bblayers_conf_header():
    return """POKY_BBLAYERS_CONF_VERSION = "2"
BBPATH = "${TOPDIR}"
BBFILES ?= ""
"""


def get_local_conf_header():
    return """PATCHRESOLVE = "noop"
CONF_VERSION = "1"
IMAGE_FSTYPES = "tar"
"""

Furthermore, you can add pre and post hooks (*_prepend, *_append) for the exection steps in kas core, e.g.

def build_prepend(config):
    # disable distro check
    with open(config.build_dir + '/conf/sanity.conf', 'w') as f:
        f.write('\n')


def build_append(config):
    if 'CI' in os.environ:
        build_native_package(config)
        run_wic(config)

TODO: Document the complete configuration API.

Environment variables

KAS_REPO_RED_DIR should point to a directory that contains repositories that should be used as references. In order for kas to find those repositories, they have to be named correctly. Those names are derived from the repo url in the kas config. (E.g. url: "https://github.com/siemens/meta-iot2000.git" resolves to the name "github.com.siemens.meta-iot2000.git")

Install

$ sudo pip install

Will install kas into your python site-package repository.

Development

This project uses pip to manage the package. If you want to work on the project yourself you can create the necessary links via:

$ sudo pip install -e .

That will install a backlink /usr/bin/kas to this project. Now you are able to call it from anywhere.

Docker image build

Just run

$ docker build -t <image_name> .

When you need a proxy to access the internet, add --build-arg http_proxy=<http_proxy> --build-arg https_proxy=<https_proxy> to the call.

shell

$ kas shell kas-project.json -c 'bitbake dosfsutils-native'