meta-silkit - Yocto Recipes for SIL Kit + Adapters

This repository contains a meta layer for the Yocto Project. It allows you to build SIL Kit as part of your custom distro build with bitbake and the Yocto Project. It contains recipes for the following packages:

• libsilkit
  • The SIL Kit library, developer and utility tools
• silkit-adapter-tap
  • Vector SIL Kit Adapter for TAP devices
• silkit-adapter-vcan
  • Vector SIL Kit Adapter for virtual CAN (SocketCAN) devices

For more information, please visit:

• https://github.com/vectorgrp/sil-kit
• https://github.com/vectorgrp/sil-kit-adapters-tap
• https://github.com/vectorgrp/sil-kit-adapters-vcan

How to build

This is a step-by-step example, how-to build a poky core-image-minimal containing libsilkit for a QEMU x86-64 image.

Setup

Warning

The build directory for a minimal image (poky core-image-minimal) is around 70GB. To be safe, it is better to have at least 100GB free on your harddrive for the build directory!

First, we need to install all prerequisite dependencies

$ > sudo apt install gawk wget git diffstat unzip texinfo gcc build-essential chrpath socat cpio python3 python3-pip python3-pexpect xz-utils debianutils iputils-ping python3-git python3-jinja2 python3-subunit zstd liblz4-tool file locales libacl1
$ > sudo locale-gen en_US.UTF-8

We now need to clone the poky distribution repository. We currently only support Poky 5.0.4 (scarthgap), so we can clone the scarthgap branch directly!

$ > git clone --depth 1 -b scarthgap https://git.yoctoproject.org/poky

To setup the build environment for the Linux image, poky comes with a handy setup script, which we can source:

$ > cd poky
$ > source oe-init-build-env

This will create the appropriate environment and drop us directly into the build directory. We can now configure our build to create the exact Linux distro we desire.

Build Configuration

But first we need to tell Yocto about our meta-silkit layer. We do this in the conf/bblayers.conf

# conf/bblayers.conf
.
.
BBLAYERS ?= " \
  /Path/to/poky/meta \
  /Path/to/poky/meta-poky \
  /Path/to/poky/meta-yocto-bsp \
  /Path/to/meta-silkit \
  "

Here we added the path to our meta-silkit layer at the end of the BBLAYERS variable.

We can now configure our build through the conf/local.conf file

# conf/bblayers.conf
.
.
MACHINE ??= "qemux86-64"
.
.
IMAGE_INSTALL:append = "libsilkit libsilkit-dev silkit-utils silkit-adapter-tap silkit-adapter-vcan"

The MACHINE variable selects the desired CPU architecture for which to build. In our case we go with a QEMU image for the x86-64 architecture. Other MACHINE values you can select out of the box include qemuarm and qemuarm64. If you develop for a specific hardware target, you should set the MACHINE to the appropriate values for the Board Support Layer of your target.

Then we must tell Yocto to include the packages build by our layer to the image via the IMAGE_INSTALL variable. Since we only want to add our packages to the default list of packages, we append them via the :append syntax.

Building the package

We build the image via

$ > bitbake core-image-minimal

This is the most minimalistic console image Yocto provides out of the box. If you want a more full-fledged console image, you can use core-image-full-cmdline or core-image-weston for an image with a minimal Wayland GUI.

Warning

The build process can take a long time even with a powerful workstation.

Running the image

$ > runqemu

This will automatically start the last build image in a QEMU instance. You should now be able to start the sil-kit-registry

root@qemux86-64: ~# sil-kit-registry
Vector SIL Kit -- Registry, SIL Kit version 4.0.54

SIL Kit Registry listening on silkit://localhost:8500
Press Ctrl-C to terminate...
_

You can now start your Happy OpenEmbedded Hacking :)