Yocto Introduction
The Yocto Project is an open source collaboration project that helps developers create custom Linux-based systems regardless of the hardware architecture.
TQ extends the Yocto Project's reference system Poky by the meta-tq layer to provide support for a selection of TQ Embedded CPU Modules, including the MOD_NAME.
In addition to the meta-tq layer TQ Systems also provides the meta-dumpling layer for evaluting the TQ Systems CPU modules and Starterkits.
To build and test the meta-tq hardware support layer TQ Systems provides ci-meta-tq. It covers the setup, configuration and dependencies to other yocto layer required for the build.
TQ Yocto Layer Overview
ci-meta-tq
The ci-meta-tq layer covers the setup, configuration and dependencies to other yocto required to build the meta-tq layer. All Yocto layers the BSP build depends on, are included as git submodules. It is intended to build and test the meta-tq hardware support layer. We recommend to use the ci-meta-tq as a basis for the starterkit evaluation.
meta-tq
This layer provides all the TQ Sytems SOM and Starterkit specific configurations, it covers the machine configuration machine, Linux kernel and U-Boot recipe. meta-tq also contains the meta-dumpling layer since Yocto
meta-dumpling
This layer provides image recipes and distro configuration for evaluation of the TQ Systems CPU modules and Starterkits.
Additionally meta-dumpling contains optional fixes and extensions for other layers as far as needed/useful for TQ Systems SOM.
These recipes can be used as a starting point to create an own image recipe.
The layers meta-tq and meta-dumpling are available via the TQ-Systems github repository. In addition to the TQ specific Yocto meta layers and ci-meta-tq, the U-Boot and Linux kernel repositories are also available via github.
Build Host setup
Basic setup
Yocto Project / Poky requires a Linux build host, so first of all you need a development workstation (or a virtual machine)) with a Linux distribution installed. We recommend to use Build Host
Please refer to section Compatible Linux Distribution of the Yocto Project Quick Start for supported linux distributions. Yocto requires some and section Build Host Packages for required build host packages for those distributions.
As we strongly recommend to use Git to clone the TQ Yocto layer, if you do not have setup git already please do this before starting to setup your build environment.
git config ‐‐global user.email your_email@example.com git config ‐‐global user.name "name surname"
The git configuration is stored in ~/.gitconfig
Additional setup
Beside the local.conf file that provides many basic variables to define the build environment, it is also possible to use the site.conf file for the configuration. This file is not created by the environment initialization script, it has to be created manually. The advantage is that it is possible to store it in the current user home directory. For example it is possivle to store the download and sstate cache directory outside of the buildspace. If the buildspace has to be reset for any reason, an easy reusage of the sstate cache and
Download and cache directory ~/.yocto/site.conf
DL_DIR ?= “<your_directory>/yocto_downloads” SSTATE_DIR ?= “<your_directory>/yocto_sstate”
Although not required by Yocto Project / Poky, we also recommend to configure and run a tftp server (for image download / update) and an nfs server (for network mounted root filesystem) on your development host.