26 Creating a Custom Template Configuration Directory

If you are producing your own customized version of the build system for use by other users, you might want to customize the message shown by the setup script or you might want to change the template configuration files (i.e. local.conf and bblayers.conf) that are created in a new build directory.

The OpenEmbedded build system uses the environment variable TEMPLATECONF to locate the directory from which it gathers configuration information that ultimately ends up in the Build Directory conf directory. By default, TEMPLATECONF is set as follows in the poky repository:

TEMPLATECONF=${TEMPLATECONF:-meta-poky/conf}

This is the directory used by the build system to find templates from which to build some key configuration files. If you look at this directory, you will see the bblayers.conf.sample, local.conf.sample, and conf-notes.txt files. The build system uses these files to form the respective bblayers.conf file, local.conf file, and display the list of BitBake targets when running the setup script.

To override these default configuration files with configurations you want used within every new Build Directory, simply set the TEMPLATECONF variable to your directory. The TEMPLATECONF variable is set in the .templateconf file, which is in the top-level Source Directory folder (e.g. poky). Edit the .templateconf so that it can locate your directory.

Best practices dictate that you should keep your template configuration directory in your custom distribution layer. For example, suppose you have a layer named meta-mylayer located in your home directory and you want your template configuration directory named myconf. Changing the .templateconf as follows causes the OpenEmbedded build system to look in your directory and base its configuration files on the *.sample configuration files it finds. The final configuration files (i.e. local.conf and bblayers.conf ultimately still end up in your Build Directory, but they are based on your *.sample files.

TEMPLATECONF=${TEMPLATECONF:-meta-mylayer/myconf}

Aside from the *.sample configuration files, the conf-notes.txt also resides in the default meta-poky/conf directory. The script that sets up the build environment (i.e. oe-init-build-env) uses this file to display BitBake targets as part of the script output. Customizing this conf-notes.txt file is a good way to make sure your list of custom targets appears as part of the script’s output.

Here is the default list of targets displayed as a result of running either of the setup scripts:

You can now run 'bitbake <target>'

Common targets are:
    core-image-minimal
    core-image-sato
    meta-toolchain
    meta-ide-support

Changing the listed common targets is as easy as editing your version of conf-notes.txt in your custom template configuration directory and making sure you have TEMPLATECONF set to your directory.