How to display new Yocto image option after source poky/oe-init-env

Question

let say i have a new yocto image call stargazer-cmd what file should i edit so that every time i source poky/oe-init-env it display as a build option to the user?

kj@kj-Aspire-V3-471G:~/stm32Yoctominimal$ source poky/oe-init-build-env  build-mp1/

### Shell environment set up for builds. ###

You can now run 'bitbake <target>'

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

I wish to add stargazer-cmd on top of core-image-minimal, i am not sure what to google and what is the file i need to change.

Answer 1

Let me explain how to add a custom configuration to the OpenEmbedded build process.

First of all, here is the process that is done when running:

source poky/oe-init-build-env

1. The oe-init-build-env script initializes OEROOT variable to point to the location of the script itself.

2. The oe-init-build-env script sources another file $OEROOT/scripts/oe-buildenv-internal which will:

• Check if OEROOT is set
• Set BUILDDIR to your custom build directory name $1, or just build if you do not provide one
• Set BBPATH to the poky/bitbake folder
• Adds $BBPATH/bin and OEROOT/scripts to PATH (This will enable commands like bitbake and bitbake-layers ...)
• Export BUILDDIR and PATH to the next file

3. The oe-init-build-env script continues by running the final build script with:

TEMPLATECONF="$TEMPLATECONF" $OEROOT/scripts/oe-setup-builddir

4. The oe-setup-builddir script will:

• Check if BUILDDIR is set
• Create the conf directory under $BUILDDIR
• Sources a template file that will check if there is a TEMPLATECONF variable is set:

. $OEROOT/.templateconf

That file contains:

# Template settings
TEMPLATECONF=${TEMPLATECONF:-meta-poky/conf}

it means that if TEMPLATECONF variable is not set, set it to meta-poky/conf, and that is where the default local.conf and bblayers.conf are coming from.

• Copy $TEMPLATECONF to $BUILDDIR/conf/templateconf.cfg
• Set some variables pointing to custom local.conf and bblayers.conf:

OECORELAYERCONF="$TEMPLATECONF/bblayers.conf.sample"
OECORELOCALCONF="$TEMPLATECONF/local.conf.sample"
OECORENOTESCONF="$TEMPLATECONF/conf-notes.txt"

In the oe-setup-builddir there is a comment saying that TEMPLATECONF can point to a directory:

# 
# $TEMPLATECONF can point to a directory for the template local.conf & bblayers.conf
#

• Copy local.conf.sample and bblayers.conf.sample from TEMPLATECONF directory into BUIDDIR/conf:

cp -f $OECORELOCALCONF "$BUILDDIR/conf/local.conf"

sed -e "s|##OEROOT##|$OEROOT|g" \
    -e "s|##COREBASE##|$OEROOT|g" \
        $OECORELAYERCONF > "$BUILDDIR/conf/bblayers.conf"

Finally it will print what is inside OECORENOTESCONF which points to TEMPLATECONF/conf-notes.txt:

[ ! -r "$OECORENOTESCONF" ] || cat $OECORENOTESCONF

and by default that is located under meta-poky/conf/conf-notes.txt:

### Shell environment set up for builds. ###

You can now run 'bitbake <target>'

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

You can also run generated qemu images with a command like 'runqemu qemux86'

Other commonly useful commands are:
 - 'devtool' and 'recipetool' handle common recipe tasks
 - 'bitbake-layers' handles common layer tasks
 - 'oe-pkgdata-util' handles common target package tasks

So, now, after understanding all of that, here is what you can do:

1. Create a custom template directory for your project, containing:

• local.conf.sample
• bblayers.conf.sample
• conf-notes.txt

2. Do not forget to set the path to poky in bblayers.conf to ##OEROOT## as it will be set automatically by the build script.

3. Set your custom message in conf-notes.txt

4. Before any new build, just set TEMPLATECONF:

TEMPLATECONF="<path/to/template-directory>" source poky/oe-init-build-env <build_name>

Then, you will find a build with your custom local.conf and bblayers.conf with additional file conf/templateconf.cfg containing the path of TEMPLATECONF