This repository contains tools for building firmwares for the Home Assistant Connect ZBT-1/SkyConnect and the Home Assistant Yellow's IEEE 802.15.4 radio. The firmware manifests are entirely generic, however, and are intended to be written easily for any Silicon Labs EFR32 device.

It uses the Silicon Labs Gecko SDK and proprietary Silicon Labs tools such as the Silicon Labs Configurator (slc) and the Simplicity Commander standalone utility.

The projects contained within this repository are configured for the BRD4001A dev kit with a BRD4179B (EFR32MG21) module. This allows base projects to be debugged using the Simplicity Studio IDE. These base projects are then retargeted for other boards using manifest files. For example, the skyconnect_ncp-uart-hw.yaml manifest file retargets the base firmware to the SkyConnect/Connect ZBT-1.

If you are going to be developing using Simplicity Studio, note that each project can potentially use a different Gecko SDK release. It is recommended to forego the typical Simplicity Studio SDK management workflow and manually manage SDKs:

1. Clone a specific version of the Gecko SDK:

   # For macOS
   mkdir ~/SimplicityStudio/SDKs/gecko_sdk_4.4.2
   cd ~/SimplicityStudio/SDKs/gecko_sdk_4.4.2
   
   git clone -b v4.4.2 https://github.com/SiliconLabs/gecko_sdk .
   git checkout -b branch_tag

2. Open preferences, navigate to Simplicity Studio > SDKs, click the Add SDK... button, and browse to the above location.

3. Once the SDK is added, select its entry and click Add Extension....

4. In this repo, add the extensions under gecko_sdk_extensions.

Repeat this process for every necessary SDK version.

Base projects can now be built normally.

Command line building requires:

• slc-cli
• Simplicity Commander (commander)
• The exact Gecko SDK version required by the project. Note that this doesn't have to be a Git working tree, you can use a GitHub release.
• A compatible toolchain. Take a look at the Dockerfile for the necessary toolchains.

slc-cli maintains its own SDK and extension trust store so you first must trust all SDK extensions for every SDK you plan to use:

slc signature trust --sdk ~/SimplicityStudio/SDKs/gecko_sdk_4.4.2
slc signature trust --sdk ~/SimplicityStudio/SDKs/gecko_sdk_4.4.2 --extension-path ~/SimplicityStudio/SDKs/gecko_sdk_4.4.2/extension/nc_efr32_watchdog_extension

tools/build_project.py is the main entry point for building firmwares. Provide paths to potential SDKs and toolchains with the --sdk and --toolchain flags. The build tool will automatically determine which SDK and toolchain to use.

pip install ruamel.yaml  # Only dependency

python tools/build_project.py \
    # The following SDK and toolchain flags can be omitted on macOS
    --sdk ~/SimplicityStudio/SDKs/gecko_sdk_4.4.0 \
    --sdk ~/SimplicityStudio/SDKs/gecko_sdk_4.4.2 \
    --toolchain '/Applications/Simplicity Studio.app/Contents/Eclipse/developer/toolchains/gnu_arm/10.3_2021.10' \
    --toolchain '/Applications/Simplicity Studio.app/Contents/Eclipse/developer/toolchains/gnu_arm/12.2.rel1_2023.7' \

    --manifest manifests/skyconnect_ncp-uart-hw.yaml \
    --build-dir build \
    --output-dir output \

    # Generate `.gbl`, `.out`, and `.hex` firmwares
    --output gbl \
    --output out \
    --output hex

Once the build is complete, the firmwares will be in the output directory.