This demo builds both a small Linux image and a FreeRTOS based image in one project that share a common "echo" library that replies to your input. It's meant as an example on how to use Bob to build multi-image code-sharing projects to ensure API and ABI compatibility in heterogeneous and complex environments with ease.

The central component, libecho (recipe, source), is built for both Linux and FreeRTOS. On Linux, the library is used by the echo-chamber application. The same code running on FreeRTOS where it is attached to the serial port. This port is connected to Linux as /dev/ttyAMA1.

Notice that the common library is declared by only one recipe. The position in the dependency graph of a recipe determines how it is build. In particular, the toolchain is inherited from downstream dependencies automatically.

This repository uses the basement and basement-gnu-linux recipe layers. They provide common recipes for Linux, busybox, cross compilers and standard build systems. For more information about recipe layers and Bob's usage in general see its documentation. If you're interested in building containers and virtual machine images with Bob, head over to the container example.

• A x86_64 system with the regular development tools installed (GCC, make, Perl, ...)
• Bob Build Tool
• Patience ☕

To actually run the built example you'll also need QEMU.

Clone the recipes and build them with Bob:

$ git clone https://github.com/BobBuildTool/bob-example-embedded.git
$ cd bob-example-embedded
$ bob layers update
$ bob build demo::linux+freertos -j

Just execute run.sh in the result (something like ./work/demo/linux+freertos/dist/1/workspace/ but the number might differ) directory. It will start the Linux system and you can interact with the FreeRTOS system via microcom. Follow the instructions on the console. Both systems are started in parallel. The UART of the FreeRTOS system is connected to ttyAMA1 in the Linux system.

Contributions are welcome in form of feedback, bug reports and code. If you want to contribute in the form of code but are unsure about how to do things exactly, feel free to open up a pull request and ask for help.