Lua Zephyr Module (WIP)

NOTE: We are currently updating this repository for compatibility with the latest versions of Zephyr. New features will be added in the following days.

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This repository provides an example of how the Lua language can be integrated in a project using the Zephyr embedded operating system. The repository is structured as a Zephyr module to simplify integration.

Features (WIP)

• Fully integrated within the Zephyr's build system.
• A Lua compiler is built in a per board basis so no runtime problems can arise due to configuration mismatch.
• Support Lua byte code embedded directly into the application firmware.
• Support for the luasocket library.

Application examples

Under the folder samples/, you can find examples of how to use Lua in a Zephyr project. Lua scripts are compiled using luac and embedded directly into the firmware. This approach avoids the need for a filesystem, making it lightweight and suitable for embedded environments.

• samples/app: Basic Lua application with a countdown loop.
• samples/socket: Test luasocket library running a simple TCP server.

Building

The Lua files are compiled and embedded directly into the firmware. The build system is integrated with Zephyr’s CMake process. A helper function lua_generate_inc_file_for_target is used to simplify building:

generate_lua_inc_file_for_target(
  app
  ${CMAKE_CURRENT_SOURCE_DIR}/lua/main.lua
)

Lua source files are located under lua/ in the corresponding application folder. Any modification to these files triggers a rebuild of the final binary firmware just like changes in .c or .h files.

Build the firmware using the west tool from the app/ directory:

west build -b <BOARD>

If you do not have a physical board, you can use Qemu. The recommended board is qemu_x86:

west build -b qemu_x86

We also provide a debug configuration file which can be used at build time:

west build -b qemu_x86 -- -DOVERLAY_CONFIG=dbg.conf

Running the app

To run the application in Qemu:

west build -t run

NOTE: Use CTRL+A then C to interact with the Qemu virtual machine.