Development Environment Setup on macOS

This section describes how to set up a macOS development system.

After completing these steps, you will be able to compile and run your Zephyr applications on the following macOS version:

  • Mac OS X 10.11 (El Capitan)
  • macOS Sierra 10.12

Developing for Zephyr on macOS generally requires you to build the toolchain yourself. However, if there is already an macOS toolchain for your target architecture you can use it directly.

Using a 3rd Party toolchain

If a toolchain is available for the architecture you plan to build for, then you can use it as explained in: Using 3rd Party Cross Compilers.

An example of an available 3rd party toolchain is GCC ARM Embedded for the Cortex-M family of cores.

Installing Requirements and Dependencies

To install the software components required to build the Zephyr kernel on a Mac, you will need to build a cross compiler for the target devices you wish to build for and install tools that the build system requires.


Minor version updates of the listed required packages might also work.

Before proceeding with the build, ensure your OS is up to date.

First, install the Homebrew (The missing package manager for macOS). Homebrew is a free and open-source software package management system that simplifies the installation of software on Apple’s macOS operating system.

To install Homebrew, visit the Homebrew site and follow the installation instructions on the site.

To complete the Homebrew installation, you might be prompted to install some missing dependency. If so, follow please follow the instructions provided.

After Homebrew is successfully installed, install the following tools using the brew command line.


Zephyr requires Python 3 in order to be built. Since macOS comes bundled only with Python 2, we will need to install Python 3 with Homebrew. After installing it you should have the macOS-bundled Python 2 in /usr/bin/ and the Homebrew-provided Python 3 in /usr/local/bin.

Install tools to build Zephyr binaries:

brew install cmake ninja dfu-util doxygen qemu dtc python3 gperf
cd ~/zephyr   # or to the folder where you cloned the zephyr repo
pip3 install --user -r scripts/requirements.txt


If pip3 does not seem to have been installed correctly use brew reinstall python3 in order to reinstall it.

Source wherever you have cloned the Zephyr Git repository:

cd <zephyr git clone location>

Finally, assuming you are using a 3rd-party toolchain you can try building the Hello World sample to check things out.

To build for the ARM-based Nordic nRF52 Development Kit:

cd $ZEPHYR_BASE/samples/hello_world
mkdir build && cd build

# Use cmake to configure a Ninja-based build system:
cmake -GNinja -DBOARD=nrf52_pca10040 ..

# Now run ninja on the generated build system:

Setting Up the Toolchain

In case a toolchain is not available for the board you are using, you can build a toolchain from scratch using crosstool-NG. Follow the steps on the crosstool-NG website to prepare your host

Follow the Zephyr SDK with Crosstool NG instructions to build the toolchain for various architectures. You will need to clone the sdk-ng repo and run the following command:

./ <arch>


Currently only i586 and arm builds are verified.

Repeat the step for all architectures you want to support in your environment.

To use the toolchain with Zephyr, export the following environment variables and use the target location where the toolchain was installed, type:

export XTOOLS_TOOLCHAIN_PATH=/Volumes/CrossToolNGNew/build/output/

To use the same toolchain in new sessions in the future you can set the variables in the file $HOME/.zephyrrc, for example:

cat <<EOF > ~/.zephyrrc
export XTOOLS_TOOLCHAIN_PATH=/Volumes/CrossToolNGNew/build/output/


In previous releases of Zephyr, the ZEPHYR_TOOLCHAIN_VARIANT variable was called ZEPHYR_GCC_VARIANT.