Getting Started Guide

Use this guide to get started with your Zephyr development.

Checking Out the Source Code Anonymously

The Zephyr source code is hosted in a GitHub repo that supports anonymous cloning via git. There are scripts and such in this repo that you’ll need to set up your development environment, and we’ll be using Git to get this repo. (If you don’t have Git installed, see the beginning of the OS-specific instructions below for help.)

We’ll begin by using Git to clone the repository anonymously. Enter:

$ cd ~
$ git clone https://github.com/zephyrproject-rtos/zephyr.git

You have successfully checked out a copy of the source code to your local machine in the ~/zephyr folder.

Set Up the Development Environment

The Zephyr project supports these operating systems:

  • Linux
  • macOS
  • Windows 8.1

Use the following procedures to create a new development environment.

Building and Running an Application

Using the ‘Hello World’ sample application as a base model, the following section will describe the pieces necessary for creating a Zephyr application.

The processes to build and run a Zephyr application are the same across operating systems. Nevertheless, the commands needed do differ from one OS to the next. The following sections contain the commands used in a Linux development environment. If you are using macOS please use the appropriate commands for your OS.

Building a Sample Application

To build an example application follow these steps:

  1. Make sure your environment is setup by exporting the following environment variables. When using the Zephyr SDK on Linux for example, type:

    $ export ZEPHYR_GCC_VARIANT=zephyr
$ export ZEPHYR_SDK_INSTALL_DIR=<sdk installation directory>

  2. Navigate to the main project directory:

    $ cd zephyr

  3. Source the project environment file to set the project environment variables:

    $ source zephyr-env.sh

  4. Build the Hello World example for the arduino_101 board, enter:

    $ cd $ZEPHYR_BASE/samples/hello_world

# Make a build directory, and use cmake to configure a Make-based build system:
$ mkdir -p build/arduino_101 && cd build/arduino_101
$ cmake -DBOARD=arduino_101 ../..

# Now run make on the generated build system:
$ make

You can build for a different board by defining the variable BOARD with another of the supported boards, for example:

$ cd $ZEPHYR_BASE/samples/hello_world

# Make a build directory, and use cmake to configure a Make-based build system:
$ mkdir -p build/arduino_due && cd build/arduino_due
$ cmake -DBOARD=arduino_due ../..

# Now run make on the generated build system:
$ make

For further information on the supported boards go see here. Alternatively, run the following command to obtain a list of the supported boards:

$ make usage

Sample projects for different features of the project are available at at $ZEPHYR_BASE/samples. After building an application successfully, the results can be found in the directory where cmake was invoked.

The ELF binaries generated by the build system are named by default zephyr.elf. This value can be overridden in the application configuration The build system generates different names for different use cases depending on the hardware and boards used.

Building without the Zephyr SDK

The Zephyr SDK is provided for convenience and ease of use. It provides cross-compilers for all ports supported by the Zephyr OS and does not require any extra flags when building applications or running tests.

In addition to cross-compilers, the Zephyr SDK also provides prebuilt host tools. To use the SDK host tools alongside a custom or 3rd party cross-compiler, keep the ZEPHYR_SDK_INSTALL_DIR environment variable set to the Zephyr SDK installation directory.

To build without the Zephyr SDK’s prebuilt host tools, the ZEPHYR_SDK_INSTALL_DIR environment variable must be unset, the host tools must be built and added to path, and a 3rd party cross-compiler must be installed.

  1. Follow the steps below to build without the Zephyr SDK:

    $ unset ZEPHYR_GCC_VARIANT
$ unset ZEPHYR_SDK_INSTALL_DIR
$ cd <zephyr git clone location>
$ source zephyr-env.sh

  2. Build Kconfig in $ZEPHYR_BASE/build and add it to path

    $ cd $ZEPHYR_BASE
$ mkdir build && cd build
$ cmake $ZEPHYR_BASE/scripts
$ make
$ echo "export PATH=$PWD/kconfig:\$PATH" >> $HOME/.zephyrrc
$ source $ZEPHYR_BASE/zephyr-env.sh

    Note

    You only need to do this once after cloning the git repository.

Now that the host tools are installed, a 3rd party cross compiler must be installed. See below for installing a cross compiler.

Using Custom and 3rd Party Cross Compilers

To use a 3rd party cross compiler that is not provided by the Zephyr SDK, follow the steps below. It is possible to use a 3rd party cross compiler and still use the Zephyr SDK’s host tools. See the section above for details.

  1. We will use the GCC ARM Embedded compiler for this example, download the package suitable for your operating system from the GCC ARM Embedded website and extract it on your file system. This example assumes the compiler was extracted to: ~/gcc-arm-none-eabi-5_3-2016q1/.

  2. Build the example Hello World project, enter:

    $ export GCCARMEMB_TOOLCHAIN_PATH="~/gcc-arm-none-eabi-5_3-2016q1/"
$ export ZEPHYR_GCC_VARIANT=gccarmemb

    $ cd $ZEPHYR_BASE/samples/hello_world

# Make a build directory, and use cmake to configure a Make-based build system:
$ mkdir build && cd build
$ cmake -DBOARD=arduino_due ..

# Now run make on the generated build system:
$ make

Running a Sample Application in QEMU

To perform rapid testing of an application in the development environment you can use the QEMU emulation board configuration available for both X86 and ARM Cortex-M3 architectures. This can be easily accomplished by calling a special target when building an application that invokes QEMU once the build process is completed.

To run an application using the x86 emulation board configuration (qemu_x86), type:

$ cd $ZEPHYR_BASE/samples/hello_world
$ mkdir qemu_build && cd qemu_build
$ cmake -DBOARD=qemu_x86 ..
$ make run

To exit the qemu emulator, press Ctrl-a, followed by x.

Use the qemu_cortex_m3 board configuration to test the ARM build.

QEMU is not supported on all boards and SoCs. When developing for a specific hardware target you should always test on the actual hardware and should not rely on testing in the QEMU emulation environment only.