Getting Started Guide¶
Follow this guide to set up a Zephyr development environment on your system, and then build and run a sample application.
Set Up a Development System¶
Follow one of the following guides for your host operating system.
Clone the Zephyr Repository¶
To clone the Zephyr source code repository from GitHub:
git clone https://github.com/zephyrproject-rtos/zephyr
Don’t clone Zephyr to a directory with spaces anywhere in the path.
For example, on Windows,
C:\Users\Your Name\zephyr will cause cryptic
errors when you try to build an application.
Install Python Dependencies¶
Next, install additional Python packages required by Zephyr in a shell or
# Linux pip3 install --user -r zephyr/scripts/requirements.txt # macOS and Windows pip3 install -r zephyr/scripts/requirements.txt
Some notes on pip’s
- Installing with
--useris the default behavior on Debian-based distributions and is generally recommended on Linux to avoid conflicts with Python packages installed using the system package manager.
- On Linux, verify the Python user install directory
~/.local/binis at the front of your PATH environment variable, otherwise installed packages won’t be found.
- On macOS, Homebrew disables the
- On Windows using
cmd.exe, although it’s possible to use the
--userflag, it makes it harder for the command prompt to find executables installed by pip.
Set Up a Toolchain¶
On Linux, you can skip this step if you installed the Zephyr SDK, which includes toolchains for all supported Zephyr architectures.
If you want, you can use the SDK host tools (such as OpenOCD) with a
different toolchain by keeping the
environment variable set to the Zephyr SDK installation directory, while
ZEPHYR_TOOLCHAIN_VARIANT appropriately for a non-SDK
Zephyr binaries are compiled using software called a toolchain. You need to install and configure a toolchain to develop Zephyr applications.
Toolchains can be installed in different ways, including using installer
programs, system package managers, or simply downloading a zip file or other
archive and extracting the files somewhere on your computer. You configure
the toolchain by setting the environment variable
ZEPHYR_TOOLCHAIN_VARIANT to a recognized value, along with some
additional variable(s) specific to that toolchain (usually, this is just one
more variable which contains the path where you installed the toolchain on your
In previous releases of Zephyr, the
The following toolchain installation options are available. The right choice for you depends on where you want to run Zephyr and any other requirements you may have. Check your board-level documentation if you are unsure about what choice to use.
To use the same toolchain in new sessions in the future you can make sure the variables are set persistently.
On macOS and Linux, you can set the variables by putting the
setting environment variables in a file
~/.zephyrrc. On Windows, you
can put the
set lines in
%userprofile%\zephyrrc.cmd. These files
are used to modify your environment when you run
zephyr-env.cmd (Windows), which you will learn about in the next
Build and Run an Application¶
Next, build a sample Zephyr application. You can then flash and run it on real hardware using any supported host system. Depending on your operating system, you can also run it in emulation with QEMU or as a native POSIX application.
A Brief Note on the Zephyr Build System¶
Unix Makefiles: Supported on UNIX-like platforms (Linux, macOS).
Ninja: Supported on all platforms.
This documentation and Zephyr’s continuous integration system mainly use
Ninja, but you should be able to use any supported generator to build
Build the Application¶
Follow these steps to build the Hello World sample application provided with Zephyr.
Zephyr applications have to be configured and built to run on some hardware
configuration, which is called a “board”. These steps show
how to build the Hello World application for the Arduino/Genuino 101 board. You
can build for a different board by changing
arduino_101 to another
supported value. See Supported Boards for more information, or run
from the build directory (once you’ve run
cmake) to get a list.
If you want to re-use your existing build directory to build for another
board, you must delete that directory’s contents first by running
Navigate to the main project directory:
Set up your build environment:
# On Linux/macOS source zephyr-env.sh # On Windows zephyr-env.cmd
Build the Hello World sample for the
# On Linux/macOS cd samples/hello_world mkdir build && cd build # On Windows cd samples\hello_world mkdir build & cd build # Use cmake to configure a Ninja-based build system: cmake -GNinja -DBOARD=arduino_101 .. # Now run ninja on the generated build system: ninja
On Linux/macOS you can also build with
cd samples/hello_world mkdir build && cd build # Use cmake to configure a Make-based build system: cmake -DBOARD=arduino_101 .. # Now run make on the generated build system: make
The main build products are in
The final application binary in ELF format is named
default. Other binary formats and byproducts such as disassembly and map files
will be present depending on the target and build system configuration.
Other sample projects demonstrating Zephyr’s features are located in
zephyr/samples and are documented in Samples and Demos.
Run the Application by Flashing to Another Board¶
Most “real hardware” boards supported by Zephyr can be flashed by running
ninja flash from the build directory. However, this may require
board-specific tool installation and configuration to work properly.
Run the Application in QEMU¶
On Linux and macOS, you can run Zephyr applications in emulation on your host system using QEMU when targeting either the X86 or ARM Cortex-M3 architectures.
To build and run Hello World using the x86 emulation board configuration
cd $ZEPHYR_BASE/samples/hello_world mkdir build && cd build # Use cmake to configure a Ninja-based build system: cmake -GNinja -DBOARD=qemu_x86 .. # Now run ninja on the generated build system: ninja ninja run
To exit, type Ctrl-a, then x.
qemu_cortex_m3 board configuration to run on an emulated Arm
Running a Sample Application natively (POSIX OS)¶
Finally, it is also possible to compile some samples to run as native processes on a POSIX OS. This is currently only tested on Linux hosts.
On 64 bit host operating systems, you will also need a 32 bit C library installed. See the Native POSIX execution (native_posix) section on host dependencies for more information.
To compile and run Hello World in this way, type:
cd $ZEPHYR_BASE/samples/hello_world mkdir build && cd build # Use cmake to configure a Ninja-based build system: cmake -GNinja -DBOARD=native_posix .. # Now run ninja on the generated build system: ninja
ninja run # or just: zephyr/zephyr.exe # Press Ctrl+C to exit
You can run
zephyr/zephyr.exe --help to get a list of available
options. See the Native POSIX execution (native_posix) document for more information.
This executable can be instrumented using standard tools, such as gdb or valgrind.
|||For details, see https://docs.brew.sh/Homebrew-and-Python#note-on-pip-install—user.|
Usually, the toolchain is a cross-compiler and related tools which are different than the host compilers and other programs available for developing software to run natively on your operating system.
One exception is when building Zephyr as a host binary to run on a POSIX operating system. In this case, you still need to set up a toolchain, but it will provide host compilers instead of cross compilers. For details on this option, see Native POSIX execution (native_posix).
|||This has become something of a misnomer over time. While the target can be, and often is, a microprocessor running on its own dedicated hardware board, Zephyr also supports using QEMU to run targets built for other architectures in emulation, targets which produce native host system binaries that implement Zephyr’s driver interfaces with POSIX APIs, and even running different Zephyr-based binaries on CPU cores of differing architectures on the same physical chip. Each of these hardware configurations is called a “board,” even though that doesn’t always make perfect sense in context.|