.. _getting_started:

Getting Started Guide
#####################

Use this guide to get started with your :ref:`Zephyr <introducing_zephyr>`
development.

Set Up the Development Environment
**********************************

The Zephyr project supports these operating systems:

* Linux
* Mac OS
* Windows 8.1

Use the following procedures to create a new development environment.

.. toctree::
   :maxdepth: 1

   installation_linux.rst
   installation_mac.rst
   installation_win.rst


Checking Out the Source Code Anonymously
========================================

The code is hosted at the Linux Foundation with a Gerrit backend that supports
anonymous cloning via git.

To clone the repository anonymously, enter:

.. code-block:: console

   $ git clone https://gerrit.zephyrproject.org/r/zephyr zephyr-project

You have successfully checked out a copy of the source code to your local
machine.

Once you're ready to start contributing, follow the steps to make yourself
a Linux Foundation account at `Gerrit Accounts`_.

.. _Gerrit Accounts: https://wiki.zephyrproject.org/view/Gerrit_accounts

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 Mac OS please use the appropriate
commands for your OS.

Building a Sample Application
=============================

To build an example application follow these steps:


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

   .. code-block:: console

      $ export ZEPHYR_GCC_VARIANT=zephyr

      $ export ZEPHYR_SDK_INSTALL_DIR=<sdk installation directory>

#. Navigate to the main project directory:

   .. code-block:: console

      $ cd zephyr-project

#. Source the project environment file to set the project environtment
   variables:

   .. code-block:: console

      $ source zephyr-env.sh

#. Build the example project, enter:

   .. code-block:: console

      $ cd $ZEPHYR_BASE/samples/hello_world/microkernel

      $ make

The above invocation of make will build the hello_world sample application
using the default settings defined in the application's Makefile. You can
build for a different board by defining the variable BOARD with one of the
supported boards, for example:

.. code-block:: console

   $ make BOARD=arduino_101

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

.. code-block:: console

   $ make help

The sample projects for the microkernel and the nanokernel are available
at :file:`$ZEPHYR_BASE/samples`.
After building an application successfully, the results can be found in the
:file:`outdir` sub-directory under the application root directory.

The ELF binaries generated by the build system are named by default
:file:`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 platforms used.

Using Custom and 3rd Party Cross Compilers
==========================================

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

If you have a custom cross-compiler or if you wish to use a vendor provided SDK,
follow the steps below to build with any custom or 3rd party cross-compilers:

#. To avoid any conflicts with the Zephyr SDK, enter the following commands.

   .. code-block:: console

      $ unset ZEPHYR_GCC_VARIANT

      $ unset ZEPHYR_SDK_INSTALL_DIR

#. 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: :file:`~/gcc-arm-none-eabi-5_3-2016q1/`.

#. Navigate to the main project directory:

   .. code-block:: console

      $ cd zephyr-project

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

   .. code-block:: console

      $ source zephyr-env.sh

#. Build the example project and make sure you supply the CROSS_COMPILE on the command
   line, enter:

   .. code-block:: console

      $ cd $ZEPHYR_BASE/samples/hello_world/microkernel

      $ make CROSS_COMPILE=~/gcc-arm-none-eabi-5_3-2016q1/bin/arm-none-eabi- BOARD=arduino_due

The above will build the sample using the toolchain downloaded from `GCC ARM Embedded`_.


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:

.. code-block:: console

   $ make BOARD=qemu_x86 qemu

To run an application using the ARM qemu_cortex_m3 board configuration, type:

.. code-block:: console

   $ make BOARD=qemu_cortex_m3 ARCH=arm qemu

QEMU is not supported on all boards and platforms. 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.


.. _Linux Foundation ID website: https://identity.linuxfoundation.org

.. _Gerrit: https://gerrit.zephyrproject.org/

.. _GCC ARM Embedded: https://launchpad.net/gcc-arm-embedded