View source for SN512 Real-Time Operating Systems for Embedded Systems

These lab series allow you to install and discover the Zephyr Real Time Operating System.

==Installation==

Note that the dependancies and Zephyr SDK are already installed on the computers of the school. The installation is required only if you install Zephyr on your own computer.

* Install the binary packages of the dependancies required by Zephyr:

<syntaxhighlight lang="text">
sudo apt install --no-install-recommends git cmake ninja-build gperf \
  ccache dfu-util device-tree-compiler wget python3-dev python3-venv python3-tk \
  xz-utils file make gcc gcc-multilib g++-multilib libsdl2-dev libmagic1
</syntaxhighlight>

* Install the Zephyr SDK. Follow the steps describe at this [https://docs.zephyrproject.org/latest/develop/toolchains/zephyr_sdk.html#toolchain-zephyr-sdk page]. The installation can be done by 2 ways: downloading and installing a bundle or installing the SDK using west.

==Getting Started==

*  In a terminal, go into a directory where you want to place your workspace

<syntaxhighlight lang="text">
$ git clone https://github.com/nicolas-barbot/zephyr_workspace.git
</syntaxhighlight>

* Enter inside the workspace, you should see 2 directories. <syntaxhighlight lang="text" inline>manifest-repo</syntaxhighlight> contains the central manifest. <syntaxhighlight lang="text" inline>hello_world</syntaxhighlight> is a project. During the lab, we will create multiple project in the workspace.

* Inside the workspace, create a virtual environment

<syntaxhighlight lang="text">
$ python3 -m venv .venv
</syntaxhighlight>

Note the <syntaxhighlight lang="text" inline>.venv</syntaxhighlight> directory in the workspace

* Activate the virtual environment using

<syntaxhighlight lang="text">
$ source .venv/bin/activate
</syntaxhighlight>

Note that if you want to deactivate your virtual environment, simply type <syntaxhighlight lang="text" inline>deactivate</syntaxhighlight>. If you want to re activate it, simply activate it with
the source command.

* In the (activated) virtual environment, install <syntaxhighlight lang="text" inline>west</syntaxhighlight>

<syntaxhighlight lang="text">
$ pip install west
</syntaxhighlight>


* Initialize <syntaxhighlight lang="text" inline>west</syntaxhighlight> with the manifest already present in our workspace:

<syntaxhighlight lang="text">
$ west init -l manifest-repo/
</syntaxhighlight>

Note that this command will create a <syntaxhighlight lang="text" inline>.west</syntaxhighlight> directory in the workspace.

* Download all the dependancies of our workspace

<syntaxhighlight lang="text">
$ west update
</syntaxhighlight>

This command will download the correct version (indicated in the manifest) of each depedancie and store them in the workspace. Note that the Zephyr source code will be downloaded at this step.

* Install some python dependancies associated with the specific versions indicated in the manifest of the workspace 

<syntaxhighlight lang="text">
$ west packages pip --install
</syntaxhighlight>


* Build the <syntaxhighlight lang="text" inline>hello_world</syntaxhighlight> project located in the workspace

<syntaxhighlight lang="text">
$ west build -p always -b nucleo_f103rb hello_world/
</syntaxhighlight>

Note that this command create a <syntaxhighlight lang="text" inline>build</syntaxhighlight> directory in the workspace. The executable file corresponding to the application in located at <syntaxhighlight lang="text" inline>.build/zephyr/zephyr.elf</syntaxhighlight>

* Flash the executable file on the STM32 board:

<syntaxhighlight lang="text">
$ west flash
</syntaxhighlight>

During this command, check that LD1 present on the STLinkv2 is blinking red and green.

*In another terminal, simply type the command:

<syntaxhighlight lang="text">
$ screen /dev/ttyACM0 115200
</syntaxhighlight>

Be careful to not close this terminal (because you will not be able to open the <syntaxhighlight lang="text" inline>/dev/ttyACM0</syntaxhighlight> file a second time). The correct procedure the close the screen session is to type <syntaxhighlight lang="text" inline>Ctrl+A</syntaxhighlight>, <syntaxhighlight lang="text" inline>k</syntaxhighlight> and finally <syntaxhighlight lang="text" inline>y</syntaxhighlight>.

*Finally, if you see in the terminal the following message:

<syntaxhighlight lang="text">
*** Booting Zephyr OS build v4.3.0 ***
Hello World! nucleo_f103rb
</syntaxhighlight>

Congratulation, you just successfully set up, build and run your first Zephyr application!