Getting Started
===============

This section covers the initial setup and steps to build your first image for the otto device.

Prerequisites
-------------

Ensure you have a Linux host with the following tools installed:

- Git (for retrieving the project and layer repositories)
- Python 3.6+
- `kas <https://github.com/siemens/kas>`_
- Git
- Docker (optional, for container-based builds)

Using KAS
---------

To build your image using the provided configurations, you can either:

**1. Combine files directly in the command:**

Use the kas checkout command to fetch each layer separately:

.. code-block:: bash

   kas checkout kas_otto/KAS/layers/poky.yml
   kas checkout kas_otto/KAS/layers/meta-arm.yml
   kas checkout kas_otto/KAS/layers/meta-openembedded.yml
   kas checkout kas_otto/KAS/layers/meta-otto-bsp.yml
   kas checkout kas_otto/KAS/layers/meta-swupdate.yml
   kas checkout kas_otto/KAS/layers/meta-virtualization.yml

This will clone the repositories specified in each YAML file into their respective directories.

After fetching all the layers, set up the build environment by running:

.. code-block:: bash

   kas shell kas_otto/KAS/machine/bashroosh.yml

This command will configure the environment as specified in the bashroosh.yml file.

Finally, initiate the build process:

.. code-block:: bash

   kas shell kas_otto/KAS/machine/bashroosh.yml

This will start the build using the configuration defined in the distro-tulipe.yml file.

Note: Ensure that the repos section in each YAML file specifies the correct paths for the layers. The kas shell and kas build commands should be run after all the necessary layers have been fetched. This approach allows you to fetch and build each layer separately, providing flexibility in managing your layers.

**2. Create a top-level `kas.yml` (requires KAS 5+) :**

If you prefer to manage all configurations in a single file, you can create a top-level kas.yml that includes all your layer configurations:

.. code-block:: yaml

   header:
     version: 11

   includes:
     - machine/bashroosh.yml
     - distro/distro-tulipe.yml
     - layers/poky.yml
     - layers/meta-openembedded.yml
     - layers/meta-arm.yml
     - layers/meta-otto-bsp.yml
     - layers/meta-swupdate.yml
     - layers/meta-virtualization.yml

Then build using:

.. code-block:: bash

   kas build kas.yml

- You can also run the build using KAS inside a Docker container:

.. code-block:: bash

   git clone https://github.com/siemens/kas.git
   git clone $PROJECT_URL meta-project
   ./kas/kas-docker build meta-project/kas.yml 

Additional Commands
-------------------

- To fetch and prepare sources only:

  .. code-block:: bash

     kas checkout kas.yml

- To start a shell in the build environment:

  .. code-block:: bash

     kas shell kas.yml

   The `kas shell` command sets up the Yocto build environment and launches a shell. Inside this shell, you can use `bitbake` directly. For example:

.. code-block:: bash

   $ bitbake otto-image

Replace `otto-image` with the target image recipe defined in the configuration.

- To clean the build environment:

  .. code-block:: bash

     kas build kas.yml -- --clean

Deployment to Device
--------------------

The build artifacts are located under:

.. code-block:: none

   build/tmp-glibc/deploy/images/<machine>/

You will get an SD-card image (`.wic`). To deploy, copy the appropriate image to a storage medium:

- For SD cards, use a tool like `dd` to write the `.wic` file to an SD card.
- For flashing onboard storage, follow the Otto hardware documentation.