# Zephyr Example Application

This repository contains Zephyr example applications. The main purpose of this
repository is to provide references and demo on the use of OpenAMP on Zephyr based applications. features demonstrated in this example are:

- [rpmsg multi service][rms_app] application
- [dual qemu ivshmem][dqi_app] application



[rms_app]: #rpmsg_multi_services/README.md
[dqi_app]: #dual_qemu_ivshmem/README.md

## Getting Started

Before getting started, make sure you have a proper Zephyr development
environment. You can follow the official
[Zephyr Getting Started Guide](https://docs.zephyrproject.org/latest/getting_started/index.html).

### Initialization

The first step is to initialize the workspace folder (``my-workspace``) where
the examples and all Zephyr modules will be cloned. You can do
that by running:

```shell
# initialize my-workspace for the example-application (main branch)
west init -m https://github.com/OpenAMP/openamp-system-reference --mr main my-workspace
# update Zephyr modules
cd my-workspace
west update
```

### Build and run on a board

The application can be built by running:

```shell
west build -b $BOARD `$ZEPHYR_EXAMPLE`
```

where `$BOARD` is the target board and `$ZEPHYR_EXAMPLE`.
Note that Zephyr sample boards may be used if an appropriate overlay is provided (see `app/boards`).

A sample debug configuration is also provided. You can apply it by running:

```shell
west build -b $BOARD $ZEPHYR_EXAMPLE -- -DOVERLAY_CONFIG=debug.conf
```

Example to compile rpmsg_multi_services on stm32mp157 discovery board:

```shell
west build -b stm32mp157c_dk2 openamp-system-reference/examples/zephyr/rpmsg_multi_services
```

### Running on a board

We consider here board on which the Zephyr image is running on a coprocessor.

1) Once you have built the application copy it on target filesystem.
2) Load the Zephyr firmware and start the coprocessor depending on the board.

Example of a Zephyr firmware image loading by the Linux kernel remoteproc framework.

```shell
cp $ZEPHYR_EXAMPLE.elf /lib/modules/
echo $ZEPHYR_EXAMPLE.elf > /sys/class/remoteproc/remoteproc0/firmware
echo start >/sys/class/remoteproc/remoteproc0/state
```

### Running in an Emulator

To be described