> ## Documentation Index
> Fetch the complete documentation index at: https://devzone.nayax.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Linux Sample Application

The Linux Sample Application ships with the RTOS SDK as portable C (C99) source code. It provides a working reference implementation for the platform abstraction layer and a demo application for testing the SDK.

The sample code was developed and tested on Ubuntu (x86\_64). When porting to other operating systems, you must adapt the Platform Abstraction Layer. See [Platform Porting](/docs/integrate-pos-device/emv-core/rtos/rtos-platform-porting).

**Notes:**

* All source code is in standard C (C99).
* Platform-specific code is under `platform/`.
* It is highly recommended **not** to modify code outside the `platform/` folder.

## Directory Structure

The sample application sources are organized as follows:

```
ecod_sdk/          # Core SDK headers and sources
  platform/        # Platform abstraction layer
  src/             # SDK implementation
  include/         # Internal and public headers
demo/              # Example / demo application
```

## Build

### Get the Sources

Obtain the SDK package from your Nayax account manager and extract the `Linux Sample Application` folder.

### Install Build Dependencies (Ubuntu Linux)

Run these commands to install the required tools:

```bash theme={null}
sudo apt-get update
sudo apt-get install build-essential automake
```

### Build the SDK and Demo

The provided sources and demo are ready to build on Ubuntu Linux x86\_64 with GCC and automake:

```bash theme={null}
autoreconf -fi       # Generate autotools configuration
./configure          # Configure build (respects CONFIGURE_FLAGS)
make                 # Build SDK library and demo
```

The build generates static libraries and the demo binary.

### Clean build artifacts

Use these targets to remove compiled output:

```bash theme={null}
make clean              # Remove build objects
make maintainer-clean   # Remove all generated files
```

## Configuration Options

The SDK supports various build-time configurations through `ecod_sdk_configs.h`:

```c theme={null}
// Memory allocation strategy
#define EC_USE_HEAP 1                    // Use malloc/free (0 = static allocation)

// Protocol settings
#define EC_USE_DATALINK_PROTOCOL 1       // Enable datalink framing with ACK/NAK
#define EC_INCOMPLETE_FRAME_TIMEOUT_MS 500  // Timeout for incomplete frames
#define EC_ACK_TIMEOUT_MS 1000           // Timeout waiting for ACK
#define EC_ACK_MAX_RETRIES 0             // Max retransmissions on missing ACK

// Network bridge settings
#define EC_SUPPORT_LONG_LIVED_SOCKETS 1  // Support persistent connections
```

<Note>
  Computed defaults are in `ecod_sdk_setup.h`. Do not modify that file directly.
</Note>

## Run the Demo

After building, run the included demo application to test the SDK:

**Manual mode:** user selects operations using the keyboard:

```bash theme={null}
./demo/ecodSdkDemo
```

**Automatic mode:** performs a payment transaction in a loop:

```bash theme={null}
./demo/ecodSdkDemo --auto
```

In `--auto` mode, transactions run in a loop. If authorized, one out of two is confirmed and the other is voided, demonstrating both use cases.

Review `demo/main.c` for example code and usage patterns.