samples: subsys: crc: add samples for CRC subsystem

# SPDX-License-Identifier: Apache-2.0

cmake_minimum_required(VERSION 3.20.0)

find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})

project(subsys_crc_example)

target_sources(app PRIVATE src/main.c)

.. zephyr:code-sample:: crc_subsys

   :name: Cyclic Redundancy Check Subsystem (CRC Subsys)

   Compute and verify a CRC computation using the CRC subsys API.

Overview

********

This sample demonstrates how to use the Cyclic Redundancy Check Subsystem

Configuration Options

*********************

This sample uses the following Kconfig options:

- ``CONFIG_CRC``: Enable CRC functionality.

- ``CONFIG_CRC*``: Use software-based CRC if a chosen node is present; otherwise, hardware acceleration is used.

These options can be modified in the project's ``prj.conf`` file or passed via CMake arguments.

Building and Running

********************

Building and Running for Renesas RA8M1

======================================

The sample can be built and executed for the

:zephyr:board:`ek_ra8m1` as follows:

.. zephyr-app-commands::

   :zephyr-app: samples/subsys/crc

   :board: ek_ra8m1

   :goals: build flash

   :compact:

To build for another board, change "ek_ra8m1" above to that board's name.

Sample Output

=============

.. code-block:: console

   subsys_crc_example: Result of CRC32 IEEE: 0xCEA4A6C2

   subsys_crc_example: Result of CRC8 CCITT: 0x96

   subsys_crc_example: CRC computation completed successfully

.. note::

   If the board does not support a hardware CRC driver, the computation will fall

   back to a software-based implementation.

Expected Behavior

*****************

When the sample runs, it should:

1. Compute the CRC32 and CRC8 values of predefined data.

2. Print the computed CRC values.

CONFIG_CRC=y

CONFIG_LOG=y

sample:

  name: CRC Subsystem

tests:

  samples.subsys.crc:

    depends_on: crc

    tags:

      - subsys

      - crc

    harness: console

    harness_config:

      type: one_line

      regex:

        - "CRC computation completed successfully"

/*

 * Copyright (c) 2025 Renesas Electronics Corporation

 *

 * SPDX-License-Identifier: Apache-2.0

 */

#include <zephyr/logging/log.h>

LOG_MODULE_REGISTER(subsys_crc_example, CONFIG_LOG_DEFAULT_LEVEL);

#include <zephyr/sys/crc.h>

int main(void)

{

	uint32_t result;

	uint8_t data[8] = {0x0A, 0x2B, 0x4C, 0x6D, 0x8E, 0x49, 0x00, 0xC4};

	/* CRC computation */

	result = crc32_ieee(data, sizeof(data));

	LOG_INF("Result of CRC32 IEEE: 0x%08X", result);

	/* CRC computation */

	result = (uint8_t)crc8_ccitt(0xFF, data, sizeof(data));

	LOG_INF("Result of CRC8 CCITT: 0x%02X", result & 0xFF);

	LOG_INF("CRC computation completed successfully");

	return 0;

}