test: fs: enable fstab devicetree integration for fatfs

# Copyright (c) 2025 Endress+Hauser AG

# SPDX-License-Identifier: Apache-2.0

cmake_minimum_required(VERSION 3.20.0)

find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})

project(fatfs_fstab_sample)

FILE(GLOB app_sources src/*.c)

target_sources(app PRIVATE ${app_sources})

.. zephyr:code-sample:: fatfs-fstab

   :name: Fatfs filesystem fstab

   :relevant-api: file_system_api

   Define fatfs filesystems in the devicetree.

Overview

***********

This sample shows how to define a fatfs fstab entry in the devicetree.

This scenario uses a fatfs on a RAM disk. The sample is run on the

``native_sim`` board.

Building and running

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

To run this sample, build it for the ``native_sim`` board

and afterwards run the generated executable file within the build folder.

The RAM disk sample for the ``native_sim`` board can be built as follows:

.. zephyr-app-commands::

   :zephyr-app: samples/subsys/fs/fatfs_fstab

   :host-os: unix

   :board: native_sim

   :gen-args: -DDTC_OVERLAY_FILE=fatfs_fstab.overlay

   :goals: build

   :compact:

Sample Output

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

When the sample runs successfully you should see following message on the screen:

.. code-block:: console

  I: Filesystem access successful

/*

 * Copyright (c) 2025 Endress+Hauser AG

 *

 * SPDX-License-Identifier: Apache-2.0

 */

/ {

	fstab {

		compatible = "zephyr,fstab";

		ffs1: ffs1 {

			compatible = "zephyr,fstab,fatfs";

			automount;

			disk-access;

			mount-point = "/RAM:";

		};

	};

	ramdisk0 {

		compatible = "zephyr,ram-disk";

		disk-name = "RAM";

		sector-size = <512>;

		sector-count = <128>;

	};

};

CONFIG_DISK_ACCESS=y

CONFIG_DISK_DRIVERS=y

CONFIG_LOG=y

CONFIG_LOG_MODE_MINIMAL=y

CONFIG_FILE_SYSTEM=y

CONFIG_FILE_SYSTEM_MKFS=y

CONFIG_FAT_FILESYSTEM_ELM=y

CONFIG_FS_FATFS_FSTAB_AUTOMOUNT=y

sample:

  name: fatfs fstab sample

tests:

  sample.filesystem.fat_fs.fstab:

    platform_allow:

      - native_sim

    extra_args:

      - EXTRA_DTC_OVERLAY_FILE="fatfs_fstab.overlay"

    tags: filesystem

    harness: console

    harness_config:

      type: one_line

      regex:

        - "I: Filesystem access successful"