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FreeRTOS and Reliance Edge Demo
Using the Fail Safe File System with the FreeRTOS Windows Port

Datalight Logo fail safe embedded flash file system download the fail safe flash file system manual fail safe fail system open source licensing Safety critical embedded flash file system

"Our products are used from the bottom of the ocean, to the depths of space, and from the factory floor, to your hip pocket" - Ken Whitaker, Datalight

"Datalight's family of Reliance fail safe file systems have delivered proven reliability in hundreds of millions of devices." - Kerri McConnell, Datalight

"The design goals and implementation of Reliance Edge means it is no ordinary file system. Reliance Edge will be a valuable resource for our users, so we are happy to accept it as an official FreeRTOS+ component." - Richard Barry, Amazon Web Services Inc.

This page presents a project that runs FreeRTOS and Datalight's Reliance edge fail safe file system in a Windows environment.

The FreeRTOS Windows port provides a convenient and non embedded target specific evaluation platform. It allows FreeRTOS, and some FreeRTOS+ components, to be executed on a standard Windows computer, using feature rich and free development tools. However, unlike when FreeRTOS is executed on real embedded hardware, the Windows port does not exhibit true real time behaviour.

On this page:

Source Code and Project Files

The project described on this page is located in the following folder of the main FreeRTOS .zip file download:

Target Hardware

The project creates a RAM disk using the FreeRTOS Windows port. The Windows port provides a convenient evaluation platform, but it does not exhibit real time behaviour. Simulated time might be slower than real time.

Compiler / Tool Chain

The project is pre-configured to build with the free Express edition of Microsoft Visual C++ (MSVC). MSVC Express Edition 2010 was used.


The demo:
  1. Creates and formats a RAM disk.
  2. Creates then reads back a set of example files in the root directory of the RAM disk.
  3. Creates sub-directories.
  4. Creates then reads back a set of example files from the created sub-directories.
  5. Creates a command console (using FreeRTOS+CLI) that implements the commands described below:

    Command and parameters Description
    dir <filename> Lists the files in the named directory
    type <filename> Prints file contents to the terminal
    append <filename> Appends data to a file (creating the file if it does not exist)
    del <filename> Deletes a file or directory
    copy <source file> <dest file> Copies <source file> to <dest file>
    create <filename> Creates an empty file
    mkdir <filename> Creates an empty directory
    rename <source file> <dest file> Rename <source file> to <dest file>
    link <source file> <dest file> Create hard link <dest file> pointing at <source file>
    stat <filename> Show file information
    statfs Show file system information
    format Re-formats the file system volume. ALL FILES WILL BE DELETED!
    transact Commits a Reliance Edge transaction point
    transmaskget Retrieves the Reliance Edge automatic transaction mask
    transmaskset <hex mask> Sets the Reliance Edge automatic transaction mask
    abort Rolls back all changes not part of the last transaction point
    test-fs Executes file system tests. ALL FILES WILL BE DELETED!

Command Console Input and Output

The command console is accessed from a UDP terminal. See the Usage Instructions section below.

Build Instructions

  1. The demo application is available in the main FreeRTOS .zip file download.

  2. Open the Visual Studio solution file FreeRTOS_Plus_Reliance_Edge_with_CLI.sln from within the Visual Studio IDE. The solution file is located in the "FreeRTOS-Plus/Demo/FreeRTOS_Plus_Reliance_Edge_and_CLI_Windows_Simulator" directory.

  3. Select "Build Solution" from the IDE's Build menu (or press F7) to build the application.

Debug Instructions

In Visual Studio, press F10 to start a debug session and break on entry to main().

The same host computer is used to build the application, debug the application, and (because the FreeRTOS Win32 port is used) run the application. There are no special debugging instructions.

Usage Instructions

  1. The demo application creates a set of files and directories on a RAM disk, outputting information to the Windows console as it goes.

    The output generated when the fail safe file system files and directories are created
    The output generated in the Windows console when the fail safe embedded file system demo application starts

  2. A local UDP connection is used to connect to the FreeRTOS+CLI command line interface. The Windows TCP/IP stack is used instead of FreeRTOS+TCP to ensure the demo remains focused on the file system. A demo application that uses the FreeRTOS Windows port and FreeRTOS+TCP to create a command console is available in the FreeRTOS+TCP section of this website.

    Free dumb terminal programs that are suitable for connecting to the command line interface using UDP include YAT and Hercules.

    The standard localhost IP address ( can be used because both the (simulated) demo application and the UDP terminal execute on the same computer. FreeRTOS+CLI listens for characters arriving on UDP port 5001 and sends its output to UDP port 5002. The required terminal configuration is shown below.

    Settings required to the safety critical file system demo
    Configuring the YAT terminal to communication with the FreeRTOS+CLI command line interface

  3. Type "help" to see a list of registered commands.

    Viewing safety critical file system related RTOS commands
    Type "help" in the UDP terminal to see a list of registered commands

  4. Experiment with the file system commands! A sample session is shown below.

    running safety critical file system RTOS commands
    Running safety critical file system commands in the YAT terminal

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