3. Sample Applications — RTEMS Development Environment Guide 5.4-rc2 (21st August 2026) documentation

# 3. Sample Applications

## 3.1. Introduction

The RTEMS source distribution includes a set of sample applications that are located in the `${RTEMS_ROOT}/testsuites/samples/` directory. These applications are intended to illustrate the basic format of RTEMS single and multiple processor applications and the use of some features. In addition, these relatively simple applications can be used to test locally developed board support packages and device drivers as they exercise a critical subset of RTEMS functionality that is often broken in new BSPs.

Some of the following sample applications will be covered in more detail in subsequent sections:

Hello World

  The RTEMS Hello World test is provided in the subdirectory `${RTEMS_ROOT}/testsuites/samples/hello/`. This test is helpful when testing new RTEMS development environment.

Clock Tick

  The `${RTEMS_ROOT}/testsuites/samples/ticker/` subdirectory provides a test for verification of clock chip device drivers of BSPs.

Base Single Processor

  A simple single processor test similar to those in the single processor test suite is provided in `${RTEMS_ROOT}/testsuites/samples/base_sp/`.

Base Multiple Processor

  A simple two node multiprocessor test capable of testing an newly developed MPCI layer is provided in `${RTEMS_ROOT}/testsuites/samples/base_mp/`.

Capture

  The RTEMS Capture test is provided in the subdirectory `${RTEMS_ROOT}/testsuites/samples/capture/`. This is an interactive test which demonstrates the capabilities of the RTEMS Capture Engine. It includes a few test threads which generate interesting execution patterns. Look at the file `${RTEMS_ROOT}/testsuites/samples/capture/capture.scn` for a sample session.

Constructor/Destructor C++ Test

  The `${RTEMS_ROOT}/testsuites/samples/cdtest/` subdirectory provides a simple C++ application using constructors and destructors. It is only built when C++ is enabled and its primary purpose is to demonstrate that global constructors and destructors work. Since this requires that the linker script for your BSP be correct, this is an important test.

File IO

  The RTEMS File IO test is provided in the subdirectory `${RTEMS_ROOT}/testsuites/samples/fileio/`. This is an interactive test which allows the user to interact with an ATA/IDE device. It will read the partition table and allow the user to dynamically mount one of the FAT32 partitions it finds. Commands are also provided to write and read files on the disk.

IO Stream

  The RTEMS IO Stream test is provided in the subdirectory `${RTEMS_ROOT}/testsuites/samples/iostream/`. This test is a simple C++ application which demonstrates that C++ iostreams are functional. This requires that the RTEMS C++ run-time support is functioning properly. This test is only build when C++ is enabled.

Network Loopback Test

  The `${RTEMS_ROOT}/testsuites/samples/loopback/` directory contains a sample test that demonstrates the use of sockets and the loopback network device. It does not require the presence of network hardware in order to run. It is only built if RTEMS was configured with networking enabled.

Minimum Size Test

  The directory `${RTEMS_ROOT}/testsuites/samples/minimum/` contains a simple RTEMS program that results in a non-functional executable. It is intended to show the size of a minimum footprint application based upon the current RTEMS configuration.

Nanoseconds

  The RTEMS Nanoseconds test is provided in the subdirectory `${RTEMS_ROOT}/testsuites/samples/nsecs/`. This test demonstrates that the BSP has support for nanosecond timestamp granularity. It prints the time of day and uptime multiple times as quickly as possible. It should be possible from the output to determine if your BSP has nanosecond accurate clock support and it is functional.

Paranoia Floating Point Test

  The directory `${RTEMS_ROOT}/testsuites/samples/paranoia/` contains the public domain floating point and math library test.

Point-to-Point Protocol Daemon

  The RTEMS Point-to-Point Protocol Daemon test is provided in the subdirectory `${RTEMS_ROOT}/testsuites/samples/pppd/`. This test primarily serves as the baseline for a user application using the PPP protocol.

Unlimited Object Allocation

  The `${RTEMS_ROOT}/testsuites/samples/unlimited/` directory contains a sample test that demonstrates the use of the*unlimited* object allocation configuration option to RTEMS.

The sample tests are written using the Classic API so the reader should be familiar with the terms used and material presented in the RTEMS Applications Users Guide.

## 3.2. Hello World

This sample application is in the following directory:

    ${RTEMS_ROOT}/testsuites/samples/hello/

It provides a rudimentary test of the BSP start up code and the console output routine. The C version of this sample application uses the printf function from the RTEMS Standard C Library to output messages. The Ada version of this sample uses the TEXT_IO package to output the hello messages. The following messages are printed:

    *** HELLO WORLD TEST ***
    Hello World
    *** END OF HELLO WORLD TEST ***

These messages are printed from the application’s single initialization task. If the above messages are not printed correctly, then either the BSP start up code or the console output routine is not operating properly.

## 3.3. Clock Tick

This sample application is in the following directory:

    ${RTEMS_ROOT}/testsuites/samples/ticker/

This application is designed as a simple test of the clock tick device driver. In addition, this application also tests the printf function from the RTEMS Standard C Library by using it to output the following messages:

    *** CLOCK TICK TEST ***
    TA1 - tm_get - 09:00:00   12/31/1988
    TA2 - tm_get - 09:00:00   12/31/1988
    TA3 - tm_get - 09:00:00   12/31/1988
    TA1 - tm_get - 09:00:05   12/31/1988
    TA1 - tm_get - 09:00:10   12/31/1988
    TA2 - tm_get - 09:00:10   12/31/1988
    TA1 - tm_get - 09:00:15   12/31/1988
    TA3 - tm_get - 09:00:15   12/31/1988
    TA1 - tm_get - 09:00:20   12/31/1988
    TA2 - tm_get - 09:00:20   12/31/1988
    TA1 - tm_get - 09:00:25   12/31/1988
    TA1 - tm_get - 09:00:30   12/31/1988
    TA2 - tm_get - 09:00:30   12/31/1988
    TA3 - tm_get - 09:00:30   12/31/1988
    *** END OF CLOCK TICK TEST ***

The clock tick sample application utilizes a single initialization task and three copies of the single application task. The initialization task prints the test herald, sets the time and date, and creates and starts the three application tasks before deleting itself. The three application tasks generate the rest of the output. Every five seconds, one or more of the tasks will print the current time obtained via the tm_get directive. The first task, TA1, executes every five seconds, the second task, TA2, every ten seconds, and the third task, TA3, every fifteen seconds. If the time printed does not match the above output, then the clock device driver is not operating properly.

## 3.4. Base Single Processor Application

This sample application is in the following directory:

    ${RTEMS_ROOT}/testsuites/samples/base_sp/

It provides a framework from which a single processor RTEMS application can be developed. The use of the task argument is illustrated. This sample application uses the printf function from the RTEMS Standard C Library or TEXT_IO functions when using the Ada version to output the following messages:

    *** SAMPLE SINGLE PROCESSOR APPLICATION ***
    Creating and starting an application task
    Application task was invoked with argument (0) and has id of 0x10002
    *** END OF SAMPLE SINGLE PROCESSOR APPLICATION ***

The first two messages are printed from the application’s single initialization task. The final messages are printed from the single application task.

## 3.5. Base Multiple Processor Application

This sample application is in the following directory:

    ${RTEMS_ROOT}/testsuites/samples/base_mp/

It provides a framework from which a multiprocessor RTEMS application can be developed. This directory has a subdirectory for each node in the multiprocessor system. The task argument is used to distinguish the node on which the application task is executed. The first node will print the following messages:

    *** SAMPLE MULTIPROCESSOR APPLICATION ***
    Creating and starting an application task
    This task was invoked with the node argument (1)
    This task has the id of 0x10002
    *** END OF SAMPLE MULTIPROCESSOR APPLICATION ***

The second node will print the following messages:

    *** SAMPLE MULTIPROCESSOR APPLICATION ***
    Creating and starting an application task
    This task was invoked with the node argument (2)
    This task has the id of 0x20002
    *** END OF SAMPLE MULTIPROCESSOR APPLICATION ***

The herald is printed from the application’s single initialization task on each node. The final messages are printed from the single application task on each node.

In this sample application, all source code is shared between the nodes except for the node dependent configuration files. These files contains the definition of the node number used in the initialization of the RTEMS Multiprocessor Configuration Table. This file is not shared because the node number field in the RTEMS Multiprocessor Configuration Table must be unique on each node.

## 3.6. Constructor/Destructor C++ Application

This sample application is in the following directory:

    ${RTEMS_ROOT}/testsuites/samples/cdtest/

This sample application demonstrates that RTEMS is compatible with C++ applications. It uses constructors, destructor, and I/O stream output in testing these various capabilities. The board support package responsible for this application must support a C++ environment.

This sample application uses the printf function from the RTEMS Standard C Library to output the following messages:

    Hey I'M in base class constructor number 1 for 0x400010cc.
    Hey I'M in base class constructor number 2 for 0x400010d4.
    Hey I'M in derived class constructor number 3 for 0x400010d4.
    *** CONSTRUCTOR/DESTRUCTOR TEST ***
    Hey I'M in base class constructor number 4 for 0x4009ee08.
    Hey I'M in base class constructor number 5 for 0x4009ee10.
    Hey I'M in base class constructor number 6 for 0x4009ee18.
    Hey I'M in base class constructor number 7 for 0x4009ee20.
    Hey I'M in derived class constructor number 8 for 0x4009ee20.
    Testing a C++ I/O stream
    Hey I'M in derived class constructor number 8 for 0x4009ee20.
    Derived class - Instantiation order 8
    Hey I'M in base class constructor number 7 for 0x4009ee20.
    Instantiation order 8
    Hey I'M in base class constructor number 6 for 0x4009ee18.
    Instantiation order 6
    Hey I'M in base class constructor number 5 for 0x4009ee10.
    Instantiation order 5
    Hey I'M in base class constructor number 4 for 0x4009ee08.
    Instantiation order 5
    *** END OF CONSTRUCTOR/DESTRUCTOR TEST ***
    Hey I'M in base class constructor number 3 for 0x400010d4.
    Hey I'M in base class constructor number 2 for 0x400010d4.
    Hey I'M in base class constructor number 1 for 0x400010cc.

## 3.7. Minimum Size Test

This sample application is in the following directory:

    ${RTEMS_ROOT}/testsuites/samples/minimum/

This sample application is designed to produce the minimum code space required for any RTEMS application based upon the current RTEMS configuration and BSP. In many situations, the bulk of this executable consists of hardware and RTEMS initialization, basic infrastructure such as malloc(), and RTEMS and hardware shutdown support.

## 3.8. Nanosecond Granularity Application

This sample application is in the following directory:

    ${RTEMS_ROOT}/testsuites/samples/nsecs/

This sample application exercises the Clock Driver for this BSP and demonstrates its ability to generate accurate timestamps. This application does this by exercising the time subsystem in three ways:

- Obtain Time of Day Twice Back to Back

- Obtain System Up Time Twice Back to Back

- Use System Up Time to Measure Loops

The following is an example of what the output of this test may appear like:

    *** NANOSECOND CLOCK TEST ***
    10 iterations of getting TOD
    Start: Sat Mar 24 11:15:00 2007:540000
    Stop : Sat Mar 24 11:15:00 2007:549000 --> 0:9000
    Start: Sat Mar 24 11:15:00 2007:3974000
    Stop : Sat Mar 24 11:15:00 2007:3983000 --> 0:9000
    Start: Sat Mar 24 11:15:00 2007:7510000
    Stop : Sat Mar 24 11:15:00 2007:7519000 --> 0:9000
    Start: Sat Mar 24 11:15:00 2007:11054000
    Stop : Sat Mar 24 11:15:00 2007:11063000 --> 0:9000
    Start: Sat Mar 24 11:15:00 2007:14638000
    Stop : Sat Mar 24 11:15:00 2007:14647000 --> 0:9000
    Start: Sat Mar 24 11:15:00 2007:18301000
    Stop : Sat Mar 24 11:15:00 2007:18310000 --> 0:9000
    Start: Sat Mar 24 11:15:00 2007:21901000
    Stop : Sat Mar 24 11:15:00 2007:21910000 --> 0:9000
    Start: Sat Mar 24 11:15:00 2007:25526000
    Stop : Sat Mar 24 11:15:00 2007:25535000 --> 0:9000
    Start: Sat Mar 24 11:15:00 2007:29196000
    Stop : Sat Mar 24 11:15:00 2007:29206000 --> 0:10000
    Start: Sat Mar 24 11:15:00 2007:32826000
    Stop : Sat Mar 24 11:15:00 2007:32835000 --> 0:9000
    10 iterations of getting Uptime
    0:38977000 0:38986000 --> 0:9000
    0:40324000 0:40332000 --> 0:8000
    0:41636000 0:41645000 --> 0:9000
    0:42949000 0:42958000 --> 0:9000
    0:44295000 0:44304000 --> 0:9000
    0:45608000 0:45617000 --> 0:9000
    0:46921000 0:46930000 --> 0:9000
    0:48282000 0:48291000 --> 0:9000
    0:49595000 0:49603000 --> 0:8000
    0:50908000 0:50917000 --> 0:9000
    10 iterations of getting Uptime with different loop values
    loop of 10000 0:119488000 0:119704000 --> 0:216000
    loop of 20000 0:124028000 0:124463000 --> 0:435000
    loop of 30000 0:128567000 0:129220000 --> 0:653000
    loop of 40000 0:133097000 0:133964000 --> 0:867000
    loop of 50000 0:137643000 0:138728000 --> 0:1085000
    loop of 60000 0:142265000 0:143572000 --> 0:1307000
    loop of 70000 0:146894000 0:148416000 --> 0:1522000
    loop of 80000 0:151519000 0:153260000 --> 0:1741000
    loop of 90000 0:156145000 0:158099000 --> 0:1954000
    loop of 100000 0:160770000 0:162942000 --> 0:2172000
    *** END OF NANOSECOND CLOCK TEST ***

## 3.9. Paranoia Floating Point Application

This sample application is in the following directory:

    ${RTEMS_ROOT}/testsuites/samples/paranoia/

This sample application uses a public domain floating point and math library test to verify these capabilities of the RTEMS executive. Deviations between actual and expected results are reported to the screen. This is a very extensive test which tests all mathematical and number conversion functions. Paranoia is also very large and requires a long period of time to run. Problems which commonly prevent this test from executing to completion include stack overflow and FPU exception handlers not installed.

## 3.10. Network Loopback Test

This sample application is in the following directory:

    ${RTEMS_ROOT}/testsuites/samples/loopback/

This sample application uses the network loopback device to demonstrate the use of the RTEMS TCP/IP stack. This sample test illustrates the basic configuration and initialization of the TCP/IP stack as well as simple socket usage.