ARM Cortex-M33 (ARMv8-M) Demo for NXP LPCXpresso55S69 Development Board
Using MCUXpresso IDE
[RTOS Ports]



This page documents a pre-configured FreeRTOS project that targets the ARM Cortex-M33 core on the NXP LPCXpresso55S69 Development Board. The project uses the MCUXpresso IDE and GCC compiler to build the FreeRTOS ARMv8-M GCC port. The project demonstrates using the ARM Cortex-M33 TrustZone and the ARM Cortex-M33 Memory Protection Unit (MPU).



IMPORTANT! Notes on using the FreeRTOS ARM Cortex-M33 port

Please read all the following points before using this RTOS port.

  1. Source Code Organization
  2. The Demo Application
  3. Building and Running the RTOS Demo Application
  4. RTOS Configuration and Usage Details
Also see the FAQ My application does not run, what could be wrong?.



Source Code Organization

The FreeRTOS zip file download contains the source code for all the FreeRTOS ports, and every demo application. That means it contains many more files than are required to use the FreeRTOS ARMv8-M Cortex-M33 port. See the Source Code Organization page for information on the zip file’s directory structure.

The project files for this demo are located in the FreeRTOS/Demo/CORTEX_MPU_M33F_NXP_LPC55S69_MCUXpresso/Projects/MCUXpresso directory. The project file for the secure side of the ARM Cortex-M33 core has the usual Eclipse project name .project and is located in the FreeRTOS/Demo/CORTEX_MPU_M33F_NXP_LPC55S69_MCUXpresso/Projects/MCUXpresso/Secure directory. The project file for the non-secure side of the ARM Cortex-M33 core has the usual Eclipse project name .project and is located in the FreeRTOS/Demo/CORTEX_MPU_M33F_NXP_LPC55S69_MCUXpresso/Projects/MCUXpresso/NonSecure directory.The FreeRTOS ARMv8-M Cortex-M33 port files compiled in these two projects are organized as follows:

  • Port files compiled in the secure project are in the FreeRTOS/Source/portable/GCC/ARM_CM33/secure directory.
  • Port files compiled in the non-secure project are in the FreeRTOS/Source/portable/GCC/ARM_CM33/non_secure directory.



The Demo Application

The project includes two demos:
  1. TrustZone Demo
  2. Memory Protection Unit (MPU) Demo

TrustZone Demo

The TrustZone demo demonstrates how to export functions from the secure side of the ARM Cortex-M33 core, and how to call them from RTOS tasks on the non-secure side.
  • NonSecure Callable Function:

    The following function is exported from the secure side and is marked as non-secure callable:

    secureportNON_SECURE_CALLABLE uint32_t NSCFunction( Callback_t pxCallback )

    Note the use of secureportNON_SECURE_CALLABLE macro to mark the function as non-secure callable. This function accepts a callback as argument. It first invokes the callback function supplied as argument and then increments a secure side counter. The incremented value of the secure side counter is returned to the caller.

  • NonSecure Callback:

    The following function is implemented on the non-secure side and is passed to the above mentioned non-secure callable function as argument:

    void prvCallback( void )

    This function increments a non-secure counter.

  • Secure Calling Task:

    An un-privileged non-secure task is created using the xTaskCreateRestricted() API. This task first calls portALLOCATE_SECURE_CONTEXT to allocate itself a secure context – any non-secure task which wants to call a function exported from the secure side must allocate itself a secure context by calling portALLOCATE_SECURE_CONTEXT.

    The task then calls the secure side function and passes the non-secure callback as the argument. The non-secure counter is incremented in the callback and the secure counter is incremented in the secure function. Therefore, both the counters must be incremented after the call to the secure function is complete – this is ensured using configASSERT(). The task sleeps for one second and then repeats the same.

TrustZone Demo Call Sequence
The TrustZone Demo Call Sequence

Memory Protection Unit (MPU) Demo

The MPU demo demonstrates how to use the MPU to grant a task different access permissions for various memory regions. The MPU demo consists of the following two tasks:
  • RW Task:

    The RW task has Read-Write access to a shared region of memory (namely ucSharedMemory).

  • RO Task:

    The RO task has Read-Only access to the same shared region of memory (namely ucSharedMemory). This task tries to write to the shared memory and since it has read only permission to the shared memory, it results in a memory fault. The fault handler checks if it is the expected fault from the RO task and if so, it recovers gracefully by incrementing the Program Counter to the next statement.



Building and Running the RTOS Demo Application

  1. Launch the MCUXpresso IDE. Note that you need the MCUXpresso IDE version 10.3.1 or higher to be able to build and run this demo.

  2. Choose the workspace directory and click “Launch”.

    MCUXpresso IDE - Launcher
    MCUXpresso IDE – Launcher. Click to enlarge.


  3. Open the Import Project dialog by clicking “File –> Import…”.

    MCUXpresso IDE - Import
    MCUXpresso IDE – Import. Click to enlarge.


  4. Select “General –> Existing Projects into Workspace” and click “Next”.

    MCUXpresso IDE - Import
    MCUXpresso IDE – Import. Click to enlarge.


  5. Click “Browse…” next to “Select root directory” and select FreeRTOS/Demo/CORTEX_MPU_M33F_NXP_LPC55S69_MCUXpresso/Projects/MCUXpresso directory. Two projects, namely FreeRTOSDemo_s and FreeRTOSDemo_ns, should be visible in the Projects pane as shown below. Click “Finish”.

    MCUXpresso IDE - Import
    MCUXpresso IDE – Import. Click to enlarge.


  6. Build the secure project by right clicking on FreeRTOSDemo_s and selecting “Build Project”.

    MCUXpresso IDE - Build Secure Project
    MCUXpresso IDE – Build Secure Project. Click to enlarge.


  7. Build the non-secure project by right clicking on FreeRTOSDemo_ns and selecting “Build Project”.

    MCUXpresso IDE - Build Non-Secure Project
    MCUXpresso IDE – Build Non-Secure Project. Click to enlarge.


  8. Power up the board using “Debug Link (P6)” micro USB port.

  9. Select the non-secure project by clicking FreeRTOSDemo_ns. Go to “Debug your project” in the Quickstart Panel and click on “Program flash action using LinkServer” in the dropdown as shown below.

    MCUXpresso IDE - Flash the Non-Secure Binary
    MCUXpresso IDE – Flash the Non-Secure Binary. Click to enlarge.


  10. LPC-LINK2 probe should be shown in the “Probes Discovered” window. Click “OK”.

    MCUXpresso IDE - Flash the Non-Secure Binary
    MCUXpresso IDE – Flash the Non-Secure Binary. Click to enlarge.


  11. SWD Device 0 should be selected in the “SWD Configuration” window. Click “OK”.

    MCUXpresso IDE - Flash the Non-Secure Binary
    MCUXpresso IDE – Flash the Non-Secure Binary. Click to enlarge.


  12. You should see “Finished writing Flash successfully” in the logs. Click “OK”.

    MCUXpresso IDE - Flash the Non-Secure Binary
    MCUXpresso IDE – Flash the Non-Secure Binary. Click to enlarge.


  13. Power cycle the board by disconnecting and reconnecting the micro USB cable.

  14. Select the secure project by clicking FreeRTOSDemo_s. Go to “Debug your project” in the Quickstart Panel and click on “Program flash action using LinkServer” in the dropdown as shown below.

    MCUXpresso IDE - Flash the Secure Binary
    MCUXpresso IDE – Flash the Secure Binary. Click to enlarge.


  15. LPC-LINK2 probe should be shown in the “Probes Discovered” window. Click “OK”.

    MCUXpresso IDE - Flash the Secure Binary
    MCUXpresso IDE – Flash the Secure Binary. Click to enlarge.


  16. SWD Device 0 should be selected in the “SWD Configuration” window. Click “OK”.

    MCUXpresso IDE - Flash the Secure Binary
    MCUXpresso IDE – Flash the Secure Binary. Click to enlarge.


  17. You should see “Finished writing Flash successfully” in the logs. Click “OK”.

    MCUXpresso IDE - Flash the Secure Binary
    MCUXpresso IDE – Flash the Secure Binary. Click to enlarge.


  18. Power cycle the board by disconnecting and reconnecting the micro USB cable.

  19. Go to “Debug your project” in the Quickstart Panel and click “Debug using LinkServer probes” in the dropdown as shown below to start the debug session.

    MCUXpresso IDE - Start the Debug Session
    MCUXpresso IDE – Start the Debug Session. Click to enlarge.




RTOS Configuration and Usage Details

  • Configuration items specific to this demo are contained in FreeRTOS/Demo/CORTEX_MPU_M33F_NXP_LPC55S69_MCUXpresso/Projects/MCUXpresso/Config/FreeRTOSConfig.h. The constants defined in that file can be edited to suit your application. The following configuration options are specific to the ARM Cortex-M33 port:

    • configENABLE_MPU – Enable/Disable Memory Protection Unit (MPU).
    • configENABLE_FPU – Enable/Disable Floating Point Unit (FPU).
    • configENABLE_TRUSTZONE – Enable/Disable TrustZone.

  • If you want to run FreeRTOS with TrustZone disabled, set configENABLE_TRUSTZONE to 0 in your FreeRTOSConfig.h and use the FreeRTOS port files in the FreeRTOS/Source/portable/GCC/ARM_CM33_NTZ directory.

  • If you want to run FreeRTOS on the secure side, set configENABLE_TRUSTZONE to 0 and configRUN_FREERTOS_SECURE_ONLY to 1 in your FreeRTOSConfig.h and use the FreeRTOS port files in the FreeRTOS/Source/portable/GCC/ARM_CM33_NTZ directory.

  • Source/Portable/MemMang/heap_4.c is included in the project to provide the memory allocation required by the RTOS kernel. Please refer to the Memory Management section of the API documentation for full information.

  • vPortEndScheduler() has not been implemented.



Copyright (C) Amazon Web Services, Inc. or its affiliates. All rights reserved.

Latest News

FreeRTOS v10.2.1 is available for immediate download. MIT licensed, includes 64-bit RISC-V, NXP Cortex-M33 demo & Nuvoton Cortex-M23 demo & STM32H745 dual core (AMP) demo.

Watch for updates in the coming months as we add new IoT-related functionality and improved website navigation and resources

View a recording of the “OTA Update Security and Reliability” webinar, presented by TI and AWS.

Careers

FreeRTOS and other embedded software careers at AWS.

FreeRTOS Partners
ARM Connected RTOS partner for all ARM microcontroller cores
Espressif ESP32
IAR Partner
Microchip Premier RTOS Partner
Renesas
STMicro RTOS partner supporting ARM7, ARM Cortex-M3, ARM Cortex-M4 and ARM Cortex-M0
Texas Instruments MCU Developer Network RTOS partner for ARM and MSP430 microcontrollers
OpenRTOS and SafeRTOS
Xilinx Microblaze and Zynq partner