Build the FreeRTOS CMake template with IAR

Introduction

This interactive example describes how to build the FreeRTOS template example with IAR.

Helpful Resources

• Generator Expressions

Interactive Example

For this example we will use the FreeRTOS official cmake_example project sources from https://github.com/freertos/freertos-kernel and build it for an Arm Cortex-M4 target:

Project files
examples/cmake_example/CMakeLists.txt
examples/cmake_example/main.c
examples/template_configuration/FreeRTOSConfig.h

The main() function starts the FreeRTOS Kernel and runs a periodic task. For more information, refer to the FreeRTOS Beginners Guide.

Tasks

Prepare the template by filling the missing information in examples/cmake_example/CMakeLists.txt (click to show/hide answers):

TODO 1: Enable Assembly.

project(example C ASM)

TODO 2: Set the FREERTOS_PORT to the desired target.

set(FREERTOS_PORT "IAR_ARM_CM3" CACHE STRING "" FORCE)

TODO 3: Compile the library for the desired target CPU.

target_compile_options(freertos_kernel PRIVATE
    ### Previous options
    ### IAR C Options
    $<$<COMPILE_LANG_AND_ID:C,IAR>:--cpu=cortex-m4> )

TODO 4: Add compiler flag for building the application for the desired target CPU.

target_compile_options(${PROJECT_NAME} PRIVATE
    $<$<COMPILE_LANG_AND_ID:C,IAR>:--cpu=cortex-m4> )

TODO 5: Add linker flag for enabling Arm semihosting for printf().

target_link_options(${PROJECT_NAME} PRIVATE
    $<$<COMPILE_LANG_AND_ID:C,IAR>:--semihosting> )

TODO 6: Set C_STANDARD to a compatible value.

In CMake, the C_STANDARD is computed automatically for the language standard provided by the IAR Compiler.

# set_property(TARGET freertos_kernel PROPERTY C_STANDARD 90)

The template configuration needs to be updated adequately for the desired target. In the examples/template_configuration/FreeRTOSConfig.h perform the following tasks (click to show/hide answers):

TODO 1: Update configTICK_TYPE_WIDTH_IN_BITS.

#define configTICK_TYPE_WIDTH_IN_BITS              TICK_TYPE_WIDTH_32_BITS

TODO 2: Update configMAX_SYSCALL_INTERRUPT_PRIORITY.

#define configMAX_SYSCALL_INTERRUPT_PRIORITY     5

NOTES See https://www.freertos.org/Documentation/02-Kernel/03-Supported-devices/04-Demos/ARM-Cortex/RTOS-Cortex-M3-M4 for more information.

• Finally, build and test the project. Refer to the tutorial for more information.