FreeRTOS application build process
Qt Quick Ultralite FreeRTOS application build process is the same as when building on bare metal with some additions. FreeRTOS being a separate library, you can build and link it yourself or use the
app_common helper together with
-DOS=FreeRTOS CMake flag and
QUL_OS target property.
app_common is a helper used to unify OS needs for examples and demos. It configures Qt Quick Ultralite for the correct OS, compiles OS-specific files, such as FreeRTOS sources, and links them to the project.
app_common is mainly for Qt Quick Ultralite examples and demos, it can be used in other projects. To use
app_common, set one of these:
STM32F7_FREERTOS_DIR=<freertos_directory_path>for STM32F769I-DISCOVERY and STM32F7508-DISCOVERY
IMXRT1050_FREERTOS_DIR=<freertos_directory_path>for NXP IMXRT1050-EVKB
IMXRT1064_FREERTOS_DIR=<freertos_directory_path>for NXP IMXRT1064-EVK
freertos_directory_path must be a path to a directory, where the include directory, portable directory, and FreeRTOS source files exist.
After setting the FreeRTOS directory, add the following line to your project's
Where, <app_name> is the name of your project's executable. This function sets up FreeRTOS for the project.
When configuring your project, use the
-DOS=FreeRTOS CMake option to select the OS. Now your project should build and link to FreeRTOS and the Qt Quick Ultralite library. If you want to change heap allocator or the Qt Quick Ultralite provided
FreeRTOSConfig.h, see Changing heap policies and Using custom FreeRTOSConfig.h.
When building project that uses FreeRTOS without
app_common, you must configure, compile, and link FreeRTOS to your project manually. You must also set
QUL_OS target property to
FreeRTOS. See How to use
QUL_OS target property for instructions on how to use
QUL_OS. For FreeRTOS building instructions, see Creating a New FreeRTOS Project.
Qt Quick Ultralite itself needs the following FreeRTOS headers and functions:
void *pvPortMalloc(size_t xSize)
void vPortFree(void *pv)
FreeRTOS includes different memory allocation implementations (see FreeRTOS developer docs, Memory management for more info about implementations). By default, Qt Quick Ultralite example application uses
heap_4, which “coalescences adjacent free blocks to avoid fragmentation. Includes absolute address placement option.” However, in some situations other custom implementation may be preferred over the ones provided by FreeRTOS. You can change the implementation by adding the following call your project's
set_property(TARGET <app_name> PROPERTY FREERTOS_HEAP_POLICY "<heap_implementation>")
Where <app_name> is the name of your project executable and <heap_implementation> is the name of the implementation without the filename extension. For example, if you want to use
heap_1.c, you must put
Note: The script expects to find the heap policy from FreeRTOS MemMang directory, where FreeRTOS’ memory manager implementations reside.
FreeRTOSConfig.h is a header file used to configure FreeRTOS while building the project.
If you have your own version of
FreeRTOSConfig.h and you are using
app_common, you can set the
FREERTOS_CONFIG_DIR target property to point to the directory where your custom FreeRTOSConfig.h file is by using:
set_property(TARGET <app_name> PROPERTY FREERTOS_CONFIG_DIR <freertos_config_directory>)
Where, <app_name> is your application target name and <freertos_config_directory> is a path to the directory where
Available under certain Qt licenses.
Find out more.