This section contains documentation of FreeRTOS types, functions, and macros. It is automatically generated from FreeRTOS header files.
Note
ESP-IDF FreeRTOS is based on Vanilla FreeRTOS v10.4.3
- For more information about the SMP changes of ESP-IDF FreeRTOS, see :doc:`/api-guides/freertos-smp`
- For more information about the features added to ESP-IDF FreeRTOS, see :doc:`/api-reference/system/freertos_additions`.
Vanilla FreeRTOS allows ports and applications to configure the kernel by adding various #define config...
macros to FreeRTOSConfig.h
. Through these macros, the kernel's scheduling behavior and various kernel features can be enabled or disabled. However, in ESP-IDF FreeRTOS, the ``FreeRTOSConfig.h`` file is considered a private and must not be modified by users. Any FreeRTOS configuration that is exposed to the user will be done so via menuconfig.
ESP-IDF FreeRTOS can be configured in the project configuration menu (idf.py menuconfig
) under Component Config/FreeRTOS
. The following section highlights some of the ESP-IDF FreeRTOS configuration options. For a full list of ESP-IDF FreeRTOS configurations, see :doc:`/api-reference/kconfig`
:ref:`CONFIG_FREERTOS_UNICORE` will run ESP-IDF FreeRTOS only on CPU0. Note that this is not equivalent to running Vanilla FreeRTOS. Futhermore, this option may affect behavior of components other than :component:`freertos`. For more details regarding the effects of running ESP-IDF FreeRTOS on a single core, refer to :ref:`freertos-smp-single-core`. Alternatively, users can also search for occurrences of
CONFIG_FREERTOS_UNICORE
in the ESP-IDF components.:ref:`CONFIG_FREERTOS_TASK_FUNCTION_WRAPPER` will enclose all task functions within a wrapper function. In the case that a task function mistakenly returns (i.e. does not call :cpp:func:`vTaskDelete`), the call flow will return to the wrapper function. The wrapper function will then log an error and abort the application, as illustrated below:
E (25) FreeRTOS: FreeRTOS task should not return. Aborting now! abort() was called at PC 0x40085c53 on core 0
.. only:: CONFIG_FREERTOS_UNICORE .. note:: As {IDF_TARGET_NAME} is a single core SoC, the :ref:`CONFIG_FREERTOS_UNICORE` configuration is always set.
Unlike Vanilla FreeRTOS, users must not call :cpp:func:`vTaskStartScheduler`. Instead, ESP-IDF FreeRTOS is started automatically. The entry point is a user defined void app_main(void)
function.
- Typically, users would spawn the rest of their applications task from
app_main
. - The
app_main
function is allowed to return at any point (i.e., before the application terminates). - The
app_main
function is called from themain
task.
The main
task is one of multiple tasks that are automatically spawned by ESP-IDF during startup. These tasks are:
.. only:: not CONFIG_FREERTOS_UNICORE .. list-table:: List of Tasks Created During Startup :widths: 25 25 5 50 :header-rows: 1 * - Task Name - Affinity - Priority - Description * - Main Task (``main``) - CPU0 - 1 - Task that simply calls ``app_main``. This task will self delete when ``app_main`` returns * - Idle Tasks (``IDLEx``) - CPU0 and CPU1 - 0 - Idle tasks created for (and pinned to) each CPU * - IPC Tasks (``ipcx``) - CPU0 and CPU1 - 24 - IPC tasks created for (and pinned to ) each CPU. IPC tasks are used to implement the IPC feature. See :doc:`/api-reference/system/ipc` for more details.
.. only:: CONFIG_FREERTOS_UNICORE .. list-table:: List of Tasks Created During Startup :widths: 25 25 5 50 :header-rows: 1 * - Task Name - Affinity - Priority - Description * - Main Task (``main``) - CPU0 - 1 - Task that simply calls ``app_main``. This task will self delete when ``app_main`` returns * - Idle Tasks (``IDLEx``) - CPU0 and CPU1 - 0 - Idle task created for (and pinned to) each CPU .. note:: Low priority numbers denote low priority tasks.
.. include-build-file:: inc/task.inc
.. include-build-file:: inc/queue.inc
.. include-build-file:: inc/semphr.inc
.. include-build-file:: inc/timers.inc
.. include-build-file:: inc/event_groups.inc
.. include-build-file:: inc/stream_buffer.inc
.. include-build-file:: inc/message_buffer.inc