esp-idf/components/freertos/Kconfig

menu "FreeRTOS"

    # This is actually also handled in the ESP32 startup code, not only in FreeRTOS.
    config FREERTOS_UNICORE
        bool "Run FreeRTOS only on first core"
        default n
        help
            This version of FreeRTOS normally takes control of all cores of
            the CPU. Select this if you only want to start it on the first core.
            This is needed when e.g. another process needs complete control
            over the second core.

            # This invisible config value sets the value of tskNO_AFFINITY in task.h.
            # Intended to be used as a constant from other Kconfig files.
            # Value is (32-bit) INT_MAX.
    config FREERTOS_NO_AFFINITY
        hex
        default 0x7FFFFFFF

    choice FREERTOS_CORETIMER
        prompt "Xtensa timer to use as the FreeRTOS tick source"
        default CONFIG_FREERTOS_CORETIMER_0
        help
            FreeRTOS needs a timer with an associated interrupt to use as
            the main tick source to increase counters, run timers and do
            pre-emptive multitasking with. There are multiple timers available
            to do this, with different interrupt priorities. Check

        config FREERTOS_CORETIMER_0
            bool "Timer 0 (int 6, level 1)"
            help
                Select this to use timer 0

        config FREERTOS_CORETIMER_1
            bool "Timer 1 (int 15, level 3)"
            help
                Select this to use timer 1

    endchoice

    config FREERTOS_HZ
        int "Tick rate (Hz)"
        range 1 1000
        default 100
        help
            Select the tick rate at which FreeRTOS does pre-emptive context switching.

    config FREERTOS_ASSERT_ON_UNTESTED_FUNCTION
        bool "Halt when an SMP-untested function is called"
        default y
        help
            Some functions in FreeRTOS have not been thoroughly tested yet when moving to
            the SMP implementation of FreeRTOS. When this option is enabled, these fuctions
            will throw an assert().

    choice FREERTOS_CHECK_STACKOVERFLOW
        prompt "Check for stack overflow"
        default FREERTOS_CHECK_STACKOVERFLOW_CANARY
        help
            FreeRTOS can check for stack overflows in threads and trigger an user function
            called vApplicationStackOverflowHook when this happens.

        config FREERTOS_CHECK_STACKOVERFLOW_NONE
            bool "No checking"
            help
                Do not check for stack overflows (configCHECK_FOR_STACK_OVERFLOW=0)

        config FREERTOS_CHECK_STACKOVERFLOW_PTRVAL
            bool "Check by stack pointer value"
            help
                Check for stack overflows on each context switch by checking if
                the stack pointer is in a valid range. Quick but does not detect
                stack overflows that happened between context switches
                (configCHECK_FOR_STACK_OVERFLOW=1)

        config FREERTOS_CHECK_STACKOVERFLOW_CANARY
            bool "Check using canary bytes"
            help
                Places some magic bytes at the end of the stack area and on each
                context switch, check if these bytes are still intact. More thorough
                than just checking the pointer, but also slightly slower.
                (configCHECK_FOR_STACK_OVERFLOW=2)
    endchoice

    config FREERTOS_WATCHPOINT_END_OF_STACK
        bool "Set a debug watchpoint as a stack overflow check"
        default n
        help
            FreeRTOS can check if a stack has overflown its bounds by checking either the value of
            the stack pointer or by checking the integrity of canary bytes. (See FREERTOS_CHECK_STACKOVERFLOW
            for more information.) These checks only happen on a context switch, and the situation that caused
            the stack overflow may already be long gone by then. This option will use the debug memory
            watchpoint 1 (the second one) to allow breaking into the debugger (or panic'ing) as soon as any
            of the last 32 bytes on the stack of a task are overwritten. The side effect is that using gdb, you
            effectively only have one watchpoint; the 2nd one is overwritten as soon as a task switch happens.

            This check only triggers if the stack overflow writes within 4 bytes of the end of the stack, rather than
            overshooting further, so it is worth combining this approach with one of the other stack overflow check
            methods.

            When this watchpoint is hit, gdb will stop with a SIGTRAP message. When no JTAG OCD is attached, esp-idf
            will panic on an unhandled debug exception.

    config FREERTOS_INTERRUPT_BACKTRACE
        bool "Enable backtrace from interrupt to task context"
        default y
        help
            If this option is enabled, interrupt stack frame will be modified to
            point to the code of the interrupted task as its return address.
            This helps the debugger (or the panic handler) show a backtrace from
            the interrupt to the task which was interrupted. This also works for
            nested interrupts: higer level interrupt stack can be traced back to the
            lower level interrupt.
            This option adds 4 instructions to the interrupt dispatching code.

    config FREERTOS_THREAD_LOCAL_STORAGE_POINTERS
        int "Number of thread local storage pointers"
        range 1 256
        default 1
        help
            FreeRTOS has the ability to store per-thread pointers in the task
            control block. This controls the number of pointers available.

            This value must be at least 1. Index 0 is reserved for use by the pthreads API
            thread-local-storage. Other indexes can be used for any desired purpose.

    choice FREERTOS_ASSERT
        prompt "FreeRTOS assertions"
        default FREERTOS_ASSERT_FAIL_ABORT
        help
            Failed FreeRTOS configASSERT() assertions can be configured to
            behave in different ways.

        config FREERTOS_ASSERT_FAIL_ABORT
            bool "abort() on failed assertions"
            help
                If a FreeRTOS configASSERT() fails, FreeRTOS will abort() and
                halt execution. The panic handler can be configured to handle
                the outcome of an abort() in different ways.

        config FREERTOS_ASSERT_FAIL_PRINT_CONTINUE
            bool "Print and continue failed assertions"
            help
                If a FreeRTOS assertion fails, print it out and continue.

        config FREERTOS_ASSERT_DISABLE
            bool "Disable FreeRTOS assertions"
            help
                FreeRTOS configASSERT() will not be compiled into the binary.

    endchoice

    config FREERTOS_IDLE_TASK_STACKSIZE
        int "Idle Task stack size"
        range 768 32768
        default 1536
        help
            The idle task has its own stack, sized in bytes. The default size is enough for most uses. Size can be
            reduced to 768 bytes if no (or simple) FreeRTOS idle hooks are used and pthread local storage or FreeRTOS
            local storage cleanup callbacks are not used.

            The stack size may need to be increased above the default if the app installs idle or thread local storage
            cleanup hooks that use a lot of stack memory.

    config FREERTOS_ISR_STACKSIZE
        int "ISR stack size"
        range 1536 32768
        default 1536
        help
            The interrupt handlers have their own stack. The size of the stack can be defined here.
            Each processor has its own stack, so the total size occupied will be twice this.

    config FREERTOS_LEGACY_HOOKS
        bool "Use FreeRTOS legacy hooks"
        default n
        help
            FreeRTOS offers a number of hooks/callback functions that are called when a timer
            tick happens, the idle thread runs etc. esp-idf replaces these by runtime registerable
            hooks using the esp_register_freertos_xxx_hook system, but for legacy reasons the old
            hooks can also still be enabled. Please enable this only if you have code that for some
            reason can't be migrated to the esp_register_freertos_xxx_hook system.

    config FREERTOS_MAX_TASK_NAME_LEN
        int "Maximum task name length"
        range 1 256
        default 16
        help
            Changes the maximum task name length. Each task allocated will
            include this many bytes for a task name. Using a shorter value
            saves a small amount of RAM, a longer value allows more complex
            names.

            For most uses, the default of 16 is OK.

    config SUPPORT_STATIC_ALLOCATION
        bool "Enable FreeRTOS static allocation API"
        default n
        help
            FreeRTOS gives the application writer the ability to instead provide the memory
            themselves, allowing the following objects to optionally be created without any
            memory being allocated dynamically:

            - Tasks
            - Software Timers (Daemon task is still dynamic. See documentation)
            - Queues
            - Event Groups
            - Binary Semaphores
            - Counting Semaphores
            - Recursive Semaphores
            - Mutexes

            Whether it is preferable to use static or dynamic memory allocation is dependent on
            the application, and the preference of the application writer. Both methods have pros
            and cons, and both methods can be used within the same RTOS application.

            Creating RTOS objects using statically allocated RAM has the benefit of providing the application writer
            with more control: RTOS objects can be placed at specific memory locations. The maximum RAM footprint can
            be determined at link time, rather than run time. The application writer does not need to concern
            themselves with graceful handling of memory allocation failures. It allows the RTOS to be used in
            applications that simply don't allow any dynamic memory allocation (although FreeRTOS includes allocation
            schemes that can overcome most objections).

    config ENABLE_STATIC_TASK_CLEAN_UP_HOOK
        bool "Enable static task clean up hook"
        depends on SUPPORT_STATIC_ALLOCATION
        default n
        help
            Enable this option to make FreeRTOS call the static task clean up hook when a task is deleted.

            Bear in mind that if this option is enabled you will need to implement the following function::

                void vPortCleanUpTCB ( void *pxTCB ) {
                    // place clean up code here
                }

    config TIMER_TASK_PRIORITY
        int "FreeRTOS timer task priority"
        range 1 25
        default 1
        help
            The timer service task (primarily) makes use of existing FreeRTOS features, allowing timer
            functionality to be added to an application with minimal impact on the size of the application's
            executable binary.

            Use this constant to define the priority that the timer task will run at.

    config TIMER_TASK_STACK_DEPTH
        int "FreeRTOS timer task stack size"
        range 1536 32768
        default 2048
        help
            The timer service task (primarily) makes use of existing FreeRTOS features, allowing timer
            functionality to be added to an application with minimal impact on the size of the application's
            executable binary.

            Use this constant to define the size (in bytes) of the stack allocated for the timer task.

    config TIMER_QUEUE_LENGTH
        int "FreeRTOS timer queue length"
        range 5 20
        default 10
        help
            FreeRTOS provides a set of timer related API functions. Many of these functions use a standard
            FreeRTOS queue to send commands to the timer service task. The queue used for this purpose is
            called the 'timer command queue'. The 'timer command queue' is private to the FreeRTOS timer
            implementation, and cannot be accessed directly.

            For most uses the default value of 10 is OK.

    config FREERTOS_QUEUE_REGISTRY_SIZE
        int "FreeRTOS queue registry size"
        range 0 20
        default 0
        help
            FreeRTOS uses the queue registry as a means for kernel aware debuggers to locate queues, semaphores,
            and mutexes. The registry allows for a textual name to be associated with a queue for easy identification
            within a debugging GUI. A value of 0 will disable queue registry functionality, and a value larger than 0
            will specify the number of queues/semaphores/mutexes that the registry can hold.

    config FREERTOS_USE_TRACE_FACILITY
        bool "Enable FreeRTOS trace facility"
        default n
        help
            If enabled, configUSE_TRACE_FACILITY will be defined as 1 in FreeRTOS.
            This will allow the usage of trace facility functions such as
            uxTaskGetSystemState().

    config FREERTOS_USE_STATS_FORMATTING_FUNCTIONS
        bool "Enable FreeRTOS stats formatting functions"
        depends on FREERTOS_USE_TRACE_FACILITY
        default n
        help
            If enabled, configUSE_STATS_FORMATTING_FUNCTIONS will be defined as 1 in
            FreeRTOS. This will allow the usage of stats formatting functions such
            as vTaskList().

    config FREERTOS_VTASKLIST_INCLUDE_COREID
        bool "Enable display of xCoreID in vTaskList"
        depends on FREERTOS_USE_STATS_FORMATTING_FUNCTIONS
        default n
        help
            If enabled, this will include an extra column when vTaskList is called
            to display the CoreID the task is pinned to (0,1) or -1 if not pinned.

    config FREERTOS_GENERATE_RUN_TIME_STATS
        bool "Enable FreeRTOS to collect run time stats"
        default n
        select FREERTOS_USE_TRACE_FACILITY
        select FREERTOS_USE_STATS_FORMATTING_FUNCTIONS
        help
            If enabled, configGENERATE_RUN_TIME_STATS will be defined as 1 in
            FreeRTOS. This will allow FreeRTOS to collect information regarding the
            usage of processor time amongst FreeRTOS tasks. Run time stats are
            generated using either the ESP Timer or the CPU Clock as the clock
            source (Note that run time stats are only valid until the clock source
            overflows). The function vTaskGetRunTimeStats() will also be available
            if FREERTOS_USE_STATS_FORMATTING_FUNCTIONS and
            FREERTOS_USE_TRACE_FACILITY are enabled. vTaskGetRunTimeStats() will
            display the run time of each task as a % of the total run time of all
            CPUs (task run time / no of CPUs) / (total run time / 100 )


    choice FREERTOS_RUN_TIME_STATS_CLK
        prompt "Choose the clock source for run time stats"
        depends on FREERTOS_GENERATE_RUN_TIME_STATS
        default FREERTOS_RUN_TIME_STATS_USING_ESP_TIMER
        help
            Choose the clock source for FreeRTOS run time stats. Options are CPU0's
            CPU Clock or the ESP Timer. Both clock sources are 32 bits. The CPU
            Clock can run at a higher frequency hence provide a finer resolution
            but will overflow much quicker. Note that run time stats are only valid
            until the clock source overflows.

        config FREERTOS_RUN_TIME_STATS_USING_ESP_TIMER
            bool "Use ESP TIMER for run time stats"
            help
                ESP Timer will be used as the clock source for FreeRTOS run time stats.
                The ESP Timer runs at a frequency of 1MHz regardless of Dynamic
                Frequency Scaling. Therefore the ESP Timer will overflow in
                approximately 4290 seconds.

        config FREERTOS_RUN_TIME_STATS_USING_CPU_CLK
            bool "Use CPU Clock for run time stats"
            help
                CPU Clock will be used as the clock source for the generation of run
                time stats. The CPU Clock has a frequency dependent on
                ESP32_DEFAULT_CPU_FREQ_MHZ and Dynamic Frequency Scaling (DFS).
                Therefore the CPU Clock frequency can fluctuate between 80 to 240MHz.
                Run time stats generated using the CPU Clock represents the number of
                CPU cycles each task is allocated and DOES NOT reflect the amount of
                time each task runs for (as CPU clock frequency can change). If the CPU
                clock consistently runs at the maximum frequency of 240MHz, it will
                overflow in approximately 17 seconds.

    endchoice

    config FREERTOS_USE_TICKLESS_IDLE
        bool "Tickless idle support"
        depends on PM_ENABLE
        default n
        help
            If power management support is enabled, FreeRTOS will be able to put
            the system into light sleep mode when no tasks need to run for a number
            of ticks. This number can be set using FREERTOS_IDLE_TIME_BEFORE_SLEEP option.
            This feature is also known as "automatic light sleep".

            Note that timers created using esp_timer APIs may prevent the system from
            entering sleep mode, even when no tasks need to run.

            If disabled, automatic light sleep support will be disabled.

    config FREERTOS_IDLE_TIME_BEFORE_SLEEP
        int "Minimum number of ticks to enter sleep mode for"
        depends on FREERTOS_USE_TICKLESS_IDLE
        default 3
        range 2 4294967295
        # Minimal value is 2 because of a check in FreeRTOS.h (search configEXPECTED_IDLE_TIME_BEFORE_SLEEP)
        help
            FreeRTOS will enter light sleep mode if no tasks need to run for this number
            of ticks.

    menuconfig FREERTOS_DEBUG_INTERNALS
        bool "Debug FreeRTOS internals"
        default n
        help
            Enable this option to show the menu with internal FreeRTOS debugging features.
            This option does not change any code by itself, it just shows/hides some options.

    if FREERTOS_DEBUG_INTERNALS

        config FREERTOS_PORTMUX_DEBUG
            bool "Debug portMUX portENTER_CRITICAL/portEXIT_CRITICAL"
            depends on FREERTOS_DEBUG_INTERNALS
            default n
            help
                If enabled, debug information (including integrity checks) will be printed
                to UART for the port-specific MUX implementation.

        if !FREERTOS_UNICORE
            config FREERTOS_PORTMUX_DEBUG_RECURSIVE
                bool "Debug portMUX Recursion"
                depends on FREERTOS_PORTMUX_DEBUG
                default n
                help
                    If enabled, additional debug information will be printed for recursive
                    portMUX usage.
        endif #FREERTOS_UNICORE

    endif # FREERTOS_DEBUG_INTERNALS

    config FREERTOS_TASK_FUNCTION_WRAPPER
        bool "Enclose all task functions in a wrapper function"
        depends on OPTIMIZATION_LEVEL_DEBUG
        default y
        help
            If enabled, all FreeRTOS task functions will be enclosed in a wrapper function.
            If a task function mistakenly returns (i.e. does not delete), the call flow will
            return to the wrapper function. The wrapper function will then log an error and
            abort the application. This option is also required for GDB backtraces and C++
            exceptions to work correctly inside top-level task functions.

endmenu