# CMSIS ## **Overview** Provides standard, universal real-time operating system \(RTOS\) APIs. These APIs comply with ARM CMSIS and are used for thread management, timer management, inter-process communications, and semaphores. **Since:** 1.0 **Version:** 1.0 ## **Summary** ## Data Structures

Data Structure Name	Description
osVersion_t	Describes the system version.
osThreadAttr_t	Describes thread attributes.
osTimerAttr_t	Describes timer attributes.
osEventFlagsAttr_t	Describes event attributes.
osMutexAttr_t	Describes mutex attributes.
osSemaphoreAttr_t	Describes semaphore attributes.
osMessageQueueAttr_t	Describes message queue attributes.

## Macros

Macro Name and Value	Description
osWaitForever 0xFFFFFFFFU	Indicates that the RTOS waits forever unless an event flag is received.
osNoWait 0x0U	Indicates that the RTOS does not wait.
osFlagsWaitAny 0x00000000U	Indicates that the RTOS waits until any event flag is triggered.
osFlagsWaitAll 0x00000001U	Indicates that the system waits until all event flags are triggered.
osFlagsNoClear 0x00000002U	Indicates that defined flags are not cleared.
osFlagsError 0x80000000U	Indicates a flag error.
osFlagsErrorUnknown 0xFFFFFFFFU	Indicates an unknown error.
osFlagsErrorTimeout 0xFFFFFFFEU	Indicates a timeout.
osFlagsErrorResource 0xFFFFFFFDU	Indicates a resource error.
osFlagsErrorParameter 0xFFFFFFFCU	Indicates an incorrect parameter.

## Typedefs

Typedef Name	Description
osThreadFunc_t) (void *argument)	typedef void(* Callback for thread scheduling.
osTimerFunc_t) (void *argument)	typedef void(* Callback for timer triggering.
osThreadId_t	typedef void * Identifies a thread.
osTimerId_t	typedef void * Identifies a timer.
osEventFlagsId_t	typedef void * Identifies an event flag.
osMutexId_t	typedef void * Identifies a mutex.
osSemaphoreId_t	typedef void * Identifies a semaphore object.
osMessageQueueId_t	typedef void * Identifies a message queue.
TZ_ModuleId_t	typedef uint32_t Identifies a TrustZone module call process.

## Enumerations

Enumeration Name	Description
osKernelState_t { osKernelInactive = 0, osKernelReady = 1, osKernelRunning = 2, osKernelLocked = 3, osKernelSuspended = 4, osKernelError = -1, osKernelReserved = 0x7FFFFFFFU }	Enumerates kernel states.
osThreadState_t { osThreadInactive = 0, osThreadReady = 1, osThreadRunning = 2, osThreadBlocked = 3, osThreadTerminated = 4, osThreadError = -1, osThreadReserved = 0x7FFFFFFF }	Enumerates thread states.
osPriority_t { osPriorityNone = 0, osPriorityIdle = 1, osPriorityLow = 8, osPriorityLow1 = 8+1, osPriorityLow2 = 8+2, osPriorityLow3 = 8+3, osPriorityLow4 = 8+4, osPriorityLow5 = 8+5, osPriorityLow6 = 8+6, osPriorityLow7 = 8+7, osPriorityBelowNormal = 16, osPriorityBelowNormal1 = 16+1, osPriorityBelowNormal2 = 16+2, osPriorityBelowNormal3 = 16+3, osPriorityBelowNormal4 = 16+4, osPriorityBelowNormal5 = 16+5, osPriorityBelowNormal6 = 16+6, osPriorityBelowNormal7 = 16+7, osPriorityNormal = 24, osPriorityNormal1 = 24+1, osPriorityNormal2 = 24+2, osPriorityNormal3 = 24+3, osPriorityNormal4 = 24+4, osPriorityNormal5 = 24+5, osPriorityNormal6 = 24+6, osPriorityNormal7 = 24+7, osPriorityAboveNormal = 32, osPriorityAboveNormal1 = 32+1, osPriorityAboveNormal2 = 32+2, osPriorityAboveNormal3 = 32+3, osPriorityAboveNormal4 = 32+4, osPriorityAboveNormal5 = 32+5, osPriorityAboveNormal6 = 32+6, osPriorityAboveNormal7 = 32+7, osPriorityHigh = 40, osPriorityHigh1 = 40+1, osPriorityHigh2 = 40+2, osPriorityHigh3 = 40+3, osPriorityHigh4 = 40+4, osPriorityHigh5 = 40+5, osPriorityHigh6 = 40+6, osPriorityHigh7 = 40+7, osPriorityRealtime = 48, osPriorityRealtime1 = 48+1, osPriorityRealtime2 = 48+2, osPriorityRealtime3 = 48+3, osPriorityRealtime4 = 48+4, osPriorityRealtime5 = 48+5, osPriorityRealtime6 = 48+6, osPriorityRealtime7 = 48+7, osPriorityISR = 56, osPriorityError = -1, osPriorityReserved = 0x7FFFFFFF }	Enumerates thread priorities.
osTimerType_t { osTimerOnce = 0, osTimerPeriodic = 1 }	Enumerates timer types.
os_timer_rouses_type { osTimerRousesIgnore = 0, osTimerRousesAllow = 1 }	Enumerates timer permissions.
os_timer_align_type { osTimerAlignIgnore = 0, osTimerAlignAllow = 1 }	Enumerates timer alignment modes.
osStatus_t { osOK = 0, osError = -1, osErrorTimeout = -2, osErrorResource = -3, osErrorParameter = -4, osErrorNoMemory = -5, osErrorISR = -6, osStatusReserved = 0x7FFFFFFF }	Enumerates return values of CMSIS-RTOS.

## Functions

Function Name	Description
osKernelInitialize (void)	osStatus_t Initializes the RTOS kernel.
osKernelGetInfo (osVersion_t version, char id_buf, uint32_t id_size)	osStatus_t Obtains the system version and name.
osKernelGetState (void)	osKernelState_t Obtains the kernel state.
osKernelStart (void)	osStatus_t Starts the kernel.
osKernelLock (void)	int32_t Locks the kernel.
osKernelUnlock (void)	int32_t Unlocks the kernel.
osKernelRestoreLock (int32_t lock)	int32_t Restores the previous lock state of the kernel.
osKernelGetTickFreq (void)	uint32_t Obtains the number of kernel ticks per second.
osKernelGetSysTimerCount (void)	uint32_t Obtains the kernel system timer.
osKernelGetSysTimerFreq (void)	uint32_t Obtains the frequency of the system timer.
osThreadNew (osThreadFunc_t func, void argument, const osThreadAttr_t attr)	osThreadId_t Creates an active thread.
osThreadGetName (osThreadId_t thread_id)	const char * Obtains the name of a thread.
osThreadGetId (void)	osThreadId_t Obtains the ID of the currently running thread.
osThreadGetState (osThreadId_t thread_id)	osThreadState_t Obtains the state of a thread.
osThreadGetStackSize (osThreadId_t thread_id)	uint32_t Obtains the stack size of a thread.
osThreadGetStackSpace (osThreadId_t thread_id)	uint32_t Obtains the size of the available stack space for a thread based on the stack watermark.
osThreadSetPriority (osThreadId_t thread_id, osPriority_t priority)	osStatus_t Changes the priority of a thread.
osThreadGetPriority (osThreadId_t thread_id)	osPriority_t Gets the prority of an active thread.
osThreadYield (void)	osStatus_t Sets the currently running thread to the ready state.
osThreadSuspend (osThreadId_t thread_id)	osStatus_t Suspends a thread.
osThreadResume (osThreadId_t thread_id)	osStatus_t Resumes a thread from the suspended state.
osThreadTerminate (osThreadId_t thread_id)	osStatus_t Terminates a thread.
osThreadGetCount (void)	uint32_t Obtains the number of active threads.
osDelay (uint32_t ticks)	osStatus_t Waits for a period of time.
osDelayUntil (uint64_t ticks)	osStatus_t Waits until a specified time arrives.
osTimerNew (osTimerFunc_t func, osTimerType_t type, void argument, const osTimerAttr_t attr)	osTimerId_t Creates and initializes a timer.
osTimerStart (osTimerId_t timer_id, uint32_t ticks)	osStatus_t Starts or restarts a timer.
osTimerStop (osTimerId_t timer_id)	osStatus_t Stops a timer.
osTimerIsRunning (osTimerId_t timer_id)	uint32_t Checks whether a timer is running.
osTimerDelete (osTimerId_t timer_id)	osStatus_t Deletes a timer.
osEventFlagsNew (const osEventFlagsAttr_t *attr)	osEventFlagsId_t Creates and initializes an event flags object.
osEventFlagsSet (osEventFlagsId_t ef_id, uint32_t flags)	uint32_t Sets event flags.
osEventFlagsClear (osEventFlagsId_t ef_id, uint32_t flags)	uint32_t Clears event flags.
osEventFlagsGet (osEventFlagsId_t ef_id)	uint32_t Obtains event flags.
osEventFlagsWait (osEventFlagsId_t ef_id, uint32_t flags, uint32_t options, uint32_t timeout)	uint32_t Waits for event flags to trigger.
osEventFlagsDelete (osEventFlagsId_t ef_id)	osStatus_t Deletes an event flags object.
osMutexNew (const osMutexAttr_t *attr)	osMutexId_t Creates and initializes a mutex.
osMutexAcquire (osMutexId_t mutex_id, uint32_t timeout)	osStatus_t Obtains a mutex.
osMutexRelease (osMutexId_t mutex_id)	osStatus_t Releases a mutex.
osMutexGetOwner (osMutexId_t mutex_id)	osThreadId_t Obtains the thread ID of the currently acquired mutex.
osMutexDelete (osMutexId_t mutex_id)	osStatus_t Deletes a mutex.
osSemaphoreNew (uint32_t max_count, uint32_t initial_count, const osSemaphoreAttr_t *attr)	osSemaphoreId_t Creates and initializes a semaphore object.
osSemaphoreAcquire (osSemaphoreId_t semaphore_id, uint32_t timeout)	osStatus_t Acquires a token of a semaphore object.
osSemaphoreRelease (osSemaphoreId_t semaphore_id)	osStatus_t Releases a token of a semaphore object.
osSemaphoreGetCount (osSemaphoreId_t semaphore_id)	uint32_t Obtains the number of available tokens of a semaphore object.
osSemaphoreDelete (osSemaphoreId_t semaphore_id)	osStatus_t Deletes a semaphore object.
osMessageQueueNew (uint32_t msg_count, uint32_t msg_size, const osMessageQueueAttr_t *attr)	osMessageQueueId_t Creates and initializes a message queue.
osMessageQueuePut (osMessageQueueId_t mq_id, const void *msg_ptr, uint8_t msg_prio, uint32_t timeout)	osStatus_t Places a message in a message queue.
osMessageQueueGet (osMessageQueueId_t mq_id, void msg_ptr, uint8_t msg_prio, uint32_t timeout)	osStatus_t Obtains a message in a message queue.
osMessageQueueGetCapacity (osMessageQueueId_t mq_id)	uint32_t Obtains the maximum number of messages that can be placed in a message queue.
osMessageQueueGetMsgSize (osMessageQueueId_t mq_id)	uint32_t Obtains the maximum size of messages that can be placed in a message queue.
osMessageQueueGetCount (osMessageQueueId_t mq_id)	uint32_t Obtains the number of queued messages in a message queue.
osMessageQueueGetSpace (osMessageQueueId_t mq_id)	uint32_t Obtains the number of available slots for messages in a message queue.
osMessageQueueDelete (osMessageQueueId_t mq_id)	osStatus_t Deletes a message queue.

## **Details** ## **Macro Definition Documentation** ## osFlagsError ``` #define osFlagsError 0x80000000U ``` **Description:** Indicates a flag error. ## osFlagsErrorParameter ``` #define osFlagsErrorParameter 0xFFFFFFFCU ``` **Description:** Indicates an incorrect parameter. ## osFlagsErrorResource ``` #define osFlagsErrorResource 0xFFFFFFFDU ``` **Description:** Indicates a resource error. ## osFlagsErrorTimeout ``` #define osFlagsErrorTimeout 0xFFFFFFFEU ``` **Description:** Indicates a timeout. ## osFlagsErrorUnknown ``` #define osFlagsErrorUnknown 0xFFFFFFFFU ``` **Description:** Indicates an unknown error. ## osFlagsNoClear ``` #define osFlagsNoClear 0x00000002U ``` **Description:** Indicates that defined flags are not cleared. ## osFlagsWaitAll ``` #define osFlagsWaitAll 0x00000001U ``` **Description:** Indicates that the system waits until all event flags are triggered. ## osFlagsWaitAny ``` #define osFlagsWaitAny 0x00000000U ``` **Description:** Indicates that the RTOS waits until any event flag is triggered. ## osNoWait ``` #define osNoWait 0x0U ``` **Description:** Indicates that the RTOS does not wait. ## osWaitForever ``` #define osWaitForever 0xFFFFFFFFU ``` **Description:** Indicates that the RTOS waits forever unless an event flag is received. ## **Typedef Documentation** ## osEventFlagsId\_t ``` typedef void* [osEventFlagsId_t](CMSIS.md#gaf0a3ba8f502ca6581ed1009005c0dadd) ``` **Description:** Identifies an event flag. ## osMessageQueueId\_t ``` typedef void* [osMessageQueueId_t](CMSIS.md#ga206dbc05367e03c39fc6d4d1ebcff317) ``` **Description:** Identifies a message queue. ## osMutexId\_t ``` typedef void* [osMutexId_t](CMSIS.md#ga29b7ba721f4fe0b11c84c55d079cc3e7) ``` **Description:** Identifies a mutex. ## osSemaphoreId\_t ``` typedef void* [osSemaphoreId_t](CMSIS.md#ga5abc2c02a86678b63a711e13894ac5b1) ``` **Description:** Identifies a semaphore object. ## osThreadFunc\_t ``` typedef void(* osThreadFunc_t) (void *argument) ``` **Description:** Callback for thread scheduling. ## osThreadId\_t ``` typedef void* [osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) ``` **Description:** Identifies a thread. ## osTimerFunc\_t ``` typedef void(* osTimerFunc_t) (void *argument) ``` **Description:** Callback for timer triggering. ## osTimerId\_t ``` typedef void* [osTimerId_t](CMSIS.md#gac2000ac2a8c6740700fd8e6c938cff44) ``` **Description:** Identifies a timer. ## TZ\_ModuleId\_t ``` typedef uint32_t [TZ_ModuleId_t](CMSIS.md#gad5ef21485fe5f60263bc0b48006202cb) ``` **Description:** Identifies a TrustZone module call process. ## **Enumeration Type Documentation** ## os\_timer\_align\_type ``` enum [os_timer_align_type](CMSIS.md#ga3d617b70715d7fb2c7c6f06809ee3913) ``` **Description:** Enumerates timer alignment modes.

Enumerator	Description
osTimerAlignIgnore	The timer ignores alignment.
osTimerAlignAllow	The timer allows alignment.

## os\_timer\_rouses\_type ``` enum [os_timer_rouses_type](CMSIS.md#ga6274cbe33c6db824bbc40dc6eaa8e578) ``` **Description:** Enumerates timer permissions.

Enumerator	Description
osTimerRousesIgnore	The timer is not allowed to wake up the RTOS.
osTimerRousesAllow	The timer is allowed to wake up the RTOS.

## osKernelState\_t ``` enum [osKernelState_t](CMSIS.md#ga08326469274b668140ca934b168a5ad4) ``` **Description:** Enumerates kernel states.

Enumerator	Description
osKernelInactive	The kernel is inactive.
osKernelReady	The kernel is ready.
osKernelRunning	The kernel is running.
osKernelLocked	The kernel is locked.
osKernelSuspended	The kernel is suspended.
osKernelError	The kernel is abnormal.
osKernelReserved	Reserved

## osPriority\_t ``` enum [osPriority_t](CMSIS.md#gad4e3e0971b41f2d17584a8c6837342ec) ``` **Description:** Enumerates thread priorities.

Enumerator	Description
osPriorityNone	Undefined
osPriorityIdle	Reserved for idle threads
osPriorityLow	Low (unsupported)
osPriorityLow1	Low + 1
osPriorityLow2	Low + 2
osPriorityLow3	Low + 3
osPriorityLow4	Low + 4
osPriorityLow5	Low + 5
osPriorityLow6	Low + 6
osPriorityLow7	Low + 7
osPriorityBelowNormal	Below normal
osPriorityBelowNormal1	Below normal + 1
osPriorityBelowNormal2	Below normal + 2
osPriorityBelowNormal3	Below normal + 3
osPriorityBelowNormal4	Below normal + 4
osPriorityBelowNormal5	Below normal + 5
osPriorityBelowNormal6	Below normal + 6
osPriorityBelowNormal7	Below normal + 7 (unsupported)
osPriorityNormal	Normal (unsupported)
osPriorityNormal1	Normal + 1 (unsupported)
osPriorityNormal2	Normal + 2 (unsupported)
osPriorityNormal3	Normal + 3 (unsupported)
osPriorityNormal4	Normal + 4 (unsupported)
osPriorityNormal5	Normal + 5 (unsupported)
osPriorityNormal6	Normal + 6 (unsupported)
osPriorityNormal7	Normal + 7 (unsupported)
osPriorityAboveNormal	Above normal (unsupported)
osPriorityAboveNormal1	Above normal + 1 (unsupported)
osPriorityAboveNormal2	Above normal + 2 (unsupported)
osPriorityAboveNormal3	Above normal + 3 (unsupported)
osPriorityAboveNormal4	Above normal + 4 (unsupported)
osPriorityAboveNormal5	Above normal + 5 (unsupported)
osPriorityAboveNormal6	Above normal + 6 (unsupported)
osPriorityAboveNormal7	Above normal + 7 (unsupported)
osPriorityHigh	High (unsupported)
osPriorityHigh1	High + 1 (unsupported)
osPriorityHigh2	High + 2 (unsupported)
osPriorityHigh3	High + 3 (unsupported)
osPriorityHigh4	High + 4 (unsupported)
osPriorityHigh5	High + 5 (unsupported)
osPriorityHigh6	High + 6 (unsupported)
osPriorityHigh7	High + 7 (unsupported)
osPriorityRealtime	Real-time (unsupported)
osPriorityRealtime1	Real-time + 1 (unsupported)
osPriorityRealtime2	Real-time + 2 (unsupported)
osPriorityRealtime3	Real-time + 3 (unsupported)
osPriorityRealtime4	Real-time + 4 (unsupported)
osPriorityRealtime5	Real-time + 5 (unsupported)
osPriorityRealtime6	Real-time + 6 (unsupported)
osPriorityRealtime7	Real-time + 7 (unsupported)
osPriorityISR	Reserved for ISR deferred threads (unsupported)
osPriorityError	Invalid
osPriorityReserved	Reserved. It enables the compiler to identify enumeration variables as 32-bit numbers and prevents the enumeration variables from being optimized.

## osStatus\_t ``` enum [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) ``` **Description:** Enumerates return values of CMSIS-RTOS.

Enumerator	Description
osOK	Operation completed successfully
osError	Unspecified error
osErrorTimeout	Timeout
osErrorResource	Resource error
osErrorParameter	Incorrect parameter
osErrorNoMemory	Insufficient memory
osErrorISR	Service interruption
osStatusReserved	Reserved. It is used to prevent the compiler from optimizing enumerations.

## osThreadState\_t ``` enum [osThreadState_t](CMSIS.md#gad3dc89e942e38d9f3af858a0269a820d) ``` **Description:** Enumerates thread states.

Enumerator	Description
osThreadInactive	The thread is inactive.
osThreadReady	The thread is ready.
osThreadRunning	The thread is running.
osThreadBlocked	The thread is blocked.
osThreadTerminated	The thread is terminated.
osThreadError	The thread is abnormal.
osThreadReserved	Reserved

## osTimerType\_t ``` enum [osTimerType_t](CMSIS.md#ga7dc24a4c2b90334427081c3da7a71915) ``` **Description:** Enumerates timer types.

Enumerator	Description
osTimerOnce	One-shot timer
osTimerPeriodic	Repeating timer

## **Function Documentation** ## osDelay\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osDelay (uint32_t ticks) ``` **Description:** Waits for a period of time. **Parameters:**

Name	Description
ticks	Indicates the number of ticks to wait for.

**Returns:** Returns the CMSIS-RTOS running result. ## osDelayUntil\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osDelayUntil (uint64_t ticks) ``` **Description:** Waits until a specified time arrives. **Parameters:**

Name	Description
ticks	Indicates the number of ticks converted from the absolute time.

**Returns:** Returns the CMSIS-RTOS running result. ## osEventFlagsClear\(\) ``` uint32_t osEventFlagsClear ([osEventFlagsId_t](CMSIS.md#gaf0a3ba8f502ca6581ed1009005c0dadd) ef_id, uint32_t flags ) ``` **Description:** Clears event flags. **Parameters:**

Name	Description
ef_id	Indicates the event flags ID, which is obtained using osEventFlagsNew.
flags	Indicates the event flags to clear.

**Returns:** Returns the event flags; returns osFlagsErrorParameter in the case of an error. ## osEventFlagsDelete\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osEventFlagsDelete ([osEventFlagsId_t](CMSIS.md#gaf0a3ba8f502ca6581ed1009005c0dadd) ef_id) ``` **Description:** Deletes an event flags object. **Parameters:**

Name	Description
ef_id	Indicates the event flags ID, which is obtained using osEventFlagsNew.

**Returns:** Returns the CMSIS-RTOS running result. ## osEventFlagsGet\(\) ``` uint32_t osEventFlagsGet ([osEventFlagsId_t](CMSIS.md#gaf0a3ba8f502ca6581ed1009005c0dadd) ef_id) ``` **Description:** Obtains event flags. **Parameters:**

Name	Description
ef_id	Indicates the event flags ID, which is obtained using osEventFlagsNew.

**Returns:** Returns the event flags triggered. ## osEventFlagsNew\(\) ``` [osEventFlagsId_t](CMSIS.md#gaf0a3ba8f502ca6581ed1009005c0dadd) osEventFlagsNew (const [osEventFlagsAttr_t](osEventFlagsAttr_t.md) * attr) ``` **Description:** Creates and initializes an event flags object. **Parameters:**

Name	Description
attr	Indicates the pointer to the event flags attributes. This parameter is not used.

**Returns:** Returns the event flags ID; returns NULL in the case of an error. ## osEventFlagsSet\(\) ``` uint32_t osEventFlagsSet ([osEventFlagsId_t](CMSIS.md#gaf0a3ba8f502ca6581ed1009005c0dadd) ef_id, uint32_t flags ) ``` **Description:** Sets event flags. **Parameters:**

Name	Description
ef_id	Indicates the event flags ID, which is obtained using osEventFlagsNew.
flags	Indicates the event flags to set.

**Returns:** Returns the event flags; returns osFlagsErrorParameter in the case of an error. ## osEventFlagsWait\(\) ``` uint32_t osEventFlagsWait ([osEventFlagsId_t](CMSIS.md#gaf0a3ba8f502ca6581ed1009005c0dadd) ef_id, uint32_t flags, uint32_t options, uint32_t timeout ) ``` **Description:** Waits for event flags to trigger. **Parameters:**

Name	Description
ef_id	Indicates the event flags ID, which is obtained using osEventFlagsNew.
flags	Indicates the event flags to trigger.
options	Indicates the configuration of the event flags to trigger.
timeout	Indicates the timeout duration.

**Returns:** Returns the triggered event flags; returns an error value in the case of an error. ## osKernelGetInfo\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osKernelGetInfo ([osVersion_t](osVersion_t.md) * version, char * id_buf, uint32_t id_size ) ``` **Description:** Obtains the system version and name. **Parameters:**

Name	Description
version	Indicates the pointer to the buffer for storing the version.
id_buf	Indicates the pointer to the buffer for storing the kernel ID.
id_size	Indicates the size of the buffer for storing the kernel ID.

**Returns:** Returns the CMSIS-RTOS running result. ## osKernelGetState\(\) ``` [osKernelState_t](CMSIS.md#ga08326469274b668140ca934b168a5ad4) osKernelGetState (void ) ``` **Description:** Obtains the kernel state. **Returns:** Returns the kernel state. ## osKernelGetSysTimerCount\(\) ``` uint32_t osKernelGetSysTimerCount (void ) ``` **Description:** Obtains the kernel system timer. **Returns:** Returns the kernel system timer. ## osKernelGetSysTimerFreq\(\) ``` uint32_t osKernelGetSysTimerFreq (void ) ``` **Description:** Obtains the frequency of the system timer. **Returns:** Returns the system timer frequency. ## osKernelGetTickFreq\(\) ``` uint32_t osKernelGetTickFreq (void ) ``` **Description:** Obtains the number of kernel ticks per second. **Returns:** Returns the number of kernel ticks. ## osKernelInitialize\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osKernelInitialize (void ) ``` **Description:** Initializes the RTOS kernel. **Returns:** Returns the CMSIS-RTOS running result. ## osKernelLock\(\) ``` int32_t osKernelLock (void ) ``` **Description:** Locks the kernel. **Returns:** Returns 1 if the kernel is locked successfully; returns 0 if the lock starts; returns a negative value in the case of an error. ## osKernelRestoreLock\(\) ``` int32_t osKernelRestoreLock (int32_t lock) ``` **Description:** Restores the previous lock state of the kernel. **Parameters:**

Name	Description
locks	Indicates the lock state to restore to. The value 1 indicates the locked state, and 0 indicates the unlocked state.

**Returns:** Returns 1 if the kernel is locked; returns 0 if the kernel is not locked; returns a negative value in the case of an error. ## osKernelStart\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osKernelStart (void ) ``` **Description:** Starts the kernel. **Returns:** Returns the CMSIS-RTOS running result. ## osKernelUnlock\(\) ``` int32_t osKernelUnlock (void ) ``` **Description:** Unlocks the kernel. **Returns:** Returns 1 if the kernel is unlocked successfully; returns 0 if the kernel is not locked; returns a negative value in the case of an error. ## osMessageQueueDelete\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osMessageQueueDelete ([osMessageQueueId_t](CMSIS.md#ga206dbc05367e03c39fc6d4d1ebcff317) mq_id) ``` **Description:** Deletes a message queue. **Parameters:**

Name	Description
osMessageQueueId_t	Indicates the message queue ID, which is obtained using osMessageQueueNew.

**Returns:** Returns the CMSIS-RTOS running result. ## osMessageQueueGet\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osMessageQueueGet ([osMessageQueueId_t](CMSIS.md#ga206dbc05367e03c39fc6d4d1ebcff317) mq_id, void * msg_ptr, uint8_t * msg_prio, uint32_t timeout ) ``` **Description:** Obtains a message in a message queue. **Parameters:**

Name	Description
osMessageQueueId_t	Indicates the message queue ID, which is obtained using osMessageQueueNew.
msg_ptr	Indicates the pointer to the buffer for storing the message to be retrieved from the message queue.
msg_prio	Indicates the pointer to the buffer for storing the priority of the message to be retrieved from the message queue. This parameter can be left empty.
timeout	Indicates the timeout duration.

**Returns:** Returns the CMSIS-RTOS running result. ## osMessageQueueGetCapacity\(\) ``` uint32_t osMessageQueueGetCapacity ([osMessageQueueId_t](CMSIS.md#ga206dbc05367e03c39fc6d4d1ebcff317) mq_id) ``` **Description:** Obtains the maximum number of messages that can be placed in a message queue. **Parameters:**

Name	Description
osMessageQueueId_t	Indicates the message queue ID, which is obtained using osMessageQueueNew.

**Returns:** Returns the maximum number. ## osMessageQueueGetCount\(\) ``` uint32_t osMessageQueueGetCount ([osMessageQueueId_t](CMSIS.md#ga206dbc05367e03c39fc6d4d1ebcff317) mq_id) ``` **Description:** Obtains the number of queued messages in a message queue. **Parameters:**

Name	Description
osMessageQueueId_t	Indicates the message queue ID, which is obtained using osMessageQueueNew.

**Returns:** Returns the number of queued messages. ## osMessageQueueGetMsgSize\(\) ``` uint32_t osMessageQueueGetMsgSize ([osMessageQueueId_t](CMSIS.md#ga206dbc05367e03c39fc6d4d1ebcff317) mq_id) ``` **Description:** Obtains the maximum size of messages that can be placed in a message queue. **Parameters:**

Name	Description
osMessageQueueId_t	Indicates the message queue ID, which is obtained using osMessageQueueNew.

**Returns:** Returns the maximum message size. ## osMessageQueueGetSpace\(\) ``` uint32_t osMessageQueueGetSpace ([osMessageQueueId_t](CMSIS.md#ga206dbc05367e03c39fc6d4d1ebcff317) mq_id) ``` **Description:** Obtains the number of available slots for messages in a message queue. **Parameters:**

Name	Description
osMessageQueueId_t	Indicates the message queue ID, which is obtained using osMessageQueueNew.

**Returns:** Returns the number of available slots for messages. ## osMessageQueueNew\(\) ``` [osMessageQueueId_t](CMSIS.md#ga206dbc05367e03c39fc6d4d1ebcff317) osMessageQueueNew (uint32_t msg_count, uint32_t msg_size, const [osMessageQueueAttr_t](osMessageQueueAttr_t.md) * attr ) ``` **Description:** Creates and initializes a message queue. **Parameters:**

Name	Description
msg_count	Indicates the number of messages in the message queue.
msg_size	Indicates the size of messages in the message queue.
attr	Indicates the pointer to the message queue attributes. This parameter is not used.

**Returns:** Returns the message queue ID; returns NULL in the case of an error. ## osMessageQueuePut\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osMessageQueuePut ([osMessageQueueId_t](CMSIS.md#ga206dbc05367e03c39fc6d4d1ebcff317) mq_id, const void * msg_ptr, uint8_t msg_prio, uint32_t timeout ) ``` **Description:** Places a message in a message queue. **Parameters:**

Name	Description
osMessageQueueId_t	Indicates the message queue ID, which is obtained using osMessageQueueNew.
msg_ptr	Indicates the pointer to the buffer for storing the message to be placed in the message queue.
msg_prio	Indicates the priority of the message to be placed in the message queue.
timeout	Indicates the timeout duration.

**Returns:** Returns the CMSIS-RTOS running result. ## osMutexAcquire\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osMutexAcquire ([osMutexId_t](CMSIS.md#ga29b7ba721f4fe0b11c84c55d079cc3e7) mutex_id, uint32_t timeout ) ``` **Description:** Obtains a mutex. **Parameters:**

Name	Description
mutex_id	Indicates the mutex ID, which is obtained using osMutexNew.
timeout	Indicates the timeout duration.

**Returns:** Returns the CMSIS-RTOS running result. ## osMutexDelete\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osMutexDelete ([osMutexId_t](CMSIS.md#ga29b7ba721f4fe0b11c84c55d079cc3e7) mutex_id) ``` **Description:** Deletes a mutex. **Parameters:**

Name	Description
mutex_id	Indicates the mutex ID, which is obtained using osMutexNew.

**Returns:** Returns the CMSIS-RTOS running result. ## osMutexGetOwner\(\) ``` [osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) osMutexGetOwner ([osMutexId_t](CMSIS.md#ga29b7ba721f4fe0b11c84c55d079cc3e7) mutex_id) ``` **Description:** Obtains the thread ID of the currently acquired mutex. **Parameters:**

Name	Description
mutex_id	Indicates the mutex ID, which is obtained using osMutexNew.

**Returns:** Returns the thread ID. ## osMutexNew\(\) ``` [osMutexId_t](CMSIS.md#ga29b7ba721f4fe0b11c84c55d079cc3e7) osMutexNew (const [osMutexAttr_t](osMutexAttr_t.md) * attr) ``` **Description:** Creates and initializes a mutex. **Parameters:**

Name	Description
attr	Indicates the pointer to the mutex attributes. This parameter is not used.

**Returns:** Returns the mutex ID; returns NULL in the case of an error. ## osMutexRelease\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osMutexRelease ([osMutexId_t](CMSIS.md#ga29b7ba721f4fe0b11c84c55d079cc3e7) mutex_id) ``` **Description:** Releases a mutex. **Parameters:**

Name	Description
mutex_id	Indicates the mutex ID, which is obtained using osMutexNew.

**Returns:** Returns the CMSIS-RTOS running result. ## osSemaphoreAcquire\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osSemaphoreAcquire ([osSemaphoreId_t](CMSIS.md#ga5abc2c02a86678b63a711e13894ac5b1) semaphore_id, uint32_t timeout ) ``` **Description:** Acquires a token of a semaphore object. **Parameters:**

Name	Description
semaphore_id	Indicates the semaphore ID, which is obtained using osSemaphoreNew.
timeout	Indicates the timeout duration.

**Returns:** Returns the CMSIS-RTOS running result. ## osSemaphoreDelete\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osSemaphoreDelete ([osSemaphoreId_t](CMSIS.md#ga5abc2c02a86678b63a711e13894ac5b1) semaphore_id) ``` **Description:** Deletes a semaphore object. **Parameters:**

Name	Description
semaphore_id	Indicates the semaphore ID, which is obtained using osSemaphoreNew.

**Returns:** Returns the CMSIS-RTOS running result. ## osSemaphoreGetCount\(\) ``` uint32_t osSemaphoreGetCount ([osSemaphoreId_t](CMSIS.md#ga5abc2c02a86678b63a711e13894ac5b1) semaphore_id) ``` **Description:** Obtains the number of available tokens of a semaphore object. **Parameters:**

Name	Description
semaphore_id	Indicates the semaphore ID, which is obtained using osSemaphoreNew.

**Returns:** Returns the number of available tokens. ## osSemaphoreNew\(\) ``` [osSemaphoreId_t](CMSIS.md#ga5abc2c02a86678b63a711e13894ac5b1) osSemaphoreNew (uint32_t max_count, uint32_t initial_count, const [osSemaphoreAttr_t](osSemaphoreAttr_t.md) * attr ) ``` **Description:** Creates and initializes a semaphore object. **Parameters:**

Name	Description
max_count	Indicates the maximum number of available tokens that can be applied for.
initial_count	Indicates the initial number of available tokens.
attr	Indicates the pointer to the semaphore attributes. This parameter is not used.

**Returns:** Returns the semaphore ID; returns NULL in the case of an error. ## osSemaphoreRelease\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osSemaphoreRelease ([osSemaphoreId_t](CMSIS.md#ga5abc2c02a86678b63a711e13894ac5b1) semaphore_id) ``` **Description:** Releases a token of a semaphore object. **Parameters:**

Name	Description
semaphore_id	Indicates the semaphore ID, which is obtained using osSemaphoreNew.

**Returns:** Returns the CMSIS-RTOS running result. ## osThreadGetCount\(\) ``` uint32_t osThreadGetCount (void ) ``` **Description:** Obtains the number of active threads. **Returns:** Returns the number; returns 0 in the case of an error. ## osThreadGetId\(\) ``` [osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) osThreadGetId (void ) ``` **Description:** Obtains the ID of the currently running thread. **Returns:** Returns the thread ID; returns NULL in the case of an error. ## osThreadGetName\(\) ``` const char* osThreadGetName ([osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) thread_id) ``` **Description:** Obtains the name of a thread. **Parameters:**

Name	Description
thread_id	Indicates the thread ID, which is obtained using osThreadNew or osThreadGetId.

**Returns:** Returns the thread name; returns NULL in the case of an error. ## osThreadGetPriority\(\) ``` [osPriority_t](CMSIS.md#gad4e3e0971b41f2d17584a8c6837342ec) osThreadGetPriority ([osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) thread_id) ``` **Description:** Gets the prority of an active thread. **Parameters:**

Name	Description
thread_id	Indicates the thread ID, which is obtained using osThreadNew or osThreadGetId.

**Returns:** Returns the prority of the thread. ## osThreadGetStackSize\(\) ``` uint32_t osThreadGetStackSize ([osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) thread_id) ``` **Description:** Obtains the stack size of a thread. **Parameters:**

Name	Description
thread_id	Indicates the thread ID, which is obtained using osThreadNew or osThreadGetId.

**Returns:** Returns the stack size, in bytes; returns 0 in the case of an error. ## osThreadGetStackSpace\(\) ``` uint32_t osThreadGetStackSpace ([osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) thread_id) ``` **Description:** Obtains the size of the available stack space for a thread based on the stack watermark. **Parameters:**

Name	Description
thread_id	Indicates the thread ID, which is obtained using osThreadNew or osThreadGetId.

**Returns:** Returns the available stack size, in bytes; returns 0 in the case of an error. ## osThreadGetState\(\) ``` [osThreadState_t](CMSIS.md#gad3dc89e942e38d9f3af858a0269a820d) osThreadGetState ([osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) thread_id) ``` **Description:** Obtains the state of a thread. **Parameters:**

Name	Description
thread_id	Indicates the thread ID, which is obtained using osThreadNew or osThreadGetId.

**Returns:** Returns the thread state. ## osThreadNew\(\) ``` [osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) osThreadNew ([osThreadFunc_t](CMSIS.md#ga8ef2773ed8ef63ab8727e0d06ebec4d2) func, void * argument, const [osThreadAttr_t](osThreadAttr_t.md) * attr ) ``` **Description:** Creates an active thread. **Parameters:**

Name	Description
func	Indicates the entry of the thread callback function.
argument	Indicates the pointer to the argument passed to the thread.
attr	Indicates the thread attributes. If this parameter is left unspecified, the default value 0 is used.

**Returns:** Returns the thread ID; returns NULL in the case of an error. ## osThreadResume\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osThreadResume ([osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) thread_id) ``` **Description:** Resumes a thread from the suspended state. **Parameters:**

Name	Description
thread_id	Indicates the thread ID, which is obtained using osThreadNew or osThreadGetId.

**Returns:** Returns the CMSIS-RTOS running result. ## osThreadSetPriority\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osThreadSetPriority ([osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) thread_id, [osPriority_t](CMSIS.md#gad4e3e0971b41f2d17584a8c6837342ec) priority ) ``` **Description:** Changes the priority of a thread. **Parameters:**

Name	Description
thread_id	Indicates the thread ID, which is obtained using osThreadNew or osThreadGetId.
priority	Indicates the new priority.

**Returns:** Returns the CMSIS-RTOS running result. ## osThreadSuspend\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osThreadSuspend ([osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) thread_id) ``` **Description:** Suspends a thread. **Parameters:**

Name	Description
thread_id	Indicates the thread ID, which is obtained using osThreadNew or osThreadGetId.

**Returns:** Returns the CMSIS-RTOS running result. ## osThreadTerminate\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osThreadTerminate ([osThreadId_t](CMSIS.md#ga6333e016ba9b008e6dd76851c38b9217) thread_id) ``` **Description:** Terminates a thread. **Parameters:**

Name	Description
thread_id	Indicates the thread ID, which is obtained using osThreadNew or osThreadGetId.

**Returns:** Returns the CMSIS-RTOS running result. ## osThreadYield\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osThreadYield (void ) ``` **Description:** Sets the currently running thread to the ready state. **Returns:** Returns the CMSIS-RTOS running result. ## osTimerDelete\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osTimerDelete ([osTimerId_t](CMSIS.md#gac2000ac2a8c6740700fd8e6c938cff44) timer_id) ``` **Description:** Deletes a timer. **Parameters:**

Name	Description
timer_id	Indicates the timer ID, which is obtained using osTimerNew.

**Returns:** Returns the CMSIS-RTOS running result. ## osTimerIsRunning\(\) ``` uint32_t osTimerIsRunning ([osTimerId_t](CMSIS.md#gac2000ac2a8c6740700fd8e6c938cff44) timer_id) ``` **Description:** Checks whether a timer is running. **Parameters:**

Name	Description
timer_id	Indicates the timer ID, which is obtained using osTimerNew.

**Returns:** Returns 1 if the timer is running; returns 0 otherwise. ## osTimerNew\(\) ``` [osTimerId_t](CMSIS.md#gac2000ac2a8c6740700fd8e6c938cff44) osTimerNew ([osTimerFunc_t](CMSIS.md#ga77a298218f3c8382b39a09a6d134d040) func, [osTimerType_t](CMSIS.md#ga7dc24a4c2b90334427081c3da7a71915) type, void * argument, const [osTimerAttr_t](osTimerAttr_t.md) * attr ) ``` **Description:** Creates and initializes a timer. **Parameters:**

Name	Description
func	Indicates the entry of the timer callback function.
type	Indicates the timer type.
argument	Indicates the pointer to the argument used in timer callback.
attr	Indicates the pointer to the timer attributes. This parameter is not used.

**Returns:** Returns the timer ID; returns NULL in the case of an error. ## osTimerStart\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osTimerStart ([osTimerId_t](CMSIS.md#gac2000ac2a8c6740700fd8e6c938cff44) timer_id, uint32_t ticks ) ``` **Description:** Starts or restarts a timer. **Parameters:**

Name	Description
timer_id	Indicates the timer ID, which is obtained using osTimerNew.
ticks	Indicates the number of ticks since the timer starts running.

**Returns:** Returns the CMSIS-RTOS running result. ## osTimerStop\(\) ``` [osStatus_t](CMSIS.md#ga6c0dbe6069e4e7f47bb4cd32ae2b813e) osTimerStop ([osTimerId_t](CMSIS.md#gac2000ac2a8c6740700fd8e6c938cff44) timer_id) ``` **Description:** Stops a timer. **Parameters:**

Name	Description
timer_id	Indicates the timer ID, which is obtained using osTimerNew.

**Returns:** Returns the CMSIS-RTOS running result. ## **Variable Documentation** ## api ``` uint32_t osVersion_t::api ``` **Description:** API version ## attr\_bits \[1/6\] ``` uint32_t osThreadAttr_t::attr_bits ``` **Description:** Thread attribute bits ## attr\_bits \[2/6\] ``` uint32_t osTimerAttr_t::attr_bits ``` **Description:** Reserved attribute bits ## attr\_bits \[3/6\] ``` uint32_t osEventFlagsAttr_t::attr_bits ``` **Description:** Reserved attribute bits ## attr\_bits \[4/6\] ``` uint32_t osMutexAttr_t::attr_bits ``` **Description:** Reserved attribute bits ## attr\_bits \[5/6\] ``` uint32_t osSemaphoreAttr_t::attr_bits ``` **Description:** Reserved attribute bits ## attr\_bits \[6/6\] ``` uint32_t osMessageQueueAttr_t::attr_bits ``` **Description:** Reserved attribute bits ## cb\_mem \[1/6\] ``` void* osThreadAttr_t::cb_mem ``` **Description:** Memory for the thread control block ## cb\_mem \[2/6\] ``` void* osTimerAttr_t::cb_mem ``` **Description:** Memory for the timer control block ## cb\_mem \[3/6\] ``` void* osEventFlagsAttr_t::cb_mem ``` **Description:** Memory for the event control block ## cb\_mem \[4/6\] ``` void* osMutexAttr_t::cb_mem ``` **Description:** Memory for the mutex control block ## cb\_mem \[5/6\] ``` void* osSemaphoreAttr_t::cb_mem ``` **Description:** Memory for the semaphore control block ## cb\_mem \[6/6\] ``` void* osMessageQueueAttr_t::cb_mem ``` **Description:** Memory for the message queue control block ## cb\_size \[1/6\] ``` uint32_t osThreadAttr_t::cb_size ``` **Description:** Size of the memory for the thread control block ## cb\_size \[2/6\] ``` uint32_t osTimerAttr_t::cb_size ``` **Description:** Size of the memory for the timer control block ## cb\_size \[3/6\] ``` uint32_t osEventFlagsAttr_t::cb_size ``` **Description:** Size of the memory for the event control block ## cb\_size \[4/6\] ``` uint32_t osMutexAttr_t::cb_size ``` **Description:** Size of the memory for the mutex control block ## cb\_size \[5/6\] ``` uint32_t osSemaphoreAttr_t::cb_size ``` **Description:** Size of the memory for the semaphore control block ## cb\_size \[6/6\] ``` uint32_t osMessageQueueAttr_t::cb_size ``` **Description:** Size of the memory for the message queue control block ## kernel ``` uint32_t osVersion_t::kernel ``` **Description:** Kernel version ## mq\_mem ``` void* osMessageQueueAttr_t::mq_mem ``` **Description:** Memory for storing data in the message queue ## mq\_size ``` uint32_t osMessageQueueAttr_t::mq_size ``` **Description:** Size of the memory for storing data in the message queue ## name \[1/6\] ``` const char* osThreadAttr_t::name ``` **Description:** Thread name ## name \[2/6\] ``` const char* osTimerAttr_t::name ``` **Description:** Timer name ## name \[3/6\] ``` const char* osEventFlagsAttr_t::name ``` **Description:** Event name ## name \[4/6\] ``` const char* osMutexAttr_t::name ``` **Description:** Mutex name ## name \[5/6\] ``` const char* osSemaphoreAttr_t::name ``` **Description:** Semaphore name ## name \[6/6\] ``` const char* osMessageQueueAttr_t::name ``` **Description:** Message queue name ## priority ``` [osPriority_t](CMSIS.md#gad4e3e0971b41f2d17584a8c6837342ec) osThreadAttr_t::priority ``` **Description:** Thread priority ## reserved ``` uint32_t osThreadAttr_t::reserved ``` **Description:** Reserved ## stack\_mem ``` void* osThreadAttr_t::stack_mem ``` **Description:** Memory for the thread stack ## stack\_size ``` uint32_t osThreadAttr_t::stack_size ``` **Description:** Size of the thread stack ## tz\_module ``` [TZ_ModuleId_t](CMSIS.md#gad5ef21485fe5f60263bc0b48006202cb) osThreadAttr_t::tz_module ``` **Description:** TrustZone module of the thread