Merge branch 'master' of https://github.com/RT-Thread/rt-thread into nuvoton

18 files changed, 1195 insertions, 683 deletions

diff --git a/src/Kconfig b/src/Kconfig
index e0582f5663..e31afc25fa 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -8,6 +8,10 @@ config RT_NAME_MAX
         Each kernel object, such as thread, timer, semaphore etc, has a name,
         the RT_NAME_MAX is the maximal size of this object name.
 
+config RT_USING_BIG_ENDIAN
+    bool
+    default n
+
 config RT_USING_ARCH_DATA_TYPE
     bool "Use the data types defined in ARCH_CPU"
     default n
@@ -131,6 +135,10 @@ config RT_KSERVICE_USING_TINY_SIZE
     bool "Enable kservice to use tiny size"
     default n
 
+config RT_USING_ASM_MEMCPY
+    bool
+    default n
+
 endmenu
 
 menuconfig RT_DEBUG
@@ -264,11 +272,18 @@ menu "Memory Management"
         help
             Using static memory fixed partition
 
-    config RT_USING_MEMHEAP
+    menuconfig RT_USING_MEMHEAP
         bool "Using memory heap object"
         default n
-        help
-            Using memory heap object to manage dynamic memory heap.
+
+        if RT_USING_MEMHEAP
+
+            if RT_USING_MEMHEAP_AS_HEAP
+            config RT_USING_MEMHEAP_AUTO_BINDING
+                bool "Use all of memheap objects as heap"
+                default y
+            endif
+        endif
 
     choice
         prompt "Dynamic Memory Management"
@@ -285,7 +300,7 @@ menu "Memory Management"
 
         if RT_USING_MEMHEAP
         config RT_USING_MEMHEAP_AS_HEAP
-            bool "Use all of memheap objects as heap"
+            bool "Use memheap objects as heap"
         endif
 
         config RT_USING_USERHEAP
@@ -352,6 +367,10 @@ menu "Kernel Device Object"
         config RT_CONSOLE_DEVICE_NAME
             string "the device name for console"
             default "uart"
+
+        config RT_PRINTF_LONGLONG
+            bool "rt_kprintf support long long"
+            default n
     endif
 
 endmenu
diff --git a/src/clock.c b/src/clock.c
index 77516b3775..21be3a4203 100644
--- a/src/clock.c
+++ b/src/clock.c
@@ -33,9 +33,9 @@ static volatile rt_tick_t rt_tick = 0;
 /**@{*/
 
 /**
- * This function will return current tick from operating system startup
+ * @brief    This function will return current tick from operating system startup.
  *
- * @return current tick
+ * @return   Return current tick.
  */
 rt_tick_t rt_tick_get(void)
 {
@@ -45,7 +45,9 @@ rt_tick_t rt_tick_get(void)
 RTM_EXPORT(rt_tick_get);
 
 /**
- * This function will set current tick
+ * @brief    This function will set current tick.
+ *
+ * @param    tick is the value that you will set.
  */
 void rt_tick_set(rt_tick_t tick)
 {
@@ -57,8 +59,8 @@ void rt_tick_set(rt_tick_t tick)
 }
 
 /**
- * This function will notify kernel there is one tick passed. Normally,
- * this function is invoked by clock ISR.
+ * @brief    This function will notify kernel there is one tick passed.
+ *           Normally, this function is invoked by clock ISR.
  */
 void rt_tick_increase(void)
 {
@@ -97,14 +99,14 @@ void rt_tick_increase(void)
 }
 
 /**
- * This function will calculate the tick from millisecond.
+ * @brief    This function will calculate the tick from millisecond.
  *
- * @param ms the specified millisecond
- *           - Negative Number wait forever
- *           - Zero not wait
- *           - Max 0x7fffffff
+ * @param    ms is the specified millisecond.
+ *              - Negative Number wait forever
+ *              - Zero not wait
+ *              - Max 0x7fffffff
  *
- * @return the calculated tick
+ * @return   Return the calculated tick.
  */
 rt_tick_t rt_tick_from_millisecond(rt_int32_t ms)
 {
@@ -126,9 +128,13 @@ rt_tick_t rt_tick_from_millisecond(rt_int32_t ms)
 RTM_EXPORT(rt_tick_from_millisecond);
 
 /**
- * This function will provide the passed millisecond from boot.
+ * @brief    This function will return the passed millisecond from boot.
+ *
+ * @note     if the value of RT_TICK_PER_SECOND is lower than 1000 or
+ *           is not an integral multiple of 1000, this function will not
+ *           provide the correct 1ms-based tick.
  *
- * @return passed millisecond from boot
+ * @return   Return passed millisecond from boot.
  */
 RT_WEAK rt_tick_t rt_tick_get_millisecond(void)
 {
diff --git a/src/components.c b/src/components.c
index e156b783e4..9433b7457c 100644
--- a/src/components.c
+++ b/src/components.c
@@ -78,7 +78,9 @@ static int rti_end(void)
 INIT_EXPORT(rti_end, "6.end");
 
 /**
- * RT-Thread Components Initialization for board
+ * @brief  Onboard components initialization. In this function, the board-level
+ *         initialization function will be called to complete the initialization
+ *         of the on-board peripherals.
  */
 void rt_components_board_init(void)
 {
@@ -102,7 +104,7 @@ void rt_components_board_init(void)
 }
 
 /**
- * RT-Thread Components Initialization
+ * @brief  RT-Thread Components Initialization.
  */
 void rt_components_init(void)
 {
@@ -169,7 +171,11 @@ static rt_uint8_t main_stack[RT_MAIN_THREAD_STACK_SIZE];
 struct rt_thread main_thread;
 #endif /* RT_USING_HEAP */
 
-/* the system main thread */
+/**
+ * @brief  The system main thread. In this thread will call the rt_components_init()
+ *         for initialization of RT-Thread Components and call the user's programming
+ *         entry main().
+ */
 void main_thread_entry(void *parameter)
 {
     extern int main(void);
@@ -193,6 +199,10 @@ void main_thread_entry(void *parameter)
 #endif
 }
 
+/**
+ * @brief  This function will create and start the main thread, but this thread
+ *         will not run until the scheduler starts.
+ */
 void rt_application_init(void)
 {
     rt_thread_t tid;
@@ -216,6 +226,10 @@ void rt_application_init(void)
     rt_thread_startup(tid);
 }
 
+/**
+ * @brief  This function will call all levels of initialization functions to complete
+ *         the initialization of the system, and finally start the scheduler.
+ */
 int rtthread_startup(void)
 {
     rt_hw_interrupt_disable();
diff --git a/src/cpu.c b/src/cpu.c
index a7d56ba999..b689ecf2d7 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -11,13 +11,13 @@
 #include <rtthread.h>
 
 #ifdef RT_USING_SMP
-static struct rt_cpu rt_cpus[RT_CPUS_NR];
+static struct rt_cpu _cpus[RT_CPUS_NR];
 rt_hw_spinlock_t _cpus_lock;
 
 /*
  * disable scheduler
  */
-static void rt_preempt_disable(void)
+static void _cpu_preempt_disable(void)
 {
     register rt_base_t level;
     struct rt_thread *current_thread;
@@ -42,7 +42,7 @@ static void rt_preempt_disable(void)
 /*
  * enable scheduler
  */
-static void rt_preempt_enable(void)
+static void _cpu_preempt_enable(void)
 {
     register rt_base_t level;
     struct rt_thread *current_thread;
@@ -65,31 +65,59 @@ static void rt_preempt_enable(void)
     rt_hw_local_irq_enable(level);
 }
 
+/**
+ * @brief   Initialize a static spinlock object.
+ *
+ * @param   lock is a pointer to the spinlock to initialize.
+ */
 void rt_spin_lock_init(struct rt_spinlock *lock)
 {
     rt_hw_spin_lock_init(&lock->lock);
 }
 RTM_EXPORT(rt_spin_lock_init)
 
+/**
+ * @brief   This function will lock the spinlock.
+ *
+ * @note    If the spinlock is locked, the current CPU will keep polling the spinlock state
+ *          until the spinlock is unlocked.
+ *
+ * @param   lock is a pointer to the spinlock.
+ */
 void rt_spin_lock(struct rt_spinlock *lock)
 {
-    rt_preempt_disable();
+    _cpu_preempt_disable();
     rt_hw_spin_lock(&lock->lock);
 }
 RTM_EXPORT(rt_spin_lock)
 
+/**
+ * @brief   This function will unlock the spinlock.
+ *
+ * @param   lock is a pointer to the spinlock.
+ */
 void rt_spin_unlock(struct rt_spinlock *lock)
 {
     rt_hw_spin_unlock(&lock->lock);
-    rt_preempt_enable();
+    _cpu_preempt_enable();
 }
 RTM_EXPORT(rt_spin_unlock)
 
+/**
+ * @brief   This function will disable the local interrupt and then lock the spinlock.
+ *
+ * @note    If the spinlock is locked, the current CPU will keep polling the spinlock state
+ *          until the spinlock is unlocked.
+ *
+ * @param   lock is a pointer to the spinlock.
+ *
+ * @return  Return current cpu interrupt status.
+ */
 rt_base_t rt_spin_lock_irqsave(struct rt_spinlock *lock)
 {
     unsigned long level;
 
-    rt_preempt_disable();
+    _cpu_preempt_disable();
 
     level = rt_hw_local_irq_disable();
     rt_hw_spin_lock(&lock->lock);
@@ -98,30 +126,46 @@ rt_base_t rt_spin_lock_irqsave(struct rt_spinlock *lock)
 }
 RTM_EXPORT(rt_spin_lock_irqsave)
 
+/**
+ * @brief   This function will unlock the spinlock and then restore current cpu interrupt status.
+ *
+ * @param   lock is a pointer to the spinlock.
+ *
+ * @param   level is interrupt status returned by rt_spin_lock_irqsave().
+ */
 void rt_spin_unlock_irqrestore(struct rt_spinlock *lock, rt_base_t level)
 {
     rt_hw_spin_unlock(&lock->lock);
     rt_hw_local_irq_enable(level);
 
-    rt_preempt_enable();
+    _cpu_preempt_enable();
 }
 RTM_EXPORT(rt_spin_unlock_irqrestore)
 
 /**
- * This fucntion will return current cpu.
+ * @brief   This fucntion will return current cpu object.
+ *
+ * @return  Return a pointer to the current cpu object.
  */
 struct rt_cpu *rt_cpu_self(void)
 {
-    return &rt_cpus[rt_hw_cpu_id()];
+    return &_cpus[rt_hw_cpu_id()];
 }
 
+/**
+ * @brief   This fucntion will return the cpu object corresponding to index.
+ *
+ * @return  Return a pointer to the cpu object corresponding to index.
+ */
 struct rt_cpu *rt_cpu_index(int index)
 {
-    return &rt_cpus[index];
+    return &_cpus[index];
 }
 
 /**
- * This function will lock all cpus's scheduler and disable local irq.
+ * @brief   This function will lock all cpus's scheduler and disable local irq.
+ *
+ * @return  Return current cpu interrupt status.
  */
 rt_base_t rt_cpus_lock(void)
 {
@@ -148,7 +192,9 @@ rt_base_t rt_cpus_lock(void)
 RTM_EXPORT(rt_cpus_lock);
 
 /**
- * This function will restore all cpus's scheduler and restore local irq.
+ * @brief   This function will restore all cpus's scheduler and restore local irq.
+ *
+ * @param   level is interrupt status returned by rt_cpus_lock().
  */
 void rt_cpus_unlock(rt_base_t level)
 {
diff --git a/src/device.c b/src/device.c
index a9c244d306..6e22c2b692 100644
--- a/src/device.c
+++ b/src/device.c
@@ -39,11 +39,13 @@
 #endif /* RT_USING_DEVICE_OPS */
 
 /**
- * This function registers a device driver with specified name.
+ * @brief This function registers a device driver with a specified name.
  *
- * @param dev the pointer of device driver structure
- * @param name the device driver's name
- * @param flags the capabilities flag of device
+ * @param dev is the pointer of device driver structure.
+ *
+ * @param name is the device driver's name.
+ *
+ * @param flags is the capabilities flag of device.
  *
  * @return the error code, RT_EOK on initialization successfully.
  */
@@ -72,9 +74,9 @@ rt_err_t rt_device_register(rt_device_t dev,
 RTM_EXPORT(rt_device_register);
 
 /**
- * This function removes a previously registered device driver
+ * @brief This function removes a previously registered device driver.
  *
- * @param dev the pointer of device driver structure
+ * @param dev is the pointer of device driver structure.
  *
  * @return the error code, RT_EOK on successfully.
  */
@@ -91,9 +93,9 @@ rt_err_t rt_device_unregister(rt_device_t dev)
 RTM_EXPORT(rt_device_unregister);
 
 /**
- * This function finds a device driver by specified name.
+ * @brief This function finds a device driver by specified name.
  *
- * @param name the device driver's name
+ * @param name is the device driver's name.
  *
  * @return the registered device driver on successful, or RT_NULL on failure.
  */
@@ -105,10 +107,11 @@ RTM_EXPORT(rt_device_find);
 
 #ifdef RT_USING_HEAP
 /**
- * This function creates a device object with user data size.
+ * @brief This function creates a device object with user data size.
  *
- * @param type, the kind type of this device object.
- * @param attach_size, the size of user data.
+ * @param type is the type of the device object.
+ *
+ * @param attach_size is the size of user data.
  *
  * @return the allocated device object, or RT_NULL when failed.
  */
@@ -134,9 +137,9 @@ rt_device_t rt_device_create(int type, int attach_size)
 RTM_EXPORT(rt_device_create);
 
 /**
- * This function destroy the specific device object.
+ * @brief This function destroy the specific device object.
  *
- * @param dev, the specific device object.
+ * @param dev is a specific device object.
  */
 void rt_device_destroy(rt_device_t dev)
 {
@@ -153,11 +156,11 @@ RTM_EXPORT(rt_device_destroy);
 #endif /* RT_USING_HEAP */
 
 /**
- * This function will initialize the specified device
+ * @brief This function will initialize the specified device.
  *
- * @param dev the pointer of device driver structure
+ * @param dev is the pointer of device driver structure.
  *
- * @return the result
+ * @return the result, RT_EOK on successfully.
  */
 rt_err_t rt_device_init(rt_device_t dev)
 {
@@ -187,12 +190,13 @@ rt_err_t rt_device_init(rt_device_t dev)
 }
 
 /**
- * This function will open a device
+ * @brief This function will open a device.
+ *
+ * @param dev is the pointer of device driver structure.
  *
- * @param dev the pointer of device driver structure
- * @param oflag the flags for device open
+ * @param oflag is the flags for device open.
  *
- * @return the result
+ * @return the result, RT_EOK on successfully.
  */
 rt_err_t rt_device_open(rt_device_t dev, rt_uint16_t oflag)
 {
@@ -253,11 +257,11 @@ rt_err_t rt_device_open(rt_device_t dev, rt_uint16_t oflag)
 RTM_EXPORT(rt_device_open);
 
 /**
- * This function will close a device
+ * @brief This function will close a device.
  *
- * @param dev the pointer of device driver structure
+ * @param dev is the pointer of device driver structure.
  *
- * @return the result
+ * @return the result, RT_EOK on successfully.
  */
 rt_err_t rt_device_close(rt_device_t dev)
 {
@@ -289,12 +293,15 @@ rt_err_t rt_device_close(rt_device_t dev)
 RTM_EXPORT(rt_device_close);
 
 /**
- * This function will read some data from a device.
+ * @brief This function will read some data from a device.
+ *
+ * @param dev is the pointer of device driver structure.
+ *
+ * @param pos is the position when reading.
+ *
+ * @param buffer is a data buffer to save the read data.
  *
- * @param dev the pointer of device driver structure
- * @param pos the position of reading
- * @param buffer the data buffer to save read data
- * @param size the size of buffer
+ * @param size is the size of buffer.
  *
  * @return the actually read size on successful, otherwise negative returned.
  *
@@ -328,12 +335,15 @@ rt_size_t rt_device_read(rt_device_t dev,
 RTM_EXPORT(rt_device_read);
 
 /**
- * This function will write some data to a device.
+ * @brief This function will write some data to a device.
  *
- * @param dev the pointer of device driver structure
- * @param pos the position of written
- * @param buffer the data buffer to be written to device
- * @param size the size of buffer
+ * @param dev is the pointer of device driver structure.
+ *
+ * @param pos is the position when writing.
+ *
+ * @param buffer is the data buffer to be written to device.
+ *
+ * @param size is the size of buffer.
  *
  * @return the actually written size on successful, otherwise negative returned.
  *
@@ -367,13 +377,15 @@ rt_size_t rt_device_write(rt_device_t dev,
 RTM_EXPORT(rt_device_write);
 
 /**
- * This function will perform a variety of control functions on devices.
+ * @brief This function will perform a variety of control functions on devices.
+ *
+ * @param dev is the pointer of device driver structure.
  *
- * @param dev the pointer of device driver structure
- * @param cmd the command sent to device
- * @param arg the argument of command
+ * @param cmd is the command sent to device.
  *
- * @return the result
+ * @param arg is the argument of command.
+ *
+ * @return the result, -RT_ENOSYS for failed.
  */
 rt_err_t rt_device_control(rt_device_t dev, int cmd, void *arg)
 {
@@ -391,11 +403,12 @@ rt_err_t rt_device_control(rt_device_t dev, int cmd, void *arg)
 RTM_EXPORT(rt_device_control);
 
 /**
- * This function will set the reception indication callback function. This callback function
- * is invoked when this device receives data.
+ * @brief This function will set the reception indication callback function. This callback function
+ *        is invoked when this device receives data.
+ *
+ * @param dev is the pointer of device driver structure.
  *
- * @param dev the pointer of device driver structure
- * @param rx_ind the indication callback function
+ * @param rx_ind is the indication callback function.
  *
  * @return RT_EOK
  */
@@ -413,11 +426,12 @@ rt_device_set_rx_indicate(rt_device_t dev,
 RTM_EXPORT(rt_device_set_rx_indicate);
 
 /**
- * This function will set the indication callback function when device has
- * written data to physical hardware.
+ * @brief This function will set a callback function. The callback function
+ *        will be called when device has written data to physical hardware.
+ *
+ * @param dev is the pointer of device driver structure.
  *
- * @param dev the pointer of device driver structure
- * @param tx_done the indication callback function
+ * @param tx_done is the indication callback function.
  *
  * @return RT_EOK
  */
diff --git a/src/idle.c b/src/idle.c
index a571e487cf..61f6a5b383 100644
--- a/src/idle.c
+++ b/src/idle.c
@@ -68,14 +68,13 @@ static struct rt_semaphore system_sem;
 static void (*idle_hook_list[RT_IDLE_HOOK_LIST_SIZE])(void);
 
 /**
- * @ingroup Hook
- * This function sets a hook function to idle thread loop. When the system performs
- * idle loop, this hook function should be invoked.
+ * @brief This function sets a hook function to idle thread loop. When the system performs
+ *        idle loop, this hook function should be invoked.
  *
- * @param hook the specified hook function
+ * @param hook the specified hook function.
  *
- * @return RT_EOK: set OK
- *         -RT_EFULL: hook list is full
+ * @return RT_EOK: set OK.
+ *         -RT_EFULL: hook list is full.
  *
  * @note the hook function must be simple and never be blocked or suspend.
  */
@@ -104,12 +103,12 @@ rt_err_t rt_thread_idle_sethook(void (*hook)(void))
 }
 
 /**
- * delete the idle hook on hook list
+ * @brief delete the idle hook on hook list.
  *
- * @param hook the specified hook function
+ * @param hook the specified hook function.
  *
- * @return RT_EOK: delete OK
- *         -RT_ENOSYS: hook was not found
+ * @return RT_EOK: delete OK.
+ *         -RT_ENOSYS: hook was not found.
  */
 rt_err_t rt_thread_idle_delhook(void (*hook)(void))
 {
@@ -139,7 +138,7 @@ rt_err_t rt_thread_idle_delhook(void (*hook)(void))
 
 #ifdef RT_USING_MODULE
 /* Return whether there is defunctional thread to be deleted. */
-rt_inline int _has_defunct_thread(void)
+rt_inline int _idle_has_defunct_thread(void)
 {
     /* The rt_list_isempty has prototype of "int rt_list_isempty(const rt_list_t *l)".
      * So the compiler has a good reason that the _rt_thread_defunct list does
@@ -153,8 +152,10 @@ rt_inline int _has_defunct_thread(void)
 }
 #endif /* RT_USING_MODULE */
 
-/* enqueue a thread to defunct queue
- * it must be called between rt_hw_interrupt_disable and rt_hw_interrupt_enable
+/**
+ * @brief Enqueue a thread to defunct queue.
+ *
+ * @note It must be called between rt_hw_interrupt_disable and rt_hw_interrupt_enable
  */
 void rt_thread_defunct_enqueue(rt_thread_t thread)
 {
@@ -164,8 +165,10 @@ void rt_thread_defunct_enqueue(rt_thread_t thread)
 #endif
 }
 
-/* dequeue a thread from defunct queue
- * it must be called between rt_hw_interrupt_disable and rt_hw_interrupt_enable
+/**
+ * @brief Dequeue a thread from defunct queue.
+ *
+ * @note It must be called between rt_hw_interrupt_disable and rt_hw_interrupt_enable.
  */
 rt_thread_t rt_thread_defunct_dequeue(void)
 {
@@ -183,9 +186,7 @@ rt_thread_t rt_thread_defunct_dequeue(void)
 }
 
 /**
- * @ingroup Thread
- *
- * This function will perform system background job when system idle.
+ * @brief This function will perform system background job when system idle.
  */
 static void rt_defunct_execute(void)
 {
@@ -207,7 +208,7 @@ static void rt_defunct_execute(void)
 
 #ifdef RT_USING_MODULE
         /* check whether list is empty */
-        if (!_has_defunct_thread())
+        if (!_idle_has_defunct_thread())
         {
             rt_hw_interrupt_enable(lock);
             break;
@@ -316,9 +317,7 @@ static void rt_thread_system_entry(void *parameter)
 #endif
 
 /**
- * @ingroup SystemInit
- *
- * This function will initialize idle thread, then start it.
+ * @brief This function will initialize idle thread, then start it.
  *
  * @note this function must be invoked when system init.
  */
@@ -365,10 +364,7 @@ void rt_thread_idle_init(void)
 }
 
 /**
- * @ingroup Thread
- *
- * This function will get the handler of the idle thread.
- *
+ * @brief This function will get the handler of the idle thread.
  */
 rt_thread_t rt_thread_idle_gethandler(void)
 {
diff --git a/src/ipc.c b/src/ipc.c
index 8acfd831d7..da2996a30e 100755
--- a/src/ipc.c
+++ b/src/ipc.c
@@ -68,7 +68,7 @@ extern void (*rt_object_put_hook)(struct rt_object *object);
  *
  * @warning  This function can be called from all IPC initialization and creation.
  */
-rt_inline rt_err_t rt_ipc_object_init(struct rt_ipc_object *ipc)
+rt_inline rt_err_t _ipc_object_init(struct rt_ipc_object *ipc)
 {
     /* initialize ipc object */
     rt_list_init(&(ipc->suspend_thread));
@@ -106,9 +106,9 @@ rt_inline rt_err_t rt_ipc_object_init(struct rt_ipc_object *ipc)
  *           rt_sem_take(),  rt_mutex_take(),  rt_event_recv(),   rt_mb_send_wait(),
  *           rt_mb_recv(),   rt_mq_recv(),     rt_mq_send_wait()
  */
-rt_inline rt_err_t rt_ipc_list_suspend(rt_list_t        *list,
-                                       struct rt_thread *thread,
-                                       rt_uint8_t        flag)
+rt_inline rt_err_t _ipc_list_suspend(rt_list_t        *list,
+                                     struct rt_thread *thread,
+                                     rt_uint8_t        flag)
 {
     /* suspend thread */
     rt_thread_suspend(thread);
@@ -175,7 +175,7 @@ rt_inline rt_err_t rt_ipc_list_suspend(rt_list_t        *list,
  *           rt_sem_release(),    rt_mutex_release(),    rt_mb_send_wait(),    rt_mq_send_wait(),
  *           rt_mb_urgent(),      rt_mb_recv(),          rt_mq_urgent(),       rt_mq_recv(),
  */
-rt_inline rt_err_t rt_ipc_list_resume(rt_list_t *list)
+rt_inline rt_err_t _ipc_list_resume(rt_list_t *list)
 {
     struct rt_thread *thread;
 
@@ -204,7 +204,7 @@ rt_inline rt_err_t rt_ipc_list_resume(rt_list_t *list)
  *           When the return value is any other values, it means this operation failed.
  *
  */
-rt_inline rt_err_t rt_ipc_list_resume_all(rt_list_t *list)
+rt_inline rt_err_t _ipc_list_resume_all(rt_list_t *list)
 {
     struct rt_thread *thread;
     register rt_ubase_t temp;
@@ -287,12 +287,13 @@ rt_err_t rt_sem_init(rt_sem_t    sem,
 {
     RT_ASSERT(sem != RT_NULL);
     RT_ASSERT(value < 0x10000U);
+    RT_ASSERT((flag == RT_IPC_FLAG_FIFO) || (flag == RT_IPC_FLAG_PRIO));
 
     /* initialize object */
     rt_object_init(&(sem->parent.parent), RT_Object_Class_Semaphore, name);
 
     /* initialize ipc object */
-    rt_ipc_object_init(&(sem->parent));
+    _ipc_object_init(&(sem->parent));
 
     /* set initial value */
     sem->value = (rt_uint16_t)value;
@@ -331,7 +332,7 @@ rt_err_t rt_sem_detach(rt_sem_t sem)
     RT_ASSERT(rt_object_is_systemobject(&sem->parent.parent));
 
     /* wakeup all suspended threads */
-    rt_ipc_list_resume_all(&(sem->parent.suspend_thread));
+    _ipc_list_resume_all(&(sem->parent.suspend_thread));
 
     /* detach semaphore object */
     rt_object_detach(&(sem->parent.parent));
@@ -377,8 +378,10 @@ rt_sem_t rt_sem_create(const char *name, rt_uint32_t value, rt_uint8_t flag)
 {
     rt_sem_t sem;
 
-    RT_DEBUG_NOT_IN_INTERRUPT;
     RT_ASSERT(value < 0x10000U);
+    RT_ASSERT((flag == RT_IPC_FLAG_FIFO) || (flag == RT_IPC_FLAG_PRIO));
+
+    RT_DEBUG_NOT_IN_INTERRUPT;
 
     /* allocate object */
     sem = (rt_sem_t)rt_object_allocate(RT_Object_Class_Semaphore, name);
@@ -386,7 +389,7 @@ rt_sem_t rt_sem_create(const char *name, rt_uint32_t value, rt_uint8_t flag)
         return sem;
 
     /* initialize ipc object */
-    rt_ipc_object_init(&(sem->parent));
+    _ipc_object_init(&(sem->parent));
 
     /* set initial value */
     sem->value = value;
@@ -419,15 +422,15 @@ RTM_EXPORT(rt_sem_create);
  */
 rt_err_t rt_sem_delete(rt_sem_t sem)
 {
-    RT_DEBUG_NOT_IN_INTERRUPT;
-
     /* parameter check */
     RT_ASSERT(sem != RT_NULL);
     RT_ASSERT(rt_object_get_type(&sem->parent.parent) == RT_Object_Class_Semaphore);
     RT_ASSERT(rt_object_is_systemobject(&sem->parent.parent) == RT_FALSE);
 
+    RT_DEBUG_NOT_IN_INTERRUPT;
+
     /* wakeup all suspended threads */
-    rt_ipc_list_resume_all(&(sem->parent.suspend_thread));
+    _ipc_list_resume_all(&(sem->parent.suspend_thread));
 
     /* delete semaphore object */
     rt_object_delete(&(sem->parent.parent));
@@ -513,7 +516,7 @@ rt_err_t rt_sem_take(rt_sem_t sem, rt_int32_t time)
                                         thread->name));
 
             /* suspend thread */
-            rt_ipc_list_suspend(&(sem->parent.suspend_thread),
+            _ipc_list_suspend(&(sem->parent.suspend_thread),
                                 thread,
                                 sem->parent.parent.flag);
 
@@ -607,7 +610,7 @@ rt_err_t rt_sem_release(rt_sem_t sem)
     if (!rt_list_isempty(&sem->parent.suspend_thread))
     {
         /* resume the suspended thread */
-        rt_ipc_list_resume(&(sem->parent.suspend_thread));
+        _ipc_list_resume(&(sem->parent.suspend_thread));
         need_schedule = RT_TRUE;
     }
     else
@@ -667,7 +670,7 @@ rt_err_t rt_sem_control(rt_sem_t sem, int cmd, void *arg)
         level = rt_hw_interrupt_disable();
 
         /* resume all waiting thread */
-        rt_ipc_list_resume_all(&sem->parent.suspend_thread);
+        _ipc_list_resume_all(&sem->parent.suspend_thread);
 
         /* set new value */
         sem->value = (rt_uint16_t)value;
@@ -730,7 +733,7 @@ rt_err_t rt_mutex_init(rt_mutex_t mutex, const char *name, rt_uint8_t flag)
     rt_object_init(&(mutex->parent.parent), RT_Object_Class_Mutex, name);
 
     /* initialize ipc object */
-    rt_ipc_object_init(&(mutex->parent));
+    _ipc_object_init(&(mutex->parent));
 
     mutex->value = 1;
     mutex->owner = RT_NULL;
@@ -771,7 +774,7 @@ rt_err_t rt_mutex_detach(rt_mutex_t mutex)
     RT_ASSERT(rt_object_is_systemobject(&mutex->parent.parent));
 
     /* wakeup all suspended threads */
-    rt_ipc_list_resume_all(&(mutex->parent.suspend_thread));
+    _ipc_list_resume_all(&(mutex->parent.suspend_thread));
 
     /* detach mutex object */
     rt_object_detach(&(mutex->parent.parent));
@@ -813,7 +816,7 @@ rt_mutex_t rt_mutex_create(const char *name, rt_uint8_t flag)
         return mutex;
 
     /* initialize ipc object */
-    rt_ipc_object_init(&(mutex->parent));
+    _ipc_object_init(&(mutex->parent));
 
     mutex->value              = 1;
     mutex->owner              = RT_NULL;
@@ -848,15 +851,15 @@ RTM_EXPORT(rt_mutex_create);
  */
 rt_err_t rt_mutex_delete(rt_mutex_t mutex)
 {
-    RT_DEBUG_NOT_IN_INTERRUPT;
-
     /* parameter check */
     RT_ASSERT(mutex != RT_NULL);
     RT_ASSERT(rt_object_get_type(&mutex->parent.parent) == RT_Object_Class_Mutex);
     RT_ASSERT(rt_object_is_systemobject(&mutex->parent.parent) == RT_FALSE);
 
+    RT_DEBUG_NOT_IN_INTERRUPT;
+
     /* wakeup all suspended threads */
-    rt_ipc_list_resume_all(&(mutex->parent.suspend_thread));
+    _ipc_list_resume_all(&(mutex->parent.suspend_thread));
 
     /* delete mutex object */
     rt_object_delete(&(mutex->parent.parent));
@@ -985,7 +988,7 @@ __again:
                 }
 
                 /* suspend current thread */
-                rt_ipc_list_suspend(&(mutex->parent.suspend_thread),
+                _ipc_list_suspend(&(mutex->parent.suspend_thread),
                                     thread,
                                     mutex->parent.parent.flag);
 
@@ -1150,7 +1153,7 @@ rt_err_t rt_mutex_release(rt_mutex_t mutex)
             }
 
             /* resume thread */
-            rt_ipc_list_resume(&(mutex->parent.suspend_thread));
+            _ipc_list_resume(&(mutex->parent.suspend_thread));
 
             need_schedule = RT_TRUE;
         }
@@ -1234,10 +1237,6 @@ RTM_EXPORT(rt_mutex_control);
  *
  * @param    name is a pointer to the name that given to the event.
  *
- * @param    value is the initial value for the event.
- *           If want to share resources, you should initialize the value as the number of available resources.
- *           If want to signal the occurrence of an event, you should initialize the value as 0.
- *
  * @param    flag is the event flag, which determines the queuing way of how multiple threads wait
  *           when the event is not available.
  *           The event flag can be ONE of the following values:
@@ -1261,6 +1260,7 @@ rt_err_t rt_event_init(rt_event_t event, const char *name, rt_uint8_t flag)
 {
     /* parameter check */
     RT_ASSERT(event != RT_NULL);
+    RT_ASSERT((flag == RT_IPC_FLAG_FIFO) || (flag == RT_IPC_FLAG_PRIO));
 
     /* initialize object */
     rt_object_init(&(event->parent.parent), RT_Object_Class_Event, name);
@@ -1269,7 +1269,7 @@ rt_err_t rt_event_init(rt_event_t event, const char *name, rt_uint8_t flag)
     event->parent.parent.flag = flag;
 
     /* initialize ipc object */
-    rt_ipc_object_init(&(event->parent));
+    _ipc_object_init(&(event->parent));
 
     /* initialize event */
     event->set = 0;
@@ -1305,7 +1305,7 @@ rt_err_t rt_event_detach(rt_event_t event)
     RT_ASSERT(rt_object_is_systemobject(&event->parent.parent));
 
     /* resume all suspended thread */
-    rt_ipc_list_resume_all(&(event->parent.suspend_thread));
+    _ipc_list_resume_all(&(event->parent.suspend_thread));
 
     /* detach event object */
     rt_object_detach(&(event->parent.parent));
@@ -1347,6 +1347,8 @@ rt_event_t rt_event_create(const char *name, rt_uint8_t flag)
 {
     rt_event_t event;
 
+    RT_ASSERT((flag == RT_IPC_FLAG_FIFO) || (flag == RT_IPC_FLAG_PRIO));
+
     RT_DEBUG_NOT_IN_INTERRUPT;
 
     /* allocate object */
@@ -1358,7 +1360,7 @@ rt_event_t rt_event_create(const char *name, rt_uint8_t flag)
     event->parent.parent.flag = flag;
 
     /* initialize ipc object */
-    rt_ipc_object_init(&(event->parent));
+    _ipc_object_init(&(event->parent));
 
     /* initialize event */
     event->set = 0;
@@ -1396,7 +1398,7 @@ rt_err_t rt_event_delete(rt_event_t event)
     RT_DEBUG_NOT_IN_INTERRUPT;
 
     /* resume all suspended thread */
-    rt_ipc_list_resume_all(&(event->parent.suspend_thread));
+    _ipc_list_resume_all(&(event->parent.suspend_thread));
 
     /* delete event object */
     rt_object_delete(&(event->parent.parent));
@@ -1628,7 +1630,7 @@ rt_err_t rt_event_recv(rt_event_t   event,
         thread->event_info = option;
 
         /* put thread to suspended thread list */
-        rt_ipc_list_suspend(&(event->parent.suspend_thread),
+        _ipc_list_suspend(&(event->parent.suspend_thread),
                             thread,
                             event->parent.parent.flag);
 
@@ -1700,7 +1702,7 @@ rt_err_t rt_event_control(rt_event_t event, int cmd, void *arg)
         level = rt_hw_interrupt_disable();
 
         /* resume all waiting thread */
-        rt_ipc_list_resume_all(&event->parent.suspend_thread);
+        _ipc_list_resume_all(&event->parent.suspend_thread);
 
         /* initialize event set */
         event->set = 0;
@@ -1741,9 +1743,6 @@ RTM_EXPORT(rt_event_control);
  *
  * @param    name is a pointer to the name that given to the mailbox.
  *
- * @param    msgpoll is a pointer to the starting address of the memory space you allocated for the mailbox in advance.
- *           In other words, msgpoll is a pointer to the mailbox buffer of the starting address.
- *
  * @param    size is the maximum number of mails in the mailbox.
  *           For example, when the mailbox buffer capacity is N, size is N/4.
  *
@@ -1773,6 +1772,7 @@ rt_err_t rt_mb_init(rt_mailbox_t mb,
                     rt_uint8_t   flag)
 {
     RT_ASSERT(mb != RT_NULL);
+    RT_ASSERT((flag == RT_IPC_FLAG_FIFO) || (flag == RT_IPC_FLAG_PRIO));
 
     /* initialize object */
     rt_object_init(&(mb->parent.parent), RT_Object_Class_MailBox, name);
@@ -1781,7 +1781,7 @@ rt_err_t rt_mb_init(rt_mailbox_t mb,
     mb->parent.parent.flag = flag;
 
     /* initialize ipc object */
-    rt_ipc_object_init(&(mb->parent));
+    _ipc_object_init(&(mb->parent));
 
     /* initialize mailbox */
     mb->msg_pool   = (rt_ubase_t *)msgpool;
@@ -1824,9 +1824,9 @@ rt_err_t rt_mb_detach(rt_mailbox_t mb)
     RT_ASSERT(rt_object_is_systemobject(&mb->parent.parent));
 
     /* resume all suspended thread */
-    rt_ipc_list_resume_all(&(mb->parent.suspend_thread));
+    _ipc_list_resume_all(&(mb->parent.suspend_thread));
     /* also resume all mailbox private suspended thread */
-    rt_ipc_list_resume_all(&(mb->suspend_sender_thread));
+    _ipc_list_resume_all(&(mb->suspend_sender_thread));
 
     /* detach mailbox object */
     rt_object_detach(&(mb->parent.parent));
@@ -1871,6 +1871,8 @@ rt_mailbox_t rt_mb_create(const char *name, rt_size_t size, rt_uint8_t flag)
 {
     rt_mailbox_t mb;
 
+    RT_ASSERT((flag == RT_IPC_FLAG_FIFO) || (flag == RT_IPC_FLAG_PRIO));
+
     RT_DEBUG_NOT_IN_INTERRUPT;
 
     /* allocate object */
@@ -1882,7 +1884,7 @@ rt_mailbox_t rt_mb_create(const char *name, rt_size_t size, rt_uint8_t flag)
     mb->parent.parent.flag = flag;
 
     /* initialize ipc object */
-    rt_ipc_object_init(&(mb->parent));
+    _ipc_object_init(&(mb->parent));
 
     /* initialize mailbox */
     mb->size     = size;
@@ -1926,18 +1928,18 @@ RTM_EXPORT(rt_mb_create);
  */
 rt_err_t rt_mb_delete(rt_mailbox_t mb)
 {
-    RT_DEBUG_NOT_IN_INTERRUPT;
-
     /* parameter check */
     RT_ASSERT(mb != RT_NULL);
     RT_ASSERT(rt_object_get_type(&mb->parent.parent) == RT_Object_Class_MailBox);
     RT_ASSERT(rt_object_is_systemobject(&mb->parent.parent) == RT_FALSE);
 
+    RT_DEBUG_NOT_IN_INTERRUPT;
+
     /* resume all suspended thread */
-    rt_ipc_list_resume_all(&(mb->parent.suspend_thread));
+    _ipc_list_resume_all(&(mb->parent.suspend_thread));
 
     /* also resume all mailbox private suspended thread */
-    rt_ipc_list_resume_all(&(mb->suspend_sender_thread));
+    _ipc_list_resume_all(&(mb->suspend_sender_thread));
 
     /* free mailbox pool */
     RT_KERNEL_FREE(mb->msg_pool);
@@ -2020,7 +2022,7 @@ rt_err_t rt_mb_send_wait(rt_mailbox_t mb,
 
         RT_DEBUG_IN_THREAD_CONTEXT;
         /* suspend current thread */
-        rt_ipc_list_suspend(&(mb->suspend_sender_thread),
+        _ipc_list_suspend(&(mb->suspend_sender_thread),
                             thread,
                             mb->parent.parent.flag);
 
@@ -2087,7 +2089,7 @@ rt_err_t rt_mb_send_wait(rt_mailbox_t mb,
     /* resume suspended thread */
     if (!rt_list_isempty(&mb->parent.suspend_thread))
     {
-        rt_ipc_list_resume(&(mb->parent.suspend_thread));
+        _ipc_list_resume(&(mb->parent.suspend_thread));
 
         /* enable interrupt */
         rt_hw_interrupt_enable(temp);
@@ -2183,7 +2185,7 @@ rt_err_t rt_mb_urgent(rt_mailbox_t mb, rt_ubase_t value)
     /* resume suspended thread */
     if (!rt_list_isempty(&mb->parent.suspend_thread))
     {
-        rt_ipc_list_resume(&(mb->parent.suspend_thread));
+        _ipc_list_resume(&(mb->parent.suspend_thread));
 
         /* enable interrupt */
         rt_hw_interrupt_enable(temp);
@@ -2266,7 +2268,7 @@ rt_err_t rt_mb_recv(rt_mailbox_t mb, rt_ubase_t *value, rt_int32_t timeout)
 
         RT_DEBUG_IN_THREAD_CONTEXT;
         /* suspend current thread */
-        rt_ipc_list_suspend(&(mb->parent.suspend_thread),
+        _ipc_list_suspend(&(mb->parent.suspend_thread),
                             thread,
                             mb->parent.parent.flag);
 
@@ -2329,7 +2331,7 @@ rt_err_t rt_mb_recv(rt_mailbox_t mb, rt_ubase_t *value, rt_int32_t timeout)
     /* resume suspended thread */
     if (!rt_list_isempty(&(mb->suspend_sender_thread)))
     {
-        rt_ipc_list_resume(&(mb->suspend_sender_thread));
+        _ipc_list_resume(&(mb->suspend_sender_thread));
 
         /* enable interrupt */
         rt_hw_interrupt_enable(temp);
@@ -2379,9 +2381,9 @@ rt_err_t rt_mb_control(rt_mailbox_t mb, int cmd, void *arg)
         level = rt_hw_interrupt_disable();
 
         /* resume all waiting thread */
-        rt_ipc_list_resume_all(&(mb->parent.suspend_thread));
+        _ipc_list_resume_all(&(mb->parent.suspend_thread));
         /* also resume all mailbox private suspended thread */
-        rt_ipc_list_resume_all(&(mb->suspend_sender_thread));
+        _ipc_list_resume_all(&(mb->suspend_sender_thread));
 
         /* re-init mailbox */
         mb->entry      = 0;
@@ -2470,6 +2472,7 @@ rt_err_t rt_mq_init(rt_mq_t     mq,
 
     /* parameter check */
     RT_ASSERT(mq != RT_NULL);
+    RT_ASSERT((flag == RT_IPC_FLAG_FIFO) || (flag == RT_IPC_FLAG_PRIO));
 
     /* initialize object */
     rt_object_init(&(mq->parent.parent), RT_Object_Class_MessageQueue, name);
@@ -2478,7 +2481,7 @@ rt_err_t rt_mq_init(rt_mq_t     mq,
     mq->parent.parent.flag = flag;
 
     /* initialize ipc object */
-    rt_ipc_object_init(&(mq->parent));
+    _ipc_object_init(&(mq->parent));
 
     /* set message pool */
     mq->msg_pool = msgpool;
@@ -2538,9 +2541,9 @@ rt_err_t rt_mq_detach(rt_mq_t mq)
     RT_ASSERT(rt_object_is_systemobject(&mq->parent.parent));
 
     /* resume all suspended thread */
-    rt_ipc_list_resume_all(&mq->parent.suspend_thread);
+    _ipc_list_resume_all(&mq->parent.suspend_thread);
     /* also resume all message queue private suspended thread */
-    rt_ipc_list_resume_all(&(mq->suspend_sender_thread));
+    _ipc_list_resume_all(&(mq->suspend_sender_thread));
 
     /* detach message queue object */
     rt_object_detach(&(mq->parent.parent));
@@ -2591,6 +2594,8 @@ rt_mq_t rt_mq_create(const char *name,
     struct rt_mq_message *head;
     register rt_base_t temp;
 
+    RT_ASSERT((flag == RT_IPC_FLAG_FIFO) || (flag == RT_IPC_FLAG_PRIO));
+
     RT_DEBUG_NOT_IN_INTERRUPT;
 
     /* allocate object */
@@ -2602,7 +2607,7 @@ rt_mq_t rt_mq_create(const char *name,
     mq->parent.parent.flag = flag;
 
     /* initialize ipc object */
-    rt_ipc_object_init(&(mq->parent));
+    _ipc_object_init(&(mq->parent));
 
     /* initialize message queue */
 
@@ -2665,17 +2670,17 @@ RTM_EXPORT(rt_mq_create);
  */
 rt_err_t rt_mq_delete(rt_mq_t mq)
 {
-    RT_DEBUG_NOT_IN_INTERRUPT;
-
     /* parameter check */
     RT_ASSERT(mq != RT_NULL);
     RT_ASSERT(rt_object_get_type(&mq->parent.parent) == RT_Object_Class_MessageQueue);
     RT_ASSERT(rt_object_is_systemobject(&mq->parent.parent) == RT_FALSE);
 
+    RT_DEBUG_NOT_IN_INTERRUPT;
+
     /* resume all suspended thread */
-    rt_ipc_list_resume_all(&(mq->parent.suspend_thread));
+    _ipc_list_resume_all(&(mq->parent.suspend_thread));
     /* also resume all message queue private suspended thread */
-    rt_ipc_list_resume_all(&(mq->suspend_sender_thread));
+    _ipc_list_resume_all(&(mq->suspend_sender_thread));
 
     /* free message queue pool */
     RT_KERNEL_FREE(mq->msg_pool);
@@ -2776,7 +2781,7 @@ rt_err_t rt_mq_send_wait(rt_mq_t     mq,
 
         RT_DEBUG_IN_THREAD_CONTEXT;
         /* suspend current thread */
-        rt_ipc_list_suspend(&(mq->suspend_sender_thread),
+        _ipc_list_suspend(&(mq->suspend_sender_thread),
                             thread,
                             mq->parent.parent.flag);
 
@@ -2862,7 +2867,7 @@ rt_err_t rt_mq_send_wait(rt_mq_t     mq,
     /* resume suspended thread */
     if (!rt_list_isempty(&mq->parent.suspend_thread))
     {
-        rt_ipc_list_resume(&(mq->parent.suspend_thread));
+        _ipc_list_resume(&(mq->parent.suspend_thread));
 
         /* enable interrupt */
         rt_hw_interrupt_enable(temp);
@@ -2991,7 +2996,7 @@ rt_err_t rt_mq_urgent(rt_mq_t mq, const void *buffer, rt_size_t size)
     /* resume suspended thread */
     if (!rt_list_isempty(&mq->parent.suspend_thread))
     {
-        rt_ipc_list_resume(&(mq->parent.suspend_thread));
+        _ipc_list_resume(&(mq->parent.suspend_thread));
 
         /* enable interrupt */
         rt_hw_interrupt_enable(temp);
@@ -3081,7 +3086,7 @@ rt_err_t rt_mq_recv(rt_mq_t    mq,
         }
 
         /* suspend current thread */
-        rt_ipc_list_suspend(&(mq->parent.suspend_thread),
+        _ipc_list_suspend(&(mq->parent.suspend_thread),
                             thread,
                             mq->parent.parent.flag);
 
@@ -3157,7 +3162,7 @@ rt_err_t rt_mq_recv(rt_mq_t    mq,
     /* resume suspended thread */
     if (!rt_list_isempty(&(mq->suspend_sender_thread)))
     {
-        rt_ipc_list_resume(&(mq->suspend_sender_thread));
+        _ipc_list_resume(&(mq->suspend_sender_thread));
 
         /* enable interrupt */
         rt_hw_interrupt_enable(temp);
@@ -3208,9 +3213,9 @@ rt_err_t rt_mq_control(rt_mq_t mq, int cmd, void *arg)
         level = rt_hw_interrupt_disable();
 
         /* resume all waiting thread */
-        rt_ipc_list_resume_all(&mq->parent.suspend_thread);
+        _ipc_list_resume_all(&mq->parent.suspend_thread);
         /* also resume all message queue private suspended thread */
-        rt_ipc_list_resume_all(&(mq->suspend_sender_thread));
+        _ipc_list_resume_all(&(mq->suspend_sender_thread));
 
         /* release all message in the queue */
         while (mq->msg_queue_head != RT_NULL)
diff --git a/src/irq.c b/src/irq.c
index 6ddcb3dd4a..3889a2a2c8 100644
--- a/src/irq.c
+++ b/src/irq.c
@@ -9,6 +9,7 @@
  * 2006-05-03     Bernard      add IRQ_DEBUG
  * 2016-08-09     ArdaFu       add interrupt enter and leave hook.
  * 2018-11-22     Jesven       rt_interrupt_get_nest function add disable irq
+ * 2021-08-15     Supperthomas fix the comment
  */
 
 #include <rthw.h>
@@ -21,19 +22,26 @@ static void (*rt_interrupt_leave_hook)(void);
 
 /**
  * @ingroup Hook
- * This function set a hook function when the system enter a interrupt
  *
- * @note the hook function must be simple and never be blocked or suspend.
+ * @brief This function set a hook function when the system enter a interrupt
+ *
+ * @note The hook function must be simple and never be blocked or suspend.
+ *
+ * @param hook the function point to be called
  */
 void rt_interrupt_enter_sethook(void (*hook)(void))
 {
     rt_interrupt_enter_hook = hook;
 }
+
 /**
  * @ingroup Hook
- * This function set a hook function when the system exit a interrupt.
  *
- * @note the hook function must be simple and never be blocked or suspend.
+ * @brief This function set a hook function when the system exit a interrupt.
+ *
+ * @note The hook function must be simple and never be blocked or suspend.
+ *
+ * @param hook the function point to be called
  */
 void rt_interrupt_leave_sethook(void (*hook)(void))
 {
@@ -53,10 +61,11 @@ void rt_interrupt_leave_sethook(void (*hook)(void))
 volatile rt_uint8_t rt_interrupt_nest = 0;
 #endif /* RT_USING_SMP */
 
+
 /**
- * This function will be invoked by BSP, when enter interrupt service routine
+ * @brief This function will be invoked by BSP, when enter interrupt service routine
  *
- * @note please don't invoke this routine in application
+ * @note Please don't invoke this routine in application
  *
  * @see rt_interrupt_leave
  */
@@ -74,10 +83,11 @@ void rt_interrupt_enter(void)
 }
 RTM_EXPORT(rt_interrupt_enter);
 
+
 /**
- * This function will be invoked by BSP, when leave interrupt service routine
+ * @brief This function will be invoked by BSP, when leave interrupt service routine
  *
- * @note please don't invoke this routine in application
+ * @note Please don't invoke this routine in application
  *
  * @see rt_interrupt_enter
  */
@@ -95,8 +105,9 @@ void rt_interrupt_leave(void)
 }
 RTM_EXPORT(rt_interrupt_leave);
 
+
 /**
- * This function will return the nest of interrupt.
+ * @brief This function will return the nest of interrupt.
  *
  * User application can invoke this function to get whether current
  * context is interrupt context.
diff --git a/src/kservice.c b/src/kservice.c
index 49e1486078..4ed30f3237 100644
--- a/src/kservice.c
+++ b/src/kservice.c
@@ -43,8 +43,8 @@ static volatile int __rt_errno;
 static rt_device_t _console_device = RT_NULL;
 #endif
 
-/*
- * This function will get errno
+/**
+ * This function gets the global errno for the current thread.
  *
  * @return errno
  */
@@ -66,10 +66,10 @@ rt_err_t rt_get_errno(void)
 }
 RTM_EXPORT(rt_get_errno);
 
-/*
- * This function will set errno
+/**
+ * This function sets the global errno for the current thread.
  *
- * @param error the errno shall be set
+ * @param error is the errno shall be set.
  */
 void rt_set_errno(rt_err_t error)
 {
@@ -96,9 +96,9 @@ void rt_set_errno(rt_err_t error)
 RTM_EXPORT(rt_set_errno);
 
 /**
- * This function returns errno.
+ * This function returns the address of the current thread errno.
  *
- * @return the errno in the system
+ * @return The errno address.
  */
 int *_rt_errno(void)
 {
@@ -116,13 +116,16 @@ int *_rt_errno(void)
 RTM_EXPORT(_rt_errno);
 
 /**
- * This function will set the content of memory to specified value
+ * This function will set the content of memory to specified value.
+ *
+ * @param  s is the address of source memory, point to the memory block to be filled.
+ *
+ * @param  c is the value to be set. The value is passed in int form, but the function
+ *         uses the unsigned character form of the value when filling the memory block.
  *
- * @param s the address of source memory
- * @param c the value shall be set in content
- * @param count the copied length
+ * @param  count number of bytes to be set.
  *
- * @return the address of source memory
+ * @return The address of source memory.
  */
 RT_WEAK void *rt_memset(void *s, int c, rt_ubase_t count)
 {
@@ -198,17 +201,19 @@ RT_WEAK void *rt_memset(void *s, int c, rt_ubase_t count)
 }
 RTM_EXPORT(rt_memset);
 
+#ifndef RT_USING_ASM_MEMCPY
 /**
- * This function will copy memory content from source address to destination
- * address.
+ * This function will copy memory content from source address to destination address.
  *
- * @param dst the address of destination memory
- * @param src  the address of source memory
- * @param count the copied length
+ * @param  dst is the address of destination memory, points to the copied content.
  *
- * @return the address of destination memory
+ * @param  src  is the address of source memory, pointing to the data source to be copied.
+ *
+ * @param  count is the copied length.
+ *
+ * @return The address of destination memory
  */
-RT_WEAK void *rt_memcpy(void *dst, const void *src, rt_ubase_t count)
+void *rt_memcpy(void *dst, const void *src, rt_ubase_t count)
 {
 #ifdef RT_KSERVICE_USING_TINY_SIZE
     char *tmp = (char *)dst, *s = (char *)src;
@@ -280,18 +285,22 @@ RT_WEAK void *rt_memcpy(void *dst, const void *src, rt_ubase_t count)
 #endif /* RT_KSERVICE_USING_TINY_SIZE */
 }
 RTM_EXPORT(rt_memcpy);
+#endif /* RT_USING_ASM_MEMCPY */
 
 #ifndef RT_KSERVICE_USING_STDLIB
 
 /**
  * This function will move memory content from source address to destination
- * address.
+ * address. If the destination memory does not overlap with the source memory,
+ * the function is the same as memcpy().
+ *
+ * @param  dest is the address of destination memory, points to the copied content.
  *
- * @param dest the address of destination memory
- * @param src  the address of source memory
- * @param n the copied length
+ * @param  src is the address of source memory, point to the data source to be copied.
  *
- * @return the address of destination memory
+ * @param  n is the copied length.
+ *
+ * @return The address of destination memory.
  */
 void *rt_memmove(void *dest, const void *src, rt_ubase_t n)
 {
@@ -316,13 +325,18 @@ void *rt_memmove(void *dest, const void *src, rt_ubase_t n)
 RTM_EXPORT(rt_memmove);
 
 /**
- * This function will compare two areas of memory
+ * This function will compare two areas of memory.
+ *
+ * @param  cs is a block of memory.
  *
- * @param cs one area of memory
- * @param ct another area of memory
- * @param count the size of the area
+ * @param  ct is another block of memory.
  *
- * @return the result
+ * @param  count is the size of the area.
+ *
+ * @return Compare the results:
+ *         If the result < 0, cs is smaller than ct.
+ *         If the result > 0, cs is greater than ct.
+ *         If the result = 0, cs is equal to ct.
  */
 RT_WEAK rt_int32_t rt_memcmp(const void *cs, const void *ct, rt_ubase_t count)
 {
@@ -338,12 +352,14 @@ RT_WEAK rt_int32_t rt_memcmp(const void *cs, const void *ct, rt_ubase_t count)
 RTM_EXPORT(rt_memcmp);
 
 /**
- * This function will return the first occurrence of a string.
+ * This function will return the first occurrence of a string, without the
+ * terminator '\0'.
+ *
+ * @param  s1 is the source string.
  *
- * @param s1 the source string
- * @param s2 the find string
+ * @param  s2 is the find string.
  *
- * @return the first occurrence of a s2 in s1, or RT_NULL if no found.
+ * @return The first occurrence of a s2 in s1, or RT_NULL if no found.
  */
 char *rt_strstr(const char *s1, const char *s2)
 {
@@ -368,10 +384,14 @@ RTM_EXPORT(rt_strstr);
 /**
  * This function will compare two strings while ignoring differences in case
  *
- * @param a the string to be compared
- * @param b the string to be compared
+ * @param  a is the string to be compared.
+ *
+ * @param  b is the string to be compared.
  *
- * @return the result
+ * @return Compare the results:
+ *         If the result < 0, a is smaller than a.
+ *         If the result > 0, a is greater than a.
+ *         If the result = 0, a is equal to a.
  */
 rt_int32_t rt_strcasecmp(const char *a, const char *b)
 {
@@ -395,11 +415,13 @@ RTM_EXPORT(rt_strcasecmp);
 /**
  * This function will copy string no more than n bytes.
  *
- * @param dst the string to copy
- * @param src the string to be copied
- * @param n the maximum copied length
+ * @param  dst points to the address used to store the copied content.
+ *
+ * @param  src is the string to be copied.
+ *
+ * @param  n is the maximum copied length.
  *
- * @return the result
+ * @return The address where the copied content is stored.
  */
 char *rt_strncpy(char *dst, const char *src, rt_ubase_t n)
 {
@@ -425,13 +447,18 @@ char *rt_strncpy(char *dst, const char *src, rt_ubase_t n)
 RTM_EXPORT(rt_strncpy);
 
 /**
- * This function will compare two strings with specified maximum length
+ * This function will compare two strings with specified maximum length.
  *
- * @param cs the string to be compared
- * @param ct the string to be compared
- * @param count the maximum compare length
+ * @param  cs is the string to be compared.
  *
- * @return the result
+ * @param  ct is the string to be compared.
+ *
+ * @param  count is the maximum compare length.
+ *
+ * @return Compare the results:
+ *         If the result < 0, cs is smaller than ct.
+ *         If the result > 0, cs is greater than ct.
+ *         If the result = 0, cs is equal to ct.
  */
 rt_int32_t rt_strncmp(const char *cs, const char *ct, rt_ubase_t count)
 {
@@ -449,12 +476,16 @@ rt_int32_t rt_strncmp(const char *cs, const char *ct, rt_ubase_t count)
 RTM_EXPORT(rt_strncmp);
 
 /**
- * This function will compare two strings without specified length
+ * This function will compare two strings without specified length.
+ *
+ * @param  cs is the string to be compared.
  *
- * @param cs the string to be compared
- * @param ct the string to be compared
+ * @param  ct is the string to be compared.
  *
- * @return the result
+ * @return Compare the results:
+ *         If the result < 0, cs is smaller than ct.
+ *         If the result > 0, cs is greater than ct.
+ *         If the result = 0, cs is equal to ct.
  */
 rt_int32_t rt_strcmp(const char *cs, const char *ct)
 {
@@ -469,55 +500,62 @@ rt_int32_t rt_strcmp(const char *cs, const char *ct)
 RTM_EXPORT(rt_strcmp);
 
 /**
- * The  strnlen()  function  returns the number of characters in the
- * string pointed to by s, excluding the terminating null byte ('\0'),
- * but at most maxlen.  In doing this, strnlen() looks only at the
- * first maxlen characters in the string pointed to by s and never
- * beyond s+maxlen.
+ * This function will return the length of a string, which terminate will
+ * null character.
  *
- * @param s the string
- * @param maxlen the max size
- * @return the length of string
+ * @param  s is the string
+ *
+ * @return The length of string.
  */
-rt_size_t rt_strnlen(const char *s, rt_ubase_t maxlen)
+rt_size_t rt_strlen(const char *s)
 {
     const char *sc;
 
-    for (sc = s; *sc != '\0' && (rt_ubase_t)(sc - s) < maxlen; ++sc) /* nothing */
+    for (sc = s; *sc != '\0'; ++sc) /* nothing */
         ;
 
     return sc - s;
 }
-RTM_EXPORT(rt_strnlen);
+RTM_EXPORT(rt_strlen);
 
+#endif /* RT_KSERVICE_USING_STDLIB */
+
+#if !defined(RT_KSERVICE_USING_STDLIB) || defined(__ARMCC_VERSION)
 /**
- * This function will return the length of a string, which terminate will
- * null character.
+ * The  strnlen()  function  returns the number of characters in the
+ * string pointed to by s, excluding the terminating null byte ('\0'),
+ * but at most maxlen.  In doing this, strnlen() looks only at the
+ * first maxlen characters in the string pointed to by s and never
+ * beyond s+maxlen.
+ *
+ * @param  s is the string.
  *
- * @param s the string
+ * @param  maxlen is the max size.
  *
- * @return the length of string
+ * @return The length of string.
  */
-rt_size_t rt_strlen(const char *s)
+rt_size_t rt_strnlen(const char *s, rt_ubase_t maxlen)
 {
     const char *sc;
 
-    for (sc = s; *sc != '\0'; ++sc) /* nothing */
+    for (sc = s; *sc != '\0' && (rt_ubase_t)(sc - s) < maxlen; ++sc) /* nothing */
         ;
 
     return sc - s;
 }
-RTM_EXPORT(rt_strlen);
-
-#endif /* RT_KSERVICE_USING_STDLIB */
+RTM_EXPORT(rt_strnlen);
+#ifdef __ARMCC_VERSION
+rt_size_t strnlen(const char *s, rt_size_t maxlen) __attribute__((alias("rt_strnlen")));
+#endif /* __ARMCC_VERSION */
+#endif /* !defined(RT_KSERVICE_USING_STDLIB) || defined(__ARMCC_VERSION) */
 
 #ifdef RT_USING_HEAP
 /**
  * This function will duplicate a string.
  *
- * @param s the string to be duplicated
+ * @param  s is the string to be duplicated.
  *
- * @return the duplicated string pointer
+ * @return The string address of the copy.
  */
 char *rt_strdup(const char *s)
 {
@@ -534,7 +572,7 @@ char *rt_strdup(const char *s)
 RTM_EXPORT(rt_strdup);
 #ifdef __ARMCC_VERSION
 char *strdup(const char *s) __attribute__((alias("rt_strdup")));
-#endif
+#endif /* __ARMCC_VERSION */
 #endif /* RT_USING_HEAP */
 
 /**
@@ -544,8 +582,8 @@ void rt_show_version(void)
 {
     rt_kprintf("\n \\ | /\n");
     rt_kprintf("- RT -     Thread Operating System\n");
-    rt_kprintf(" / | \\     %d.%d.%d build %s\n",
-               RT_VERSION, RT_SUBVERSION, RT_REVISION, __DATE__);
+    rt_kprintf(" / | \\     %d.%d.%d build %s %s\n",
+               RT_VERSION, RT_SUBVERSION, RT_REVISION, __DATE__, __TIME__);
     rt_kprintf(" 2006 - 2021 Copyright by rt-thread team\n");
 }
 RTM_EXPORT(rt_show_version);
@@ -554,6 +592,15 @@ RTM_EXPORT(rt_show_version);
 #define _ISDIGIT(c)  ((unsigned)((c) - '0') < 10)
 
 #ifdef RT_PRINTF_LONGLONG
+/**
+ * This function will duplicate a string.
+ *
+ * @param  n is the string to be duplicated.
+ *
+ * @param  base is support divide instructions value.
+ *
+ * @return the duplicated string pointer.
+ */
 rt_inline int divide(long long *n, int base)
 {
     int res;
@@ -782,6 +829,19 @@ static char *print_number(char *buf,
     return buf;
 }
 
+/**
+ * This function will fill a formatted string to buffer.
+ *
+ * @param  buf is the buffer to save formatted string.
+ *
+ * @param  size is the size of buffer.
+ *
+ * @param  fmt is the format parameters.
+ *
+ * @param  args is a list of variable parameters.
+ *
+ * @return The number of characters actually written to buffer.
+ */
 rt_int32_t rt_vsnprintf(char       *buf,
                         rt_size_t   size,
                         const char *fmt,
@@ -1049,11 +1109,15 @@ rt_int32_t rt_vsnprintf(char       *buf,
 RTM_EXPORT(rt_vsnprintf);
 
 /**
- * This function will fill a formatted string to buffer
+ * This function will fill a formatted string to buffer.
+ *
+ * @param  buf is the buffer to save formatted string.
+ *
+ * @param  size is the size of buffer.
  *
- * @param buf the buffer to save formatted string
- * @param size the size of buffer
- * @param fmt the format
+ * @param  fmt is the format parameters.
+ *
+ * @return The number of characters actually written to buffer.
  */
 rt_int32_t rt_snprintf(char *buf, rt_size_t size, const char *fmt, ...)
 {
@@ -1069,11 +1133,15 @@ rt_int32_t rt_snprintf(char *buf, rt_size_t size, const char *fmt, ...)
 RTM_EXPORT(rt_snprintf);
 
 /**
- * This function will fill a formatted string to buffer
+ * This function will fill a formatted string to buffer.
  *
- * @param buf the buffer to save formatted string
- * @param arg_ptr the arg_ptr
- * @param format the format
+ * @param  buf is the buffer to save formatted string.
+ *
+ * @param  format is the format parameters.
+ *
+ * @param  arg_ptr is a list of variable parameters.
+ *
+ * @return The number of characters actually written to buffer.
  */
 rt_int32_t rt_vsprintf(char *buf, const char *format, va_list arg_ptr)
 {
@@ -1084,8 +1152,11 @@ RTM_EXPORT(rt_vsprintf);
 /**
  * This function will fill a formatted string to buffer
  *
- * @param buf the buffer to save formatted string
- * @param format the format
+ * @param  buf the buffer to save formatted string.
+ *
+ * @param  format is the format parameters.
+ *
+ * @return The number of characters actually written to buffer.
  */
 rt_int32_t rt_sprintf(char *buf, const char *format, ...)
 {
@@ -1106,7 +1177,7 @@ RTM_EXPORT(rt_sprintf);
 /**
  * This function returns the device using in console.
  *
- * @return the device using in console or RT_NULL
+ * @return Returns the console device pointer or RT_NULL.
  */
 rt_device_t rt_console_get_device(void)
 {
@@ -1119,7 +1190,7 @@ RTM_EXPORT(rt_console_get_device);
  * After set a device to console, all output of rt_kprintf will be
  * redirected to this new device.
  *
- * @param name the name of new console device
+ * @param  name is the name of new console device.
  *
  * @return the old console device handler on successful, or RT_NULL on failure.
  */
@@ -1163,7 +1234,7 @@ RTM_EXPORT(rt_hw_console_output);
 /**
  * This function will put string to the console.
  *
- * @param str the string output to the console.
+ * @param str is the string output to the console.
  */
 void rt_kputs(const char *str)
 {
@@ -1176,11 +1247,7 @@ void rt_kputs(const char *str)
     }
     else
     {
-        rt_uint16_t old_flag = _console_device->open_flag;
-
-        _console_device->open_flag |= RT_DEVICE_FLAG_STREAM;
         rt_device_write(_console_device, 0, str, rt_strlen(str));
-        _console_device->open_flag = old_flag;
     }
 #else
     rt_hw_console_output(str);
@@ -1188,9 +1255,9 @@ void rt_kputs(const char *str)
 }
 
 /**
- * This function will print a formatted string on system console
+ * This function will print a formatted string on system console.
  *
- * @param fmt the format
+ * @param fmt is the format parameters.
  */
 RT_WEAK void rt_kprintf(const char *fmt, ...)
 {
@@ -1214,11 +1281,7 @@ RT_WEAK void rt_kprintf(const char *fmt, ...)
     }
     else
     {
-        rt_uint16_t old_flag = _console_device->open_flag;
-
-        _console_device->open_flag |= RT_DEVICE_FLAG_STREAM;
         rt_device_write(_console_device, 0, rt_log_buf, length);
-        _console_device->open_flag = old_flag;
     }
 #else
     rt_hw_console_output(rt_log_buf);
@@ -1233,10 +1296,12 @@ RTM_EXPORT(rt_kprintf);
  * This function allocates a memory block, which address is aligned to the
  * specified alignment size.
  *
- * @param size the allocated memory block size
- * @param align the alignment size
+ * @param  size is the allocated memory block size.
+ *
+ * @param  align is the alignment size.
  *
- * @return the allocated memory block on successful, otherwise returns RT_NULL
+ * @return The memory block address was returned successfully, otherwise it was
+ *         returned empty RT_NULL.
  */
 RT_WEAK void *rt_malloc_align(rt_size_t size, rt_size_t align)
 {
@@ -1282,7 +1347,7 @@ RTM_EXPORT(rt_malloc_align);
  * This function release the memory block, which is allocated by
  * rt_malloc_align function and address is aligned.
  *
- * @param ptr the memory block pointer
+ * @param ptr is the memory block pointer.
  */
 RT_WEAK void rt_free_align(void *ptr)
 {
@@ -1322,8 +1387,8 @@ const rt_uint8_t __lowest_bit_bitmap[] =
  * Bits are numbered starting at 1 (the least significant bit).  A return value of
  * zero from any of these functions means that the argument was zero.
  *
- * @return return the index of the first bit set. If value is 0, then this function
- * shall return 0.
+ * @return Return the index of the first bit set. If value is 0, then this function
+ *         shall return 0.
  */
 int __rt_ffs(int value)
 {
@@ -1350,7 +1415,7 @@ void (*rt_assert_hook)(const char *ex, const char *func, rt_size_t line);
 /**
  * This function will set a hook function to RT_ASSERT(EX). It will run when the expression is false.
  *
- * @param hook the hook function
+ * @param hook is the hook function.
  */
 void rt_assert_set_hook(void (*hook)(const char *ex, const char *func, rt_size_t line))
 {
@@ -1360,9 +1425,11 @@ void rt_assert_set_hook(void (*hook)(const char *ex, const char *func, rt_size_t
 /**
  * The RT_ASSERT function.
  *
- * @param ex the assertion condition string
- * @param func the function name when assertion.
- * @param line the file line number when assertion.
+ * @param ex_string is the assertion condition string.
+ *
+ * @param func is the function name when assertion.
+ *
+ * @param line is the file line number when assertion.
  */
 void rt_assert_handler(const char *ex_string, const char *func, rt_size_t line)
 {
diff --git a/src/mem.c b/src/mem.c
index 20ac0e588c..3c0816748e 100644
--- a/src/mem.c
+++ b/src/mem.c
@@ -66,10 +66,10 @@ static void (*rt_free_hook)(void *ptr);
 /**@{*/
 
 /**
- * This function will set a hook function, which will be invoked when a memory
- * block is allocated from heap memory.
+ * @brief This function will set a hook function, which will be invoked when a memory
+ *        block is allocated from heap memory.
  *
- * @param hook the hook function
+ * @param hook the hook function.
  */
 void rt_malloc_sethook(void (*hook)(void *ptr, rt_size_t size))
 {
@@ -77,8 +77,8 @@ void rt_malloc_sethook(void (*hook)(void *ptr, rt_size_t size))
 }
 
 /**
- * This function will set a hook function, which will be invoked when a memory
- * block is released to heap memory.
+ * @brief This function will set a hook function, which will be invoked when a memory
+ *        block is released to heap memory.
  *
  * @param hook the hook function
  */
@@ -194,11 +194,10 @@ static void plug_holes(struct heap_mem *mem)
 }
 
 /**
- * @ingroup SystemInit
- *
- * This function will initialize system heap memory.
+ * @brief This function will initialize system heap memory.
  *
  * @param begin_addr the beginning address of system heap memory.
+ *
  * @param end_addr the end address of system heap memory.
  */
 void rt_system_heap_init(void *begin_addr, void *end_addr)
@@ -263,11 +262,11 @@ void rt_system_heap_init(void *begin_addr, void *end_addr)
 /**@{*/
 
 /**
- * Allocate a block of memory with a minimum of 'size' bytes.
+ * @brief Allocate a block of memory with a minimum of 'size' bytes.
  *
  * @param size is the minimum size of the requested block in bytes.
  *
- * @return pointer to allocated memory or NULL if no free memory was found.
+ * @return the pointer to allocated memory or NULL if no free memory was found.
  */
 void *rt_malloc(rt_size_t size)
 {
@@ -411,12 +410,13 @@ void *rt_malloc(rt_size_t size)
 RTM_EXPORT(rt_malloc);
 
 /**
- * This function will change the previously allocated memory block.
+ * @brief This function will change the size of previously allocated memory block.
  *
- * @param rmem pointer to memory allocated by rt_malloc
- * @param newsize the required new size
+ * @param rmem is the pointer to memory allocated by rt_malloc.
  *
- * @return the changed memory block address
+ * @param newsize is the required new size.
+ *
+ * @return the changed memory block address.
  */
 void *rt_realloc(void *rmem, rt_size_t newsize)
 {
@@ -517,16 +517,17 @@ void *rt_realloc(void *rmem, rt_size_t newsize)
 RTM_EXPORT(rt_realloc);
 
 /**
- * This function will contiguously allocate enough space for count objects
- * that are size bytes of memory each and returns a pointer to the allocated
- * memory.
+ * @brief  This function will contiguously allocate enough space for count objects
+ *         that are size bytes of memory each and returns a pointer to the allocated
+ *         memory.
+ *
+ * @note   The allocated memory is filled with bytes of value zero.
  *
- * The allocated memory is filled with bytes of value zero.
+ * @param  count is the number of objects to allocate.
  *
- * @param count number of objects to allocate
- * @param size size of the objects to allocate
+ * @param  size is the size of one object to allocate.
  *
- * @return pointer to allocated memory / NULL pointer if there is an error
+ * @return pointer to allocated memory / NULL pointer if there is an error.
  */
 void *rt_calloc(rt_size_t count, rt_size_t size)
 {
@@ -544,10 +545,10 @@ void *rt_calloc(rt_size_t count, rt_size_t size)
 RTM_EXPORT(rt_calloc);
 
 /**
- * This function will release the previously allocated memory block by
- * rt_malloc. The released memory block is taken back to system heap.
+ * @brief This function will release the previously allocated memory block by
+ *        rt_malloc. The released memory block is taken back to system heap.
  *
- * @param rmem the address of memory which will be released
+ * @param rmem the address of memory which will be released.
  */
 void rt_free(void *rmem)
 {
@@ -616,6 +617,16 @@ void rt_free(void *rmem)
 RTM_EXPORT(rt_free);
 
 #ifdef RT_MEM_STATS
+/**
+* @brief This function will caculate the total memory, the used memory, and
+*        the max used memory.
+*
+* @param total is a pointer to get the total size of the memory.
+*
+* @param used is a pointer to get the size of memory used.
+*
+* @param max_used is a pointer to get the maximum memory used.
+*/
 void rt_memory_info(rt_uint32_t *total,
                     rt_uint32_t *used,
                     rt_uint32_t *max_used)
diff --git a/src/memheap.c b/src/memheap.c
index d77c95601e..68a15d1a8e 100644
--- a/src/memheap.c
+++ b/src/memheap.c
@@ -39,6 +39,13 @@
 #define MEMITEM(ptr)            (struct rt_memheap_item*)((rt_uint8_t*)ptr - RT_MEMHEAP_SIZE)
 
 #ifdef RT_USING_MEMTRACE
+/**
+ * @brief This function will set a new name for memheap.
+ *
+ * @param item is a pointer point to a memheap object.
+ *
+ * @param name is the new name to be set.
+ */
 rt_inline void rt_memheap_setname(struct rt_memheap_item *item, const char *name)
 {
     int index;
@@ -64,6 +71,13 @@ rt_inline void rt_memheap_setname(struct rt_memheap_item *item, const char *name
     }
 }
 
+/**
+ * @brief This function will set a new name for memheap.
+ *
+ * @param ptr is a pointer point to a memheap object.
+ *
+ * @param name is the new name to be set.
+ */
 void rt_mem_set_tag(void *ptr, const char *name)
 {
     struct rt_memheap_item *item;
@@ -76,16 +90,28 @@ void rt_mem_set_tag(void *ptr, const char *name)
 }
 #endif /* RT_USING_MEMTRACE */
 
-/*
- * The initialized memory pool will be:
- * +-----------------------------------+--------------------------+
- * | whole freed memory block          | Used Memory Block Tailer |
- * +-----------------------------------+--------------------------+
+/**
+ * @brief   This function initializes a piece of memory called memheap.
  *
- * block_list --> whole freed memory block
+ * @note    The initialized memory pool will be:
+ *          +-----------------------------------+--------------------------+
+ *          | whole freed memory block          | Used Memory Block Tailer |
+ *          +-----------------------------------+--------------------------+
  *
- * The length of Used Memory Block Tailer is 0,
- * which is prevents block merging across list
+ *          block_list --> whole freed memory block
+ *
+ *          The length of Used Memory Block Tailer is 0,
+ *          which is prevents block merging across list
+ *
+ * @param   memheap is a pointer of the memheap object.
+ *
+ * @param   name is the name of the memheap.
+ *
+ * @param   start_addr is the start address of the memheap.
+ *
+ * @param   size is the size of the memheap.
+ *
+ * @return  RT_EOK
  */
 rt_err_t rt_memheap_init(struct rt_memheap *memheap,
                          const char        *name,
@@ -165,6 +191,13 @@ rt_err_t rt_memheap_init(struct rt_memheap *memheap,
 }
 RTM_EXPORT(rt_memheap_init);
 
+/**
+ * @brief   This function will remove a memheap from the system.
+ *
+ * @param   heap is a pointer of memheap object.
+ *
+ * @return  RT_EOK
+ */
 rt_err_t rt_memheap_detach(struct rt_memheap *heap)
 {
     RT_ASSERT(heap);
@@ -179,6 +212,15 @@ rt_err_t rt_memheap_detach(struct rt_memheap *heap)
 }
 RTM_EXPORT(rt_memheap_detach);
 
+/**
+ * @brief  Allocate a block of memory with a minimum of 'size' bytes on memheap.
+ *
+ * @param   heap is a pointer for memheap object.
+ *
+ * @param   size is the minimum size of the requested block in bytes.
+ *
+ * @return  the pointer to allocated memory or NULL if no free memory was found.
+ */
 void *rt_memheap_alloc(struct rt_memheap *heap, rt_size_t size)
 {
     rt_err_t result;
@@ -336,6 +378,18 @@ void *rt_memheap_alloc(struct rt_memheap *heap, rt_size_t size)
 }
 RTM_EXPORT(rt_memheap_alloc);
 
+/**
+ * @brief This function will change the size of previously allocated memory block.
+ *
+ * @param heap is a pointer to the memheap object, which will reallocate
+ *             memory from the block
+ *
+ * @param ptr is a pointer to start address of memory.
+ *
+ * @param newsize is the required new size.
+ *
+ * @return the changed memory block address.
+ */
 void *rt_memheap_realloc(struct rt_memheap *heap, void *ptr, rt_size_t newsize)
 {
     rt_err_t result;
@@ -438,7 +492,7 @@ void *rt_memheap_realloc(struct rt_memheap *heap, void *ptr, rt_size_t newsize)
                 next_ptr->pool_ptr = heap;
 
 #ifdef RT_USING_MEMTRACE
-                rt_memset(next_ptr->owner_thread_name, ' ', sizeof(next_ptr->owner_thread_name));
+                rt_memset((void *)next_ptr->owner_thread_name, ' ', sizeof(next_ptr->owner_thread_name));
 #endif /* RT_USING_MEMTRACE */
 
                 next_ptr->prev          = header_ptr;
@@ -556,6 +610,12 @@ void *rt_memheap_realloc(struct rt_memheap *heap, void *ptr, rt_size_t newsize)
 }
 RTM_EXPORT(rt_memheap_realloc);
 
+/**
+ * @brief This function will release the allocated memory block by
+ *        rt_malloc. The released memory block is taken back to system heap.
+ *
+ * @param ptr the address of memory which will be released.
+ */
 void rt_memheap_free(void *ptr)
 {
     rt_err_t result;
@@ -680,7 +740,13 @@ static void _memheap_dump_tag(struct rt_memheap_item *item)
 
     rt_kprintf("%.*s", 2 * sizeof(void *), name);
 }
-
+/**
+ * @brief   This function will print the memheap infomation.
+ *
+ * @param   heap is the pointer  to the memheap to get information.
+ *
+ * @return  0
+ */
 int rt_memheap_dump(struct rt_memheap *heap)
 {
     struct rt_memheap_item *item, *end;
@@ -730,13 +796,15 @@ int memheaptrace(void)
     if (count > 0)
     {
         int index;
+#if defined(RT_USING_FINSH) && defined(MSH_USING_BUILT_IN_COMMANDS)
         extern int list_memheap(void);
+#endif
 
         heaps = (struct rt_memheap **)rt_malloc(sizeof(struct rt_memheap *) * count);
         if (heaps == RT_NULL) return 0;
-
+#if defined(RT_USING_FINSH) && defined(MSH_USING_BUILT_IN_COMMANDS)
         list_memheap();
-
+#endif
         rt_kprintf("memheap header size: %d\n", RT_MEMHEAP_SIZE);
         count = rt_object_get_pointers(RT_Object_Class_MemHeap, (rt_object_t *)heaps, count);
         for (index = 0; index < count; index++)
@@ -755,6 +823,13 @@ MSH_CMD_EXPORT(memheaptrace, dump memory trace information);
 #ifdef RT_USING_MEMHEAP_AS_HEAP
 static struct rt_memheap _heap;
 
+/**
+ * @brief   This function initializes a heap for system.
+ *
+ * @param   begin_addr is the start address of the memory.
+ *
+ * @param   end_addr is the end address of the memory.
+ */
 void rt_system_heap_init(void *begin_addr, void *end_addr)
 {
     RT_ASSERT((rt_uint32_t)end_addr > (rt_uint32_t)begin_addr);
@@ -766,12 +841,18 @@ void rt_system_heap_init(void *begin_addr, void *end_addr)
                     (rt_uint32_t)end_addr - (rt_uint32_t)begin_addr);
 }
 
+/**
+ * @brief Allocate a block of memory with a minimum of 'size' bytes.
+ *
+ * @param size is the minimum size of the requested block in bytes.
+ */
 void *rt_malloc(rt_size_t size)
 {
     void *ptr;
 
     /* try to allocate in system heap */
     ptr = rt_memheap_alloc(&_heap, size);
+#ifdef RT_USING_MEMHEAP_AUTO_BINDING
     if (ptr == RT_NULL)
     {
         struct rt_object *object;
@@ -801,7 +882,7 @@ void *rt_malloc(rt_size_t size)
                 break;
         }
     }
-
+#endif /* RT_USING_MEMHEAP_AUTO_BINDING */
 
 #ifdef RT_USING_MEMTRACE
     if (ptr == RT_NULL)
@@ -824,12 +905,27 @@ void *rt_malloc(rt_size_t size)
 }
 RTM_EXPORT(rt_malloc);
 
+/**
+ * @brief This function will release the previously allocated memory block by
+ *        rt_malloc. The released memory block is taken back to system heap.
+ *
+ * @param rmem the address of memory which will be released.
+ */
 void rt_free(void *rmem)
 {
     rt_memheap_free(rmem);
 }
 RTM_EXPORT(rt_free);
 
+/**
+ * @brief This function will change the size of previously allocated memory block.
+ *
+ * @param rmem is the pointer to memory allocated by rt_malloc.
+ *
+ * @param newsize is the required new size.
+ *
+ * @return the changed memory block address.
+ */
 void *rt_realloc(void *rmem, rt_size_t newsize)
 {
     void *new_ptr;
@@ -890,6 +986,19 @@ void *rt_realloc(void *rmem, rt_size_t newsize)
 }
 RTM_EXPORT(rt_realloc);
 
+/**
+ * @brief  This function will contiguously allocate enough space for count objects
+ *         that are size bytes of memory each and returns a pointer to the allocated
+ *         memory.
+ *
+ * @note   The allocated memory is filled with bytes of value zero.
+ *
+ * @param  count is the number of objects to allocate.
+ *
+ * @param  size is the size of one object to allocate.
+ *
+ * @return pointer to allocated memory pointer.
+ */
 void *rt_calloc(rt_size_t count, rt_size_t size)
 {
     void *ptr;
@@ -920,6 +1029,16 @@ void *rt_calloc(rt_size_t count, rt_size_t size)
 }
 RTM_EXPORT(rt_calloc);
 
+/**
+* @brief This function will caculate the total memory, the used memory, and
+*        the max used memory.
+*
+* @param total is a pointer to get the total size of the memory.
+*
+* @param used is a pointer to get the size of memory used.
+*
+* @param max_used is a pointer to get the maximum memory used.
+*/
 void rt_memory_info(rt_uint32_t *total,
                     rt_uint32_t *used,
                     rt_uint32_t *max_used)
@@ -938,12 +1057,16 @@ void rt_memory_info(rt_uint32_t *total,
 
 #ifdef RT_USING_MEMTRACE
 
+/**
+ * @brief  This function will print the used memheap infomation.
+ *
+ * @param  mh is a pointer of the memheap object.
+ */
 void dump_used_memheap(struct rt_memheap *mh)
 {
     struct rt_memheap_item *header_ptr;
     rt_uint32_t block_size;
 
-
     rt_kprintf("\nmemory heap address:\n");
     rt_kprintf("heap_ptr: 0x%08x\n", mh->start_addr);
     rt_kprintf("free    : 0x%08x\n", mh->available_size);
diff --git a/src/mempool.c b/src/mempool.c
index 5ac87d2bc8..09a4955eee 100644
--- a/src/mempool.c
+++ b/src/mempool.c
@@ -32,8 +32,8 @@ static void (*rt_mp_free_hook)(struct rt_mempool *mp, void *block);
 /**@{*/
 
 /**
- * This function will set a hook function, which will be invoked when a memory
- * block is allocated from memory pool.
+ * @brief This function will set a hook function, which will be invoked when a memory
+ *        block is allocated from the memory pool.
  *
  * @param hook the hook function
  */
@@ -43,8 +43,8 @@ void rt_mp_alloc_sethook(void (*hook)(struct rt_mempool *mp, void *block))
 }
 
 /**
- * This function will set a hook function, which will be invoked when a memory
- * block is released to memory pool.
+ * @brief This function will set a hook function, which will be invoked when a memory
+ *        block is released to the memory pool.
  *
  * @param hook the hook function
  */
@@ -63,14 +63,18 @@ void rt_mp_free_sethook(void (*hook)(struct rt_mempool *mp, void *block))
 /**@{*/
 
 /**
- * This function will initialize a memory pool object, normally which is used
- * for static object.
+ * @brief  This function will initialize a memory pool object, normally which is used
+ *         for static object.
  *
- * @param mp the memory pool object
- * @param name the name of memory pool
- * @param start the star address of memory pool
- * @param size the total size of memory pool
- * @param block_size the size for each block
+ * @param  mp is the memory pool object.
+ *
+ * @param  name is the name of the memory pool.
+ *
+ * @param  start is the start address of the memory pool.
+ *
+ * @param  size is the total size of the memory pool.
+ *
+ * @param  block_size is the size for each block..
  *
  * @return RT_EOK
  */
@@ -125,9 +129,9 @@ rt_err_t rt_mp_init(struct rt_mempool *mp,
 RTM_EXPORT(rt_mp_init);
 
 /**
- * This function will detach a memory pool from system object management.
+ * @brief  This function will detach a memory pool from system object management.
  *
- * @param mp the memory pool object
+ * @param  mp is the memory pool object.
  *
  * @return RT_EOK
  */
@@ -172,12 +176,14 @@ RTM_EXPORT(rt_mp_detach);
 
 #ifdef RT_USING_HEAP
 /**
- * This function will create a mempool object and allocate the memory pool from
- * heap.
+ * @brief This function will create a mempool object and allocate the memory pool from
+ *        heap.
  *
- * @param name the name of memory pool
- * @param block_count the count of blocks in memory pool
- * @param block_size the size for each block
+ * @param name is the name of memory pool.
+ *
+ * @param block_count is the count of blocks in memory pool.
+ *
+ * @param block_size is the size for each block.
  *
  * @return the created mempool object
  */
@@ -241,9 +247,9 @@ rt_mp_t rt_mp_create(const char *name,
 RTM_EXPORT(rt_mp_create);
 
 /**
- * This function will delete a memory pool and release the object memory.
+ * @brief This function will delete a memory pool and release the object memory.
  *
- * @param mp the memory pool object
+ * @param mp is the memory pool object.
  *
  * @return RT_EOK
  */
@@ -293,12 +299,14 @@ RTM_EXPORT(rt_mp_delete);
 #endif /* RT_USING_HEAP */
 
 /**
- * This function will allocate a block from memory pool
+ * @brief This function will allocate a block from memory pool.
+ *
+ * @param mp is the memory pool object.
  *
- * @param mp the memory pool object
- * @param time the waiting time
+ * @param time is the maximum waiting time for allocating memory.
+ *             - 0 for not waiting, allocating memory immediately.
  *
- * @return the allocated memory block or RT_NULL on allocated failed
+ * @return the allocated memory block or RT_NULL on allocated failed.
  */
 void *rt_mp_alloc(rt_mp_t mp, rt_int32_t time)
 {
@@ -392,9 +400,9 @@ void *rt_mp_alloc(rt_mp_t mp, rt_int32_t time)
 RTM_EXPORT(rt_mp_alloc);
 
 /**
- * This function will release a memory block
+ * @brief This function will release a memory block.
  *
- * @param block the address of memory block to be released
+ * @param block the address of memory block to be released.
  */
 void rt_mp_free(void *block)
 {
diff --git a/src/object.c b/src/object.c
index ff96037c52..66d5775bd7 100644
--- a/src/object.c
+++ b/src/object.c
@@ -23,7 +23,7 @@
 #endif /* RT_USING_MODULE */
 
 /*
- * define object_info for the number of rt_object_container items.
+ * define object_info for the number of _object_container items.
  */
 enum rt_object_info_type
 {
@@ -60,8 +60,9 @@ enum rt_object_info_type
 };
 
 #define _OBJ_CONTAINER_LIST_INIT(c)     \
-    {&(rt_object_container[c].object_list), &(rt_object_container[c].object_list)}
-static struct rt_object_information rt_object_container[RT_Object_Info_Unknown] =
+    {&(_object_container[c].object_list), &(_object_container[c].object_list)}
+
+static struct rt_object_information _object_container[RT_Object_Info_Unknown] =
 {
     /* initialize object container - thread */
     {RT_Object_Class_Thread, _OBJ_CONTAINER_LIST_INIT(RT_Object_Info_Thread), sizeof(struct rt_thread)},
@@ -119,10 +120,10 @@ void (*rt_object_put_hook)(struct rt_object *object);
 /**@{*/
 
 /**
- * This function will set a hook function, which will be invoked when object
- * attaches to kernel object system.
+ * @brief This function will set a hook function, which will be invoked when object
+ *        attaches to kernel object system.
  *
- * @param hook the hook function
+ * @param hook is the hook function.
  */
 void rt_object_attach_sethook(void (*hook)(struct rt_object *object))
 {
@@ -130,10 +131,10 @@ void rt_object_attach_sethook(void (*hook)(struct rt_object *object))
 }
 
 /**
- * This function will set a hook function, which will be invoked when object
- * detaches from kernel object system.
+ * @brief This function will set a hook function, which will be invoked when object
+ *        detaches from kernel object system.
  *
- * @param hook the hook function
+ * @param hook is the hook function
  */
 void rt_object_detach_sethook(void (*hook)(struct rt_object *object))
 {
@@ -141,17 +142,17 @@ void rt_object_detach_sethook(void (*hook)(struct rt_object *object))
 }
 
 /**
- * This function will set a hook function, which will be invoked when object
- * is taken from kernel object system.
+ * @brief This function will set a hook function, which will be invoked when object
+ *        is taken from kernel object system.
  *
- * The object is taken means:
- * semaphore - semaphore is taken by thread
- * mutex - mutex is taken by thread
- * event - event is received by thread
- * mailbox - mail is received by thread
- * message queue - message is received by thread
+ *        The object is taken means:
+ *            semaphore - semaphore is taken by thread
+ *            mutex - mutex is taken by thread
+ *            event - event is received by thread
+ *            mailbox - mail is received by thread
+ *            message queue - message is received by thread
  *
- * @param hook the hook function
+ * @param hook is the hook function.
  */
 void rt_object_trytake_sethook(void (*hook)(struct rt_object *object))
 {
@@ -159,18 +160,18 @@ void rt_object_trytake_sethook(void (*hook)(struct rt_object *object))
 }
 
 /**
- * This function will set a hook function, which will be invoked when object
- * have been taken from kernel object system.
+ * @brief This function will set a hook function, which will be invoked when object
+ *        have been taken from kernel object system.
  *
- * The object have been taken means:
- * semaphore - semaphore have been taken by thread
- * mutex - mutex have been taken by thread
- * event - event have been received by thread
- * mailbox - mail have been received by thread
- * message queue - message have been received by thread
- * timer - timer is started
+ *        The object have been taken means:
+ *            semaphore - semaphore have been taken by thread
+ *            mutex - mutex have been taken by thread
+ *            event - event have been received by thread
+ *            mailbox - mail have been received by thread
+ *            message queue - message have been received by thread
+ *            timer - timer is started
  *
- * @param hook the hook function
+ * @param hook the hook function.
  */
 void rt_object_take_sethook(void (*hook)(struct rt_object *object))
 {
@@ -178,10 +179,10 @@ void rt_object_take_sethook(void (*hook)(struct rt_object *object))
 }
 
 /**
- * This function will set a hook function, which will be invoked when object
- * is put to kernel object system.
+ * @brief This function will set a hook function, which will be invoked when object
+ *        is put to kernel object system.
  *
- * @param hook the hook function
+ * @param hook is the hook function
  */
 void rt_object_put_sethook(void (*hook)(struct rt_object *object))
 {
@@ -198,9 +199,9 @@ void rt_object_put_sethook(void (*hook)(struct rt_object *object))
 /**@{*/
 
 /**
- * This function will return the specified type of object information.
+ * @brief This function will return the specified type of object information.
  *
- * @param type the type of object, which can be
+ * @param type is the type of object, which can be
  *             RT_Object_Class_Thread/Semaphore/Mutex... etc
  *
  * @return the object type information or RT_NULL
@@ -211,17 +212,18 @@ rt_object_get_information(enum rt_object_class_type type)
     int index;
 
     for (index = 0; index < RT_Object_Info_Unknown; index ++)
-        if (rt_object_container[index].type == type) return &rt_object_container[index];
+        if (_object_container[index].type == type) return &_object_container[index];
 
     return RT_NULL;
 }
 RTM_EXPORT(rt_object_get_information);
 
 /**
- * This function will return the length of object list in object container.
+ * @brief This function will return the length of object list in object container.
  *
- * @param type the type of object, which can be
+ * @param type is the type of object, which can be
  *             RT_Object_Class_Thread/Semaphore/Mutex... etc
+ *
  * @return the length of object list
  */
 int rt_object_get_length(enum rt_object_class_type type)
@@ -247,15 +249,17 @@ int rt_object_get_length(enum rt_object_class_type type)
 RTM_EXPORT(rt_object_get_length);
 
 /**
- * This function will copy the object pointer of the specified type,
- * with the maximum size specified by maxlen.
+ * @brief This function will copy the object pointer of the specified type,
+ *        with the maximum size specified by maxlen.
  *
- * @param type the type of object, which can be
+ * @param type is the type of object, which can be
  *             RT_Object_Class_Thread/Semaphore/Mutex... etc
- * @param pointers the pointers will be saved to
- * @param maxlen the maximum number of pointers can be saved
  *
- * @return the copied number of object pointers
+ * @param pointers is the pointer will be saved to.
+ *
+ * @param maxlen is the maximum number of pointers can be saved.
+ *
+ * @return the copied number of object pointers.
  */
 int rt_object_get_pointers(enum rt_object_class_type type, rt_object_t *pointers, int maxlen)
 {
@@ -289,12 +293,14 @@ int rt_object_get_pointers(enum rt_object_class_type type, rt_object_t *pointers
 RTM_EXPORT(rt_object_get_pointers);
 
 /**
- * This function will initialize an object and add it to object system
- * management.
+ * @brief This function will initialize an object and add it to object system
+ *        management.
+ *
+ * @param object is the specified object to be initialized.
  *
- * @param object the specified object to be initialized.
- * @param type the object type.
- * @param name the object name. In system, the object's name must be unique.
+ * @param type is the object type.
+ *
+ * @param name is the object name. In system, the object's name must be unique.
  */
 void rt_object_init(struct rt_object         *object,
                     enum rt_object_class_type type,
@@ -360,8 +366,8 @@ void rt_object_init(struct rt_object         *object,
 }
 
 /**
- * This function will detach a static object from object system,
- * and the memory of static object is not freed.
+ * @brief This function will detach a static object from object system,
+ *        and the memory of static object is not freed.
  *
  * @param object the specified object to be detached.
  */
@@ -389,10 +395,11 @@ void rt_object_detach(rt_object_t object)
 
 #ifdef RT_USING_HEAP
 /**
- * This function will allocate an object from object system
+ * @brief This function will allocate an object from object system.
+ *
+ * @param type is the type of object.
  *
- * @param type the type of object
- * @param name the object name. In system, the object's name must be unique.
+ * @param name is the object name. In system, the object's name must be unique.
  *
  * @return object
  */
@@ -458,9 +465,9 @@ rt_object_t rt_object_allocate(enum rt_object_class_type type, const char *name)
 }
 
 /**
- * This function will delete an object and release object memory.
+ * @brief This function will delete an object and release object memory.
  *
- * @param object the specified object to be deleted.
+ * @param object is the specified object to be deleted.
  */
 void rt_object_delete(rt_object_t object)
 {
@@ -490,11 +497,12 @@ void rt_object_delete(rt_object_t object)
 #endif /* RT_USING_HEAP */
 
 /**
- * This function will judge the object is system object or not.
- * Normally, the system object is a static object and the type
- * of object set to RT_Object_Class_Static.
+ * @brief This function will judge the object is system object or not.
  *
- * @param object the specified object to be judged.
+ * @note  Normally, the system object is a static object and the type
+ *        of object set to RT_Object_Class_Static.
+ *
+ * @param object is the specified object to be judged.
  *
  * @return RT_TRUE if a system object, RT_FALSE for others.
  */
@@ -510,10 +518,10 @@ rt_bool_t rt_object_is_systemobject(rt_object_t object)
 }
 
 /**
- * This function will return the type of object without
- * RT_Object_Class_Static flag.
+ * @brief This function will return the type of object without
+ *        RT_Object_Class_Static flag.
  *
- * @param object the specified object to be get type.
+ * @param object is the specified object to be get type.
  *
  * @return the type of object.
  */
@@ -526,11 +534,12 @@ rt_uint8_t rt_object_get_type(rt_object_t object)
 }
 
 /**
- * This function will find specified name object from object
- * container.
+ * @brief This function will find specified name object from object
+ *        container.
+ *
+ * @param name is the specified name of object.
  *
- * @param name the specified name of object.
- * @param type the type of object
+ * @param type is the type of object
  *
  * @return the found object or RT_NULL if there is no this object
  * in object container.
diff --git a/src/scheduler.c b/src/scheduler.c
index 353fdad5cb..6ef02f3d3c 100644
--- a/src/scheduler.c
+++ b/src/scheduler.c
@@ -23,7 +23,7 @@
  * 2013-12-21     Grissiom     add rt_critical_level
  * 2018-11-22     Jesven       remove the current task from ready queue
  *                             add per cpu ready queue
- *                             add _get_highest_priority_thread to find highest priority task
+ *                             add _scheduler_get_highest_priority_thread to find highest priority task
  *                             rt_schedule_insert_thread won't insert current task to ready queue
  *                             in smp version, rt_hw_context_switch_interrupt maybe switch to
  *                               new task directly
@@ -58,19 +58,23 @@ static void (*rt_scheduler_switch_hook)(struct rt_thread *tid);
 /**@{*/
 
 /**
- * This function will set a hook function, which will be invoked when thread
- * switch happens.
+ * @brief This function will set a hook function, which will be invoked when thread
+ *        switch happens.
  *
- * @param hook the hook function
+ * @param hook is the hook function.
  */
-void
-rt_scheduler_sethook(void (*hook)(struct rt_thread *from, struct rt_thread *to))
+void rt_scheduler_sethook(void (*hook)(struct rt_thread *from, struct rt_thread *to))
 {
     rt_scheduler_hook = hook;
 }
 
-void
-rt_scheduler_switch_sethook(void (*hook)(struct rt_thread *tid))
+/**
+ * @brief This function will set a hook function, which will be invoked when context
+ *        switch happens.
+ *
+ * @param hook is the hook function.
+ */
+void rt_scheduler_switch_sethook(void (*hook)(struct rt_thread *tid))
 {
     rt_scheduler_switch_hook = hook;
 }
@@ -119,7 +123,7 @@ static void _rt_scheduler_stack_check(struct rt_thread *thread)
  * get the highest priority thread in ready queue
  */
 #ifdef RT_USING_SMP
-static struct rt_thread* _get_highest_priority_thread(rt_ubase_t *highest_prio)
+static struct rt_thread* _scheduler_get_highest_priority_thread(rt_ubase_t *highest_prio)
 {
     register struct rt_thread *highest_priority_thread;
     register rt_ubase_t highest_ready_priority, local_highest_ready_priority;
@@ -155,7 +159,7 @@ static struct rt_thread* _get_highest_priority_thread(rt_ubase_t *highest_prio)
     return highest_priority_thread;
 }
 #else
-static struct rt_thread* _get_highest_priority_thread(rt_ubase_t *highest_prio)
+static struct rt_thread* _scheduler_get_highest_priority_thread(rt_ubase_t *highest_prio)
 {
     register struct rt_thread *highest_priority_thread;
     register rt_ubase_t highest_ready_priority;
@@ -181,8 +185,7 @@ static struct rt_thread* _get_highest_priority_thread(rt_ubase_t *highest_prio)
 #endif /* RT_USING_SMP */
 
 /**
- * @ingroup SystemInit
- * This function will initialize the system scheduler
+ * @brief This function will initialize the system scheduler.
  */
 void rt_system_scheduler_init(void)
 {
@@ -232,16 +235,15 @@ void rt_system_scheduler_init(void)
 }
 
 /**
- * @ingroup SystemInit
- * This function will startup scheduler. It will select one thread
- * with the highest priority level, then switch to it.
+ * @brief This function will startup the scheduler. It will select one thread
+ *        with the highest priority level, then switch to it.
  */
 void rt_system_scheduler_start(void)
 {
     register struct rt_thread *to_thread;
     rt_ubase_t highest_ready_priority;
 
-    to_thread = _get_highest_priority_thread(&highest_ready_priority);
+    to_thread = _scheduler_get_highest_priority_thread(&highest_ready_priority);
 
 #ifdef RT_USING_SMP
     to_thread->oncpu = rt_hw_cpu_id();
@@ -271,12 +273,13 @@ void rt_system_scheduler_start(void)
 
 #ifdef RT_USING_SMP
 /**
- * This function will handle IPI interrupt and do a scheduling in system;
+ * @brief This function will handle IPI interrupt and do a scheduling in system.
  *
- * @param vector, the number of IPI interrupt for system scheduling
- * @param param, use RT_NULL
+ * @param vector is the number of IPI interrupt for system scheduling.
  *
- * NOTE: this function should be invoke or register as ISR in BSP.
+ * @param param is not used, and can be set to RT_NULL.
+ *
+ * @note this function should be invoke or register as ISR in BSP.
  */
 void rt_scheduler_ipi_handler(int vector, void *param)
 {
@@ -284,9 +287,9 @@ void rt_scheduler_ipi_handler(int vector, void *param)
 }
 
 /**
- * This function will perform one scheduling. It will select one thread
- * with the highest priority level in global ready queue or local ready queue,
- * then switch to it.
+ * @brief This function will perform one scheduling. It will select one thread
+ *        with the highest priority level in global ready queue or local ready queue,
+ *        then switch to it.
  */
 void rt_schedule(void)
 {
@@ -329,7 +332,7 @@ void rt_schedule(void)
 
         if (rt_thread_ready_priority_group != 0 || pcpu->priority_group != 0)
         {
-            to_thread = _get_highest_priority_thread(&highest_ready_priority);
+            to_thread = _scheduler_get_highest_priority_thread(&highest_ready_priority);
             current_thread->oncpu = RT_CPU_DETACHED;
             if ((current_thread->stat & RT_THREAD_STAT_MASK) == RT_THREAD_RUNNING)
             {
@@ -407,8 +410,8 @@ __exit:
 }
 #else
 /**
- * This function will perform one schedule. It will select one thread
- * with the highest priority level, and switch to it immediately.
+ * @brief This function will perform scheduling once. It will select one thread
+ *        with the highest priority, and switch to it immediately.
  */
 void rt_schedule(void)
 {
@@ -429,7 +432,7 @@ void rt_schedule(void)
             /* need_insert_from_thread: need to insert from_thread to ready queue */
             int need_insert_from_thread = 0;
 
-            to_thread = _get_highest_priority_thread(&highest_ready_priority);
+            to_thread = _scheduler_get_highest_priority_thread(&highest_ready_priority);
 
             if ((rt_current_thread->stat & RT_THREAD_STAT_MASK) == RT_THREAD_RUNNING)
             {
@@ -536,9 +539,9 @@ __exit:
 #endif /* RT_USING_SMP */
 
 /**
- * This function checks if a scheduling is needed after IRQ context. If yes,
- * it will select one thread with the highest priority level, and then switch
- * to it.
+ * @brief This function checks whether a scheduling is needed after an IRQ context switching. If yes,
+ *        it will select one thread with the highest priority level, and then switch
+ *        to it.
  */
 #ifdef RT_USING_SMP
 void rt_scheduler_do_irq_switch(void *context)
@@ -582,7 +585,7 @@ void rt_scheduler_do_irq_switch(void *context)
 
         if (rt_thread_ready_priority_group != 0 || pcpu->priority_group != 0)
         {
-            to_thread = _get_highest_priority_thread(&highest_ready_priority);
+            to_thread = _scheduler_get_highest_priority_thread(&highest_ready_priority);
             current_thread->oncpu = RT_CPU_DETACHED;
             if ((current_thread->stat & RT_THREAD_STAT_MASK) == RT_THREAD_RUNNING)
             {
@@ -631,12 +634,13 @@ void rt_scheduler_do_irq_switch(void *context)
 }
 #endif /* RT_USING_SMP */
 
-/*
- * This function will insert a thread to system ready queue. The state of
- * thread will be set as READY and remove from suspend queue.
+/**
+ * @brief This function will insert a thread to the system ready queue. The state of
+ *        thread will be set as READY and the thread will be removed from suspend queue.
+ *
+ * @param thread is the thread to be inserted.
  *
- * @param thread the thread to be inserted
- * @note Please do not invoke this function in user application.
+ * @note  Please do not invoke this function in user application.
  */
 #ifdef RT_USING_SMP
 void rt_schedule_insert_thread(struct rt_thread *thread)
@@ -741,12 +745,12 @@ __exit:
 }
 #endif /* RT_USING_SMP */
 
-/*
- * This function will remove a thread from system ready queue.
+/**
+ * @brief This function will remove a thread from system ready queue.
  *
- * @param thread the thread to be removed
+ * @param thread is the thread to be removed.
  *
- * @note Please do not invoke this function in user application.
+ * @note  Please do not invoke this function in user application.
  */
 #ifdef RT_USING_SMP
 void rt_schedule_remove_thread(struct rt_thread *thread)
@@ -835,7 +839,7 @@ void rt_schedule_remove_thread(struct rt_thread *thread)
 #endif /* RT_USING_SMP */
 
 /**
- * This function will lock the thread scheduler.
+ * @brief This function will lock the thread scheduler.
  */
 #ifdef RT_USING_SMP
 void rt_enter_critical(void)
@@ -897,7 +901,7 @@ void rt_enter_critical(void)
 RTM_EXPORT(rt_enter_critical);
 
 /**
- * This function will unlock the thread scheduler.
+ * @brief This function will unlock the thread scheduler.
  */
 #ifdef RT_USING_SMP
 void rt_exit_critical(void)
@@ -971,7 +975,7 @@ void rt_exit_critical(void)
 RTM_EXPORT(rt_exit_critical);
 
 /**
- * Get the scheduler lock level
+ * @brief Get the scheduler lock level.
  *
  * @return the level of the scheduler lock. 0 means unlocked.
  */
diff --git a/src/signal.c b/src/signal.c
index bb7706d9ef..14201ee948 100644
--- a/src/signal.c
+++ b/src/signal.c
@@ -35,7 +35,7 @@ struct siginfo_node
     struct rt_slist_node list;
 };
 
-static struct rt_mempool *_rt_siginfo_pool;
+static struct rt_mempool *_siginfo_pool;
 static void _signal_deliver(rt_thread_t tid);
 void rt_thread_handle_sig(rt_bool_t clean_state);
 
@@ -206,6 +206,22 @@ void *rt_signal_check(void* context)
 }
 #endif /* RT_USING_SMP */
 
+/**
+ * @brief    This function will install a processing function to a specific
+ *           signal and return the old processing function of this signal.
+ *
+ * @note     This function needs to be used in conjunction with the
+ *           rt_signal_unmask() function to make the signal effective.
+ *
+ * @see      rt_signal_unmask()
+ *
+ * @param    signo is a specific signal value (range: 0 ~ RT_SIG_MAX).
+ *
+ * @param    handler is sets the processing of signal value.
+ *
+ * @return   Return the old processing function of this signal. ONLY When the
+ *           return value is SIG_ERR, the operation is failed.
+ */
 rt_sighandler_t rt_signal_install(int signo, rt_sighandler_t handler)
 {
     rt_base_t level;
@@ -233,6 +249,17 @@ rt_sighandler_t rt_signal_install(int signo, rt_sighandler_t handler)
     return old;
 }
 
+/**
+ * @brief    This function will block the specified signal.
+ *
+ * @note     This function will block the specified signal, even if the
+ *           rt_thread_kill() function is called to send this signal to
+ *           the current thread, it will no longer take effect.
+ *
+ * @see      rt_thread_kill()
+ *
+ * @param    signo is a specific signal value (range: 0 ~ RT_SIG_MAX).
+ */
 void rt_signal_mask(int signo)
 {
     rt_base_t level;
@@ -245,6 +272,17 @@ void rt_signal_mask(int signo)
     rt_hw_interrupt_enable(level);
 }
 
+/**
+ * @brief    This function will unblock the specified signal.
+ *
+ * @note     This function will unblock the specified signal. After calling
+ *           the rt_thread_kill() function to send this signal to the current
+ *           thread, it will take effect.
+ *
+ * @see      rt_thread_kill()
+ *
+ * @param    signo is a specific signal value (range: 0 ~ RT_SIG_MAX).
+ */
 void rt_signal_unmask(int signo)
 {
     rt_base_t level;
@@ -266,6 +304,20 @@ void rt_signal_unmask(int signo)
     }
 }
 
+/**
+ * @brief    This function will wait for the arrival of the set signal. If it does not wait for this signal, the thread will be
+ *           suspended until it waits for this signal or the waiting time exceeds the specified timeout: timeout.
+ *
+ * @param    set is the set of signal values to be waited for. Use the function
+ *           sigaddset() to add the signal.
+ *
+ * @param    si is a pointer to the received signal info. If you don't care about this value, you can use RT_NULL to set.
+ *
+ * @param    timeout is a timeout period (unit: an OS tick).
+ *
+ * @return   Return the operation status. When the return value is RT_EOK, the operation is successful.
+ *           If the return value is any other values, it means that the signal wait failed.
+ */
 int rt_signal_wait(const rt_sigset_t *set, rt_siginfo_t *si, rt_int32_t timeout)
 {
     int ret = RT_EOK;
@@ -497,6 +549,16 @@ void rt_thread_free_sig(rt_thread_t tid)
     }
 }
 
+/**
+ * @brief    This function can be used to send any signal to any thread.
+ *
+ * @param    tid is a pointer to the thread that receives the signal.
+ *
+ * @param    sig is a specific signal value (range: 0 ~ RT_SIG_MAX).
+ *
+ * @return   Return the operation status. When the return value is RT_EOK, the operation is successful.
+ *           If the return value is any other values, it means that the signal send failed.
+ */
 int rt_thread_kill(rt_thread_t tid, int sig)
 {
     siginfo_t si;
@@ -538,7 +600,7 @@ int rt_thread_kill(rt_thread_t tid, int sig)
     }
     rt_hw_interrupt_enable(level);
 
-    si_node = (struct siginfo_node *) rt_mp_alloc(_rt_siginfo_pool, 0);
+    si_node = (struct siginfo_node *) rt_mp_alloc(_siginfo_pool, 0);
     if (si_node)
     {
         rt_slist_init(&(si_node->list));
@@ -576,8 +638,8 @@ int rt_thread_kill(rt_thread_t tid, int sig)
 
 int rt_system_signal_init(void)
 {
-    _rt_siginfo_pool = rt_mp_create("signal", RT_SIG_INFO_MAX, sizeof(struct siginfo_node));
-    if (_rt_siginfo_pool == RT_NULL)
+    _siginfo_pool = rt_mp_create("signal", RT_SIG_INFO_MAX, sizeof(struct siginfo_node));
+    if (_siginfo_pool == RT_NULL)
     {
         LOG_E("create memory pool for signal info failed.");
         RT_ASSERT(0);
diff --git a/src/slab.c b/src/slab.c
index ad1dc71811..8e0ce7bc83 100644
--- a/src/slab.c
+++ b/src/slab.c
@@ -74,10 +74,10 @@ static void (*rt_free_hook)(void *ptr);
 /**@{*/
 
 /**
- * This function will set a hook function, which will be invoked when a memory
- * block is allocated from heap memory.
+ * @brief This function will set a hook function, which will be invoked when a memory
+ *        block is allocated from heap memory.
  *
- * @param hook the hook function
+ * @param hook the hook function.
  */
 void rt_malloc_sethook(void (*hook)(void *ptr, rt_size_t size))
 {
@@ -86,8 +86,8 @@ void rt_malloc_sethook(void (*hook)(void *ptr, rt_size_t size))
 RTM_EXPORT(rt_malloc_sethook);
 
 /**
- * This function will set a hook function, which will be invoked when a memory
- * block is released to heap memory.
+ * @brief This function will set a hook function, which will be invoked when a memory
+ *        block is released to heap memory.
  *
  * @param hook the hook function
  */
@@ -233,6 +233,11 @@ struct rt_page_head
 static struct rt_page_head *rt_page_list;
 static struct rt_semaphore heap_sem;
 
+/**
+ * @brief Alloc memory size by page.
+ *
+ * @param npages the number of pages.
+ */
 void *rt_page_alloc(rt_size_t npages)
 {
     struct rt_page_head *b, *n;
@@ -269,6 +274,13 @@ void *rt_page_alloc(rt_size_t npages)
     return b;
 }
 
+/**
+ * @brief Free memory by page.
+ *
+ * @param addr is the head address of first page.
+ *
+ * @param npages is the number of pages.
+ */
 void rt_page_free(void *addr, rt_size_t npages)
 {
     struct rt_page_head *b, *n;
@@ -334,12 +346,11 @@ static void rt_page_init(void *addr, rt_size_t npages)
 }
 
 /**
- * @ingroup SystemInit
+ * @brief This function will init system heap.
  *
- * This function will init system heap
+ * @param begin_addr the beginning address of system page.
  *
- * @param begin_addr the beginning address of system page
- * @param end_addr the end address of system page
+ * @param end_addr the end address of system page.
  */
 void rt_system_heap_init(void *begin_addr, void *end_addr)
 {
@@ -465,15 +476,15 @@ rt_inline int zoneindex(rt_size_t *bytes)
 /**@{*/
 
 /**
- * This function will allocate a block from system heap memory.
- * - If the nbytes is less than zero,
- * or
- * - If there is no nbytes sized memory valid in system,
- * the RT_NULL is returned.
+ * @brief This function will allocate a block from system heap memory.
+ *
+ * @note the RT_NULL is returned if
+ *         - the nbytes is less than zero.
+ *         - there is no nbytes sized memory valid in system.
  *
- * @param size the size of memory to be allocated
+ * @param size is the size of memory to be allocated.
  *
- * @return the allocated memory
+ * @return the allocated memory.
  */
 void *rt_malloc(rt_size_t size)
 {
@@ -668,12 +679,13 @@ __exit:
 RTM_EXPORT(rt_malloc);
 
 /**
- * This function will change the size of previously allocated memory block.
+ * @brief This function will change the size of previously allocated memory block.
+ *
+ * @param ptr is the previously allocated memory block.
  *
- * @param ptr the previously allocated memory block
- * @param size the new size of memory block
+ * @param size is the new size of memory block.
  *
- * @return the allocated memory
+ * @return the allocated memory.
  */
 void *rt_realloc(void *ptr, rt_size_t size)
 {
@@ -736,16 +748,17 @@ void *rt_realloc(void *ptr, rt_size_t size)
 RTM_EXPORT(rt_realloc);
 
 /**
- * This function will contiguously allocate enough space for count objects
- * that are size bytes of memory each and returns a pointer to the allocated
- * memory.
+ * @brief This function will contiguously allocate enough space for count objects
+ *        that are size bytes of memory each and returns a pointer to the allocated
+ *        memory.
  *
- * The allocated memory is filled with bytes of value zero.
+ * @note The allocated memory is filled with bytes of value zero.
  *
- * @param count number of objects to allocate
- * @param size size of the objects to allocate
+ * @param count is the number of objects to allocate.
  *
- * @return pointer to allocated memory / NULL pointer if there is an error
+ * @param size is the size of the objects to allocate.
+ *
+ * @return pointer to allocated memory / NULL pointer if there is an error.
  */
 void *rt_calloc(rt_size_t count, rt_size_t size)
 {
@@ -763,10 +776,11 @@ void *rt_calloc(rt_size_t count, rt_size_t size)
 RTM_EXPORT(rt_calloc);
 
 /**
- * This function will release the previous allocated memory block by rt_malloc.
- * The released memory block is taken back to system heap.
+ * @brief This function will release the previous allocated memory block by rt_malloc.
+ *
+ * @note The released memory block is taken back to system heap.
  *
- * @param ptr the address of memory which will be released
+ * @param ptr is the address of memory which will be released
  */
 void rt_free(void *ptr)
 {
@@ -905,6 +919,16 @@ void rt_free(void *ptr)
 RTM_EXPORT(rt_free);
 
 #ifdef RT_MEM_STATS
+/**
+* @brief This function will caculate the total memory, the used memory, and
+*        the max used memory.
+*
+* @param total is a pointer to get the total size of the memory.
+*
+* @param used is a pointer to get the size of memory used.
+*
+* @param max_used is a pointer to get the maximum memory used.
+*/
 void rt_memory_info(rt_uint32_t *total,
                     rt_uint32_t *used,
                     rt_uint32_t *max_used)
diff --git a/src/thread.c b/src/thread.c
index 60e6ab91d1..ab5264053e 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -38,12 +38,11 @@ static void (*rt_thread_resume_hook) (rt_thread_t thread);
 static void (*rt_thread_inited_hook) (rt_thread_t thread);
 
 /**
- * @ingroup Hook
- * This function sets a hook function when the system suspend a thread.
+ * @brief   This function sets a hook function when the system suspend a thread.
  *
- * @param hook the specified hook function
+ * @note    The hook function must be simple and never be blocked or suspend.
  *
- * @note the hook function must be simple and never be blocked or suspend.
+ * @param   hook is the specified hook function.
  */
 void rt_thread_suspend_sethook(void (*hook)(rt_thread_t thread))
 {
@@ -51,12 +50,11 @@ void rt_thread_suspend_sethook(void (*hook)(rt_thread_t thread))
 }
 
 /**
- * @ingroup Hook
- * This function sets a hook function when the system resume a thread.
+ * @brief   This function sets a hook function when the system resume a thread.
  *
- * @param hook the specified hook function
+ * @note    The hook function must be simple and never be blocked or suspend.
  *
- * @note the hook function must be simple and never be blocked or suspend.
+ * @param   hook is the specified hook function.
  */
 void rt_thread_resume_sethook(void (*hook)(rt_thread_t thread))
 {
@@ -64,10 +62,9 @@ void rt_thread_resume_sethook(void (*hook)(rt_thread_t thread))
 }
 
 /**
- * @ingroup Hook
- * This function sets a hook function when a thread is initialized.
+ * @brief   This function sets a hook function when a thread is initialized.
  *
- * @param hook the specified hook function
+ * @param   hook is the specified hook function.
  */
 void rt_thread_inited_sethook(void (*hook)(rt_thread_t thread))
 {
@@ -76,8 +73,7 @@ void rt_thread_inited_sethook(void (*hook)(rt_thread_t thread))
 
 #endif /* RT_USING_HOOK */
 
-/* must be invoke witch rt_hw_interrupt_disable */
-static void _rt_thread_cleanup_execute(rt_thread_t thread)
+static void _thread_cleanup_execute(rt_thread_t thread)
 {
     register rt_base_t level;
 #ifdef RT_USING_MODULE
@@ -101,7 +97,7 @@ static void _rt_thread_cleanup_execute(rt_thread_t thread)
     rt_hw_interrupt_enable(level);
 }
 
-static void _rt_thread_exit(void)
+static void _thread_exit(void)
 {
     struct rt_thread *thread;
     register rt_base_t level;
@@ -112,7 +108,7 @@ static void _rt_thread_exit(void)
     /* disable interrupt */
     level = rt_hw_interrupt_disable();
 
-    _rt_thread_cleanup_execute(thread);
+    _thread_cleanup_execute(thread);
 
     /* remove from schedule */
     rt_schedule_remove_thread(thread);
@@ -139,14 +135,14 @@ static void _rt_thread_exit(void)
     rt_hw_interrupt_enable(level);
 }
 
-static rt_err_t _rt_thread_init(struct rt_thread *thread,
-                                const char       *name,
-                                void (*entry)(void *parameter),
-                                void             *parameter,
-                                void             *stack_start,
-                                rt_uint32_t       stack_size,
-                                rt_uint8_t        priority,
-                                rt_uint32_t       tick)
+static rt_err_t _thread_init(struct rt_thread *thread,
+                             const char       *name,
+                             void (*entry)(void *parameter),
+                             void             *parameter,
+                             void             *stack_start,
+                             rt_uint32_t       stack_size,
+                             rt_uint8_t        priority,
+                             rt_uint32_t       tick)
 {
     /* init thread list */
     rt_list_init(&(thread->tlist));
@@ -163,11 +159,11 @@ static rt_err_t _rt_thread_init(struct rt_thread *thread,
 #ifdef ARCH_CPU_STACK_GROWS_UPWARD
     thread->sp = (void *)rt_hw_stack_init(thread->entry, thread->parameter,
                                           (void *)((char *)thread->stack_addr),
-                                          (void *)_rt_thread_exit);
+                                          (void *)_thread_exit);
 #else
     thread->sp = (void *)rt_hw_stack_init(thread->entry, thread->parameter,
                                           (rt_uint8_t *)((char *)thread->stack_addr + thread->stack_size - sizeof(rt_ubase_t)),
-                                          (void *)_rt_thread_exit);
+                                          (void *)_thread_exit);
 #endif /* ARCH_CPU_STACK_GROWS_UPWARD */
 
     /* priority init */
@@ -244,19 +240,27 @@ static rt_err_t _rt_thread_init(struct rt_thread *thread,
 /**@{*/
 
 /**
- * This function will initialize a thread, normally it's used to initialize a
- * static thread object.
+ * @brief   This function will initialize a thread. It's used to initialize a
+ *          static thread object.
+ *
+ * @param   thread is the static thread object.
+ *
+ * @param   name is the name of thread, which shall be unique.
+ *
+ * @param   entry is the entry function of thread.
+ *
+ * @param   parameter is the parameter of thread enter function.
+ *
+ * @param   stack_start is the start address of thread stack.
  *
- * @param thread the static thread object
- * @param name the name of thread, which shall be unique
- * @param entry the entry function of thread
- * @param parameter the parameter of thread enter function
- * @param stack_start the start address of thread stack
- * @param stack_size the size of thread stack
- * @param priority the priority of thread
- * @param tick the time slice if there are same priority thread
+ * @param   stack_size is the size of thread stack.
  *
- * @return the operation status, RT_EOK on OK, -RT_ERROR on error
+ * @param   priority is the priority of thread.
+ *
+ * @param   tick is the time slice if there are same priority thread.
+ *
+ * @return  Return the operation status. If the return value is RT_EOK, the function is successfully executed.
+ *          If the return value is any other values, it means this operation failed.
  */
 rt_err_t rt_thread_init(struct rt_thread *thread,
                         const char       *name,
@@ -274,21 +278,21 @@ rt_err_t rt_thread_init(struct rt_thread *thread,
     /* initialize thread object */
     rt_object_init((rt_object_t)thread, RT_Object_Class_Thread, name);
 
-    return _rt_thread_init(thread,
-                           name,
-                           entry,
-                           parameter,
-                           stack_start,
-                           stack_size,
-                           priority,
-                           tick);
+    return _thread_init(thread,
+                        name,
+                        entry,
+                        parameter,
+                        stack_start,
+                        stack_size,
+                        priority,
+                        tick);
 }
 RTM_EXPORT(rt_thread_init);
 
 /**
- * This function will return self thread object
+ * @brief   This function will return self thread object.
  *
- * @return the self thread object
+ * @return  The self thread object.
  */
 rt_thread_t rt_thread_self(void)
 {
@@ -309,11 +313,12 @@ rt_thread_t rt_thread_self(void)
 RTM_EXPORT(rt_thread_self);
 
 /**
- * This function will start a thread and put it to system ready queue
+ * @brief   This function will start a thread and put it to system ready queue.
  *
- * @param thread the thread to be started
+ * @param   thread is the thread to be started.
  *
- * @return the operation status, RT_EOK on OK, -RT_ERROR on error
+ * @return  Return the operation status. If the return value is RT_EOK, the function is successfully executed.
+ *          If the return value is any other values, it means this operation failed.
  */
 rt_err_t rt_thread_startup(rt_thread_t thread)
 {
@@ -351,12 +356,13 @@ rt_err_t rt_thread_startup(rt_thread_t thread)
 RTM_EXPORT(rt_thread_startup);
 
 /**
- * This function will detach a thread. The thread object will be removed from
- * thread queue and detached/deleted from system object management.
+ * @brief   This function will detach a thread. The thread object will be removed from
+ *          thread queue and detached/deleted from the system object management.
  *
- * @param thread the thread to be deleted
+ * @param   thread is the thread to be deleted.
  *
- * @return the operation status, RT_EOK on OK, -RT_ERROR on error
+ * @return  Return the operation status. If the return value is RT_EOK, the function is successfully executed.
+ *          If the return value is any other values, it means this operation failed.
  */
 rt_err_t rt_thread_detach(rt_thread_t thread)
 {
@@ -376,7 +382,7 @@ rt_err_t rt_thread_detach(rt_thread_t thread)
         rt_schedule_remove_thread(thread);
     }
 
-    _rt_thread_cleanup_execute(thread);
+    _thread_cleanup_execute(thread);
 
     /* release thread timer */
     rt_timer_detach(&(thread->thread_timer));
@@ -404,17 +410,23 @@ RTM_EXPORT(rt_thread_detach);
 
 #ifdef RT_USING_HEAP
 /**
- * This function will create a thread object and allocate thread object memory
- * and stack.
+ * @brief   This function will create a thread object and allocate thread object memory.
+ *          and stack.
+ *
+ * @param   name is the name of thread, which shall be unique.
+ *
+ * @param   entry is the entry function of thread.
+ *
+ * @param   parameter is the parameter of thread enter function.
  *
- * @param name the name of thread, which shall be unique
- * @param entry the entry function of thread
- * @param parameter the parameter of thread enter function
- * @param stack_size the size of thread stack
- * @param priority the priority of thread
- * @param tick the time slice if there are same priority thread
+ * @param   stack_size is the size of thread stack.
  *
- * @return the created thread object
+ * @param   priority is the priority of thread.
+ *
+ * @param   tick is the time slice if there are same priority thread.
+ *
+ * @return  If the return value is a rt_thread structure pointer, the function is successfully executed.
+ *          If the return value is RT_NULL, it means this operation failed.
  */
 rt_thread_t rt_thread_create(const char *name,
                              void (*entry)(void *parameter),
@@ -440,7 +452,7 @@ rt_thread_t rt_thread_create(const char *name,
         return RT_NULL;
     }
 
-    _rt_thread_init(thread,
+    _thread_init(thread,
                     name,
                     entry,
                     parameter,
@@ -454,12 +466,13 @@ rt_thread_t rt_thread_create(const char *name,
 RTM_EXPORT(rt_thread_create);
 
 /**
- * This function will delete a thread. The thread object will be removed from
- * thread queue and deleted from system object management in the idle thread.
+ * @brief   This function will delete a thread. The thread object will be removed from
+ *          thread queue and deleted from system object management in the idle thread.
  *
- * @param thread the thread to be deleted
+ * @param   thread is the thread to be deleted.
  *
- * @return the operation status, RT_EOK on OK, -RT_ERROR on error
+ * @return  Return the operation status. If the return value is RT_EOK, the function is successfully executed.
+ *          If the return value is any other values, it means this operation failed.
  */
 rt_err_t rt_thread_delete(rt_thread_t thread)
 {
@@ -479,7 +492,7 @@ rt_err_t rt_thread_delete(rt_thread_t thread)
         rt_schedule_remove_thread(thread);
     }
 
-    _rt_thread_cleanup_execute(thread);
+    _thread_cleanup_execute(thread);
 
     /* release thread timer */
     rt_timer_detach(&(thread->thread_timer));
@@ -502,11 +515,12 @@ RTM_EXPORT(rt_thread_delete);
 #endif /* RT_USING_HEAP */
 
 /**
- * This function will let current thread yield processor, and scheduler will
- * choose a highest thread to run. After yield processor, the current thread
- * is still in READY state.
+ * @brief   This function will let current thread yield processor, and scheduler will
+ *          choose the highest thread to run. After yield processor, the current thread
+ *          is still in READY state.
  *
- * @return RT_EOK
+ * @return  Return the operation status. If the return value is RT_EOK, the function is successfully executed.
+ *          If the return value is any other values, it means this operation failed.
  */
 rt_err_t rt_thread_yield(void)
 {
@@ -525,11 +539,13 @@ rt_err_t rt_thread_yield(void)
 RTM_EXPORT(rt_thread_yield);
 
 /**
- * This function will let current thread sleep for some ticks.
+ * @brief   This function will let current thread sleep for some ticks. Change current thread state to suspend,
+ *          when the thread timer reaches the tick value, scheduler will awaken this thread.
  *
- * @param tick the sleep ticks
+ * @param   tick is the sleep ticks.
  *
- * @return RT_EOK
+ * @return  Return the operation status. If the return value is RT_EOK, the function is successfully executed.
+ *          If the return value is any other values, it means this operation failed.
  */
 rt_err_t rt_thread_sleep(rt_tick_t tick)
 {
@@ -564,11 +580,12 @@ rt_err_t rt_thread_sleep(rt_tick_t tick)
 }
 
 /**
- * This function will let current thread delay for some ticks.
+ * @brief   This function will let current thread delay for some ticks.
  *
- * @param tick the delay ticks
+ * @param   tick is the delay ticks.
  *
- * @return RT_EOK
+ * @return  Return the operation status. If the return value is RT_EOK, the function is successfully executed.
+ *          If the return value is any other values, it means this operation failed.
  */
 rt_err_t rt_thread_delay(rt_tick_t tick)
 {
@@ -577,12 +594,14 @@ rt_err_t rt_thread_delay(rt_tick_t tick)
 RTM_EXPORT(rt_thread_delay);
 
 /**
- * This function will let current thread delay until (*tick + inc_tick).
+ * @brief   This function will let current thread delay until (*tick + inc_tick).
+ *
+ * @param   tick is the tick of last wakeup.
  *
- * @param tick the tick of last wakeup.
- * @param inc_tick the increment tick
+ * @param   inc_tick is the increment tick.
  *
- * @return RT_EOK
+ * @return  Return the operation status. If the return value is RT_EOK, the function is successfully executed.
+ *          If the return value is any other values, it means this operation failed.
  */
 rt_err_t rt_thread_delay_until(rt_tick_t *tick, rt_tick_t inc_tick)
 {
@@ -637,11 +656,12 @@ rt_err_t rt_thread_delay_until(rt_tick_t *tick, rt_tick_t inc_tick)
 RTM_EXPORT(rt_thread_delay_until);
 
 /**
- * This function will let current thread delay for some milliseconds.
+ * @brief   This function will let current thread delay for some milliseconds.
  *
- * @param ms the delay ms time
+ * @param   ms is the delay ms time.
  *
- * @return RT_EOK
+ * @return  Return the operation status. If the return value is RT_EOK, the function is successfully executed.
+ *          If the return value is any other values, it means this operation failed.
  */
 rt_err_t rt_thread_mdelay(rt_int32_t ms)
 {
@@ -654,17 +674,24 @@ rt_err_t rt_thread_mdelay(rt_int32_t ms)
 RTM_EXPORT(rt_thread_mdelay);
 
 /**
- * This function will control thread behaviors according to control command.
+ * @brief   This function will control thread behaviors according to control command.
+ *
+ * @param   thread is the specified thread to be controlled.
+ *
+ * @param   cmd is the control command, which includes.
  *
- * @param thread the specified thread to be controlled
- * @param cmd the control command, which includes
- *  RT_THREAD_CTRL_CHANGE_PRIORITY for changing priority level of thread;
- *  RT_THREAD_CTRL_STARTUP for starting a thread;
- *  RT_THREAD_CTRL_CLOSE for delete a thread;
- *  RT_THREAD_CTRL_BIND_CPU for bind the thread to a CPU.
- * @param arg the argument of control command
+ *              RT_THREAD_CTRL_CHANGE_PRIORITY for changing priority level of thread.
  *
- * @return RT_EOK
+ *              RT_THREAD_CTRL_STARTUP for starting a thread.
+ *
+ *              RT_THREAD_CTRL_CLOSE for delete a thread.
+ *
+ *              RT_THREAD_CTRL_BIND_CPU for bind the thread to a CPU.
+ *
+ * @param   arg is the argument of control command.
+ *
+ * @return  Return the operation status. If the return value is RT_EOK, the function is successfully executed.
+ *          If the return value is any other values, it means this operation failed.
  */
 rt_err_t rt_thread_control(rt_thread_t thread, int cmd, void *arg)
 {
@@ -755,7 +782,7 @@ rt_err_t rt_thread_control(rt_thread_t thread, int cmd, void *arg)
                 return RT_ERROR;
             }
 
-            cpu = (rt_uint8_t)(size_t)arg;
+            cpu = (rt_uint8_t)(rt_size_t)arg;
             thread->bind_cpu = cpu > RT_CPUS_NR? RT_CPUS_NR : cpu;
             break;
         }
@@ -770,14 +797,15 @@ rt_err_t rt_thread_control(rt_thread_t thread, int cmd, void *arg)
 RTM_EXPORT(rt_thread_control);
 
 /**
- * This function will suspend the specified thread.
+ * @brief   This function will suspend the specified thread and change it to suspend state.
  *
- * @param thread the thread to be suspended
+ * @note    If suspend self thread, after this function call, the
+ *          rt_schedule() must be invoked.
  *
- * @return the operation status, RT_EOK on OK, -RT_ERROR on error
+ * @param   thread is the thread to be suspended.
  *
- * @note if suspend self thread, after this function call, the
- * rt_schedule() must be invoked.
+ * @return  Return the operation status. If the return value is RT_EOK, the function is successfully executed.
+ *          If the return value is any other values, it means this operation failed.
  */
 rt_err_t rt_thread_suspend(rt_thread_t thread)
 {
@@ -822,11 +850,12 @@ rt_err_t rt_thread_suspend(rt_thread_t thread)
 RTM_EXPORT(rt_thread_suspend);
 
 /**
- * This function will resume a thread and put it to system ready queue.
+ * @brief   This function will resume a thread and put it to system ready queue.
  *
- * @param thread the thread to be resumed
+ * @param   thread is the thread to be resumed.
  *
- * @return the operation status, RT_EOK on OK, -RT_ERROR on error
+ * @return  Return the operation status. If the return value is RT_EOK, the function is successfully executed.
+ *          If the return value is any other values, it means this operation failed.
  */
 rt_err_t rt_thread_resume(rt_thread_t thread)
 {
@@ -866,10 +895,10 @@ rt_err_t rt_thread_resume(rt_thread_t thread)
 RTM_EXPORT(rt_thread_resume);
 
 /**
- * This function is the timeout function for thread, normally which is invoked
- * when thread is timeout to wait some resource.
+ * @brief   This function is the timeout function for thread, normally which is invoked
+ *          when thread is timeout to wait some resource.
  *
- * @param parameter the parameter of thread timeout function
+ * @param   parameter is the parameter of thread timeout function
  */
 void rt_thread_timeout(void *parameter)
 {
@@ -904,18 +933,20 @@ void rt_thread_timeout(void *parameter)
 RTM_EXPORT(rt_thread_timeout);
 
 /**
- * This function will find the specified thread.
+ * @brief   This function will find the specified thread.
  *
- * @param name the name of thread finding
+ * @note    Please don't invoke this function in interrupt status.
  *
- * @return the found thread
+ * @param   name is the name of thread finding.
  *
- * @note please don't invoke this function in interrupt status.
+ * @return  If the return value is a rt_thread structure pointer, the function is successfully executed.
+ *          If the return value is RT_NULL, it means this operation failed.
  */
 rt_thread_t rt_thread_find(char *name)
 {
     return (rt_thread_t)rt_object_find(name, RT_Object_Class_Thread);
 }
+
 RTM_EXPORT(rt_thread_find);
 
 /**@}*/
diff --git a/src/timer.c b/src/timer.c
index 1c8e70fccc..25ba175306 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -16,13 +16,14 @@
  * 2012-12-15     Bernard      fix the next timeout issue in soft timer
  * 2014-07-12     Bernard      does not lock scheduler when invoking soft-timer
  *                             timeout function.
+ * 2021-08-15     supperthomas add the comment
  */
 
 #include <rtthread.h>
 #include <rthw.h>
 
 /* hard timer list */
-static rt_list_t rt_timer_list[RT_TIMER_SKIP_LIST_LEVEL];
+static rt_list_t _timer_list[RT_TIMER_SKIP_LIST_LEVEL];
 
 #ifdef RT_USING_TIMER_SOFT
 
@@ -38,12 +39,12 @@ static rt_list_t rt_timer_list[RT_TIMER_SKIP_LIST_LEVEL];
 #endif /* RT_TIMER_THREAD_PRIO */
 
 /* soft timer status */
-static rt_uint8_t soft_timer_status = RT_SOFT_TIMER_IDLE;
+static rt_uint8_t _soft_timer_status = RT_SOFT_TIMER_IDLE;
 /* soft timer list */
-static rt_list_t rt_soft_timer_list[RT_TIMER_SKIP_LIST_LEVEL];
-static struct rt_thread timer_thread;
+static rt_list_t _soft_timer_list[RT_TIMER_SKIP_LIST_LEVEL];
+static struct rt_thread _timer_thread;
 ALIGN(RT_ALIGN_SIZE)
-static rt_uint8_t timer_thread_stack[RT_TIMER_THREAD_STACK_SIZE];
+static rt_uint8_t _timer_thread_stack[RT_TIMER_THREAD_STACK_SIZE];
 #endif /* RT_USING_TIMER_SOFT */
 
 #ifdef RT_USING_HOOK
@@ -59,10 +60,10 @@ static void (*rt_timer_exit_hook)(struct rt_timer *timer);
 /**@{*/
 
 /**
- * This function will set a hook function, which will be invoked when enter
- * timer timeout callback function.
+ * @brief This function will set a hook function on timer,
+ *        which will be invoked when enter timer timeout callback function.
  *
- * @param hook the hook function
+ * @param hook is the function point of timer
  */
 void rt_timer_enter_sethook(void (*hook)(struct rt_timer *timer))
 {
@@ -70,10 +71,10 @@ void rt_timer_enter_sethook(void (*hook)(struct rt_timer *timer))
 }
 
 /**
- * This function will set a hook function, which will be invoked when exit
- * timer timeout callback function.
+ * @brief This function will set a hook function, which will be
+ *        invoked when exit timer timeout callback function.
  *
- * @param hook the hook function
+ * @param hook is the function point of timer
  */
 void rt_timer_exit_sethook(void (*hook)(struct rt_timer *timer))
 {
@@ -83,7 +84,25 @@ void rt_timer_exit_sethook(void (*hook)(struct rt_timer *timer))
 /**@}*/
 #endif /* RT_USING_HOOK */
 
-static void _rt_timer_init(rt_timer_t timer,
+
+/**
+ * @brief [internal] The init funtion of timer
+ *
+ *        The internal called function of rt_timer_init
+ *
+ * @see rt_timer_init
+ *
+ * @param timer is timer object
+ *
+ * @param timeout is the timeout function
+ *
+ * @param parameter is the parameter of timeout function
+ *
+ * @param time is the tick of timer
+ *
+ * @param flag the flag of timer
+ */
+static void _timer_init(rt_timer_t timer,
                            void (*timeout)(void *parameter),
                            void      *parameter,
                            rt_tick_t  time,
@@ -110,8 +129,14 @@ static void _rt_timer_init(rt_timer_t timer,
     }
 }
 
-/* the fist timer always in the last row */
-static rt_tick_t rt_timer_list_next_timeout(rt_list_t timer_list[])
+/**
+ * @brief  Find the next emtpy timer ticks
+ *
+ * @param timer_list is the array of time list
+ *
+ * @return the next timer's ticks
+ */
+static rt_tick_t _timer_list_next_timeout(rt_list_t timer_list[])
 {
     struct rt_timer *timer;
     register rt_base_t level;
@@ -133,7 +158,12 @@ static rt_tick_t rt_timer_list_next_timeout(rt_list_t timer_list[])
     return timeout_tick;
 }
 
-rt_inline void _rt_timer_remove(rt_timer_t timer)
+/**
+ * @brief Remove the timer
+ *
+ * @param timer the point of the timer
+ */
+rt_inline void _timer_remove(rt_timer_t timer)
 {
     int i;
 
@@ -144,7 +174,14 @@ rt_inline void _rt_timer_remove(rt_timer_t timer)
 }
 
 #if RT_DEBUG_TIMER
-static int rt_timer_count_height(struct rt_timer *timer)
+/**
+ * @brief The number of timer
+ *
+ * @param timer the head of timer
+ *
+ * @return count of timer
+ */
+static int _timer_count_height(struct rt_timer *timer)
 {
     int i, cnt = 0;
 
@@ -155,7 +192,11 @@ static int rt_timer_count_height(struct rt_timer *timer)
     }
     return cnt;
 }
-
+/**
+ * @brief dump the all timer information
+ *
+ * @param timer_heads the head of timer
+ */
 void rt_timer_dump(rt_list_t timer_heads[])
 {
     rt_list_t *list;
@@ -167,7 +208,7 @@ void rt_timer_dump(rt_list_t timer_heads[])
         struct rt_timer *timer = rt_list_entry(list,
                                                struct rt_timer,
                                                row[RT_TIMER_SKIP_LIST_LEVEL - 1]);
-        rt_kprintf("%d", rt_timer_count_height(timer));
+        rt_kprintf("%d", _timer_count_height(timer));
     }
     rt_kprintf("\n");
 }
@@ -180,15 +221,20 @@ void rt_timer_dump(rt_list_t timer_heads[])
 /**@{*/
 
 /**
- * This function will initialize a timer, normally this function is used to
- * initialize a static timer object.
+ * @brief This function will initialize a timer
+ *        normally this function is used to initialize a static timer object.
  *
- * @param timer the static timer object
- * @param name the name of timer
- * @param timeout the timeout function
- * @param parameter the parameter of timeout function
- * @param time the tick of timer
- * @param flag the flag of timer
+ * @param timer is the point of timer
+ *
+ * @param name is a pointer to the name of the timer
+ *
+ * @param timeout is the callback of timer
+ *
+ * @param parameter is the param of the callback
+ *
+ * @param time is the ticks of timer
+ *
+ * @param flag is the flag of timer
  */
 void rt_timer_init(rt_timer_t  timer,
                    const char *name,
@@ -203,16 +249,16 @@ void rt_timer_init(rt_timer_t  timer,
     /* timer object initialization */
     rt_object_init(&(timer->parent), RT_Object_Class_Timer, name);
 
-    _rt_timer_init(timer, timeout, parameter, time, flag);
+    _timer_init(timer, timeout, parameter, time, flag);
 }
 RTM_EXPORT(rt_timer_init);
 
 /**
- * This function will detach a timer from timer management.
+ * @brief This function will detach a timer from timer management.
  *
- * @param timer the static timer object
+ * @param timer is the timer to be detached
  *
- * @return the operation status, RT_EOK on OK; RT_ERROR on error
+ * @return the status of detach
  */
 rt_err_t rt_timer_detach(rt_timer_t timer)
 {
@@ -226,7 +272,7 @@ rt_err_t rt_timer_detach(rt_timer_t timer)
     /* disable interrupt */
     level = rt_hw_interrupt_disable();
 
-    _rt_timer_remove(timer);
+    _timer_remove(timer);
     /* stop timer */
     timer->parent.flag &= ~RT_TIMER_FLAG_ACTIVATED;
 
@@ -241,12 +287,16 @@ RTM_EXPORT(rt_timer_detach);
 
 #ifdef RT_USING_HEAP
 /**
- * This function will create a timer
+ * @brief This function will create a timer
  *
  * @param name the name of timer
+ *
  * @param timeout the timeout function
+ *
  * @param parameter the parameter of timeout function
+ *
  * @param time the tick of timer
+ *
  * @param flag the flag of timer
  *
  * @return the created timer object
@@ -266,14 +316,14 @@ rt_timer_t rt_timer_create(const char *name,
         return RT_NULL;
     }
 
-    _rt_timer_init(timer, timeout, parameter, time, flag);
+    _timer_init(timer, timeout, parameter, time, flag);
 
     return timer;
 }
 RTM_EXPORT(rt_timer_create);
 
 /**
- * This function will delete a timer and release timer memory
+ * @brief This function will delete a timer and release timer memory
  *
  * @param timer the timer to be deleted
  *
@@ -291,7 +341,7 @@ rt_err_t rt_timer_delete(rt_timer_t timer)
     /* disable interrupt */
     level = rt_hw_interrupt_disable();
 
-    _rt_timer_remove(timer);
+    _timer_remove(timer);
     /* stop timer */
     timer->parent.flag &= ~RT_TIMER_FLAG_ACTIVATED;
 
@@ -306,7 +356,7 @@ RTM_EXPORT(rt_timer_delete);
 #endif /* RT_USING_HEAP */
 
 /**
- * This function will start the timer
+ * @brief This function will start the timer
  *
  * @param timer the timer to be started
  *
@@ -317,6 +367,7 @@ rt_err_t rt_timer_start(rt_timer_t timer)
     unsigned int row_lvl;
     rt_list_t *timer_list;
     register rt_base_t level;
+    register rt_bool_t need_schedule;
     rt_list_t *row_head[RT_TIMER_SKIP_LIST_LEVEL];
     unsigned int tst_nr;
     static unsigned int random_nr;
@@ -325,10 +376,12 @@ rt_err_t rt_timer_start(rt_timer_t timer)
     RT_ASSERT(timer != RT_NULL);
     RT_ASSERT(rt_object_get_type(&timer->parent) == RT_Object_Class_Timer);
 
+    need_schedule = RT_FALSE;
+
     /* stop timer firstly */
     level = rt_hw_interrupt_disable();
     /* remove timer from list */
-    _rt_timer_remove(timer);
+    _timer_remove(timer);
     /* change status of timer */
     timer->parent.flag &= ~RT_TIMER_FLAG_ACTIVATED;
 
@@ -345,13 +398,13 @@ rt_err_t rt_timer_start(rt_timer_t timer)
     if (timer->parent.flag & RT_TIMER_FLAG_SOFT_TIMER)
     {
         /* insert timer to soft timer list */
-        timer_list = rt_soft_timer_list;
+        timer_list = _soft_timer_list;
     }
     else
 #endif /* RT_USING_TIMER_SOFT */
     {
         /* insert timer to system timer list */
-        timer_list = rt_timer_list;
+        timer_list = _timer_list;
     }
 
     row_head[0]  = &timer_list[0];
@@ -407,29 +460,34 @@ rt_err_t rt_timer_start(rt_timer_t timer)
 
     timer->parent.flag |= RT_TIMER_FLAG_ACTIVATED;
 
-    /* enable interrupt */
-    rt_hw_interrupt_enable(level);
-
 #ifdef RT_USING_TIMER_SOFT
     if (timer->parent.flag & RT_TIMER_FLAG_SOFT_TIMER)
     {
         /* check whether timer thread is ready */
-        if ((soft_timer_status == RT_SOFT_TIMER_IDLE) &&
-           ((timer_thread.stat & RT_THREAD_STAT_MASK) == RT_THREAD_SUSPEND))
+        if ((_soft_timer_status == RT_SOFT_TIMER_IDLE) &&
+           ((_timer_thread.stat & RT_THREAD_STAT_MASK) == RT_THREAD_SUSPEND))
         {
             /* resume timer thread to check soft timer */
-            rt_thread_resume(&timer_thread);
-            rt_schedule();
+            rt_thread_resume(&_timer_thread);
+            need_schedule = RT_TRUE;
         }
     }
 #endif /* RT_USING_TIMER_SOFT */
 
+    /* enable interrupt */
+    rt_hw_interrupt_enable(level);
+
+    if (need_schedule)
+    {
+        rt_schedule();
+    }
+
     return RT_EOK;
 }
 RTM_EXPORT(rt_timer_start);
 
 /**
- * This function will stop the timer
+ * @brief This function will stop the timer
  *
  * @param timer the timer to be stopped
  *
@@ -451,7 +509,7 @@ rt_err_t rt_timer_stop(rt_timer_t timer)
     /* disable interrupt */
     level = rt_hw_interrupt_disable();
 
-    _rt_timer_remove(timer);
+    _timer_remove(timer);
     /* change status */
     timer->parent.flag &= ~RT_TIMER_FLAG_ACTIVATED;
 
@@ -463,13 +521,13 @@ rt_err_t rt_timer_stop(rt_timer_t timer)
 RTM_EXPORT(rt_timer_stop);
 
 /**
- * This function will get or set some options of the timer
+ * @brief This function will get or set some options of the timer
  *
  * @param timer the timer to be get or set
  * @param cmd the control command
  * @param arg the argument
  *
- * @return RT_EOK
+ * @return the statu of control
  */
 rt_err_t rt_timer_control(rt_timer_t timer, int cmd, void *arg)
 {
@@ -521,10 +579,10 @@ rt_err_t rt_timer_control(rt_timer_t timer, int cmd, void *arg)
 RTM_EXPORT(rt_timer_control);
 
 /**
- * This function will check timer list, if a timeout event happens, the
- * corresponding timeout function will be invoked.
+ * @brief This function will check timer list, if a timeout event happens,
+ *        the corresponding timeout function will be invoked.
  *
- * @note this function shall be invoked in operating system timer interrupt.
+ * @note This function shall be invoked in operating system timer interrupt.
  */
 void rt_timer_check(void)
 {
@@ -542,9 +600,9 @@ void rt_timer_check(void)
     /* disable interrupt */
     level = rt_hw_interrupt_disable();
 
-    while (!rt_list_isempty(&rt_timer_list[RT_TIMER_SKIP_LIST_LEVEL - 1]))
+    while (!rt_list_isempty(&_timer_list[RT_TIMER_SKIP_LIST_LEVEL - 1]))
     {
-        t = rt_list_entry(rt_timer_list[RT_TIMER_SKIP_LIST_LEVEL - 1].next,
+        t = rt_list_entry(_timer_list[RT_TIMER_SKIP_LIST_LEVEL - 1].next,
                           struct rt_timer, row[RT_TIMER_SKIP_LIST_LEVEL - 1]);
 
         /*
@@ -556,7 +614,7 @@ void rt_timer_check(void)
             RT_OBJECT_HOOK_CALL(rt_timer_enter_hook, (t));
 
             /* remove timer from timer list firstly */
-            _rt_timer_remove(t);
+            _timer_remove(t);
             if (!(t->parent.flag & RT_TIMER_FLAG_PERIODIC))
             {
                 t->parent.flag &= ~RT_TIMER_FLAG_ACTIVATED;
@@ -596,19 +654,19 @@ void rt_timer_check(void)
 }
 
 /**
- * This function will return the next timeout tick in the system.
+ * @brief This function will return the next timeout tick in the system.
  *
  * @return the next timeout tick in the system
  */
 rt_tick_t rt_timer_next_timeout_tick(void)
 {
-    return rt_timer_list_next_timeout(rt_timer_list);
+    return _timer_list_next_timeout(_timer_list);
 }
 
 #ifdef RT_USING_TIMER_SOFT
 /**
- * This function will check software-timer list, if a timeout event happens, the
- * corresponding timeout function will be invoked.
+ * @brief This function will check software-timer list, if a timeout event happens, the
+ *        corresponding timeout function will be invoked.
  */
 void rt_soft_timer_check(void)
 {
@@ -624,9 +682,9 @@ void rt_soft_timer_check(void)
     /* disable interrupt */
     level = rt_hw_interrupt_disable();
 
-    while (!rt_list_isempty(&rt_soft_timer_list[RT_TIMER_SKIP_LIST_LEVEL - 1]))
+    while (!rt_list_isempty(&_soft_timer_list[RT_TIMER_SKIP_LIST_LEVEL - 1]))
     {
-        t = rt_list_entry(rt_soft_timer_list[RT_TIMER_SKIP_LIST_LEVEL - 1].next,
+        t = rt_list_entry(_soft_timer_list[RT_TIMER_SKIP_LIST_LEVEL - 1].next,
                             struct rt_timer, row[RT_TIMER_SKIP_LIST_LEVEL - 1]);
 
         current_tick = rt_tick_get();
@@ -640,7 +698,7 @@ void rt_soft_timer_check(void)
             RT_OBJECT_HOOK_CALL(rt_timer_enter_hook, (t));
 
             /* remove timer from timer list firstly */
-            _rt_timer_remove(t);
+            _timer_remove(t);
             if (!(t->parent.flag & RT_TIMER_FLAG_PERIODIC))
             {
                 t->parent.flag &= ~RT_TIMER_FLAG_ACTIVATED;
@@ -648,7 +706,7 @@ void rt_soft_timer_check(void)
             /* add timer to temporary list  */
             rt_list_insert_after(&list, &(t->row[RT_TIMER_SKIP_LIST_LEVEL - 1]));
 
-            soft_timer_status = RT_SOFT_TIMER_BUSY;
+            _soft_timer_status = RT_SOFT_TIMER_BUSY;
             /* enable interrupt */
             rt_hw_interrupt_enable(level);
 
@@ -661,7 +719,7 @@ void rt_soft_timer_check(void)
             /* disable interrupt */
             level = rt_hw_interrupt_disable();
 
-            soft_timer_status = RT_SOFT_TIMER_IDLE;
+            _soft_timer_status = RT_SOFT_TIMER_IDLE;
             /* Check whether the timer object is detached or started again */
             if (rt_list_isempty(&list))
             {
@@ -684,15 +742,19 @@ void rt_soft_timer_check(void)
     RT_DEBUG_LOG(RT_DEBUG_TIMER, ("software timer check leave\n"));
 }
 
-/* system timer thread entry */
-static void rt_thread_timer_entry(void *parameter)
+/**
+ * @brief System timer thread entry
+ *
+ * @param parameter is the arg of the thread
+ */
+static void _timer_thread_entry(void *parameter)
 {
     rt_tick_t next_timeout;
 
     while (1)
     {
         /* get the next timeout tick */
-        next_timeout = rt_timer_list_next_timeout(rt_soft_timer_list);
+        next_timeout = _timer_list_next_timeout(_soft_timer_list);
         if (next_timeout == RT_TICK_MAX)
         {
             /* no software timer exist, suspend self. */
@@ -723,22 +785,22 @@ static void rt_thread_timer_entry(void *parameter)
 /**
  * @ingroup SystemInit
  *
- * This function will initialize system timer
+ * @brief This function will initialize system timer
  */
 void rt_system_timer_init(void)
 {
     int i;
 
-    for (i = 0; i < sizeof(rt_timer_list) / sizeof(rt_timer_list[0]); i++)
+    for (i = 0; i < sizeof(_timer_list) / sizeof(_timer_list[0]); i++)
     {
-        rt_list_init(rt_timer_list + i);
+        rt_list_init(_timer_list + i);
     }
 }
 
 /**
  * @ingroup SystemInit
  *
- * This function will initialize system timer thread
+ * @brief This function will initialize system timer thread
  */
 void rt_system_timer_thread_init(void)
 {
@@ -746,24 +808,24 @@ void rt_system_timer_thread_init(void)
     int i;
 
     for (i = 0;
-         i < sizeof(rt_soft_timer_list) / sizeof(rt_soft_timer_list[0]);
+         i < sizeof(_soft_timer_list) / sizeof(_soft_timer_list[0]);
          i++)
     {
-        rt_list_init(rt_soft_timer_list + i);
+        rt_list_init(_soft_timer_list + i);
     }
 
     /* start software timer thread */
-    rt_thread_init(&timer_thread,
+    rt_thread_init(&_timer_thread,
                    "timer",
-                   rt_thread_timer_entry,
+                   _timer_thread_entry,
                    RT_NULL,
-                   &timer_thread_stack[0],
-                   sizeof(timer_thread_stack),
+                   &_timer_thread_stack[0],
+                   sizeof(_timer_thread_stack),
                    RT_TIMER_THREAD_PRIO,
                    10);
 
     /* startup */
-    rt_thread_startup(&timer_thread);
+    rt_thread_startup(&_timer_thread);
 #endif /* RT_USING_TIMER_SOFT */
 }