arch.h

這是一個實時嵌入式作業系統 實作了MCS51 ARM等MCU

EXTERN void up_block_task(FAR _TCB *tcb, tstate_t task_state);

/****************************************************************************
 * Name: up_release_pending
 *
 * Description:
 *   When tasks become ready-to-run but cannot run because
 *   pre-emption is disabled, they are placed into a pending
 *   task list.  This function releases and makes ready-to-run
 *   all of the tasks that have collected in the pending task
 *   list.  This can cause a context switch if a new task is
 *   placed at the head of the ready to run list.
 *
 *   This function is called only from the NuttX scheduling
 *   logic when pre-emptioni is re-enabled.  Interrupts will
 *   always be disabled when this function is called.
 *
 ****************************************************************************/

EXTERN void up_release_pending(void);

/****************************************************************************
 * Name: up_reprioritize_rtr
 *
 * Description:
 *   Called when the priority of a running or
 *   ready-to-run task changes and the reprioritization will 
 *   cause a context switch.  Two cases:
 *
 *   1) The priority of the currently running task drops and the next
 *      task in the ready to run list has priority.
 *   2) An idle, ready to run task's priority has been raised above the
 *      the priority of the current, running task and it now has the
 *      priority.
 *
 *   This function is called only from the NuttX scheduling
 *   logic.  Interrupts will always be disabled when this
 *   function is called.
 *
 * Inputs:
 *   tcb: The TCB of the task that has been reprioritized
 *   priority: The new task priority
 *
 ****************************************************************************/

EXTERN void up_reprioritize_rtr(FAR _TCB *tcb, ubyte priority);

/****************************************************************************
 * Name: _exit
 *
 * Description:
 *   This function causes the currently executing task to cease
 *   to exist.  This is a special case of task_delete() where the task to
 *   be deleted is the currently executing task.  It is more complex because
 *   a context switch must be perform to the the next ready to run task.
 *
 *   Unlike other UP APIs, this function may be called directly from user
 *   programs in various states.  The implementation of this function should
 *   disable interrupts before performing scheduling operations.
 *
 ****************************************************************************/
/* Prototype is in unistd.h */

/****************************************************************************
 * Name: up_assert and up_assert_code
 *
 * Description:
 *   Assertions may be handled in an architecture-specific
 *   way.
 *
 ****************************************************************************/
/* Prototype is in assert.h */

/****************************************************************************
 * Name: up_schedule_sigaction
 *
 * Description:
 *   This function is called by the OS when one or more
 *   signal handling actions have been queued for execution.
 *   The architecture specific code must configure things so
 *   that the 'igdeliver' callback is executed on the thread
 *   specified by 'tcb' as soon as possible.
 *
 *   This function may be called from interrupt handling logic.
 *
 *   This operation should not cause the task to be unblocked
 *   nor should it cause any immediate execution of sigdeliver.
 *   Typically, a few cases need to be considered:
 *
 *   (1) This function may be called from an interrupt handler
 *       During interrupt processing, all xcptcontext structures
 *       should be valid for all tasks.  That structure should
 *       be modified to invoke sigdeliver() either on return
 *       from (this) interrupt or on some subsequent context
 *       switch to the recipient task.
 *   (2) If not in an interrupt handler and the tcb is NOT
 *       the currently executing task, then again just modify
 *       the saved xcptcontext structure for the recipient
 *       task so it will invoke sigdeliver when that task is
 *       later resumed.
 *   (3) If not in an interrupt handler and the tcb IS the
 *       currently executing task -- just call the signal
 *       handler now.
 *
 ****************************************************************************/

#ifndef CONFIG_DISABLE_SIGNALS
EXTERN void up_schedule_sigaction(FAR _TCB *tcb, sig_deliver_t sigdeliver);
#endif

/****************************************************************************
 * Name: up_allocate_heap
 *
 * Description:
 *   The heap may be statically allocated by
 *   defining CONFIG_HEAP_BASE and CONFIG_HEAP_SIZE.  If these
 *   are not defined, then this function will be called to
 *   dynamically set aside the heap region.
 *
 ****************************************************************************/

#ifndef CONFIG_HEAP_BASE
EXTERN void up_allocate_heap(FAR void **heap_start, size_t *heap_size);
#endif

/****************************************************************************
 * Name: up_interrupt_context
 *
 * Description:
 *   Return TRUE is we are currently executing in
 *   the interrupt handler context.
 *
 ****************************************************************************/

EXTERN boolean up_interrupt_context(void);

/****************************************************************************
 * Name: up_enable_irq
 *
 * Description:
 *   On many architectures, there are three levels of interrupt enabling: (1)
 *   at the global level, (2) at the level of the interrupt controller,
 *   and (3) at the device level.  In order to receive interrupts, they
 *   must be enabled at all three levels.
 *
 *   This function implements enabling of the device specified by 'irq'
 *   at the interrupt controller level if supported by the architecture
 *   (irqsave() supports the global level, the device level is hardware
 *   specific).
 *
 *   Since this API is not supported on all architectures, it should be
 *   avoided in common implementations where possible.
 *
 ****************************************************************************/

EXTERN void up_enable_irq(int irq);

/****************************************************************************
 * Name: up_disable_irq
 *
 * Description:
 *   This function implements disabling of the device specified by 'irq'
 *   at the interrupt controller level if supported by the architecture
 *   (irqsave() supports the global level, the device level is hardware
 *   specific).
 *
 *   Since this API is not supported on all architectures, it should be
 *   avoided in common implementations where possible.
 *
 ****************************************************************************/

EXTERN void up_disable_irq(int irq);

/****************************************************************************
 * These are standard interfaces that are exported by the OS
 * for use by the architecture specific logic
 ****************************************************************************/

/****************************************************************************
 * Name: sched_process_timer
 *
 * Description:
 *   This function handles system timer events.
 *   The timer interrupt logic itself is implemented in the
 *   architecture specific code, but must call the following OS
 *   function periodically -- the calling interval must be
 *   MSEC_PER_TICK.
 *
 ****************************************************************************/

EXTERN void sched_process_timer(void);

/****************************************************************************
 * Name: irq_dispatch
 *
 * Description:
 *   This function must be called from the achitecture-
 *   specific logic in order to dispatch an interrupt to
 *   the appropriate, registered handling logic.
 *
 ***************************************************************************/

EXTERN void irq_dispatch(int irq, FAR void *context);

/****************************************************************************
 * Name: up_mdelay and up_udelay
 *
 * Description:
 *   Some device drivers may require that the plaform-specific logic
 *   provide these timing loops for short delays.
 *
 ***************************************************************************/

EXTERN void up_mdelay(unsigned int milliseconds);
EXTERN void up_udelay(unsigned int microseconds);

/****************************************************************************
 * Debug interfaces exported by the architecture-specific logic
 ****************************************************************************/

/****************************************************************************
 * Name: up_putc
 *
 * Description:
 *   Output one character on the console
 *
 ****************************************************************************/

EXTERN int up_putc(int ch);

#undef EXTERN
#ifdef __cplusplus
}
#endif

#endif /* __ARCH_H */