⭐ 欢迎来到虫虫下载站! | 📦 资源下载 📁 资源专辑 ℹ️ 关于我们
⭐ 虫虫下载站

📄 portmacro.h

📁 freertosV4.40 是一种small的嵌入式系统。利于嵌入式开好者入门学习嵌入式操作系统。通过对于源码的学习可以很好的掌握freertos的运行机制。
💻 H
📖 第 1 页 / 共 2 页
字号:
  __asm__ __volatile__ (																			\
    "ld.w    r0, sp[9*4]																			\n\t" /* Read SR in stack */\
    "bfextu  r0, r0, 22, 3																			\n\t" /* Extract the mode bits to R0. */\
    "cp.w    r0, 1																					\n\t" /* Compare the mode bits with supervisor mode(b'001) */\
    "brhi    LABEL_INT_SKIP_RESTORE_CONTEXT_"ASTRINGZ(__LINE__)										\
  );																								\
																									\
  /* Else */																						\
  /* because it is here safe, always call vTaskSwitchContext() since an OS tick occurred. */		\
  /* A critical section has to be used here because vTaskSwitchContext handles FreeRTOS linked lists. */\
  portENTER_CRITICAL();																				\
  vTaskSwitchContext();																				\
  portEXIT_CRITICAL();																				\
																									\
  /* Restore all registers */																		\
																									\
  __asm__ __volatile__ (																			\
    /* Set SP to point to new stack */																\
    "mov     r8, LWRD("ASTRINGZ(pxCurrentTCB)")														\n\t"\
    "orh     r8, HWRD("ASTRINGZ(pxCurrentTCB)")														\n\t"\
    "ld.w    r0, r8[0]																				\n\t"\
    "ld.w    sp, r0[0]																				\n"\
																									\
    "LABEL_INT_SKIP_RESTORE_CONTEXT_"ASTRINGZ(__LINE__)":											\n\t"\
																									\
    /* Restore ulCriticalNesting variable */														\
    "ld.w    r0, sp++																				\n\t"\
    "mov     r8, LWRD("ASTRINGZ(ulCriticalNesting)")												\n\t"\
    "orh     r8, HWRD("ASTRINGZ(ulCriticalNesting)")												\n\t"\
    "st.w    r8[0], r0																				\n\t"\
																									\
    /* Restore R0..R7 */																			\
    "ldm     sp++, r0-r7																			\n\t"\
																									\
    /* Now, the stack should be R8..R12, LR, PC and SR */											\
    "rete"																							\
  );																								\
																									\
  /* Force import of global symbols from assembly */												\
  ulCriticalNesting;																				\
  pxCurrentTCB;																						\
}

#endif


/*
 * portSAVE_CONTEXT_SCALL() for SupervisorCALL exception.
 *
 * NOTE: taskYIELD()(== SCALL) MUST NOT be called in a mode > supervisor mode.
 *
 */
#define portSAVE_CONTEXT_SCALL()																	\
{																									\
  extern volatile unsigned portLONG ulCriticalNesting;												\
  extern volatile void *volatile pxCurrentTCB;														\
																									\
  /* Warning: the stack layout after SCALL doesn't match the one after an interrupt. */				\
  /* If SR[M2:M0] == 001 */																			\
  /*    PC and SR are on the stack.  */																\
  /* Else (other modes) */																			\
  /*    Nothing on the stack. */																	\
																									\
  /* WARNING NOTE: the else case cannot happen as it is strictly forbidden to call */				\
  /* vTaskDelay() and vTaskDelayUntil() OS functions (that result in a taskYield()) */				\
  /* in an interrupt|exception handler. */															\
																									\
  __asm__ __volatile__ (																			\
    /* in order to save R0-R7 */																	\
    "sub     sp, 6*4																				\n\t"\
    /* Save R0..R7 */																				\
    "stm     --sp, r0-r7																			\n\t"\
																									\
    /* in order to save R8-R12 and LR */															\
    /* do not use SP if interrupts occurs, SP must be left at bottom of stack */					\
    "sub     r7, sp,-16*4																			\n\t"\
    /* Copy PC and SR in other places in the stack. */												\
    "ld.w    r0, r7[-2*4]																			\n\t" /* Read SR */\
    "st.w    r7[-8*4], r0																			\n\t" /* Copy SR */\
    "ld.w    r0, r7[-1*4]																			\n\t" /* Read PC */\
    "st.w    r7[-7*4], r0																			\n\t" /* Copy PC */\
																									\
    /* Save R8..R12 and LR on the stack. */															\
    "stm     --r7, r8-r12, lr																		\n\t"\
																									\
    /* Arriving here we have the following stack organizations: */									\
    /* R8..R12, LR, PC, SR, R0..R7. */																\
																									\
    /* Now we can finalize the save. */																\
																									\
    /* Save ulCriticalNesting variable  - R0 is overwritten */										\
    "mov     r8, LWRD("ASTRINGZ(ulCriticalNesting)")												\n\t"\
    "orh     r8, HWRD("ASTRINGZ(ulCriticalNesting)")												\n\t"\
    "ld.w    r0, r8[0]																				\n\t"\
    "st.w    --sp, r0"																				\
  );																								\
																									\
  /* Disable the its which may cause a context switch (i.e. cause a change of */					\
  /* pxCurrentTCB). */																				\
  /* Basically, all accesses to the pxCurrentTCB structure should be put in a */					\
  /* critical section because it is a global structure. */											\
  portENTER_CRITICAL();																				\
																									\
  /* Store SP in the first member of the structure pointed to by pxCurrentTCB */					\
  __asm__ __volatile__ (																			\
    "mov     r8, LWRD("ASTRINGZ(pxCurrentTCB)")														\n\t"\
    "orh     r8, HWRD("ASTRINGZ(pxCurrentTCB)")														\n\t"\
    "ld.w    r0, r8[0]																				\n\t"\
    "st.w    r0[0], sp"																				\
  );																								\
}

/*
 * portRESTORE_CONTEXT() for SupervisorCALL exception.
 */
#define portRESTORE_CONTEXT_SCALL()																	\
{																									\
  extern volatile unsigned portLONG ulCriticalNesting;												\
  extern volatile void *volatile pxCurrentTCB;														\
																									\
  /* Restore all registers */																		\
																									\
  /* Set SP to point to new stack */																\
  __asm__ __volatile__ (																			\
    "mov     r8, LWRD("ASTRINGZ(pxCurrentTCB)")														\n\t"\
    "orh     r8, HWRD("ASTRINGZ(pxCurrentTCB)")														\n\t"\
    "ld.w    r0, r8[0]																				\n\t"\
    "ld.w    sp, r0[0]"																				\
  );																								\
																									\
  /* Leave pxCurrentTCB variable access critical section */											\
  portEXIT_CRITICAL();																				\
																									\
  __asm__ __volatile__ (																			\
    /* Restore ulCriticalNesting variable */														\
    "ld.w    r0, sp++																				\n\t"\
    "mov     r8, LWRD("ASTRINGZ(ulCriticalNesting)")												\n\t"\
    "orh     r8, HWRD("ASTRINGZ(ulCriticalNesting)")												\n\t"\
    "st.w    r8[0], r0																				\n\t"\
																									\
    /* skip PC and SR */																			\
    /* do not use SP if interrupts occurs, SP must be left at bottom of stack */					\
    "sub     r7, sp, -10*4																			\n\t"\
    /* Restore r8-r12 and LR */																		\
    "ldm     r7++, r8-r12, lr																		\n\t"\
																									\
    /* RETS will take care of the extra PC and SR restore. */										\
    /* So, we have to prepare the stack for this. */												\
    "ld.w    r0, r7[-8*4]																			\n\t" /* Read SR */\
    "st.w    r7[-2*4], r0																			\n\t" /* Copy SR */\
    "ld.w    r0, r7[-7*4]																			\n\t" /* Read PC */\
    "st.w    r7[-1*4], r0																			\n\t" /* Copy PC */\
																									\
    /* Restore R0..R7 */																			\
    "ldm     sp++, r0-r7																			\n\t"\
																									\
    "sub     sp, -6*4																				\n\t"\
																									\
    "rets"																							\
  );																								\
																									\
  /* Force import of global symbols from assembly */												\
  ulCriticalNesting;																				\
  pxCurrentTCB;																						\
}


/*
 * The ISR used depends on whether the cooperative or
 * the preemptive scheduler is being used.
 */
#if configUSE_PREEMPTION == 0

/*
 * ISR entry and exit macros.  These are only required if a task switch
 * is required from the ISR.
 */
#define portENTER_SWITCHING_ISR()																	\
{																									\
  /* Save R0..R7 */																					\
  __asm__ __volatile__ ("stm     --sp, r0-r7");														\
																									\
  /* With the cooperative scheduler, as there is no context switch by interrupt, */					\
  /* there is also no context save. */																\
}

/*
 * Input parameter: in R12, boolean. Perform a vTaskSwitchContext() if 1
 */
#define portEXIT_SWITCHING_ISR()																	\
{																									\
  __asm__ __volatile__ (																			\
    /* Restore R0..R7 */																			\
    "ldm     sp++, r0-r7																			\n\t"\
																									\
    /* With the cooperative scheduler, as there is no context switch by interrupt, */				\
    /* there is also no context restore. */															\
    "rete"																							\
  );																								\
}

#else

/*
 * ISR entry and exit macros.  These are only required if a task switch
 * is required from the ISR.
 */
#define portENTER_SWITCHING_ISR()																	\
{																									\
  extern volatile unsigned portLONG ulCriticalNesting;												\
  extern volatile void *volatile pxCurrentTCB;														\
																									\
  /* When we come here */																			\
  /* Registers R8..R12, LR, PC and SR had already been pushed to system stack */					\
																									\
  __asm__ __volatile__ (																			\
    /* Save R0..R7 */																				\
    "stm     --sp, r0-r7																			\n\t"\
																									\
    /* Save ulCriticalNesting variable  - R0 is overwritten */										\
    "mov     r8, LWRD("ASTRINGZ(ulCriticalNesting)")												\n\t"\
    "orh     r8, HWRD("ASTRINGZ(ulCriticalNesting)")												\n\t"\
    "ld.w    r0, r8[0]																				\n\t"\
    "st.w    --sp, r0																				\n\t"\
																									\
    /* Check if INT0 or higher were being handled (case where the OS tick interrupted another */	\
    /* interrupt handler (which was of a higher priority level but decided to lower its priority */	\
    /* level and allow other lower interrupt level to occur). */									\
    /* In this case we don't want to do a task switch because we don't know what the stack */		\
    /* currently looks like (we don't know what the interrupted interrupt handler was doing). */	\
    /* Saving SP in pxCurrentTCB and then later restoring it (thinking restoring the task) */		\
    /* will just be restoring the interrupt handler, no way!!! */									\
    /* So, since we won't do a vTaskSwitchContext(), it's of no use to save SP. */					\
    "ld.w    r0, sp[9*4]																			\n\t" /* Read SR in stack */\
    "bfextu  r0, r0, 22, 3																			\n\t" /* Extract the mode bits to R0. */\
    "cp.w    r0, 1																					\n\t" /* Compare the mode bits with supervisor mode(b'001) */\
    "brhi    LABEL_ISR_SKIP_SAVE_CONTEXT_"ASTRINGZ(__LINE__)"										\n\t"\
																									\
    /* Store SP in the first member of the structure pointed to by pxCurrentTCB */					\
    "mov     r8, LWRD("ASTRINGZ(pxCurrentTCB)")														\n\t"\
    "orh     r8, HWRD("ASTRINGZ(pxCurrentTCB)")														\n\t"\
    "ld.w    r0, r8[0]																				\n\t"\
    "st.w    r0[0], sp																				\n"\
																									\
    "LABEL_ISR_SKIP_SAVE_CONTEXT_"ASTRINGZ(__LINE__)":"												\
  );																								\
}


/*
 * Input parameter: in R12, boolean. Perform a vTaskSwitchContext() if 1
 */
#define portEXIT_SWITCHING_ISR()																	\
{																									\
  extern volatile unsigned portLONG ulCriticalNesting;												\
  extern volatile void *volatile pxCurrentTCB;														\
																									\
  __asm__ __volatile__ (																			\
    /* Check if INT0 or higher were being handled (case where the OS tick interrupted another */	\
    /* interrupt handler (which was of a higher priority level but decided to lower its priority */	\
    /* level and allow other lower interrupt level to occur). */									\
    /* In this case it's of no use to switch context and restore a new SP because we purposedly */	\
    /* did not previously save SP in its TCB. */													\
    "ld.w    r0, sp[9*4]																			\n\t" /* Read SR in stack */\
    "bfextu  r0, r0, 22, 3																			\n\t" /* Extract the mode bits to R0. */\
    "cp.w    r0, 1																					\n\t" /* Compare the mode bits with supervisor mode(b'001) */\
    "brhi    LABEL_ISR_SKIP_RESTORE_CONTEXT_"ASTRINGZ(__LINE__)"									\n\t"\
																									\
    /* If a switch is required then we just need to call */											\
    /* vTaskSwitchContext() as the context has already been */										\
    /* saved. */																					\
    "cp.w    r12, 1																					\n\t" /* Check if Switch context is required. */\
    "brne    LABEL_ISR_RESTORE_CONTEXT_"ASTRINGZ(__LINE__)":C"										\
  );																								\
																									\
  /* A critical section has to be used here because vTaskSwitchContext handles FreeRTOS linked lists. */\
  portENTER_CRITICAL();																				\
  vTaskSwitchContext();																				\
  portEXIT_CRITICAL();																				\
																									\
  __asm__ __volatile__ (																			\
    "LABEL_ISR_RESTORE_CONTEXT_"ASTRINGZ(__LINE__)":												\n\t"\
    /* Restore the context of which ever task is now the highest */									\
    /* priority that is ready to run. */															\
																									\
    /* Restore all registers */																		\
																									\
    /* Set SP to point to new stack */																\
    "mov     r8, LWRD("ASTRINGZ(pxCurrentTCB)")														\n\t"\
    "orh     r8, HWRD("ASTRINGZ(pxCurrentTCB)")														\n\t"\
    "ld.w    r0, r8[0]																				\n\t"\
    "ld.w    sp, r0[0]																				\n"\
																									\
    "LABEL_ISR_SKIP_RESTORE_CONTEXT_"ASTRINGZ(__LINE__)":											\n\t"\
																									\
    /* Restore ulCriticalNesting variable */														\
    "ld.w    r0, sp++																				\n\t"\
    "mov     r8, LWRD("ASTRINGZ(ulCriticalNesting)")												\n\t"\
    "orh     r8, HWRD("ASTRINGZ(ulCriticalNesting)")												\n\t"\
    "st.w    r8[0], r0																				\n\t"\
																									\
    /* Restore R0..R7 */																			\
    "ldm     sp++, r0-r7																			\n\t"\
																									\
    /* Now, the stack should be R8..R12, LR, PC and SR  */											\
    "rete"																							\
  );																								\
																									\
  /* Force import of global symbols from assembly */												\
  ulCriticalNesting;																				\
  pxCurrentTCB;																						\
}

#endif


#define portYIELD()                 {__asm__ __volatile__ ("scall");}

/* Task function macros as described on the FreeRTOS.org WEB site. */
#define portTASK_FUNCTION_PROTO( vFunction, pvParameters ) void vFunction( void *pvParameters )
#define portTASK_FUNCTION( vFunction, pvParameters ) void vFunction( void *pvParameters )

#define inline

#endif /* PORTMACRO_H */

⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -