📄 portmacro.h
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"brhi LABEL_INT_SKIP_RESTORE_CONTEXT_%[LINE]" \
: \
: [LINE] "i" (__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, LO(%[pxCurrentTCB]) \n\t"\
"orh r8, HI(%[pxCurrentTCB]) \n\t"\
"ld.w r0, r8[0] \n\t"\
"ld.w sp, r0[0] \n"\
\
"LABEL_INT_SKIP_RESTORE_CONTEXT_%[LINE]: \n\t"\
\
/* Restore ulCriticalNesting variable */ \
"ld.w r0, sp++ \n\t" \
"mov r8, LO(%[ulCriticalNesting]) \n\t"\
"orh r8, HI(%[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" \
: \
: [ulCriticalNesting] "i" (&ulCriticalNesting), \
[pxCurrentTCB] "i" (&pxCurrentTCB), \
[LINE] "i" (__LINE__) \
); \
}
#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, LO(%[ulCriticalNesting]) \n\t"\
"orh r8, HI(%[ulCriticalNesting]) \n\t"\
"ld.w r0, r8[0] \n\t"\
"st.w --sp, r0" \
: \
: [ulCriticalNesting] "i" (&ulCriticalNesting) \
); \
\
/* 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, LO(%[pxCurrentTCB]) \n\t"\
"orh r8, HI(%[pxCurrentTCB]) \n\t"\
"ld.w r0, r8[0] \n\t"\
"st.w r0[0], sp" \
: \
: [pxCurrentTCB] "i" (&pxCurrentTCB) \
); \
}
/*
* 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, LO(%[pxCurrentTCB]) \n\t"\
"orh r8, HI(%[pxCurrentTCB]) \n\t"\
"ld.w r0, r8[0] \n\t"\
"ld.w sp, r0[0]" \
: \
: [pxCurrentTCB] "i" (&pxCurrentTCB) \
); \
\
/* Leave pxCurrentTCB variable access critical section */ \
portEXIT_CRITICAL(); \
\
__asm__ __volatile__ ( \
/* Restore ulCriticalNesting variable */ \
"ld.w r0, sp++ \n\t"\
"mov r8, LO(%[ulCriticalNesting]) \n\t"\
"orh r8, HI(%[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" \
: \
: [ulCriticalNesting] "i" (&ulCriticalNesting) \
); \
}
/*
* 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, LO(%[ulCriticalNesting]) \n\t"\
"orh r8, HI(%[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_%[LINE] \n\t"\
\
/* Store SP in the first member of the structure pointed to by pxCurrentTCB */ \
"mov r8, LO(%[pxCurrentTCB]) \n\t"\
"orh r8, HI(%[pxCurrentTCB]) \n\t"\
"ld.w r0, r8[0] \n\t"\
"st.w r0[0], sp \n"\
\
"LABEL_ISR_SKIP_SAVE_CONTEXT_%[LINE]:" \
: \
: [ulCriticalNesting] "i" (&ulCriticalNesting), \
[pxCurrentTCB] "i" (&pxCurrentTCB), \
[LINE] "i" (__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_%[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_%[LINE]" \
: \
: [LINE] "i" (__LINE__) \
); \
\
/* 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_%[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, LO(%[pxCurrentTCB]) \n\t"\
"orh r8, HI(%[pxCurrentTCB]) \n\t"\
"ld.w r0, r8[0] \n\t"\
"ld.w sp, r0[0] \n"\
\
"LABEL_ISR_SKIP_RESTORE_CONTEXT_%[LINE]: \n\t"\
\
/* Restore ulCriticalNesting variable */ \
"ld.w r0, sp++ \n\t"\
"mov r8, LO(%[ulCriticalNesting]) \n\t"\
"orh r8, HI(%[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" \
: \
: [ulCriticalNesting] "i" (&ulCriticalNesting), \
[pxCurrentTCB] "i" (&pxCurrentTCB), \
[LINE] "i" (__LINE__) \
); \
}
#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 )
#endif /* PORTMACRO_H */
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