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26 ; This file is part of the FreeRTOS distribution.
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55 EXTERN vTaskSwitchContext
56 EXTERN ulCriticalNesting
58 EXTERN ulPortTaskHasFPUContext
59 EXTERN ulAsmAPIPriorityMask
61 portSAVE_CONTEXT macro
63 ; Save the LR and SPSR onto the system mode stack before switching to
64 ; system mode to save the remaining system mode registers
69 ; Push the critical nesting count
70 LDR R2, =ulCriticalNesting
74 ; Does the task have a floating point context that needs saving? If
75 ; ulPortTaskHasFPUContext is 0 then no.
76 LDR R2, =ulPortTaskHasFPUContext
80 ; Save the floating point context, if any
86 ; Save ulPortTaskHasFPUContext itself
89 ; Save the stack pointer in the TCB
96 ; /**********************************************************************/
98 portRESTORE_CONTEXT macro
100 ; Set the SP to point to the stack of the task being restored.
101 LDR R0, =pxCurrentTCB
105 ; Is there a floating point context to restore? If the restored
106 ; ulPortTaskHasFPUContext is zero then no.
107 LDR R0, =ulPortTaskHasFPUContext
112 ; Restore the floating point context, if any
118 ; Restore the critical section nesting depth
119 LDR R0, =ulCriticalNesting
123 ; Ensure the priority mask is correct for the critical nesting depth
124 LDR R2, =portICCPMR_PRIORITY_MASK_REGISTER_ADDRESS
127 LDRNE R4, =( configMAX_API_CALL_INTERRUPT_PRIORITY << portPRIORITY_SHIFT )
130 ; Restore all system mode registers other than the SP (which is already
134 ; Return to the task code, loading CPSR on the way.