os_sw.asm

来自「ucos2.52在2812上的移植」· 汇编 代码 · 共 40 行

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_OSCtxSw:
	.ref _OSTCBHighRdy
	.ref _OSTCBCur
	.ref _OSPrioHighRdy
	.ref _OSPrioCur
	.global _OSCtxSw
	 
	 PUSH   RPC   ;必须入栈

     MOVW     DP,#_OSTCBCur	 ; OSTCBCur->OSTCBStkPtr = SP
     MOVL     XAR4,@_OSTCBCur  
     MOV      AL,SP     
     MOV      *+XAR4[0],AL         

;=================================================================================	
     MOVW DP,#_OSTCBHighRdy	 	; OSTCBCur = OSTCBHighRdy
     MOVL ACC,@_OSTCBHighRdy    
     MOVW DP,#_OSTCBCur
     MOVL @_OSTCBCur,ACC        
	
     MOVW DP,#_OSPrioHighRdy    	;OSPrioCur = OSPrioHighRdy
     MOV  AL,@_OSPrioHighRdy    
     MOVW DP,#_OSPrioCur
     MOV  @_OSPrioCur,AL        
;=================================================================================	     
	
     MOVW    DP,#_OSTCBHighRdy	 ;SP = OSTCBhighRdy->OSTCBStkPtr	
     MOVL    XAR4,@_OSTCBHighRdy   
     MOV     AL,*+XAR4[0]                    
     MOV     @SP,AL

     POP RPC
     IRET
	.end