idle_task.s.bak

Nuclues嵌入式RTOS源码

	AREA IDLE_TASK, CODE, READONLY

	INCLUDE asm_defs.s

	IMPORT	ST_Idle_Count
	IMPORT	TCD_Interrupt_Level

Idle_Count	DCD	ST_Idle_Count
Int_Level	DCD	TCD_Interrupt_Level
;
;idle task:just do counting, the interrupt MUST be disabled during counting
;
	EXPORT	ST_Idle_Loop
ST_Idle_Loop
	
	;close arm interrupt
        MRS     a1,CPSR                     ; Pickup current CPSR
        ORR     a1,a1,#LOCKOUT              ; Build interrupt lockout value
        MSR     CPSR_cxsf,a1                ; Lockout interrupts

	;do counting
        LDR     a2,[pc,#Idle_Count-.-8] ; Pickup idle count address
        LDR     a1,[a2, #0]                 ; Pickup current count
	ADD	a1,a1,#1
	STR	a1,[a2,#0]

	;restore interrupt according to TCD_Interrupt_Level	
        LDR     a2,[pc, #Int_Level-.-8]     ; Pickup address of interrupt 
                                            ; lockout
        BIC     a1,a1,#LOCK_MSK             ; Clear lockout mask
        LDR     a3,[a2, #0]                 ; Pickup interrupt lockout mask
        ORR     a1,a1,a3                    ; Build new interrupt lockout mask
        MSR     CPSR_cxsf,a1                ; Place it into the SPSR 

	B	ST_Idle_Loop		    ;loop again
	
	END