bsp_a.asm

来自「ucosII 修改移植到 freescale MCF51JM128」· 汇编 代码 · 共 71 行

;
;************************************************************************************************
;                                         uC/OS-II
;                                    The Real-Time Kernel
; 
;                         (c) Copyright 2006, Micrium, Inc., Weston, FL
;                                     All Rights Reserved
;  
; File        : bsp_a.asm
; By          : Jean J. Labrosse
;*************************************************************************************************
;

;
;*************************************************************************************************
;                                       PUBLIC DECLARATIONS
;*************************************************************************************************
;

		.global  _OSTickISR

;
;**************************************************************************************************
;                                     EXTERNAL DECLARATIONS
;**************************************************************************************************
;

        .extern  _OSIntNesting
        .extern  _OSIntExit
        .extern  _OSTCBCur
        .extern  _OSTickISR_Handler

        .text
      
;
;*******************************************************************************************
;                                   uC/OS-II's TICK ISR
;
; Description : This function services uC/OS-II's tick interrupts
;
; Arguments   : none
;*******************************************************************************************
;

_OSTickISR:
        MOVE.W     #0x2700,SR               ; Disable interrupts                         
                                            
        LEA        -60(A7),A7               ; Save processor registers onto stack        
        MOVEM.L    D0-D7/A0-A6,(A7)

        MOVEQ.L    #0,D0                    ; OSIntNesting++                             
        MOVE.B     (_OSIntNesting),D0
        ADDQ.L     #1,D0            
        MOVE.B     D0,(_OSIntNesting)

        CMPI.L     #1, D0                   ; if (OSIntNesting == 1)                     
        BNE        _OSTickISR1
        MOVE.L     (_OSTCBCur), A1          ;     OSTCBCur-<OSTCBStkPtr = SP             
        MOVE.L     A7,(A1)

_OSTickISR1:
        JSR        _OSTickISR_Handler       ; OSTickISR_Handler()                        

        JSR        _OSIntExit               ; Exit the ISR                               

        MOVEM.L    (A7),D0-D7/A0-A6         ; Restore processor registers from stack     
        LEA        60(A7),A7

        RTE                                 ; Return to task or nested ISR