?? os_cpu_a.asm
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/*;************************************************************************************************; uC/OS-II; The Real-Time Kernel; ; (c) Copyright 2006, Micrium, Inc., Weston, FL; All Rights Reserved; ; File : OS_CPU_A.ASM; By : Jean J. Labrosse;; Note(s) : 1) This port uses the MOVEM.L (A7),D0-D7/A0-A6, LEA 60(A7)A7 construct instead of ; the traditional 68xxx MOVEM.L (A7)+,D0-D7/A0-A6. It is perfectly in order to ; push/pop individual registers using MOVEM.L (A7)+,D2, etc. but it's a bit slower; (and more verbose). ; ; 2) The LEA instruction is required because the ColdFire cannot push multiple ; registers directly to the stack. ;; 3) Changed OSIntCtxSw for new uC/OS-II version 2.51 features.;**************************************************************************************************//*;*************************************************************************************************; PUBLIC DECLARATIONS;**************************************************************************************************/ .global _OS_CPU_SR_Save .global _OS_CPU_SR_Restore .global _OSCtxSw .global _OSIntCtxSw .global _OSStartHighRdy .global _OS_My_ISR/*;**************************************************************************************************; EXTERNAL DECLARATIONS;***************************************************************************************************/ .extern _OSRunning .extern _OSIntExit .extern _OSIntNesting .extern _OSLockNesting .extern _OSPrioCur .extern _OSPrioHighRdy .extern _OSRdyGrp .extern _OSRdyTbl .extern _OSTaskSwHook .extern _OSTCBCur .extern _OSTCBHighRdy .extern _OSIntEnter .text .align 4/*;********************************************************************************************************; OSCPUSaveSR() for OS_CRITICAL_METHOD #3;; Description : This functions implements the OS_CRITICAL_METHOD #3 function to preserve the state of the ; interrupt disable flag in order to be able to restore it later.;; Arguments : none;; Returns : It is assumed that the return value is placed in the D0 register as expected by the; compiler.;*********************************************************************************************************/_OS_CPU_SR_Save: MOVE.W SR,D0 ; Copy SR into D0 MOVE.L D0,-(A7) ; Save D0 ORI.L #0x0700,D0 ; Disable interrupts MOVE D0,SR MOVE.L (A7)+,D0 ; Restore D0 RTS/*;********************************************************************************************************; OSCPURestoreSR() for OS_CRITICAL_METHOD #3;; Description : This functions implements the OS_CRITICAL_METHOD #3 function to restore the state of the; interrupt flag.;; Arguments : os_cpu_sr is the contents of the SR to restore. It is assumed that this 'argument' is ; passed on the stack as follows:;; A7 + 0 -> D0; + 4 return address; + 8 return address; + 4 D0; A7 + 0 ->;; Returns : None ;*********************************************************************************************************/_OS_CPU_SR_Restore: MOVE.L D0,-(A7) ; Save D0 MOVE.W 10(A7),D0 MOVE.W D0,SR MOVE.L (A7)+,D0 ; Restore D0 RTS/*;*******************************************************************************************; START HIGHEST PRIORITY TASK READY-TO-RUN;; Description: This function is called by OSStart() to start the highest priority task that; was created by your application before calling OSStart().;; Arguments : none;; Note(s) : 1) The stack frame is assumed to look as follows:; ; OSTCBHighRdy->OSTCBStkPtr + 0 ----> D0 Low Memory; + 4 D1 ; + 8 D2; + 12 D3; + 16 D4; + 20 D5; + 24 D6; + 28 D7; + 32 A0; + 36 A1; + 40 A2; + 44 A3; + 48 A4; + 52 A5; + 56 A6; + 60 Format, Vector, OS_INITIAL_SR; + 64 task; + 68 task; + 72 p_arg High Memory;; 2) OSStartHighRdy() MUST:; a) Call OSTaskSwHook() then,; b) Set OSRunning to TRUE,; c) Switch to the highest priority task.;********************************************************************************************/_OSStartHighRdy: JSR _OSTaskSwHook /* Invoke user defined context switch hook */ MOVEQ.L #1, D4 /* OSRunning = TRUE; */ MOVE.B D4,_OSRunning /* Indicates that we are multitasking */ MOVE.L (_OSTCBHighRdy),A1 /* Point to TCB of highest prio task ready to run*/ MOVE.L (A1),A7 /* Get the stack pointer of the task to resume */ MOVEM.L (A7),D0-D7/A0-A6 /* Store all the regs */ LEA 60(A7),A7 /* Advance the stack pointer */ RTE /* Return to task *//*;*******************************************************************************************; TASK LEVEL CONTEXT SWITCH;; Description : This function is called when a task makes a higher prio task ready-to-run.; ; Arguments : none;; Note(s) : 1) Upon entry,; OSTCBCur points to the OS_TCB of the task to suspend; OSTCBHighRdy points to the OS_TCB of the task to resume;; 2) The stack frame of the task to suspend looks as follows (the registers ; for task to suspend need to be saved):;; SP + 0 ----> Format, Vector, SR Low Memory; + 4 PC of task High Memory;; 3) The stack frame of the task to resume looks as follows:; ; OSTCBHighRdy->OSTCBStkPtr + 0 ----> D0 Low Memory; + 4 D1; + 8 D2; + 12 D3; + 16 D4; + 20 D5; + 24 D6; + 28 D7; + 32 A0; + 36 A1; + 40 A2; + 44 A3; + 48 A4; + 52 A5; + 56 A6; + 60 SR of task; + 64 PC of task High Memory;;********************************************************************************************/_OSCtxSw: LEA -60(A7),A7 MOVEM.L D0-D7/A0-A6,(A7) /* Save the registers of the current task */ MOVE.L (_OSTCBCur),A1 /* Save stack pointer in the suspended task TCB */ MOVE.L A7,(A1) JSR _OSTaskSwHook /* Invoke user defined context switch hook */ MOVE.L (_OSTCBHighRdy),A1 /* OSTCBCur = OSTCBHighRdy */ MOVE.L A1,(_OSTCBCur) MOVE.L (A1),A7 /* Get the stack pointer of the task to resume */ MOVE.B (_OSPrioHighRdy),D0 /* OSPrioCur = OSPrioHighRdy */ MOVE.B D0,(_OSPrioCur) MOVEM.L (A7),D0-D7/A0-A6 /* Restore the CPU registers */ LEA 60(A7),A7 RTE /* Run task *//*;*******************************************************************************************; INTERRUPT LEVEL CONTEXT SWITCH;;; Description : This function is provided for backward compatibility and to ; satisfy OSIntExit() ; in OS_CORE.C.;; Arguments : none;********************************************************************************************/_OSIntCtxSw: JSR _OSTaskSwHook /* Invoke user defined context switch hook */ MOVE.B (_OSPrioHighRdy),D0 /* OSPrioCur = OSPrioHighRdy */ MOVE.B D0,(_OSPrioCur) MOVE.L (_OSTCBHighRdy),A1 /* OSTCBCur = OSTCBHighRdy */ MOVE.L A1,(_OSTCBCur) MOVE.L (A1),A7 /* SP = OSTCBHighRdy->OSTCBStkPtr */ MOVEM.L (A7),D0-D7/A0-A6 /* Restore ALL CPU registers from new task stack */ LEA 60(A7),A7 RTE /* Run task *//*;*******************************************************************************************; GENERIC ISR;; Description : This function shows how to write ISRs;; Arguments : none;; Notes : 1) You MUST save ALL the CPU registers as shown below; 2) You MUST increment 'OSIntNesting' and NOT call OSIntEnter(); 3) You MUST JUMP to OSIntExitCF() instead of call the function.; 4) You MUST NOT use OSIntExit() to exit an ISR with the MCF5275.;********************************************************************************************/_OS_My_ISR: 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.L (_OSIntNesting),D0 ADDQ.L #1,D0 MOVE.L D0,(_OSIntNesting) CMPI.L #1, D0 /* if (OSIntNesting == 1) */ BNE _OS_My_ISR_1 MOVE.L (_OSTCBCur), A1 /* OSTCBCur-<OSTCBStkPtr = SP */ MOVE.L A7,(A1)_OS_My_ISR_1: JSR _OS_My_ISR_Handler /* OS_My_ISR_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 */_OS_My_ISR_Handler: RTS .end?? 快捷鍵說明
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