?? os_cpu_a.s
字號:
;********************************************************************************************************
; uC/OS-II
; The Real-Time Kernel
;
; ATmega128 Specific code for V2.8x
; (AVR-GCC 4.1.1)
;
;
; File : OS_CPU_A.ASM
; By : Xiawei <xiawei0311@gmail.com>
; AVR-GCC version : 4.1.1 , WinAVR 20070122
; Date : September 9th,2007
;
;********************************************************************************************************
#include <avr/io.h>
#define OS_CPU_A
#include "../Config/OS_CFG.h"
#include "OS_CPU.h"
;********************************************************************************************************
; I/O PORT ADDRESSES
;********************************************************************************************************
;********************************************************************************************************
; PUBLIC DECLARATIONS
;********************************************************************************************************
.global OSStartHighRdy
.global OSCtxSw
.global OSIntCtxSw
.global TIMER0_COMP_vect
.global OSTickISR
.global OSTickISR2
.global OS_CPU_SR_Save
.global OS_CPU_SR_Restore
;********************************************************************************************************
; EXTERNAL DECLARATIONS
;********************************************************************************************************
.extern OSIntExit
.extern OSIntNesting
.extern OSPrioCur
.extern OSPrioHighRdy
.extern OSRunning
.extern OSTaskSwHook
.extern OSTCBCur
.extern OSTCBHighRdy
.extern OSTimeTick
;********************************************************************************************************
; MACROS
;********************************************************************************************************
; Push all registers and the status register
.macro PUSHRS
push r0
push r1
push r2
push r3
push r4
push r5
push r6
push r7
push r8
push r9
push r10
push r11
push r12
push r13
push r14
push r15
push r16
push r17
push r18
push r19
push r20
push r21
push r22
push r23
push r24
push r25
push r26
push r27
push r28
push r29
push r30
push r31
in r16,_SFR_IO_ADDR(SREG)
push r16
.endm
; Pop all registers and the status registers
.macro POPRS
pop r16
out _SFR_IO_ADDR(SREG),r16
pop r31
pop r30
pop r29
pop r28
pop r27
pop r26
pop r25
pop r24
pop r23
pop r22
pop r21
pop r20
pop r19
pop r18
pop r17
pop r16
pop r15
pop r14
pop r13
pop r12
pop r11
pop r10
pop r9
pop r8
pop r7
pop r6
pop r5
pop r4
pop r3
pop r2
pop r1
pop r0
.endm
.text
.section .text
;********************************************************************************************************
; 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().
;
; Note(s) : 1) The (data)stack frame is assumed to look as follows:
;
; OSTCBHighRdy->OSTCBStkPtr --> LSB of (return) stack pointer (Low memory)
; SPH of (return) stack pointer
; Flags to load in status register
; R31
; R30
; R7
; .
; .
; .
; R0 (High memory)
;
; where the stack pointer points to the task start address.
;
;
; 2) OSStartHighRdy() MUST:
; a) Call OSTaskSwHook() then,
; b) Set OSRunning to TRUE,
; c) Switch to the highest priority task.
;********************************************************************************************************
OSStartHighRdy:
#if OS_CPU_HOOKS_EN > 0
CALL OSTaskSwHook ; Invoke user defined context switch hook
#endif
LDS R16,OSRunning ; Indicate that we are multitasking
INC R16 ;
STS OSRunning,R16 ;
LDS R30,OSTCBHighRdy ; Let Z point to TCB of highest priority task
LDS R31,OSTCBHighRdy+1 ; ready to run
LD R28,Z+ ; Load stack L pointer
OUT _SFR_IO_ADDR(SPL),R28
LD R29,Z+ ;
OUT _SFR_IO_ADDR(SPH),R29
POPRS ; Pop all registers and status register
RET ; Start task
;********************************************************************************************************
; TASK LEVEL CONTEXT SWITCH
;
; Description : This function is called when a task makes a higher priority task ready-to-run.
;
; 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:
;
; SP+0 --> LSB of task code address
; +1 MSB of task code address (High memory)
;
; 3) The saved context of the task to resume looks as follows:
;
; OSTCBHighRdy->OSTCBStkPtr --> LSB of (return) stack pointer (Low memory)
; SPH of (return) stack pointer
; Flags to load in status register
; R31
; R30
; R7
; .
; .
; .
; R0 (High memory)
;********************************************************************************************************
OSCtxSw:
PUSHRS ; Save current tasks context
LDS R30,OSTCBCur ; Z = OSTCBCur->OSTCBStkPtr
LDS R31,OSTCBCur+1 ;
IN r28,_SFR_IO_ADDR(SPL)
ST Z+,R28 ; Save Y (R29:R28) pointer
IN r29,_SFR_IO_ADDR(SPH)
ST Z+,R29 ;
#if OS_CPU_HOOKS_EN > 0
CALL OSTaskSwHook ; Call user defined task switch hook
#endif
LDS R16,OSPrioHighRdy ; OSPrioCur = OSPrioHighRdy
STS OSPrioCur,R16
LDS R30,OSTCBHighRdy ; Let Z point to TCB of highest priority task
LDS R31,OSTCBHighRdy+1 ; ready to run
STS OSTCBCur,R30 ; OSTCBCur = OSTCBHighRdy
STS OSTCBCur+1,R31 ;
LD R28,Z+ ; Restore Y pointer
OUT _SFR_IO_ADDR(SPL),R28
LD R29,Z+ ;
OUT _SFR_IO_ADDR(SPH),R29
POPRS ; Restore all registers and the status register
RETI
;*********************************************************************************************************
; INTERRUPT LEVEL CONTEXT SWITCH
;
; Description : This function is called by OSIntExit() to perform a context switch to a task that has
; been made ready-to-run by an ISR.
;
; 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:
;
; SP+0 --> LSB of return address of OSIntCtxSw() (Low memory)
; +1 MSB of return address of OSIntCtxSw()
; +2 LSB of return address of OSIntExit()
; +3 MSB of return address of OSIntExit()
; possible SREG save
; +4 LSB of task code address
; +5 MSB of task code address (High memory)
;
; 3) The saved context of the task to resume looks as follows:
;
; OSTCBHighRdy->OSTCBStkPtr --> Flags to load in status register (Low memory)
; R31
; R30
; R7
; .
; .
; .
; R0 (High memory)
;*********************************************************************************************************
OSIntCtxSw:
#if OS_CPU_HOOKS_EN > 0
CALL OSTaskSwHook ; Call user defined task switch hook
#endif
LDS R16,OSPrioHighRdy ; OSPrioCur = OSPrioHighRdy
STS OSPrioCur,R16 ;
LDS R30,OSTCBHighRdy ; Z = OSTCBHighRdy->OSTCBStkPtr
LDS R31,OSTCBHighRdy+1 ;
STS OSTCBCur,R30 ; OSTCBCur = OSTCBHighRdy
STS OSTCBCur+1,R31 ;
LD R28,Z+ ; Restore Y pointer
OUT _SFR_IO_ADDR(SPL),R28
LD R29,Z+ ;
OUT _SFR_IO_ADDR(SPH),R29
POPRS ; Restore all registers and status register
RET
;********************************************************************************************************
; SYSTEM TICK ISR
;
; Description : This function is the ISR used to notify uC/OS-II that a system tick has occurred.
;
;
;********************************************************************************************************
TIMER0_COMP_vect:
OSTickISR:
PUSHRS ; Save all registers and status register
LDS R16,OSIntNesting ; Notify uC/OS-II of ISR
INC R16 ;
STS OSIntNesting,R16 ;
CLZ ;清零Z標志位,為下面的比較做好準備
CPI R16,1 ;比較OSIntNesting是否為1
BREQ OSTickISR2 ;如果是1,則跳轉至OSTickISR2
SEI ; Enable interrupts
CALL OSTimeTick ; Call uC/OS-IIs tick updating function
CALL OSIntExit ; Notify uC/OS-II about end of ISR
POPRS ; Restore all registers and status register
RET ; Note: RET instead of RETI
OSTickISR2:
LDS R30,OSTCBCur ; Z = OSTCBCur->OSTCBStkPtr
LDS R31,OSTCBCur+1 ;
IN r28,_SFR_IO_ADDR(SPL)
ST Z+,R28 ; Save Y (R29:R28) pointer
IN r29,_SFR_IO_ADDR(SPH)
ST Z+,R29 ;OSTCBCur->OSTCBStkPtr=SP
SEI ; 使能中斷,繼續執行OSTickISR中被打斷的指令(可選用)
CALL OSTimeTick ; Call uC/OS-IIs tick updating function
CALL OSIntExit ; Notify uC/OS-II about end of ISR
POPRS ; Restore all registers and status register
RET ;
;********************************************************************************************************
; DISABLE/ENABLE INTERRUPTS USING OS_CRITICAL_METHOD #3
;
; Description : These functions are used to disable and enable interrupts using OS_CRITICAL_METHOD #3.
;
; OS_CPU_SR OSCPUSaveSR (void)
; Get current value of SREG
; Disable interrupts
; Return original value of SREG
;
; void OSCPURestoreSR (OS_CPU_SR cpu_sr)
; Set SREG to cpu_sr
; Return
;********************************************************************************************************
OS_CPU_SR_Save:
IN R16,_SFR_IO_ADDR(SREG) ; Get current state of interrupts disable flag
CLI ; Disable interrupts
RET ; Return original SREG value in R16
OS_CPU_SR_Restore:
OUT _SFR_IO_ADDR(SREG),R16 ; Restore SREG
RET ; Return
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