pinebuds/rtos/rtx5/ARM/irq_cm3.s
2022-08-15 17:20:27 +08:00

146 lines
5.5 KiB
ArmAsm

;/*
; * Copyright (c) 2013-2018 Arm Limited. All rights reserved.
; *
; * SPDX-License-Identifier: Apache-2.0
; *
; * Licensed under the Apache License, Version 2.0 (the License); you may
; * not use this file except in compliance with the License.
; * You may obtain a copy of the License at
; *
; * www.apache.org/licenses/LICENSE-2.0
; *
; * Unless required by applicable law or agreed to in writing, software
; * distributed under the License is distributed on an AS IS BASIS, WITHOUT
; * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
; * See the License for the specific language governing permissions and
; * limitations under the License.
; *
; * -----------------------------------------------------------------------------
; *
; * Project: CMSIS-RTOS RTX
; * Title: Cortex-M3 Exception handlers
; *
; * -----------------------------------------------------------------------------
; */
I_T_RUN_OFS EQU 20 ; osRtxInfo.thread.run offset
TCB_SP_OFS EQU 56 ; TCB.SP offset
PRESERVE8
THUMB
AREA |.constdata|, DATA, READONLY
EXPORT irqRtxLib
irqRtxLib DCB 0 ; Non weak library reference
AREA |.text|, CODE, READONLY
SVC_Handler PROC
EXPORT SVC_Handler
IMPORT osRtxUserSVC
IMPORT osRtxInfo
IF :DEF:MPU_LOAD
IMPORT osRtxMpuLoad
ENDIF
TST LR,#0x04 ; Determine return stack from EXC_RETURN bit 2
ITE EQ
MRSEQ R0,MSP ; Get MSP if return stack is MSP
MRSNE R0,PSP ; Get PSP if return stack is PSP
LDR R1,[R0,#24] ; Load saved PC from stack
LDRB R1,[R1,#-2] ; Load SVC number
CBNZ R1,SVC_User ; Branch if not SVC 0
PUSH {R0,LR} ; Save SP and EXC_RETURN
LDM R0,{R0-R3,R12} ; Load function parameters and address from stack
BLX R12 ; Call service function
POP {R12,LR} ; Restore SP and EXC_RETURN
STM R12,{R0-R1} ; Store function return values
SVC_Context
LDR R3,=osRtxInfo+I_T_RUN_OFS; Load address of osRtxInfo.run
LDM R3,{R1,R2} ; Load osRtxInfo.thread.run: curr & next
CMP R1,R2 ; Check if thread switch is required
IT EQ
BXEQ LR ; Exit when threads are the same
CBZ R1,SVC_ContextSwitch ; Branch if running thread is deleted
SVC_ContextSave
STMDB R12!,{R4-R11} ; Save R4..R11
STR R12,[R1,#TCB_SP_OFS] ; Store SP
SVC_ContextSwitch
STR R2,[R3] ; osRtxInfo.thread.run: curr = next
IF :DEF:MPU_LOAD
PUSH {R2,R3} ; Save registers
MOV R0,R2 ; osRtxMpuLoad parameter
BL osRtxMpuLoad ; Load MPU for next thread
POP {R2,R3} ; Restore registers
ENDIF
SVC_ContextRestore
LDR R0,[R2,#TCB_SP_OFS] ; Load SP
LDMIA R0!,{R4-R11} ; Restore R4..R11
MSR PSP,R0 ; Set PSP
MVN LR,#~0xFFFFFFFD ; Set EXC_RETURN value
SVC_Exit
BX LR ; Exit from handler
SVC_User
LDR R2,=osRtxUserSVC ; Load address of SVC table
LDR R3,[R2] ; Load SVC maximum number
CMP R1,R3 ; Check SVC number range
BHI SVC_Exit ; Branch if out of range
PUSH {R0,LR} ; Save SP and EXC_RETURN
LDR R12,[R2,R1,LSL #2] ; Load address of SVC function
LDM R0,{R0-R3} ; Load function parameters from stack
BLX R12 ; Call service function
POP {R12,LR} ; Restore SP and EXC_RETURN
STR R0,[R12] ; Store function return value
BX LR ; Return from handler
ALIGN
ENDP
PendSV_Handler PROC
EXPORT PendSV_Handler
IMPORT osRtxPendSV_Handler
PUSH {R0,LR} ; Save EXC_RETURN
BL osRtxPendSV_Handler ; Call osRtxPendSV_Handler
POP {R0,LR} ; Restore EXC_RETURN
MRS R12,PSP
B SVC_Context
ALIGN
ENDP
SysTick_Handler PROC
EXPORT SysTick_Handler
IMPORT osRtxTick_Handler
PUSH {R0,LR} ; Save EXC_RETURN
BL osRtxTick_Handler ; Call osRtxTick_Handler
POP {R0,LR} ; Restore EXC_RETURN
MRS R12,PSP
B SVC_Context
ALIGN
ENDP
END