xmclib/CMSIS/RTOS2/RTX/Source/ARM/irq_cm4f.s

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2024-10-17 17:09:59 +02:00
;/*
; * Copyright (c) 2013-2017 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-M4F Exception handlers
; *
; * -----------------------------------------------------------------------------
; */
I_T_RUN_OFS EQU 28 ; osRtxInfo.thread.run offset
TCB_SP_OFS EQU 56 ; TCB.SP offset
TCB_SF_OFS EQU 34 ; TCB.stack_frame 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
MRS R0,PSP ; Get 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 PSP and EXC_RETURN
LDM R0,{R0-R3,R12} ; Load function parameters and address from stack
BLX R12 ; Call service function
POP {R12,LR} ; Restore PSP 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
BXEQ LR ; Exit when threads are the same
CBNZ R1,SVC_ContextSave ; Branch if running thread is not deleted
TST LR,#0x10 ; Check if extended stack frame
BNE SVC_ContextSwitch
LDR R1,=0xE000EF34 ; FPCCR Address
LDR R0,[R1] ; Load FPCCR
BIC R0,#1 ; Clear LSPACT (Lazy state)
STR R0,[R1] ; Store FPCCR
B SVC_ContextSwitch
SVC_ContextSave
STMDB R12!,{R4-R11} ; Save R4..R11
TST LR,#0x10 ; Check if extended stack frame
VSTMDBEQ R12!,{S16-S31} ; Save VFP S16.S31
STR R12,[R1,#TCB_SP_OFS] ; Store SP
STRB LR, [R1,#TCB_SF_OFS] ; Store stack frame information
SVC_ContextSwitch
STR R2,[R3] ; osRtxInfo.thread.run: curr = next
SVC_ContextRestore
LDRB R1,[R2,#TCB_SF_OFS] ; Load stack frame information
LDR R0,[R2,#TCB_SP_OFS] ; Load SP
ORR LR,R1,#0xFFFFFF00 ; Set EXC_RETURN
TST LR,#0x10 ; Check if extended stack frame
VLDMIAEQ R0!,{S16-S31} ; Restore VFP S16..S31
LDMIA R0!,{R4-R11} ; Restore R4..R11
MSR PSP,R0 ; Set PSP
SVC_Exit
BX LR ; Exit from handler
SVC_User
PUSH {R4,LR} ; Save registers
LDR R2,=osRtxUserSVC ; Load address of SVC table
LDR R3,[R2] ; Load SVC maximum number
CMP R1,R3 ; Check SVC number range
BHI SVC_Done ; Branch if out of range
LDR R4,[R2,R1,LSL #2] ; Load address of SVC function
LDM R0,{R0-R3} ; Load function parameters from stack
BLX R4 ; Call service function
MRS R4,PSP ; Get PSP
STR R0,[R4] ; Store function return value
SVC_Done
POP {R4,PC} ; Return from handler
ALIGN
ENDP
PendSV_Handler PROC
EXPORT PendSV_Handler
IMPORT osRtxPendSV_Handler
PUSH {R4,LR} ; Save EXC_RETURN
BL osRtxPendSV_Handler ; Call osRtxPendSV_Handler
POP {R4,LR} ; Restore EXC_RETURN
MRS R12,PSP
B SVC_Context
ALIGN
ENDP
SysTick_Handler PROC
EXPORT SysTick_Handler
IMPORT osRtxTick_Handler
PUSH {R4,LR} ; Save EXC_RETURN
BL osRtxTick_Handler ; Call osRtxTick_Handler
POP {R4,LR} ; Restore EXC_RETURN
MRS R12,PSP
B SVC_Context
ALIGN
ENDP
END