pinebuds/rtos/rtx5/GCC/irq_cm4f.S

162 lines
5.7 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-M4F Exception handlers
*
* -----------------------------------------------------------------------------
*/
.file "irq_cm4f.S"
.syntax unified
.equ I_T_RUN_OFS, 20 // osRtxInfo.thread.run offset
.equ TCB_SP_OFS, 56 // TCB.SP offset
.equ TCB_SF_OFS, 34 // TCB.stack_frame offset
.section ".rodata"
.global irqRtxLib // Non weak library reference
irqRtxLib:
.byte 0
.thumb
.section ".text"
.align 2
.thumb_func
.type SVC_Handler, %function
.global SVC_Handler
.fnstart
.cantunwind
SVC_Handler:
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
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,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
IT EQ
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
IT EQ
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:
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
.fnend
.size SVC_Handler, .-SVC_Handler
.thumb_func
.type PendSV_Handler, %function
.global PendSV_Handler
.fnstart
.cantunwind
PendSV_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
.fnend
.size PendSV_Handler, .-PendSV_Handler
.thumb_func
.type SysTick_Handler, %function
.global SysTick_Handler
.fnstart
.cantunwind
SysTick_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
.fnend
.size SysTick_Handler, .-SysTick_Handler
.end