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2025-10-18 16:51:59 +08:00

256 lines
9.4 KiB
ArmAsm

/*
* Copyright (c) 2013-2023 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: ARMv6-M Exception handlers
*
* -----------------------------------------------------------------------------
*/
.syntax unified
#include "rtx_def.h"
.equ I_T_RUN_OFS, 20 // osRtxInfo.thread.run offset
.equ TCB_SP_OFS, 56 // TCB.SP offset
.equ TCB_ZONE_OFS, 68 // TCB.zone offset
.equ osRtxErrorStackOverflow, 1 // Stack overflow
.equ osRtxErrorSVC, 6 // Invalid SVC function called
.section ".rodata"
.global irqRtxLib // Non weak library reference
irqRtxLib:
.byte 0
.thumb
.section ".text"
.align 2
.eabi_attribute Tag_ABI_align_preserved, 1
.thumb_func
.type SVC_Handler, %function
.global SVC_Handler
.fnstart
.cantunwind
SVC_Handler:
mov r0,lr
lsrs r0,r0,#3 // Determine return stack from EXC_RETURN bit 2
bcc SVC_MSP // Branch if return stack is MSP
mrs r0,psp // Get PSP
SVC_Number:
ldr r1,[r0,#24] // Load saved PC from stack
subs r1,r1,#2 // Point to SVC instruction
ldrb r1,[r1] // Load SVC number
cmp r1,#0 // Check SVC number
bne SVC_User // Branch if not SVC 0
#ifdef RTX_SVC_PTR_CHECK
subs r1,r7,#0x01 // Clear T-bit of function address
lsls r2,r1,#29 // Check if 8-byte aligned
beq SVC_PtrBoundsCheck // Branch if address is aligned
SVC_PtrInvalid:
push {r0,lr} // Save SP and EXC_RETURN
movs r0,#osRtxErrorSVC // Parameter: code
mov r1,r7 // Parameter: object_id
bl osRtxKernelErrorNotify // Call osRtxKernelErrorNotify
pop {r2,r3} // Restore SP and EXC_RETURN
mov lr,r3 // Set EXC_RETURN
b SVC_Context // Branch to context handling
SVC_PtrBoundsCheck:
ldr r2,=Image$$RTX_SVC_VENEERS$$Base
ldr r3,=Image$$RTX_SVC_VENEERS$$Length
subs r2,r1,r2 // Subtract SVC table base address
cmp r2,r3 // Compare with SVC table boundaries
bhs SVC_PtrInvalid // Branch if address is out of bounds
#endif // RTX_SVC_PTR_CHECK
push {r0,lr} // Save SP and EXC_RETURN
ldmia r0,{r0-r3} // Load function parameters from stack
blx r7 // Call service function
pop {r2,r3} // Restore SP and EXC_RETURN
str r0,[r2] // Store function return value
mov lr,r3 // Set EXC_RETURN
SVC_Context:
ldr r3,=osRtxInfo+I_T_RUN_OFS // Load address of osRtxInfo.thread.run
ldmia r3!,{r1,r2} // Load osRtxInfo.thread.run: curr & next
cmp r1,r2 // Check if thread switch is required
beq SVC_Exit // Branch when threads are the same
subs r3,r3,#8 // Adjust address
str r2,[r3] // osRtxInfo.thread.run: curr = next
cmp r1,#0
beq SVC_ContextRestore // Branch if running thread is deleted
SVC_ContextSave:
mrs r0,psp // Get PSP
subs r0,r0,#32 // Calculate SP: space for R4..R11
str r0,[r1,#TCB_SP_OFS] // Store SP
#ifdef RTX_STACK_CHECK
push {r1,r2} // Save osRtxInfo.thread.run: curr & next
mov r0,r1 // Parameter: osRtxInfo.thread.run.curr
bl osRtxThreadStackCheck // Check if thread stack is overrun
pop {r1,r2} // Restore osRtxInfo.thread.run: curr & next
cmp r0,#0
bne SVC_ContextSaveRegs // Branch when stack check is ok
movs r0,#osRtxErrorStackOverflow // Parameter: r0=code, r1=object_id
bl osRtxKernelErrorNotify // Call osRtxKernelErrorNotify
ldr r3,=osRtxInfo+I_T_RUN_OFS // Load address of osRtxInfo.thread.run
ldr r2,[r3,#4] // Load osRtxInfo.thread.run: next
str r2,[r3] // osRtxInfo.thread.run: curr = next
movs r1,#0 // Simulate deleted running thread
b SVC_ContextRestore // Branch to context restore handling
SVC_ContextSaveRegs:
ldr r0,[r1,#TCB_SP_OFS] // Load SP
#endif // RTX_STACK_CHECK
stmia r0!,{r4-r7} // Save R4..R7
mov r4,r8
mov r5,r9
mov r6,r10
mov r7,r11
stmia r0!,{r4-r7} // Save R8..R11
SVC_ContextRestore:
movs r4,r2 // Assign osRtxInfo.thread.run.next to R4
#ifdef RTX_EXECUTION_ZONE
movs r3,#TCB_ZONE_OFS // Get TCB.zone offset
ldrb r0,[r2,r3] // Load osRtxInfo.thread.run.next: zone
cmp r1,#0
beq SVC_ZoneSetup // Branch if running thread is deleted
ldrb r1,[r1,r3] // Load osRtxInfo.thread.run.curr: zone
cmp r0,r1 // Check if next:zone == curr:zone
beq SVC_ContextRestore_N // Branch if zone has not changed
SVC_ZoneSetup:
bl osZoneSetup_Callback // Setup zone for next thread
#endif // RTX_EXECUTION_ZONE
SVC_ContextRestore_N:
ldr r0,[r4,#TCB_SP_OFS] // Load SP
adds r0,r0,#16 // Adjust address
ldmia r0!,{r4-r7} // Restore R8..R11
mov r8,r4
mov r9,r5
mov r10,r6
mov r11,r7
msr psp,r0 // Set PSP
subs r0,r0,#32 // Adjust address
ldmia r0!,{r4-r7} // Restore R4..R7
movs r0,#2 // Binary complement of 0xFFFFFFFD
mvns r0,r0 // Set EXC_RETURN value
bx r0 // Exit from handler
SVC_MSP:
mrs r0,msp // Get MSP
b SVC_Number
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
lsls r1,r1,#2
ldr r3,[r2,r1] // Load address of SVC function
mov r12,r3
ldmia r0,{r0-r3} // Load function parameters from stack
blx r12 // Call service function
pop {r2,r3} // Restore SP and EXC_RETURN
str r0,[r2] // Store function return value
bx r3 // 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,r1} // Restore EXC_RETURN
mov lr,r1 // Set EXC_RETURN
b SVC_Context // Branch to context handling
.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,r1} // Restore EXC_RETURN
mov lr,r1 // Set EXC_RETURN
b SVC_Context // Branch to context handling
.fnend
.size SysTick_Handler, .-SysTick_Handler
#ifdef RTX_SAFETY_FEATURES
.thumb_func
.type osFaultResume, %function
.global osFaultResume
.fnstart
.cantunwind
osFaultResume:
b SVC_Context // Branch to context handling
.fnend
.size osFaultResume, .-osFaultResume
#endif // RTX_SAFETY_FEATURES
.end