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- ;/*
- ; * FreeRTOS Kernel V10.4.6
- ; * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
- ; *
- ; * SPDX-License-Identifier: MIT
- ; *
- ; * Permission is hereby granted, free of charge, to any person obtaining a copy of
- ; * this software and associated documentation files (the "Software"), to deal in
- ; * the Software without restriction, including without limitation the rights to
- ; * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
- ; * the Software, and to permit persons to whom the Software is furnished to do so,
- ; * subject to the following conditions:
- ; *
- ; * The above copyright notice and this permission notice shall be included in all
- ; * copies or substantial portions of the Software.
- ; *
- ; * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- ; * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
- ; * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
- ; * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
- ; * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- ; * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- ; *
- ; * https://www.FreeRTOS.org
- ; * https://github.com/FreeRTOS
- ; *
- ; */
- IMPORT ulCriticalNesting ;
- IMPORT pxCurrentTCB ;
- MACRO
- portRESTORE_CONTEXT
- LDR R0, =pxCurrentTCB ; Set the LR to the task stack. The location was...
- LDR R0, [R0] ; ... stored in pxCurrentTCB
- LDR LR, [R0]
- LDR R0, =ulCriticalNesting ; The critical nesting depth is the first item on...
- LDMFD LR!, {R1} ; ...the stack. Load it into the ulCriticalNesting var.
- STR R1, [R0] ;
- LDMFD LR!, {R0} ; Get the SPSR from the stack.
- MSR SPSR_cxsf, R0 ;
- LDMFD LR, {R0-R14}^ ; Restore all system mode registers for the task.
- NOP ;
- LDR LR, [LR, #+60] ; Restore the return address
- ; And return - correcting the offset in the LR to obtain ...
- SUBS PC, LR, #4 ; ...the correct address.
- MEND
- ; /**********************************************************************/
- MACRO
- portSAVE_CONTEXT
- STMDB SP!, {R0} ; Store R0 first as we need to use it.
- STMDB SP,{SP}^ ; Set R0 to point to the task stack pointer.
- NOP ;
- SUB SP, SP, #4 ;
- LDMIA SP!,{R0} ;
- STMDB R0!, {LR} ; Push the return address onto the stack.
- MOV LR, R0 ; Now we have saved LR we can use it instead of R0.
- LDMIA SP!, {R0} ; Pop R0 so we can save it onto the system mode stack.
- STMDB LR,{R0-LR}^ ; Push all the system mode registers onto the task stack.
- NOP ;
- SUB LR, LR, #60 ;
- MRS R0, SPSR ; Push the SPSR onto the task stack.
- STMDB LR!, {R0} ;
- LDR R0, =ulCriticalNesting ;
- LDR R0, [R0] ;
- STMDB LR!, {R0} ;
- LDR R0, =pxCurrentTCB ; Store the new top of stack for the task.
- LDR R1, [R0] ;
- STR LR, [R1] ;
- MEND
- END
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