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;/*
; * FreeRTOS Kernel V10.3.0
; * Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
; *
; * 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.
; *
; * http://www.FreeRTOS.org
; * http://aws.amazon.com/freertos
; *
; * 1 tab == 4 spaces!
; */
SYS_MODE EQU 0x1f
SVC_MODE EQU 0x13
IRQ_MODE EQU 0x12
IMPORT ulCriticalNesting
IMPORT pxCurrentTCB
IMPORT ulPortTaskHasFPUContext
IMPORT ulAsmAPIPriorityMask
IMPORT ulICCPMR
MACRO
portSAVE_CONTEXT
; Save the LR and SPSR onto the system mode stack before switching to
; system mode to save the remaining system mode registers
SRSDB sp!, #SYS_MODE
CPS #SYS_MODE
PUSH {R0-R12, R14}
; Push the critical nesting count
LDR R2, =ulCriticalNesting
LDR R1, [R2]
PUSH {R1}
; Does the task have a floating point context that needs saving? If
; ulPortTaskHasFPUContext is 0 then no.
LDR R2, =ulPortTaskHasFPUContext
LDR R3, [R2]
CMP R3, #0
; Save the floating point context, if any
FMRXNE R1, FPSCR
VPUSHNE {D0-D15}
VPUSHNE {D16-D31}
PUSHNE {R1}
; Save ulPortTaskHasFPUContext itself
PUSH {R3}
; Save the stack pointer in the TCB
LDR R0, =pxCurrentTCB
LDR R1, [R0]
STR SP, [R1]
MEND
; /**********************************************************************/
MACRO
portRESTORE_CONTEXT
; Set the SP to point to the stack of the task being restored.
LDR R0, =pxCurrentTCB
LDR R1, [R0]
LDR SP, [R1]
; Is there a floating point context to restore? If the restored
; ulPortTaskHasFPUContext is zero then no.
LDR R0, =ulPortTaskHasFPUContext
POP {R1}
STR R1, [R0]
CMP R1, #0
; Restore the floating point context, if any
POPNE {R0}
VPOPNE {D16-D31}
VPOPNE {D0-D15}
VMSRNE FPSCR, R0
; Restore the critical section nesting depth
LDR R0, =ulCriticalNesting
POP {R1}
STR R1, [R0]
; Ensure the priority mask is correct for the critical nesting depth
LDR R2, =ulICCPMR
CMP R1, #0
MOVEQ R4, #255
LDRNE R4, =ulAsmAPIPriorityMask
STR R4, [r2]
; Restore all system mode registers other than the SP (which is already
; being used)
POP {R0-R12, R14}
; Return to the task code, loading CPSR on the way.
RFEIA sp!
MEND
END
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