;/*
; * FreeRTOS Kernel V10.4.3
; * 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
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; * 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
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; */

	EXTERN	vTaskSwitchContext
	EXTERN  ulCriticalNesting
	EXTERN	pxCurrentTCB
	EXTERN	ulPortTaskHasFPUContext
	EXTERN  ulAsmAPIPriorityMask

portSAVE_CONTEXT macro

	; 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]

	endm

; /**********************************************************************/

portRESTORE_CONTEXT macro

	; 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, =portICCPMR_PRIORITY_MASK_REGISTER_ADDRESS
	CMP		R1, #0
	MOVEQ	R4, #255
	LDRNE	R4, =( configMAX_API_CALL_INTERRUPT_PRIORITY << portPRIORITY_SHIFT )
	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!

	endm





