;/*
;    FreeRTOS V8.2.2 - Copyright (C) 2015 Real Time Engineers Ltd.
;    All rights reserved
;	
;
;    ***************************************************************************
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;     *    Complete, revised, and edited pdf reference manuals are also       *
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;     *    professional grade, cross platform, de facto standard solutions    *
;     *    for microcontrollers - completely free of charge!                  *
;     *                                                                       *
;     *    >>> See http://www.FreeRTOS.org/Documentation for details. <<<     *
;     *                                                                       *
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;
;
;    This file is part of the FreeRTOS distribution.
;
;    FreeRTOS is free software; you can redistribute it and/or modify it under
;    the terms of the GNU General Public License (version 2) as published by the
;    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
;    >>>NOTE<<< The modification to the GPL is included to allow you to
;    distribute a combined work that includes FreeRTOS without being obliged to
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;    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
;    more details. You should have received a copy of the GNU General Public
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;    can be viewed here: http://www.freertos.org/a00114.html and also obtained
;    by writing to Richard Barry, contact details for whom are available on the
;    FreeRTOS WEB site.
;
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;    http://www.FreeRTOS.org - Documentation, latest information, license and
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;    http://www.SafeRTOS.com - A version that is certified for use in safety
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;*/

	EXTERN pxCurrentTCB
	EXTERN ulCriticalNesting

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Context save and restore macro definitions
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

portSAVE_CONTEXT MACRO

	; Push R0 as we are going to use the register. 					
	STMDB	SP!, {R0}

	; Set R0 to point to the task stack pointer. 					
	STMDB	SP, {SP}^
	NOP
	SUB		SP, SP, #4
	LDMIA	SP!, {R0}

	; Push the return address onto the stack. 						
	STMDB	R0!, {LR}

	; Now we have saved LR we can use it instead of R0. 				
	MOV		LR, R0

	; Pop R0 so we can save it onto the system mode stack. 			
	LDMIA	SP!, {R0}

	; Push all the system mode registers onto the task stack. 		
	STMDB	LR, {R0-LR}^
	NOP
	SUB		LR, LR, #60

	; Push the SPSR onto the task stack. 							
	MRS		R0, SPSR
	STMDB	LR!, {R0}

	LDR		R0, =ulCriticalNesting 
	LDR		R0, [R0]
	STMDB	LR!, {R0}

	; Store the new top of stack for the task. 						
	LDR		R1, =pxCurrentTCB
	LDR		R0, [R1]
	STR		LR, [R0]

	ENDM


portRESTORE_CONTEXT MACRO

	; Set the LR to the task stack. 									
	LDR		R1, =pxCurrentTCB
	LDR		R0, [R1]
	LDR		LR, [R0]

	; The critical nesting depth is the first item on the stack. 	
	; Load it into the ulCriticalNesting variable. 					
	LDR		R0, =ulCriticalNesting
	LDMFD	LR!, {R1}
	STR		R1, [R0]

	; Get the SPSR from the stack. 									
	LDMFD	LR!, {R0}
	MSR		SPSR_cxsf, R0

	; Restore all system mode registers for the task. 				
	LDMFD	LR, {R0-R14}^
	NOP

	; Restore the return address. 									
	LDR		LR, [LR, #+60]

	; And return - correcting the offset in the LR to obtain the 	
	; correct address. 												
	SUBS	PC, LR, #4

	ENDM