;/*
;    FreeRTOS V6.0.0 - Copyright (C) 2009 Real Time Engineers Ltd.
;
;    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 exception to the GPL is included to allow you to distribute a
;    combined work that includes FreeRTOS without being obliged to provide the
;    source code for proprietary components outside of the FreeRTOS kernel.
;    Alternative commercial license and support terms are also available upon
;    request.  See the licensing section of http://www.FreeRTOS.org for full
;    license details.
;
;    FreeRTOS is distributed in the hope that it will be useful,    but WITHOUT
;    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 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 License along
;    with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
;    Temple Place, Suite 330, Boston, MA  02111-1307  USA.
;
;
;    ***************************************************************************
;    *                                                                         *
;    * The FreeRTOS eBook and reference manual are available to purchase for a *
;    * small fee. Help yourself get started quickly while also helping the     *
;    * FreeRTOS project! See http://www.FreeRTOS.org/Documentation for details *
;    *                                                                         *
;    ***************************************************************************
;
;    1 tab == 4 spaces!
;
;    Please ensure to read the configuration and relevant port sections of the
;    online documentation.
;
;    http://www.FreeRTOS.org - Documentation, latest information, license and
;    contact details.
;
;    http://www.SafeRTOS.com - A version that is certified for use in safety
;    critical systems.
;
;    http://www.OpenRTOS.com - Commercial support, development, porting,
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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