FreeRTOS/Source/portable/RVDS/ARM7_LPC21xx/portmacro.inc

;/*
;    FreeRTOS V7.2.0 - Copyright (C) 2012 Real Time Engineers Ltd.
;	
;
;    ***************************************************************************
;     *                                                                       *
;     *    FreeRTOS tutorial books are available in pdf and paperback.        *
;     *    Complete, revised, and edited pdf reference manuals are also       *
;     *    available.                                                         *
;     *                                                                       *
;     *    Purchasing FreeRTOS documentation will not only help you, by       *
;     *    ensuring you get running as quickly as possible and with an        *
;     *    in-depth knowledge of how to use FreeRTOS, it will also help       *
;     *    the FreeRTOS project to continue with its mission of providing     *
;     *    professional grade, cross platform, de facto standard solutions    *
;     *    for microcontrollers - completely free of charge!                  *
;     *                                                                       *
;     *    >>> See http://www.FreeRTOS.org/Documentation for details. <<<     *
;     *                                                                       *
;     *    Thank you for using FreeRTOS, and thank you for your support!      *
;     *                                                                       *
;    ***************************************************************************
;
;
;    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
;    provide the source code for proprietary components outside of the FreeRTOS
;    kernel.  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 and the FreeRTOS license exception along with FreeRTOS; if not it
;    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.
;
;    1 tab == 4 spaces!
;
;    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,
;    licensing and training services.
;*/

	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