/*
    FreeRTOS V6.0.5 - Copyright (C) 2010 Real Time Engineers Ltd.

    ***************************************************************************
    *                                                                         *
    * If you are:                                                             *
    *                                                                         *
    *    + New to FreeRTOS,                                                   *
    *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
    *    + Looking for basic training,                                        *
    *    + Wanting to improve your FreeRTOS skills and productivity           *
    *                                                                         *
    * then take a look at the FreeRTOS eBook                                  *
    *                                                                         *
    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
    *                  http://www.FreeRTOS.org/Documentation                  *
    *                                                                         *
    * A pdf reference manual is also available.  Both are usually delivered   *
    * to your inbox within 20 minutes to two hours when purchased between 8am *
    * and 8pm GMT (although please allow up to 24 hours in case of            *
    * exceptional circumstances).  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 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.
    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.
*/

/* 
Changes from V3.0.0

Changes from V3.0.1
*/
#ifndef PORTMACRO_H
#define PORTMACRO_H

#if !defined(_SERIES) || _SERIES != 18
	#error "WizC supports FreeRTOS on the Microchip PIC18-series only"
#endif

#if !defined(QUICKCALL) || QUICKCALL != 1
	#error "QuickCall must be enabled (see ProjectOptions/Optimisations)"
#endif

#include <stddef.h>
#include <pic.h>

#define portCHAR		char
#define portFLOAT		float
#define portDOUBLE		portFLOAT
#define portLONG		long
#define portSHORT		short
#define portSTACK_TYPE	unsigned char
#define portBASE_TYPE	char

#if( configUSE_16_BIT_TICKS == 1 )
	typedef unsigned portSHORT portTickType;
	#define portMAX_DELAY ( portTickType )	( 0xFFFF )
#else
	typedef unsigned portLONG portTickType;
	#define portMAX_DELAY ( portTickType )	( 0xFFFFFFFF )
#endif

#define portBYTE_ALIGNMENT			1

/*-----------------------------------------------------------*/

/*
 * Constant used for context switch macro when we require the interrupt 
 * enable state to be forced when the interrupted task is switched back in.
 */
#define portINTERRUPTS_FORCED				(0x01)

/*
 * Constant used for context switch macro when we require the interrupt 
 * enable state to be unchanged when the interrupted task is switched back in.
 */
#define portINTERRUPTS_UNCHANGED			(0x00)

/* Initial interrupt enable state for newly created tasks.  This value is
 * used when a task switches in for the first time.
 */
#define portINTERRUPTS_INITIAL_STATE		(portINTERRUPTS_FORCED)

/*
 * Macros to modify the global interrupt enable bit in INTCON.
 */
#define portDISABLE_INTERRUPTS()	\
	do								\
	{								\
		bGIE=0;						\
	} while(bGIE)	// MicroChip recommends this check!
	
#define portENABLE_INTERRUPTS()		\
	do								\
	{								\
		bGIE=1;						\
	} while(0)

/*-----------------------------------------------------------*/	

/*
 * Critical section macros.
 */
extern unsigned portCHAR ucCriticalNesting;

#define portNO_CRITICAL_SECTION_NESTING		( ( unsigned portCHAR ) 0 )

#define portENTER_CRITICAL()										\
	do																\
	{																\
		portDISABLE_INTERRUPTS();									\
																	\
		/*															\
		 * Now interrupts are disabled ucCriticalNesting			\
		 * can be accessed directly. Increment						\
		 * ucCriticalNesting to keep a count of how					\
		 * many times portENTER_CRITICAL() has been called. 		\
		 */															\
		ucCriticalNesting++;										\
	} while(0)

#define portEXIT_CRITICAL()											\
	do																\
	{																\
		if(ucCriticalNesting > portNO_CRITICAL_SECTION_NESTING)		\
		{															\
			/*														\
			 * Decrement the nesting count as we are leaving a		\
			 * critical section.									\
			 */														\
			ucCriticalNesting--;									\
		}															\
																	\
		/*															\
		 * If the nesting level has reached zero then				\
		 * interrupts should be re-enabled.							\
		 */															\
		if( ucCriticalNesting == portNO_CRITICAL_SECTION_NESTING )	\
		{															\
			portENABLE_INTERRUPTS();								\
		}															\
	} while(0)

/*-----------------------------------------------------------*/

/*
 * The minimal stacksize is calculated on the first reference of
 * portMINIMAL_STACK_SIZE. Some input to this calculation is
 * compiletime determined, other input is port-defined (see port.c)
 */
extern unsigned portSHORT usPortCALCULATE_MINIMAL_STACK_SIZE( void );
extern unsigned portSHORT usCalcMinStackSize;

#define portMINIMAL_STACK_SIZE					\
	((usCalcMinStackSize == 0)					\
		? usPortCALCULATE_MINIMAL_STACK_SIZE()	\
		: usCalcMinStackSize )

/*
 * WizC uses a downgrowing stack
 */
#define portSTACK_GROWTH			( -1 )

/*-----------------------------------------------------------*/

/*
 * Macro's that pushes all the registers that make up the context of a task onto
 * the stack, then saves the new top of stack into the TCB. TOSU and TBLPTRU
 * are only saved/restored on devices with more than 64kB (32k Words) ROM.
 * 
 * The stackpointer is helt by WizC in FSR2 and points to the first free byte.
 * WizC uses a "downgrowing" stack. There is no framepointer.
 *
 * We keep track of the interruptstatus using ucCriticalNesting. When this
 * value equals zero, interrupts have to be enabled upon exit from the
 * portRESTORE_CONTEXT macro.
 * 
 * If this is called from an ISR then the interrupt enable bits must have been 
 * set for the ISR to ever get called.  Therefore we want to save
 * ucCriticalNesting with value zero. This means the interrupts will again be
 * re-enabled when the interrupted task is switched back in.
 *
 * If this is called from a manual context switch (i.e. from a call to yield),
 * then we want to keep the current value of ucCritialNesting so it is restored
 * with its current value. This allows a yield from within a critical section.
 *
 * The compiler uses some locations at the bottom of RAM for temporary
 * storage. The compiler may also have been instructed to optimize
 * function-parameters and local variables to global storage. The compiler
 * uses an area called LocOpt for this wizC feature.
 * The total overheadstorage has to be saved in it's entirety as part of
 * a task context. These macro's store/restore from data address 0x0000 to
 * (OVERHEADPAGE0-LOCOPTSIZE+MAXLOCOPTSIZE - 1).
 * OVERHEADPAGE0, LOCOPTSIZE and MAXLOCOPTSIZE are compiler-generated
 * assembler definitions.
 */

#define	portSAVE_CONTEXT( ucInterruptForced )						\
	do																\
	{																\
		portDISABLE_INTERRUPTS();									\
																	\
		_Pragma("asm")												\
			;														\
			; Push the relevant SFR's onto the task's stack			\
			;														\
			movff   STATUS,POSTDEC2									\
			movff	WREG,POSTDEC2									\
			movff	BSR,POSTDEC2									\
			movff	PRODH,POSTDEC2									\
			movff	PRODL,POSTDEC2									\
			movff	FSR0H,POSTDEC2									\
			movff	FSR0L,POSTDEC2									\
			movff	FSR1H,POSTDEC2									\
			movff	FSR1L,POSTDEC2									\
			movff	TABLAT,POSTDEC2									\
			if __ROMSIZE > 0x8000									\
				movff	TBLPTRU,POSTDEC2							\
			endif													\
			movff	TBLPTRH,POSTDEC2								\
			movff	TBLPTRL,POSTDEC2								\
			if __ROMSIZE > 0x8000									\
				movff	PCLATU,POSTDEC2								\
			endif													\
			movff	PCLATH,POSTDEC2									\
			;														\
			; Store the compiler-scratch-area as described above.	\
			;														\
			movlw	OVERHEADPAGE0-LOCOPTSIZE+MAXLOCOPTSIZE			\
			clrf	FSR0L,ACCESS									\
			clrf	FSR0H,ACCESS									\
		_rtos_S1:													\
			movff	POSTINC0,POSTDEC2								\
			decfsz	WREG,W,ACCESS									\
			SMARTJUMP _rtos_S1										\
			;														\
			; Save the pic call/return-stack belonging to the		\
			; current task by copying it to the task's software-	\
			; stack. We save the hardware stack pointer (which		\
			; is the number of addresses on the stack) in the		\
			; W-register first because we need it later and it		\
			; is modified in the save-loop by executing pop's.		\
			; After the loop the W-register is stored on the		\
			; stack, too.											\
			;														\
			movf	STKPTR,W,ACCESS									\
			bz		_rtos_s3										\
		_rtos_S2:													\
			if __ROMSIZE > 0x8000									\
				movff	TOSU,POSTDEC2								\
			endif													\
			movff	TOSH,POSTDEC2									\
			movff	TOSL,POSTDEC2									\
			pop														\
			tstfsz	STKPTR,ACCESS									\
			SMARTJUMP _rtos_S2										\
		_rtos_s3:													\
			movwf	POSTDEC2,ACCESS									\
			;														\
			; Next the value for ucCriticalNesting used by the		\
			; task is stored on the stack. When						\
			; (ucInterruptForced == portINTERRUPTS_FORCED), we save	\
			; it as 0 (portNO_CRITICAL_SECTION_NESTING).			\
			;														\
			if ucInterruptForced == portINTERRUPTS_FORCED			\
				clrf POSTDEC2,ACCESS								\
			else													\
				movff	ucCriticalNesting,POSTDEC2					\
			endif													\
			;														\
			; Save the new top of the software stack in the TCB.	\
			;														\
			movff	pxCurrentTCB,FSR0L								\
			movff	pxCurrentTCB+1,FSR0H							\
			movff	FSR2L,POSTINC0									\
			movff	FSR2H,POSTINC0									\
		_Pragma("asmend")											\
	} while(0)

/************************************************************/

/*
 * This is the reverse of portSAVE_CONTEXT.
 */
#define portRESTORE_CONTEXT()										\
	do																\
	{																\
		_Pragma("asm")												\
			;														\
			; Set FSR0 to point to pxCurrentTCB->pxTopOfStack.		\
			;														\
			movff	pxCurrentTCB,FSR0L								\
			movff	pxCurrentTCB+1,FSR0H							\
			;														\
			; De-reference FSR0 to set the address it holds into	\
			; FSR2 (i.e. *( pxCurrentTCB->pxTopOfStack ) ). FSR2	\
			; is used by wizC as stackpointer.						\
			;														\
			movff	POSTINC0,FSR2L									\
			movff	POSTINC0,FSR2H									\
			;														\
			; Next, the value for ucCriticalNesting used by the		\
			; task is retrieved from the stack.						\
			;														\
			movff	PREINC2,ucCriticalNesting						\
			;														\
			; Rebuild the pic call/return-stack. The number of		\
			; return addresses is the next item on the task stack.	\
			; Save this number in PRODL. Then fetch the addresses	\
			; and store them on the hardwarestack.					\
			; The datasheets say we can't use movff here...			\
			;														\
			movff	PREINC2,PRODL	// Use PRODL as tempregister	\
			clrf	STKPTR,ACCESS									\
		_rtos_R1:													\
			push													\
			movf	PREINC2,W,ACCESS								\
			movwf	TOSL,ACCESS										\
			movf	PREINC2,W,ACCESS								\
			movwf	TOSH,ACCESS										\
			if __ROMSIZE > 0x8000									\
				movf	PREINC2,W,ACCESS							\
				movwf	TOSU,ACCESS									\
			else													\
				clrf	TOSU,ACCESS									\
			endif													\
			decfsz	PRODL,F,ACCESS									\
			SMARTJUMP _rtos_R1										\
			;														\
			; Restore the compiler's working storage area to page 0	\
			;														\
			movlw	OVERHEADPAGE0-LOCOPTSIZE+MAXLOCOPTSIZE			\
			movwf	FSR0L,ACCESS									\
			clrf	FSR0H,ACCESS									\
		_rtos_R2:													\
			decf	FSR0L,F,ACCESS									\
			movff	PREINC2,INDF0									\
			tstfsz	FSR0L,ACCESS									\
			SMARTJUMP _rtos_R2										\
			;														\
			; Restore the sfr's forming the tasks context.			\
			; We cannot yet restore bsr, w and status because		\
			; we need these	registers for a final test.				\
			;														\
			movff	PREINC2,PCLATH									\
			if __ROMSIZE > 0x8000									\
				movff	PREINC2,PCLATU								\
			else													\
				clrf	PCLATU,ACCESS								\
			endif													\
			movff	PREINC2,TBLPTRL									\
			movff	PREINC2,TBLPTRH									\
			if __ROMSIZE > 0x8000									\
				movff	PREINC2,TBLPTRU								\
			else													\
				clrf	TBLPTRU,ACCESS								\
			endif													\
			movff	PREINC2,TABLAT									\
			movff	PREINC2,FSR1L									\
			movff	PREINC2,FSR1H									\
			movff	PREINC2,FSR0L									\
			movff	PREINC2,FSR0H									\
			movff	PREINC2,PRODL									\
			movff	PREINC2,PRODH									\
			;														\
			; The return from portRESTORE_CONTEXT() depends on		\
			; the value of ucCriticalNesting. When it is zero,		\
			; interrupts need to be enabled. This is done via a		\
			; retfie instruction because we need the				\
			; interrupt-enabling and the return to the restored		\
			; task to be uninterruptable.							\
	 		; Because bsr, status and W are affected by the test	\
	 		; they are restored after the test.						\
			;														\
			movlb	ucCriticalNesting>>8							\
			tstfsz	ucCriticalNesting,BANKED						\
			SMARTJUMP _rtos_R4										\
		_rtos_R3:													\
			movff	PREINC2,BSR										\
			movff	PREINC2,WREG									\
			movff	PREINC2,STATUS									\
			retfie	0		; Return enabling interrupts			\
		_rtos_R4:													\
			movff	PREINC2,BSR										\
			movff	PREINC2,WREG									\
			movff	PREINC2,STATUS									\
			return	0		; Return without affecting interrupts	\
		_Pragma("asmend")											\
	} while(0)

/*-----------------------------------------------------------*/

#define portTICK_RATE_MS	( ( portTickType ) 1000 / configTICK_RATE_HZ )		

/*-----------------------------------------------------------*/

extern void vPortYield( void );
#define portYIELD()				vPortYield()

#define portNOP()	_Pragma("asm")									\
						nop											\
					_Pragma("asmend")

/*-----------------------------------------------------------*/

#define portTASK_FUNCTION( xFunction, pvParameters )	 	\
	void pointed xFunction( void *pvParameters )		\
	_Pragma(asmfunc xFunction)

#define portTASK_FUNCTION_PROTO		portTASK_FUNCTION
/*-----------------------------------------------------------*/


#define volatile
#define register

#endif /* PORTMACRO_H */