Source/portable/GCC/HCS12/portmacro.h

/*
	FreeRTOS.org V5.1.1 - Copyright (C) 2003-2008 Richard Barry.

	This file is part of the FreeRTOS.org distribution.

	FreeRTOS.org is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	FreeRTOS.org 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.org; if not, write to the Free Software
	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

	A special exception to the GPL can be applied should you wish to distribute
	a combined work that includes FreeRTOS.org, without being obliged to provide
	the source code for any proprietary components.  See the licensing section 
	of http://www.FreeRTOS.org for full details of how and when the exception
	can be applied.

    ***************************************************************************
    ***************************************************************************
    *                                                                         *
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	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.

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*/


#ifndef PORTMACRO_H
#define PORTMACRO_H

#ifdef __cplusplus
extern "C" {
#endif

/*-----------------------------------------------------------
 * Port specific definitions.  
 *
 * The settings in this file configure FreeRTOS correctly for the
 * given hardware and compiler.
 *
 * These settings should not be altered.
 *-----------------------------------------------------------
 */

/* Type definitions. */
#define portCHAR		char
#define portFLOAT		float
#define portDOUBLE		double
#define portLONG		long
#define portSHORT		short
#define portSTACK_TYPE	unsigned portCHAR
#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
/*-----------------------------------------------------------*/

/* Hardware specifics. */
#define portBYTE_ALIGNMENT			1
#define portSTACK_GROWTH			( -1 )
#define portTICK_RATE_MS			( ( portTickType ) 1000 / configTICK_RATE_HZ )
#define portYIELD()					__asm( "swi" );
/*-----------------------------------------------------------*/

/* Critical section handling. */
#define portENABLE_INTERRUPTS()				__asm( "cli" )	
#define portDISABLE_INTERRUPTS()			__asm( "sei" )

/*
 * Disable interrupts before incrementing the count of critical section nesting.
 * The nesting count is maintained so we know when interrupts should be
 * re-enabled.  Once interrupts are disabled the nesting count can be accessed
 * directly.  Each task maintains its own nesting count.
 */
#define portENTER_CRITICAL()  									\
{																\
	extern volatile unsigned portBASE_TYPE uxCriticalNesting;	\
																\
	portDISABLE_INTERRUPTS();									\
	uxCriticalNesting++;										\
}

/*
 * Interrupts are disabled so we can access the nesting count directly.  If the
 * nesting is found to be 0 (no nesting) then we are leaving the critical 
 * section and interrupts can be re-enabled.
 */
#define  portEXIT_CRITICAL()									\
{																\
	extern volatile unsigned portBASE_TYPE uxCriticalNesting;	\
																\
	uxCriticalNesting--;										\
	if( uxCriticalNesting == 0 )								\
	{															\
		portENABLE_INTERRUPTS();								\
	}															\
}
/*-----------------------------------------------------------*/

/* Task utilities. */

/* 
 * These macros are very simple as the processor automatically saves and 
 * restores its registers as interrupts are entered and exited.  In
 * addition to the (automatically stacked) registers we also stack the 
 * critical nesting count.  Each task maintains its own critical nesting
 * count as it is legitimate for a task to yield from within a critical
 * section.  If the banked memory model is being used then the PPAGE
 * register is also stored as part of the tasks context.
 */

#ifdef BANKED_MODEL
	/* 
	 * Load the stack pointer for the task, then pull the critical nesting
	 * count and PPAGE register from the stack.  The remains of the 
	 * context are restored by the RTI instruction.
	 */
	#define portRESTORE_CONTEXT()							\
	{										\
		__asm( "								\n\
		.globl pxCurrentTCB			; void *			\n\
		.globl uxCriticalNesting		; char				\n\
											\n\
		ldx  pxCurrentTCB							\n\
		lds  0,x				; Stack				\n\
											\n\
		movb 1,sp+,uxCriticalNesting						\n\
		movb 1,sp+,0x30				; PPAGE				\n\
		" );									\
	}

	/* 
	 * By the time this macro is called the processor has already stacked the
	 * registers.  Simply stack the nesting count and PPAGE value, then save 
	 * the task stack pointer.
	 */
	#define portSAVE_CONTEXT()							\
	{										\
		__asm( "								\n\
		.globl pxCurrentTCB			; void *			\n\
		.globl uxCriticalNesting		; char				\n\
											\n\
		movb 0x30, 1,-sp			; PPAGE				\n\
		movb uxCriticalNesting, 1,-sp						\n\
											\n\
		ldx  pxCurrentTCB							\n\
		sts  0,x				; Stack				\n\
		" );									\
	}
#else

	/* 
	 * These macros are as per the BANKED versions above, but without saving
	 * and restoring the PPAGE register.
	 */

	#define portRESTORE_CONTEXT()							\
	{										\
		__asm( "								\n\
		.globl pxCurrentTCB			; void *			\n\
		.globl uxCriticalNesting		; char				\n\
											\n\
		ldx  pxCurrentTCB							\n\
		lds  0,x				; Stack				\n\
											\n\
		movb 1,sp+,uxCriticalNesting						\n\
		" );									\
	}

	#define portSAVE_CONTEXT()							\
	{										\
		__asm( "								\n\
		.globl pxCurrentTCB			; void *			\n\
		.globl uxCriticalNesting		; char				\n\
											\n\
		movb uxCriticalNesting, 1,-sp						\n\
											\n\
		ldx  pxCurrentTCB							\n\
		sts  0,x				; Stack				\n\
		" );									\
	}
#endif

/*
 * Utility macros to save/restore correct software registers for GCC. This is
 * useful when GCC does not generate appropriate ISR head/tail code.
 */
#define portISR_HEAD()									\
{											\
		__asm("									\n\
		movw _.frame, 2,-sp							\n\
		movw _.tmp, 2,-sp							\n\
		movw _.z, 2,-sp								\n\
		movw _.xy, 2,-sp							\n\
		;movw _.d2, 2,-sp							\n\
		;movw _.d1, 2,-sp							\n\
		");									\
}

#define portISR_TAIL()									\
{											\
		__asm("									\n\
		movw 2,sp+, _.xy							\n\
		movw 2,sp+, _.z								\n\
		movw 2,sp+, _.tmp							\n\
		movw 2,sp+, _.frame							\n\
		;movw 2,sp+, _.d1							\n\
		;movw 2,sp+, _.d2							\n\
		rti									\n\
		");									\
}

/*
 * Utility macro to call macros above in correct order in order to perform a
 * task switch from within a standard ISR.  This macro can only be used if
 * the ISR does not use any local (stack) variables.  If the ISR uses stack
 * variables portYIELD() should be used in it's place.
 */

#define portTASK_SWITCH_FROM_ISR()								\
	portSAVE_CONTEXT();											\
	vTaskSwitchContext();										\
	portRESTORE_CONTEXT();


/* Task function macros as described on the FreeRTOS.org WEB site. */
#define portTASK_FUNCTION_PROTO( vFunction, pvParameters ) void vFunction( void *pvParameters )
#define portTASK_FUNCTION( vFunction, pvParameters ) void vFunction( void *pvParameters )

#ifdef __cplusplus
}
#endif

#endif /* PORTMACRO_H */