FreeRTOS-Kernel/Source/portable/CodeWarrior/HCS12/portmacro.h

/*
    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.

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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.
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*/


#ifndef PORTMACRO_H
#define PORTMACRO_H

/*-----------------------------------------------------------
 * 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" );
#define portNOP()					__asm( "nop" );
/*-----------------------------------------------------------*/

/* 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()									\
	{																\
		extern volatile void * pxCurrentTCB;						\
		extern volatile unsigned portBASE_TYPE uxCriticalNesting;	\
																	\
		__asm( "ldx pxCurrentTCB" );								\
		__asm( "lds 0, x" );										\
		__asm( "pula" );											\
		__asm( "staa uxCriticalNesting" );							\
		__asm( "pula" );											\
		__asm( "staa 0x30" ); /* 0x30 = PPAGE */					\
	}

	/* 
	 * 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()										\
	{																\
		extern volatile void * pxCurrentTCB;						\
		extern volatile unsigned portBASE_TYPE uxCriticalNesting;	\
																	\
		__asm( "ldaa 0x30" );  /* 0x30 = PPAGE */					\
		__asm( "psha" );											\
		__asm( "ldaa uxCriticalNesting" );							\
		__asm( "psha" );											\
		__asm( "ldx pxCurrentTCB" );								\
		__asm( "sts 0, x" );										\
	}
#else

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

	#define portRESTORE_CONTEXT()									\
	{																\
		extern volatile void * pxCurrentTCB;						\
		extern volatile unsigned portBASE_TYPE uxCriticalNesting;	\
																	\
		__asm( "ldx pxCurrentTCB" );								\
		__asm( "lds 0, x" );										\
		__asm( "pula" );											\
		__asm( "staa uxCriticalNesting" );							\
	}

	#define portSAVE_CONTEXT()										\
	{																\
		extern volatile void * pxCurrentTCB;						\
		extern volatile unsigned portBASE_TYPE uxCriticalNesting;	\
																	\
		__asm( "ldaa uxCriticalNesting" );							\
		__asm( "psha" );											\
		__asm( "ldx pxCurrentTCB" );								\
		__asm( "sts 0, x" );										\
	}
#endif

/*
 * 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 )

#endif /* PORTMACRO_H */