portmacro.h

FreeRTOS

/*
	FreeRTOS V2.6.0 - Copyright (C) 2003 - 2005 Richard Barry.

	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 as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	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

	A special exception to the GPL can be applied should you wish to distribute
	a combined work that includes FreeRTOS, 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.

	***************************************************************************
	See http://www.FreeRTOS.org for documentation, latest information, license 
	and contact details.  Please ensure to read the configuration and relevant 
	port sections of the online documentation.
	***************************************************************************
*/


#ifndef PORTMACRO_H
#define PORTMACRO_H

#include <lpc21xx.h>

/*-----------------------------------------------------------
 * Port specific definitions for the ARM7 Keil port.
 *----------------------------------------------------------*/

/* These are the only definitions that can be modified!. */

#define portUSE_PREEMPTION		1
#define portCPU_CLOCK_HZ		( ( unsigned portLONG ) 60000000 )	/* =12.0MHz xtal multiplied by 5 using the PLL. */
#define portTICK_RATE_HZ		( ( portTickType ) 1000 )
#define portMAX_PRIORITIES		( ( unsigned portCHAR ) 5 )
#define portMINIMAL_STACK_SIZE	( ( unsigned portSHORT ) 100 )
#define portTOTAL_HEAP_SIZE		( ( unsigned portSHORT ) 14200 )

/* Set the following definitions to 1 to include the component, or zero
to exclude the component. */

/* Include/exclude the stated API function. */
#define INCLUDE_vTaskPrioritySet		1
#define INCLUDE_ucTaskPriorityGet		1
#define INCLUDE_vTaskDelete				1
#define INCLUDE_vTaskCleanUpResources	0
#define INCLUDE_vTaskSuspend			1
#define INCLUDE_vTaskDelayUntil			1
#define INCLUDE_vTaskDelay				1

/* Use/don't use the trace visualisation. */
#define USE_TRACE_FACILITY				0

/* 
 * The tick count (and times defined in tick count units) can be either a 16bit
 * or a 32 bit value.  See documentation on http://www.FreeRTOS.org to decide
 * which to use.
 */
#define USE_16_BIT_TICKS	0


/*-----------------------------------------------------------
 * Do not modify anything below here. 
 *----------------------------------------------------------*/

#define portCHAR		char
#define portFLOAT		float
#define portDOUBLE		double
#define portLONG		long
#define portSHORT		short
#define portSTACK_TYPE	unsigned portLONG

#if( USE_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 portSTACK_GROWTH			( -1 )
#define portTICK_RATE_MS			( ( portTickType ) 1000 / portTICK_RATE_HZ )		
#define portBYTE_ALIGNMENT			4

/*-----------------------------------------------------------
 * Context switch macros.
 *
 * These can only be called from ARM mode.
 *----------------------------------------------------------*/

#define portRESTORE_CONTEXT()																			\
{																										\
extern volatile unsigned portLONG ulCriticalNesting;													\
extern volatile void * volatile pxCurrentTCB;															\
																										\
	__asm{ LDR		R1, =pxCurrentTCB };/* Set the LR to the task stack.  The location was ... */		\
	__asm{ LDR		R0, [R1]		};	/* ... stored in pxCurrentTCB. */								\
	__asm{ LDR		LR, [R0]		};																	\
																										\
	__asm{ LDR		R0, =ulCriticalNesting }; /* The critical nesting depth is the first item on ... */	\
	__asm{ LDMFD	LR!, {R1 }		}  /* ... the stack.  Load it into the ulCriticalNesting var. */	\
	__asm{ STR		R1, [R0]		}																	\
																										\
	__asm{ LDMFD	LR!, {R0}		}; /* Get the SPSR from the stack. */								\
	__asm{ MSR		SPSR_CXSF, R0	};																	\
																										\
	__asm{ LDMFD	LR, {R0-R14}^	}; /* Restore all system mode registers for the task. */			\
	__asm{ NOP						};																	\
																										\
	__asm{ LDR		LR, [LR, #+60]	}; /* Restore the return address. */								\
																										\
									   /* And return - correcting the offset in the LR to obtain ... */ \
	__asm{ SUBS	PC, LR, #4			}; /* ... the correct address. */									\
}

/*----------------------------------------------------------*/

#define portSAVE_CONTEXT()																				\
{																										\
extern volatile unsigned portLONG ulCriticalNesting;													\
extern volatile void * volatile pxCurrentTCB;															\
																										\
	__asm{ STMDB 	SP!, {R0}		};	/* Store R0 first as we need to use it.						*/	\
																										\
	__asm{ STMDB	SP,{SP}^		}; /* Set R0 to point to the task stack pointer.				*/	\
	__asm{ SUB		SP, SP, #4		};																	\
	__asm{ LDMIA	SP!,{R0}		};																	\
																										\																	
	__asm{ STMDB	R0!, {LR}		}; /* Push the return address onto the stack.					*/	\
	__asm{ MOV		LR, R0			}; /* Now we have saved LR we can use it instead of R0.			*/	\
	__asm{ LDMIA	SP!, {R0}		}; /* Pop R0 so we can save it onto the system mode stack.		*/	\
																										\
	__asm{ STMDB	LR,{R0-LR}^		}; /* Push all the system mode registers onto the task stack.	*/	\
	__asm{ SUB		LR, LR, #60		};																	\
																										\
	__asm{ MRS		R0, SPSR		}; /* Push the SPSR onto the task stack.						*/	\
	__asm{ STMDB	LR!, {R0}		};																	\
																										\
	__asm{ LDR		R0, =ulCriticalNesting };															\
	__asm{ LDR		R0, [R0]		};																	\
	__asm{ STMDB	LR!, {R0}		};																	\
																										\
	__asm{ LDR		R0, =pxCurrentTCB };/* Store the new top of stack for the task.					*/	\
	__asm{ LDR		R1, [R0]		};																	\
	__asm{ STR		LR, [R1]		};																	\
}


/*-----------------------------------------------------------
 * ISR entry and exit macros.  These are only required if a task switch
 * is required from an ISR.
 *----------------------------------------------------------*/

#define portENTER_SWITCHING_ISR()										\
		portSAVE_CONTEXT();												\
		{

#define portEXIT_SWITCHING_ISR( SwitchRequired )						\
		/* If a switch is required then we just need to call */			\
		/* vTaskSwitchContext() as the context has already been */		\
		/* saved. */													\
		if( SwitchRequired )											\
		{																\
			vTaskSwitchContext();										\
		}																\
	}																	\
	/* Restore the context of which ever task is now the highest */		\
	/* priority that is ready to run. */								\
	portRESTORE_CONTEXT();


/* Yield the processor - force a context switch. */
#define portYIELD()					__asm{ SWI 0 };	

/*-----------------------------------------------------------
 * Interrupt control macros.
 *
 * The interrupt management utilities can only be called from ARM mode.  When
 * KEIL_THUMB_INTERWORK is defined the utilities are defined as functions in 
 * portISR.c to ensure a switch to ARM mode.  When KEIL_THUMB_INTERWORK is not 
 * defined then the utilities are defined as macros here - as per other ports.
 *----------------------------------------------------------*/

#ifdef KEIL_THUMB_INTERWORK

	extern void vPortDisableInterruptsFromThumb( void ) __task;
	extern void vPortEnableInterruptsFromThumb( void ) __task;

	#define portDISABLE_INTERRUPTS()	vPortDisableInterruptsFromThumb()
	#define portENABLE_INTERRUPTS()		vPortEnableInterruptsFromThumb()

#else

	/*-----------------------------------------------------------*/

	#define portDISABLE_INTERRUPTS()														\
		__asm{ STMDB	SP!, {R0}		};	/* Push R0.									*/	\
		__asm{ MRS		R0, CPSR		};	/* Get CPSR.								*/	\
		__asm{ ORR		R0, R0, #0xC0	};	/* Disable IRQ, FIQ.						*/	\
		__asm{ MSR		CPSR_CXSF, R0	};	/* Write back modified value.				*/	\
		__asm{ LDMIA	SP!, {R0}		}	/* Pop R0.									*/
			
	#define portENABLE_INTERRUPTS()															\
		__asm{ STMDB	SP!, {R0}		};	/* Push R0.									*/	\
		__asm{ MRS		R0, CPSR		};	/* Get CPSR.								*/	\
		__asm{ BIC		R0, R0, #0xC0	};	/* Enable IRQ, FIQ.							*/	\
		__asm{ MSR		CPSR_CXSF, R0	};	/* Write back modified value.				*/	\
		__asm{ LDMIA	SP!, {R0}		}	/* Pop R0. */

#endif /* KEIL_THUMB_INTERWORK */

/*-----------------------------------------------------------
 * Critical section control
 *
 * The code generated by the Keil compiler does not maintain separate
 * stack and frame pointers. The portENTER_CRITICAL macro cannot therefore
 * use the stack as per other ports.  Instead a variable is used to keep
 * track of the critical section nesting.  This necessitates the use of a 
 * function in place of the macro.
 *----------------------------------------------------------*/

extern void vPortEnterCritical( void );
extern void vPortExitCritical( void );

#define portENTER_CRITICAL()		vPortEnterCritical();
#define portEXIT_CRITICAL()			vPortExitCritical();


/* Define away the register keyword to prevent compiler warnings. */
#define register
#define inline

#endif /* PORTMACRO_H */