First version under SVN is V4.0.1

git-svn-id: https://freertos.svn.sourceforge.net/svnroot/freertos/trunk@4 1d2547de-c912-0410-9cb9-b8ca96c0e9e2

1 files changed, 432 insertions, 0 deletions

diff --git a/Source/portable/GCC/ATMega323/port.c b/Source/portable/GCC/ATMega323/port.c
new file mode 100644
index 00000000..aa59e9fc
--- /dev/null
+++ b/Source/portable/GCC/ATMega323/port.c
@@ -0,0 +1,432 @@
+/*

+	FreeRTOS V4.0.1 - Copyright (C) 2003-2006 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.

+	***************************************************************************

+*/

+

+/* 

+

+Changes from V2.6.0

+

+	+ AVR port - Replaced the inb() and outb() functions with direct memory

+	  access.  This allows the port to be built with the 20050414 build of

+	  WinAVR.

+*/

+

+#include <stdlib.h>

+#include <avr/interrupt.h>

+

+#include "FreeRTOS.h"

+#include "task.h"

+

+/*-----------------------------------------------------------

+ * Implementation of functions defined in portable.h for the AVR port.

+ *----------------------------------------------------------*/

+

+/* Start tasks with interrupts enables. */

+#define portFLAGS_INT_ENABLED					( ( portSTACK_TYPE ) 0x80 )

+

+/* Hardware constants for timer 1. */

+#define portCLEAR_COUNTER_ON_MATCH				( ( unsigned portCHAR ) 0x08 )

+#define portPRESCALE_64							( ( unsigned portCHAR ) 0x03 )

+#define portCLOCK_PRESCALER						( ( unsigned portLONG ) 64 )

+#define portCOMPARE_MATCH_A_INTERRUPT_ENABLE	( ( unsigned portCHAR ) 0x10 )

+

+/*-----------------------------------------------------------*/

+

+/* We require the address of the pxCurrentTCB variable, but don't want to know

+any details of its type. */

+typedef void tskTCB;

+extern volatile tskTCB * volatile pxCurrentTCB;

+

+/*-----------------------------------------------------------*/

+

+/* 

+ * Macro to save all the general purpose registers, the save the stack pointer

+ * into the TCB.  

+ * 

+ * The first thing we do is save the flags then disable interrupts.  This is to 

+ * guard our stack against having a context switch interrupt after we have already 

+ * pushed the registers onto the stack - causing the 32 registers to be on the 

+ * stack twice. 

+ * 

+ * r1 is set to zero as the compiler expects it to be thus, however some

+ * of the math routines make use of R1. 

+ * 

+ * The interrupts will have been disabled during the call to portSAVE_CONTEXT()

+ * so we need not worry about reading/writing to the stack pointer. 

+ */

+

+#define portSAVE_CONTEXT()									\

+	asm volatile (	"push	r0						\n\t"	\

+					"in		r0, __SREG__			\n\t"	\

+					"cli							\n\t"	\

+					"push	r0						\n\t"	\

+					"push	r1						\n\t"	\

+					"clr	r1						\n\t"	\

+					"push	r2						\n\t"	\

+					"push	r3						\n\t"	\

+					"push	r4						\n\t"	\

+					"push	r5						\n\t"	\

+					"push	r6						\n\t"	\

+					"push	r7						\n\t"	\

+					"push	r8						\n\t"	\

+					"push	r9						\n\t"	\

+					"push	r10						\n\t"	\

+					"push	r11						\n\t"	\

+					"push	r12						\n\t"	\

+					"push	r13						\n\t"	\

+					"push	r14						\n\t"	\

+					"push	r15						\n\t"	\

+					"push	r16						\n\t"	\

+					"push	r17						\n\t"	\

+					"push	r18						\n\t"	\

+					"push	r19						\n\t"	\

+					"push	r20						\n\t"	\

+					"push	r21						\n\t"	\

+					"push	r22						\n\t"	\

+					"push	r23						\n\t"	\

+					"push	r24						\n\t"	\

+					"push	r25						\n\t"	\

+					"push	r26						\n\t"	\

+					"push	r27						\n\t"	\

+					"push	r28						\n\t"	\

+					"push	r29						\n\t"	\

+					"push	r30						\n\t"	\

+					"push	r31						\n\t"	\

+					"lds	r26, pxCurrentTCB		\n\t"	\

+					"lds	r27, pxCurrentTCB + 1	\n\t"	\

+					"in		r0, 0x3d				\n\t"	\

+					"st		x+, r0					\n\t"	\

+					"in		r0, 0x3e				\n\t"	\

+					"st		x+, r0					\n\t"	\

+				);

+

+/* 

+ * Opposite to portSAVE_CONTEXT().  Interrupts will have been disabled during

+ * the context save so we can write to the stack pointer. 

+ */

+

+#define portRESTORE_CONTEXT()								\

+	asm volatile (	"lds	r26, pxCurrentTCB		\n\t"	\

+					"lds	r27, pxCurrentTCB + 1	\n\t"	\

+					"ld		r28, x+					\n\t"	\

+					"out	__SP_L__, r28			\n\t"	\

+					"ld		r29, x+					\n\t"	\

+					"out	__SP_H__, r29			\n\t"	\

+					"pop	r31						\n\t"	\

+					"pop	r30						\n\t"	\

+					"pop	r29						\n\t"	\

+					"pop	r28						\n\t"	\

+					"pop	r27						\n\t"	\

+					"pop	r26						\n\t"	\

+					"pop	r25						\n\t"	\

+					"pop	r24						\n\t"	\

+					"pop	r23						\n\t"	\

+					"pop	r22						\n\t"	\

+					"pop	r21						\n\t"	\

+					"pop	r20						\n\t"	\

+					"pop	r19						\n\t"	\

+					"pop	r18						\n\t"	\

+					"pop	r17						\n\t"	\

+					"pop	r16						\n\t"	\

+					"pop	r15						\n\t"	\

+					"pop	r14						\n\t"	\

+					"pop	r13						\n\t"	\

+					"pop	r12						\n\t"	\

+					"pop	r11						\n\t"	\

+					"pop	r10						\n\t"	\

+					"pop	r9						\n\t"	\

+					"pop	r8						\n\t"	\

+					"pop	r7						\n\t"	\

+					"pop	r6						\n\t"	\

+					"pop	r5						\n\t"	\

+					"pop	r4						\n\t"	\

+					"pop	r3						\n\t"	\

+					"pop	r2						\n\t"	\

+					"pop	r1						\n\t"	\

+					"pop	r0						\n\t"	\

+					"out	__SREG__, r0			\n\t"	\

+					"pop	r0						\n\t"	\

+				);

+

+/*-----------------------------------------------------------*/

+

+/*

+ * Perform hardware setup to enable ticks from timer 1, compare match A.

+ */

+static void prvSetupTimerInterrupt( void );

+/*-----------------------------------------------------------*/

+

+/* 

+ * See header file for description. 

+ */

+portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )

+{

+unsigned portSHORT usAddress;

+

+	/* Place a few bytes of known values on the bottom of the stack. 

+	This is just useful for debugging. */

+

+	*pxTopOfStack = 0x11;

+	pxTopOfStack--;

+	*pxTopOfStack = 0x22;

+	pxTopOfStack--;

+	*pxTopOfStack = 0x33;

+	pxTopOfStack--;

+

+	/* Simulate how the stack would look after a call to vPortYield() generated by 

+	the compiler. */

+

+	/*lint -e950 -e611 -e923 Lint doesn't like this much - but nothing I can do about it. */

+

+	/* The start of the task code will be popped off the stack last, so place

+	it on first. */

+	usAddress = ( unsigned portSHORT ) pxCode;

+	*pxTopOfStack = ( portSTACK_TYPE ) ( usAddress & ( unsigned portSHORT ) 0x00ff );

+	pxTopOfStack--;

+

+	usAddress >>= 8;

+	*pxTopOfStack = ( portSTACK_TYPE ) ( usAddress & ( unsigned portSHORT ) 0x00ff );

+	pxTopOfStack--;

+

+	/* Next simulate the stack as if after a call to portSAVE_CONTEXT().  

+	portSAVE_CONTEXT places the flags on the stack immediately after r0

+	to ensure the interrupts get disabled as soon as possible, and so ensuring

+	the stack use is minimal should a context switch interrupt occur. */

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x00;	/* R0 */

+	pxTopOfStack--;

+	*pxTopOfStack = portFLAGS_INT_ENABLED;

+	pxTopOfStack--;

+

+

+	/* Now the remaining registers.   The compiler expects R1 to be 0. */

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x00;	/* R1 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x02;	/* R2 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x03;	/* R3 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x04;	/* R4 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x05;	/* R5 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x06;	/* R6 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x07;	/* R7 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x08;	/* R8 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x09;	/* R9 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x10;	/* R10 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x11;	/* R11 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x12;	/* R12 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x13;	/* R13 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x14;	/* R14 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x15;	/* R15 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x16;	/* R16 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x17;	/* R17 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x18;	/* R18 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x19;	/* R19 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x20;	/* R20 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x21;	/* R21 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x22;	/* R22 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x23;	/* R23 */

+	pxTopOfStack--;

+

+	/* Place the parameter on the stack in the expected location. */

+	usAddress = ( unsigned portSHORT ) pvParameters;

+	*pxTopOfStack = ( portSTACK_TYPE ) ( usAddress & ( unsigned portSHORT ) 0x00ff );

+	pxTopOfStack--;

+

+	usAddress >>= 8;

+	*pxTopOfStack = ( portSTACK_TYPE ) ( usAddress & ( unsigned portSHORT ) 0x00ff );

+	pxTopOfStack--;

+

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x26;	/* R26 X */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x27;	/* R27 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x28;	/* R28 Y */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x29;	/* R29 */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x30;	/* R30 Z */

+	pxTopOfStack--;

+	*pxTopOfStack = ( portSTACK_TYPE ) 0x031;	/* R31 */

+	pxTopOfStack--;

+

+	/*lint +e950 +e611 +e923 */

+

+	return pxTopOfStack;

+}

+/*-----------------------------------------------------------*/

+

+portBASE_TYPE xPortStartScheduler( void )

+{

+	/* In this port we ignore the parameter and use the configUSE_PREEMPTION

+	definition instead. */

+

+	/* Setup the hardware to generate the tick. */

+	prvSetupTimerInterrupt();

+

+	/* Restore the context of the first task that is going to run. */

+	portRESTORE_CONTEXT();

+

+	/* Simulate a function call end as generated by the compiler.  We will now

+	jump to the start of the task the context of which we have just restored. */

+	asm volatile ( "ret" );

+

+	/* Should not get here. */

+	return pdTRUE;

+}

+/*-----------------------------------------------------------*/

+

+void vPortEndScheduler( void )

+{

+	/* It is unlikely that the AVR port will get stopped.  If required simply

+	disable the tick interrupt here. */

+}

+/*-----------------------------------------------------------*/

+

+/*

+ * Manual context switch.  The first thing we do is save the registers so we

+ * can use a naked attribute.

+ */

+void vPortYield( void ) __attribute__ ( ( naked ) );

+void vPortYield( void )

+{

+	portSAVE_CONTEXT();

+	vTaskSwitchContext();

+	portRESTORE_CONTEXT();

+

+	asm volatile ( "ret" );

+}

+/*-----------------------------------------------------------*/

+

+/*

+ * Context switch function used by the tick.  This must be identical to 

+ * vPortYield() from the call to vTaskSwitchContext() onwards.  The only

+ * difference from vPortYield() is the tick count is incremented as the

+ * call comes from the tick ISR.

+ */

+void vPortYieldFromTick( void ) __attribute__ ( ( naked ) );

+void vPortYieldFromTick( void )

+{

+	portSAVE_CONTEXT();

+	vTaskIncrementTick();

+	vTaskSwitchContext();

+	portRESTORE_CONTEXT();

+

+	asm volatile ( "ret" );

+}

+/*-----------------------------------------------------------*/

+

+/*

+ * Setup timer 1 compare match A to generate a tick interrupt.

+ */

+static void prvSetupTimerInterrupt( void )

+{

+unsigned portLONG ulCompareMatch;

+unsigned portCHAR ucHighByte, ucLowByte;

+

+	/* Using 16bit timer 1 to generate the tick.  Correct fuses must be

+	selected for the configCPU_CLOCK_HZ clock. */

+

+	ulCompareMatch = configCPU_CLOCK_HZ / configTICK_RATE_HZ;

+

+	/* We only have 16 bits so have to scale to get our required tick rate. */

+	ulCompareMatch /= portCLOCK_PRESCALER;

+

+	/* Adjust for correct value. */

+	ulCompareMatch -= ( unsigned portLONG ) 1;

+

+	/* Setup compare match value for compare match A.  Interrupts are disabled 

+	before this is called so we need not worry here. */

+	ucLowByte = ( unsigned portCHAR ) ( ulCompareMatch & ( unsigned portLONG ) 0xff );

+	ulCompareMatch >>= 8;

+	ucHighByte = ( unsigned portCHAR ) ( ulCompareMatch & ( unsigned portLONG ) 0xff );

+	OCR1AH = ucHighByte;

+	OCR1AL = ucLowByte;

+

+	/* Setup clock source and compare match behaviour. */

+	ucLowByte = portCLEAR_COUNTER_ON_MATCH | portPRESCALE_64;

+	TCCR1B = ucLowByte;

+

+	/* Enable the interrupt - this is okay as interrupt are currently globally

+	disabled. */

+	ucLowByte = TIMSK;

+	ucLowByte |= portCOMPARE_MATCH_A_INTERRUPT_ENABLE;

+	TIMSK = ucLowByte;

+}

+/*-----------------------------------------------------------*/

+

+#if configUSE_PREEMPTION == 1

+

+	/*

+	 * Tick ISR for preemptive scheduler.  We can use a naked attribute as

+	 * the context is saved at the start of vPortYieldFromTick().  The tick

+	 * count is incremented after the context is saved.

+	 */

+	void SIG_OUTPUT_COMPARE1A( void ) __attribute__ ( ( signal, naked ) );

+	void SIG_OUTPUT_COMPARE1A( void )

+	{

+		vPortYieldFromTick();

+		asm volatile ( "reti" );

+	}

+#else

+

+	/*

+	 * Tick ISR for the cooperative scheduler.  All this does is increment the

+	 * tick count.  We don't need to switch context, this can only be done by

+	 * manual calls to taskYIELD();

+	 */

+	void SIG_OUTPUT_COMPARE1A( void ) __attribute__ ( ( signal ) );

+	void SIG_OUTPUT_COMPARE1A( void )

+	{

+		vTaskIncrementTick();

+	}

+#endif

+

+

+