2 FreeRTOS V6.0.0 - Copyright (C) 2009 Real Time Engineers Ltd.
\r
4 ***************************************************************************
\r
8 * + New to FreeRTOS, *
\r
9 * + Wanting to learn FreeRTOS or multitasking in general quickly *
\r
10 * + Looking for basic training, *
\r
11 * + Wanting to improve your FreeRTOS skills and productivity *
\r
13 * then take a look at the FreeRTOS eBook *
\r
15 * "Using the FreeRTOS Real Time Kernel - a Practical Guide" *
\r
16 * http://www.FreeRTOS.org/Documentation *
\r
18 * A pdf reference manual is also available. Both are usually delivered *
\r
19 * to your inbox within 20 minutes to two hours when purchased between 8am *
\r
20 * and 8pm GMT (although please allow up to 24 hours in case of *
\r
21 * exceptional circumstances). Thank you for your support! *
\r
23 ***************************************************************************
\r
25 This file is part of the FreeRTOS distribution.
\r
27 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
28 the terms of the GNU General Public License (version 2) as published by the
\r
29 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
\r
30 ***NOTE*** The exception to the GPL is included to allow you to distribute
\r
31 a combined work that includes FreeRTOS without being obliged to provide the
\r
32 source code for proprietary components outside of the FreeRTOS kernel.
\r
33 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
\r
34 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
\r
35 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
\r
36 more details. You should have received a copy of the GNU General Public
\r
37 License and the FreeRTOS license exception along with FreeRTOS; if not it
\r
38 can be viewed here: http://www.freertos.org/a00114.html and also obtained
\r
39 by writing to Richard Barry, contact details for whom are available on the
\r
44 http://www.FreeRTOS.org - Documentation, latest information, license and
\r
47 http://www.SafeRTOS.com - A version that is certified for use in safety
\r
50 http://www.OpenRTOS.com - Commercial support, development, porting,
\r
51 licensing and training services.
\r
54 /*-----------------------------------------------------------
\r
55 * Implementation of functions defined in portable.h for the ST STR75x ARM7
\r
57 *----------------------------------------------------------*/
\r
59 /* Library includes. */
\r
61 #include "75x_eic.h"
\r
63 /* Scheduler includes. */
\r
64 #include "FreeRTOS.h"
\r
67 /* Constants required to setup the initial stack. */
\r
68 #define portINITIAL_SPSR ( ( portSTACK_TYPE ) 0x1f ) /* System mode, ARM mode, interrupts enabled. */
\r
69 #define portTHUMB_MODE_BIT ( ( portSTACK_TYPE ) 0x20 )
\r
70 #define portINSTRUCTION_SIZE ( ( portSTACK_TYPE ) 4 )
\r
72 /* Constants required to handle critical sections. */
\r
73 #define portNO_CRITICAL_NESTING ( ( unsigned long ) 0 )
\r
75 /* Prescale used on the timer clock when calculating the tick period. */
\r
76 #define portPRESCALE 20
\r
79 /*-----------------------------------------------------------*/
\r
81 /* Setup the TB to generate the tick interrupts. */
\r
82 static void prvSetupTimerInterrupt( void );
\r
84 /*-----------------------------------------------------------*/
\r
87 * Initialise the stack of a task to look exactly as if a call to
\r
88 * portSAVE_CONTEXT had been called.
\r
90 * See header file for description.
\r
92 portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )
\r
94 portSTACK_TYPE *pxOriginalTOS;
\r
96 pxOriginalTOS = pxTopOfStack;
\r
98 /* Setup the initial stack of the task. The stack is set exactly as
\r
99 expected by the portRESTORE_CONTEXT() macro. */
\r
101 /* First on the stack is the return address - which in this case is the
\r
102 start of the task. The offset is added to make the return address appear
\r
103 as it would within an IRQ ISR. */
\r
104 *pxTopOfStack = ( portSTACK_TYPE ) pxCode + portINSTRUCTION_SIZE;
\r
107 *pxTopOfStack = ( portSTACK_TYPE ) 0xaaaaaaaa; /* R14 */
\r
109 *pxTopOfStack = ( portSTACK_TYPE ) pxOriginalTOS; /* Stack used when task starts goes in R13. */
\r
111 *pxTopOfStack = ( portSTACK_TYPE ) 0x12121212; /* R12 */
\r
113 *pxTopOfStack = ( portSTACK_TYPE ) 0x11111111; /* R11 */
\r
115 *pxTopOfStack = ( portSTACK_TYPE ) 0x10101010; /* R10 */
\r
117 *pxTopOfStack = ( portSTACK_TYPE ) 0x09090909; /* R9 */
\r
119 *pxTopOfStack = ( portSTACK_TYPE ) 0x08080808; /* R8 */
\r
121 *pxTopOfStack = ( portSTACK_TYPE ) 0x07070707; /* R7 */
\r
123 *pxTopOfStack = ( portSTACK_TYPE ) 0x06060606; /* R6 */
\r
125 *pxTopOfStack = ( portSTACK_TYPE ) 0x05050505; /* R5 */
\r
127 *pxTopOfStack = ( portSTACK_TYPE ) 0x04040404; /* R4 */
\r
129 *pxTopOfStack = ( portSTACK_TYPE ) 0x03030303; /* R3 */
\r
131 *pxTopOfStack = ( portSTACK_TYPE ) 0x02020202; /* R2 */
\r
133 *pxTopOfStack = ( portSTACK_TYPE ) 0x01010101; /* R1 */
\r
136 /* When the task starts is will expect to find the function parameter in
\r
138 *pxTopOfStack = ( portSTACK_TYPE ) pvParameters; /* R0 */
\r
141 /* The status register is set for system mode, with interrupts enabled. */
\r
142 *pxTopOfStack = ( portSTACK_TYPE ) portINITIAL_SPSR;
\r
144 #ifdef THUMB_INTERWORK
\r
146 /* We want the task to start in thumb mode. */
\r
147 *pxTopOfStack |= portTHUMB_MODE_BIT;
\r
153 /* Interrupt flags cannot always be stored on the stack and will
\r
154 instead be stored in a variable, which is then saved as part of the
\r
156 *pxTopOfStack = portNO_CRITICAL_NESTING;
\r
158 return pxTopOfStack;
\r
160 /*-----------------------------------------------------------*/
\r
162 portBASE_TYPE xPortStartScheduler( void )
\r
164 extern void vPortISRStartFirstTask( void );
\r
166 /* Start the timer that generates the tick ISR. Interrupts are disabled
\r
168 prvSetupTimerInterrupt();
\r
170 /* Start the first task. */
\r
171 vPortISRStartFirstTask();
\r
173 /* Should not get here! */
\r
176 /*-----------------------------------------------------------*/
\r
178 void vPortEndScheduler( void )
\r
180 /* It is unlikely that the ARM port will require this function as there
\r
181 is nothing to return to. */
\r
183 /*-----------------------------------------------------------*/
\r
185 static void prvSetupTimerInterrupt( void )
\r
187 EIC_IRQInitTypeDef EIC_IRQInitStructure;
\r
188 TB_InitTypeDef TB_InitStructure;
\r
190 /* Setup the EIC for the TB. */
\r
191 EIC_IRQInitStructure.EIC_IRQChannelCmd = ENABLE;
\r
192 EIC_IRQInitStructure.EIC_IRQChannel = TB_IRQChannel;
\r
193 EIC_IRQInitStructure.EIC_IRQChannelPriority = 1;
\r
194 EIC_IRQInit(&EIC_IRQInitStructure);
\r
196 /* Setup the TB for the generation of the tick interrupt. */
\r
197 TB_InitStructure.TB_Mode = TB_Mode_Timing;
\r
198 TB_InitStructure.TB_CounterMode = TB_CounterMode_Down;
\r
199 TB_InitStructure.TB_Prescaler = portPRESCALE - 1;
\r
200 TB_InitStructure.TB_AutoReload = ( ( configCPU_CLOCK_HZ / ( portPRESCALE + 1 ) ) / configTICK_RATE_HZ ) + 1;
\r
201 TB_Init(&TB_InitStructure);
\r
203 /* Enable TB Update interrupt */
\r
204 TB_ITConfig(TB_IT_Update, ENABLE);
\r
206 /* Clear TB Update interrupt pending bit */
\r
207 TB_ClearITPendingBit(TB_IT_Update);
\r
212 /*-----------------------------------------------------------*/
\r