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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Source/] [portable/] [Softune/] [MB91460/] [port.c] - Blame information for rev 609

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1 572 jeremybenn
/*
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    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.
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    ***************************************************************************
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    *                                                                         *
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    * If you are:                                                             *
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    *                                                                         *
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    *    + New to FreeRTOS,                                                   *
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    *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
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    *    + Looking for basic training,                                        *
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    *    + Wanting to improve your FreeRTOS skills and productivity           *
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    *                                                                         *
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    * then take a look at the FreeRTOS books - available as PDF or paperback  *
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    *                                                                         *
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    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
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    *                  http://www.FreeRTOS.org/Documentation                  *
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    *                                                                         *
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    * A pdf reference manual is also available.  Both are usually delivered   *
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    * to your inbox within 20 minutes to two hours when purchased between 8am *
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    * and 8pm GMT (although please allow up to 24 hours in case of            *
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    * exceptional circumstances).  Thank you for your support!                *
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    *                                                                         *
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    ***************************************************************************
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    This file is part of the FreeRTOS distribution.
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    FreeRTOS is free software; you can redistribute it and/or modify it under
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    the terms of the GNU General Public License (version 2) as published by the
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    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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    ***NOTE*** The exception to the GPL is included to allow you to distribute
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    a combined work that includes FreeRTOS without being obliged to provide the
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    source code for proprietary components outside of the FreeRTOS kernel.
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    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
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    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
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    more details. You should have received a copy of the GNU General Public
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    License and the FreeRTOS license exception along with FreeRTOS; if not it
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    can be viewed here: http://www.freertos.org/a00114.html and also obtained
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    by writing to Richard Barry, contact details for whom are available on the
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    FreeRTOS WEB site.
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    1 tab == 4 spaces!
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    http://www.FreeRTOS.org - Documentation, latest information, license and
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    contact details.
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    http://www.SafeRTOS.com - A version that is certified for use in safety
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    critical systems.
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    http://www.OpenRTOS.com - Commercial support, development, porting,
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    licensing and training services.
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*/
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#include "FreeRTOS.h"
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#include "task.h"
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#include "mb91467d.h"
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58
/*-----------------------------------------------------------*/
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60
/* We require the address of the pxCurrentTCB variable, but don't want to know
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any details of its type. */
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typedef void tskTCB;
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extern volatile tskTCB * volatile pxCurrentTCB;
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65
/*-----------------------------------------------------------*/
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#pragma asm
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#macro  SaveContext
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         ORCCR #0x20                                                            ;Switch to user stack
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         ST RP,@-R15                                                            ;Store RP
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         STM0 (R7,R6,R5,R4,R3,R2,R1,R0)                         ;Store R7-R0
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         STM1 (R14,R13,R12,R11,R10,R9,R8)                       ;Store R14-R8
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         ST MDH, @-R15                                                          ;Store MDH
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         ST MDL, @-R15                                                          ;Store MDL
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         ANDCCR #0xDF                                                           ;Switch back to system stack
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         LD @R15+,R0                                                            ;Store PC to R0
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         ORCCR #0x20                                                            ;Switch to user stack
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         ST R0,@-R15                                                            ;Store PC to User stack
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81
         ANDCCR #0xDF                                                           ;Switch back to system stack
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         LD @R15+,R0                                                            ;Store PS to R0
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         ORCCR #0x20                                                            ;Switch to user stack
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         ST R0,@-R15                                                            ;Store PS to User stack
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         LDI #_pxCurrentTCB, R0                                         ;Get pxCurrentTCB address
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         LD @R0, R0                                                                     ;Get the pxCurrentTCB->pxTopOfStack address
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         ST R15,@R0                                                                     ;Store USP to pxCurrentTCB->pxTopOfStack
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         ANDCCR #0xDF                                                           ;Switch back to system stack for the rest of tick ISR
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#endm
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#macro RestoreContext
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         LDI #_pxCurrentTCB, R0                                         ;Get pxCurrentTCB address
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         LD @R0, R0                                                                     ;Get the pxCurrentTCB->pxTopOfStack address
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         ORCCR #0x20                                                            ;Switch to user stack
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         LD @R0, R15                                                            ;Restore USP from pxCurrentTCB->pxTopOfStack
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         LD @R15+,R0                                                            ;Store PS to R0
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         ANDCCR #0xDF                                                           ;Switch to system stack
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         ST R0,@-R15                                                            ;Store PS to system stack
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         ORCCR #0x20                                                            ;Switch to user stack
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         LD @R15+,R0                                                            ;Store PC to R0
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         ANDCCR #0xDF                                                           ;Switch to system stack
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         ST R0,@-R15                                                            ;Store PC to system stack
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         ORCCR #0x20                                                            ;Switch back to retrieve the remaining context
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         LD @R15+, MDL                                                          ;Restore MDL
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         LD @R15+, MDH                                                          ;Restore MDH
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         LDM1 (R14,R13,R12,R11,R10,R9,R8)                       ;Restore R14-R8
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         LDM0 (R7,R6,R5,R4,R3,R2,R1,R0)                         ;Restore R7-R0
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         LD @R15+, RP                                                           ;Restore RP
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         ANDCCR #0xDF                                                           ;Switch back to system stack for the rest of tick ISR
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#endm
118
#pragma endasm
119
 
120
/*-----------------------------------------------------------*/
121
 
122
/*
123
 * Perform hardware setup to enable ticks from timer 1,
124
 */
125
static void prvSetupTimerInterrupt( void );
126
/*-----------------------------------------------------------*/
127
 
128
/*
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 * Initialise the stack of a task to look exactly as if a call to
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 * portSAVE_CONTEXT had been called.
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 *
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 * See the header file portable.h.
133
 */
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portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )
135
{
136
        /* Place a few bytes of known values on the bottom of the stack.
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        This is just useful for debugging. */
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139
        *pxTopOfStack = 0x11111111;
140
        pxTopOfStack--;
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        *pxTopOfStack = 0x22222222;
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        pxTopOfStack--;
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        *pxTopOfStack = 0x33333333;
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        pxTopOfStack--;
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        /* This is a redundant push to the stack, it may be required if
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        in some implementations of the compiler the parameter to the task
148
        is passed on to the stack rather than in R4 register. */
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        *pxTopOfStack = (portSTACK_TYPE)(pvParameters);
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        pxTopOfStack--;
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152
        *pxTopOfStack = ( portSTACK_TYPE ) 0x00000000;  /* RP */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x00007777;  /* R7 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x00006666;  /* R6 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x00005555;  /* R5 */
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        pxTopOfStack--;
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161
        /* In the current implementation of the compiler the first
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        parameter to the task (or function) is passed via R4 parameter
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        to the task, hence the pvParameters pointer is copied into the R4
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        register. See compiler manual section 4.6.2 for more information. */
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        *pxTopOfStack = ( portSTACK_TYPE ) (pvParameters);      /* R4 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x00003333;  /* R3 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x00002222;  /* R2 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x00001111;  /* R1 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x00000001;  /* R0 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x0000EEEE;  /* R14 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x0000DDDD;  /* R13 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x0000CCCC;  /* R12 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x0000BBBB;  /* R11 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x0000AAAA;  /* R10 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x00009999;  /* R9 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x00008888;  /* R8 */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x11110000;  /* MDH */
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        pxTopOfStack--;
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x22220000;  /* MDL */
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        pxTopOfStack--;
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        /* The start of the task code. */
195
        *pxTopOfStack = ( portSTACK_TYPE ) pxCode;      /* PC */
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        pxTopOfStack--;
197
 
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    /* PS - User Mode, USP, ILM=31, Interrupts enabled */
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        *pxTopOfStack = ( portSTACK_TYPE ) 0x001F0030;  /* PS */
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201
        return pxTopOfStack;
202
}
203
/*-----------------------------------------------------------*/
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portBASE_TYPE xPortStartScheduler( void )
206
{
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        /* Setup the hardware to generate the tick. */
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        prvSetupTimerInterrupt();
209
 
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        /* Restore the context of the first task that is going to run. */
211
        #pragma asm
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                RestoreContext
213
        #pragma endasm
214
 
215
        /* Simulate a function call end as generated by the compiler.  We will now
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        jump to the start of the task the context of which we have just restored. */
217
        __asm(" reti ");
218
 
219
        /* Should not get here. */
220
        return pdFAIL;
221
}
222
/*-----------------------------------------------------------*/
223
 
224
void vPortEndScheduler( void )
225
{
226
        /* Not implemented - unlikely to ever be required as there is nothing to
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        return to. */
228
}
229
/*-----------------------------------------------------------*/
230
 
231
static void prvSetupTimerInterrupt( void )
232
{
233
/* The peripheral clock divided by 32 is used by the timer. */
234
const unsigned short usReloadValue = ( unsigned short ) ( ( ( configPER_CLOCK_HZ / configTICK_RATE_HZ ) / 32UL ) - 1UL );
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236
        /* Setup RLT0 to generate a tick interrupt. */
237
 
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        TMCSR0_CNTE = 0;         /* Count Disable */
239
    TMCSR0_CSL = 0x2;           /* CLKP/32 */
240
    TMCSR0_MOD = 0;                      /* Software trigger */
241
    TMCSR0_RELD = 1;            /* Reload */
242
 
243
    TMCSR0_UF = 0;                       /* Clear underflow flag */
244
        TMRLR0 = usReloadValue;
245
        TMCSR0_INTE = 1;                /* Interrupt Enable */
246
        TMCSR0_CNTE = 1;                /* Count Enable */
247
        TMCSR0_TRG = 1;                 /* Trigger */
248
 
249
    PORTEN = 0x3;                       /* Port Enable */
250
}
251
/*-----------------------------------------------------------*/
252
 
253
#if configUSE_PREEMPTION == 1
254
 
255
        /*
256
         * Tick ISR for preemptive scheduler. The tick count is incremented
257
         * after the context is saved. Then the context is switched if required,
258
         * and last the context of the task which is to be resumed is restored.
259
         */
260
 
261
        #pragma asm
262
 
263
        .global _ReloadTimer0_IRQHandler
264
        _ReloadTimer0_IRQHandler:
265
 
266
        ANDCCR #0xEF                                                    ;Disable Interrupts
267
        SaveContext                                                             ;Save context
268
        ORCCR #0x10                                                             ;Re-enable Interrupts
269
 
270
        LDI #0xFFFB,R1
271
        LDI #_tmcsr0, R0
272
        AND R1,@R0                                                              ;Clear RLT0 interrupt flag
273
 
274
        CALL32   _vTaskIncrementTick,R12                ;Increment Tick
275
        CALL32   _vTaskSwitchContext,R12                ;Switch context if required
276
 
277
        ANDCCR #0xEF                                                    ;Disable Interrupts
278
        RestoreContext                                                  ;Restore context
279
        ORCCR #0x10                                                             ;Re-enable Interrupts
280
 
281
        RETI
282
 
283
        #pragma endasm
284
 
285
#else
286
 
287
        /*
288
         * Tick ISR for the cooperative scheduler.  All this does is increment the
289
         * tick count.  We don't need to switch context, this can only be done by
290
         * manual calls to taskYIELD();
291
         */
292
        __interrupt void ReloadTimer0_IRQHandler( void )
293
        {
294
                /* Clear RLT0 interrupt flag */
295
                TMCSR0_UF = 0;
296
                vTaskIncrementTick();
297
        }
298
 
299
#endif
300
 
301
/*
302
 * Manual context switch. We can use a __nosavereg attribute  as the context
303
 * would be saved by PortSAVE_CONTEXT().  The context is switched and then
304
 * the context of the new task is restored saved.
305
 */
306
#pragma asm
307
 
308
        .global _vPortYieldDelayed
309
        _vPortYieldDelayed:
310
 
311
        ANDCCR #0xEF                                                    ;Disable Interrupts
312
        SaveContext                                                             ;Save context
313
        ORCCR #0x10                                                             ;Re-enable Interrupts
314
 
315
        LDI #_dicr, R0
316
        BANDL #0x0E, @R0                                                ;Clear Delayed interrupt flag
317
 
318
        CALL32   _vTaskSwitchContext,R12                ;Switch context if required
319
 
320
        ANDCCR #0xEF                                                    ;Disable Interrupts
321
        RestoreContext                                                  ;Restore context
322
        ORCCR #0x10                                                             ;Re-enable Interrupts
323
 
324
        RETI
325
 
326
#pragma endasm
327
/*-----------------------------------------------------------*/
328
 
329
/*
330
 * Manual context switch. We can use a __nosavereg attribute  as the context
331
 * would be saved by PortSAVE_CONTEXT().  The context is switched and then
332
 * the context of the new task is restored saved.
333
 */
334
#pragma asm
335
 
336
        .global _vPortYield
337
        _vPortYield:
338
 
339
        SaveContext                                                             ;Save context
340
        CALL32   _vTaskSwitchContext,R12                ;Switch context if required
341
        RestoreContext                                                  ;Restore context
342
 
343
        RETI
344
 
345
#pragma endasm
346
/*-----------------------------------------------------------*/
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