Simple RTOS for Microchip Baseline and Midrange MCUs
This is file "SimpleRTOS.h"
//==============================================================================
// SimpleRTOS - Very simple RTOS for Microchip(R) Baseline and Midrange uCs
// v1.00 (2008-09-23)
// isaacbavaresco@yahoo.com.br
//==============================================================================
/*
Copyright (c) 2007-2008, Isaac Marino Bavaresco
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Neither the name of the author nor the
names of its contributors may be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ''AS IS'' AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
//==============================================================================
/*
Notes: - Works with Hi-Tech PICC v9.60PL2;
- Assembler optimizations must be OFF for every file that implements
task functions (it is better to have the task functions in one or
more files with no standard functions, to minimize the un-optimized
code length).
- Every task function must have a call to the macro
"TASK_INIT( <task function name> );" as the first statement;
- Every function called directly or indirectly by more than one task
must have a call to the macro "FUNC_INIT( <function name> );" as the
first statement, unless it doesn't have any parameters nor automatic
variables, or all paths through the call-graphs that it belongs have
at least one function that calls "FUNC_INIT" before the function is
called.
Unfortunately this impose certain restrictions when using library
functions, unless each library function is called from just one
task, or it is present only in call-graphs that at least one
function calls "FUNC_INIT" before the library function is called,
or you rebuild the library adding the call to "FUNC_INIT" to the
library functions that need it.
- SimpleRTOS functions and macros that may cause a context switch
(Eg: Yield, Sleep, DeleteTask (when deleting itself) and
MutexTake ) must be called only directly inside the task function,
never indirectly by other functions.
TO DO: - Find a way to reuse local variables of tasks that are never active
at the same time.
- Implement semaphores.
- Implement priorities and slice length.
*/
//==============================================================================
#if !defined __SimpleRTOS_H__
#define __SimpleRTOS_H__
//==============================================================================
#include <pic.h>
//==============================================================================
#if !defined NULL
#define NULL 0
#endif // !defined NULL
//==============================================================================
#define USE_BLOCKINGS
//==============================================================================
#define Yield() { \
SavePCLATH = PCLATH; \
asm("global _SavePCH " ); \
asm("global _SavePCL " ); \
asm("global _Scheduler " ); \
asm("movlw high ($+7) " ); \
asm("movwf _SavePCH " ); \
asm("movlw low ($+5) " ); \
asm("movwf _SavePCL " ); \
asm("movlw high _Scheduler " ); \
asm("movwf 10 " ); \
asm("goto _Scheduler " ); \
PCLATH = SavePCLATH; \
}
//==============================================================================
#define DeleteTask(t) { \
if( _DeleteTask((t)) ) \
{ \
asm( "global _AbortTask " ); \
asm( "movlw high _AbortTask " ); \
asm( "movwf 10 " ); \
asm( "goto _AbortTask " ); \
} \
}
//==============================================================================
// Put the current task to sleep for 't' ticks. If 't' is greater than 127 then
// the task is suspended (sleeping forever).
#define Sleep(t) { \
_Sleep( t ); \
Yield(); \
}
//==============================================================================
#define TASK_INIT(f) asm( "FNROOT _" #f )
//==============================================================================
#define FUNC_INIT(f) asm( "FNCALL intlevel1,_" #f ); \
#pragma interrupt_level 1
//==============================================================================
#define StartRTOS() { \
asm( "global __StartRTOS " ); \
asm( "movlw high __StartRTOS" ); \
asm( "movwf 10 " ); \
asm( "goto __StartRTOS " ); \
}
//==============================================================================
#define MutexTake(m,t) { \
if( !_MutexTake( (m), (t) )) \
Yield(); \
}
//==============================================================================
#define OwnTheMutex(m) ((m)->Owner == CurrentTask)
//==============================================================================
typedef bank2 struct
{
/// Saves the high byte of the program counter
unsigned char PCH;
/// Saves the low byte of the program counter
unsigned char PCL;
unsigned char PCLATH;
unsigned char FSR;
unsigned char TDelay;
#ifdef USE_BLOCKINGS
void bank2 *PreviousDelayedTask;
void bank2 *NextDelayedTask;
void bank2 *DelayList;
#else // USE_BLOCKINGS
#define PreviousDelayedTask Previous
#define NextDelayedTask Next
#define DelayList List
#endif // USE_BLOCKINGS
#ifdef USE_SLICE_LENGTH
unsigned char SliceLength;
#endif // USE_SLICE_LENGTH
#ifdef USE_PRIORITIES
unsigned char Priority;
#endif // USE_PRIORITIES
void bank2 *Previous;
void bank2 *Next;
void bank2 *List;
} TS_Context;
//==============================================================================
typedef bank2 struct
{
TS_Context *Owner;
TS_Context *WaitingList;
} TS_Mutex;
//==============================================================================
extern unsigned char Ticks;
extern unsigned char SavePCH;
extern unsigned char SavePCL;
extern unsigned char SaveFSR;
extern unsigned char SavePCLATH;
extern TS_Context *CurrentTask;
//==============================================================================
void InitRTOS ( TS_Context *Contexts, unsigned char Number );
void _StartRTOS ( void );
void Scheduler ( void );
void _Sleep ( unsigned char t );
TS_Context *CreateTask ( void(*TaskFunc)(void) );
bit _DeleteTask ( TS_Context *Task );
bit ResumeTask ( TS_Context *Task );
bit _MutexTake ( TS_Mutex *Mutex, unsigned char t );
bit MutexGive ( TS_Mutex *Mutex );
//==============================================================================
#endif // !defined __SimpleRTOS_H__
//==============================================================================