This file is part of SimpleRTOS2
/*============================================================================*/
/*
SimpleRTOS - Very simple RTOS for Microcontrollers - ARM Cortex-M3 ATSAM3 port
v2.00 (2014-01-21)
isaacbavaresco@yahoo.com.br
*/
/*============================================================================*/
/*
Copyright (c) 2007-2014, 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.
*/
/*============================================================================*/
#include <asf.h>
#include <string.h>
#include "PortSAM3.h"
#include "SimpleRTOSInternals.h"
/*============================================================================*/
//extern void __attribute__((weak)) TickHook( void );
/*============================================================================*/
void __attribute__((noinline)) Switch( void )
{
SystemTick++;
CheckDelayList();
/* The current task ran for at least one full time slice... */
if( AlreadySwitched == 0 && CurrentTask->Priority == HighestReadyPriority )
/* ... it doesn't deserve an additional time slice. */
ReadyTasks[HighestReadyPriority]
= ReadyTasks[HighestReadyPriority]->Next;
CurrentTask = ReadyTasks[HighestReadyPriority];
/*
The upcoming task will run from the very beginning of its time slice,
at the end of this slice it will be switched off.
*/
AlreadySwitched = 0;
if( TickHook != NULL )
TickHook();
}
/*============================================================================*/
/* Constants required to manipulate the NVIC. */
#define NVIC_SYST_CSR (*(volatile unsigned long *)0xe000e010)
#define NVIC_SYST_CSR_ENABLE 0x00000001
#define NVIC_SYST_CSR_TICKINT 0x00000002
#define NVIC_SYST_CSR_CLKSOURCE 0x00000004
#define NVIC_SYST_RVR ( *(volatile unsigned long*)0xe000e014 )
#define NVIC_SYST_CVR ( *(volatile unsigned long*)0xe000e018 )
#define portNVIC_INT_CTRL ((volatile unsigned long *) 0xe000ed04)
#define NVIC_SHPR2 ( *(volatile unsigned long*)0xe000ed1c )
#define NVIC_SHPR3_SVCALL_PRI ( 0ul << 24 )
#define NVIC_SHPR3 ( *(volatile unsigned long*)0xe000ed20 )
#define NVIC_SHPR3_PENDSV_PRI (( (unsigned long)(( KERNEL_INTERRUPT_PRIORITY << ( 8 - __NVIC_PRIO_BITS )) & 0xff )) << 16 )
#define NVIC_SHPR3_SYSTICK_PRI (( (unsigned long)(( KERNEL_INTERRUPT_PRIORITY << ( 8 - __NVIC_PRIO_BITS )) & 0xff )) << 24 )
#define portNVIC_PENDSVSET 0x10000000
/*============================================================================*/
void __attribute__ ((naked)) SysTick_Handler( void )
{
SAVE_CONTEXT();
Switch();
RESTORE_CONTEXT();
}
/*============================================================================*/
void __attribute__ ((naked)) SVC_Handler( void )
{
SAVE_CONTEXT();
CurrentTask = ReadyTasks[HighestReadyPriority];
RESTORE_CONTEXT();
}
/*============================================================================*/
void ContextInit( context_t *Context, unsigned char *Stack, unsigned long StackSize, void *Parameter, void (*TaskFunc)( void* ), unsigned int Priority )
{
unsigned long *StackTop, Aux;
memset( Context, 0x00, sizeof( context_t ));
StackTop = (unsigned long*)Stack + StackSize / sizeof( unsigned long );
/* Registers saved automatically */
*--StackTop = 0x01000000ul; /* PSR */
*--StackTop = (unsigned long)TaskFunc | 0x00000001ul; /* r15 (PC) */
*--StackTop = (unsigned long)TaskFinish; /* r14 (LR)) */
*--StackTop = 0; /* r12 */
*--StackTop = 0; /* r3 */
*--StackTop = 0; /* r2 */
*--StackTop = 0; /* r1 */
*--StackTop = (unsigned long)Parameter; /* r0 */
*--StackTop = 0; /* basepri (r12) */
*--StackTop = 0; /* r11*/
*--StackTop = 0; /* r10 */
*--StackTop = 0; /* r9 */
*--StackTop = 0; /* r8 */
*--StackTop = 0; /* r7 */
*--StackTop = 0; /* r6 */
*--StackTop = 0; /* r5 */
*--StackTop = 0; /* r4 */
Context->sp = (unsigned long)StackTop;
Context->Priority = Priority;
Context->TDelay = 0;
Context->PreviousDelayedTask = NULL;
Context->NextDelayedTask = NULL;
Context->DelayList = NULL;
#ifdef USE_SLICE_LENGTH
Context->SliceLength = 0;
#endif /* USE_SLICE_LENGTH */
Context->Previous = NULL;
Context->Next = NULL;
Context->List = NULL;
}
/*============================================================================*/
void InitRTOS( context_t *ctxts, unsigned int Number )
{
unsigned int i;
/* No contexts to be initialized... The RTOS is useless.*/
if( ctxts == NULL || Number == 0 )
{
FreeContexts = NULL;
return;
}
CurrentTask = ctxts;
for( i = 0; i < MaxPriorities; i++ )
ReadyTasks[i] = NULL;
/*------------------------------------------------------------------------*/
/* Initialize all contexts and link them to the free contexts list.*/
FreeContexts = ctxts;
for( i = 0; i < Number - 1; i++, ctxts++ )
{
ctxts->Next = ctxts + 1;
ctxts->List = &FreeContexts;
}
ctxts->Next = NULL;
ctxts->List = &FreeContexts;
/*------------------------------------------------------------------------*/
}
/*============================================================================*/
void SetupTimerInterrupt( tickcount_t TickRate )
{
volatile unsigned long Clk = sysclk_get_cpu_hz();
volatile unsigned long Aux = Clk / TickRate - 1UL;
/* Configure SysTick to interrupt at the requested rate. */
NVIC_SYST_CVR = 0ul;
NVIC_SYST_RVR = sysclk_get_cpu_hz() / TickRate - 1UL;
NVIC_SYST_CSR = NVIC_SYST_CSR_CLKSOURCE | NVIC_SYST_CSR_TICKINT | NVIC_SYST_CSR_ENABLE;
}
/*============================================================================*/
void __attribute__((noreturn)) StartRTOS( tickcount_t TickRate )
{
/* Make PendSV, CallSV and SysTick the same priroity as the kernel. */
NVIC_SHPR2 = NVIC_SHPR3_SVCALL_PRI;
NVIC_SHPR3 = NVIC_SHPR3_PENDSV_PRI | NVIC_SHPR3_SYSTICK_PRI;
SystemTick = 0;
CurrentTask = ReadyTasks[HighestReadyPriority];
SetupTimerInterrupt( TickRate );
#if defined USE_PSP
__asm volatile(
"ldr r0,=0xE000ED08 \n" /* Use the NVIC offset register to locate the stack. */
"ldr r0,[r0] \n"
"ldr r0,[r0] \n"
"msr msp,r0 \n" /* Set the msp back to the start of the stack. */
"isb \n"
"mov r0,2 \n"
"msr control,r0 \n"
"isb \n"
::: "r0"
);
#endif /* defined USE_PSP */
asm volatile(
"ldr r0,=CurrentTask \n" /* r0 = &CurrentTask */
"ldr r0,[r0] \n" /* r0 = CurrentTask */
"ldr r13,[r0,0] \n" /* r13 = StackTop */
"ldmia r13!,{r4-r11} \n"
"add r13,#4 \n"
"ldmia r13!,{r0-r3,r12,r14} \n"
"add r13,#8 \n"
"ldr r15,[r13,-8] \n"
::: "r0"
);
while( 1 )
{}
}
/*============================================================================*/