mirror of
https://github.com/FreeRTOS/FreeRTOS-Kernel.git
synced 2025-11-04 11:09:01 +01:00
240 lines
8.0 KiB
C
240 lines
8.0 KiB
C
/*
|
|
* FreeRTOS Kernel <DEVELOPMENT BRANCH>
|
|
* Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
|
|
*
|
|
* SPDX-License-Identifier: MIT
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy of
|
|
* this software and associated documentation files (the "Software"), to deal in
|
|
* the Software without restriction, including without limitation the rights to
|
|
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
|
|
* the Software, and to permit persons to whom the Software is furnished to do so,
|
|
* subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in all
|
|
* copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
|
|
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
|
|
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
|
|
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
|
|
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
*
|
|
* https://www.FreeRTOS.org
|
|
* https://github.com/FreeRTOS
|
|
*
|
|
*/
|
|
|
|
/* GCC/HCS12 port by Jefferson L Smith, 2005 */
|
|
|
|
/* Scheduler includes. */
|
|
#include "FreeRTOS.h"
|
|
#include "task.h"
|
|
|
|
/* Port includes */
|
|
#include <sys/ports_def.h>
|
|
|
|
/*-----------------------------------------------------------
|
|
* Implementation of functions defined in portable.h for the HCS12 port.
|
|
*----------------------------------------------------------*/
|
|
|
|
|
|
/*
|
|
* Configure a timer to generate the RTOS tick at the frequency specified
|
|
* within FreeRTOSConfig.h.
|
|
*/
|
|
static void prvSetupTimerInterrupt( void );
|
|
|
|
/* NOTE: Interrupt service routines must be in non-banked memory - as does the
|
|
* scheduler startup function. */
|
|
#define ATTR_NEAR __attribute__( ( near ) )
|
|
|
|
/* Manual context switch function. This is the SWI ISR. */
|
|
/* __attribute__((interrupt)) */
|
|
void ATTR_NEAR vPortYield( void );
|
|
|
|
/* Tick context switch function. This is the timer ISR. */
|
|
/* __attribute__((interrupt)) */
|
|
void ATTR_NEAR vPortTickInterrupt( void );
|
|
|
|
/* Function in non-banked memory which actually switches to first task. */
|
|
BaseType_t ATTR_NEAR xStartSchedulerNear( void );
|
|
|
|
/* Calls to portENTER_CRITICAL() can be nested. When they are nested the
|
|
* critical section should not be left (i.e. interrupts should not be re-enabled)
|
|
* until the nesting depth reaches 0. This variable simply tracks the nesting
|
|
* depth. Each task maintains it's own critical nesting depth variable so
|
|
* uxCriticalNesting is saved and restored from the task stack during a context
|
|
* switch. */
|
|
volatile UBaseType_t uxCriticalNesting = 0x80; /* un-initialized */
|
|
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/*
|
|
* See header file for description.
|
|
*/
|
|
StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack,
|
|
TaskFunction_t pxCode,
|
|
void * pvParameters )
|
|
{
|
|
/* Setup the initial stack of the task. The stack is set exactly as
|
|
* expected by the portRESTORE_CONTEXT() macro. In this case the stack as
|
|
* expected by the HCS12 RTI instruction. */
|
|
|
|
|
|
/* The address of the task function is placed in the stack byte at a time. */
|
|
*pxTopOfStack = ( StackType_t ) *( ( ( StackType_t * ) ( &pxCode ) ) + 1 );
|
|
*--pxTopOfStack = ( StackType_t ) *( ( ( StackType_t * ) ( &pxCode ) ) + 0 );
|
|
|
|
/* Next are all the registers that form part of the task context. */
|
|
|
|
/* Y register */
|
|
*--pxTopOfStack = ( StackType_t ) 0xff;
|
|
*--pxTopOfStack = ( StackType_t ) 0xee;
|
|
|
|
/* X register */
|
|
*--pxTopOfStack = ( StackType_t ) 0xdd;
|
|
*--pxTopOfStack = ( StackType_t ) 0xcc;
|
|
|
|
/* A register contains parameter high byte. */
|
|
*--pxTopOfStack = ( StackType_t ) *( ( ( StackType_t * ) ( &pvParameters ) ) + 0 );
|
|
|
|
/* B register contains parameter low byte. */
|
|
*--pxTopOfStack = ( StackType_t ) *( ( ( StackType_t * ) ( &pvParameters ) ) + 1 );
|
|
|
|
/* CCR: Note that when the task starts interrupts will be enabled since
|
|
* "I" bit of CCR is cleared */
|
|
*--pxTopOfStack = ( StackType_t ) 0x80; /* keeps Stop disabled (MCU default) */
|
|
|
|
/* tmp softregs used by GCC. Values right now don't matter. */
|
|
__asm( "\n\
|
|
movw _.frame, 2,-%0 \n\
|
|
movw _.tmp, 2,-%0 \n\
|
|
movw _.z, 2,-%0 \n\
|
|
movw _.xy, 2,-%0 \n\
|
|
;movw _.d2, 2,-%0 \n\
|
|
;movw _.d1, 2,-%0 \n\
|
|
" : "=A" ( pxTopOfStack ) : "0" ( pxTopOfStack ) );
|
|
|
|
#ifdef BANKED_MODEL
|
|
/* The page of the task. */
|
|
*--pxTopOfStack = 0x30; /* can only directly start in PPAGE 0x30 */
|
|
#endif
|
|
|
|
/* The critical nesting depth is initialised with 0 (meaning not in
|
|
* a critical section). */
|
|
*--pxTopOfStack = ( StackType_t ) 0x00;
|
|
|
|
|
|
return pxTopOfStack;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vPortEndScheduler( void )
|
|
{
|
|
/* It is unlikely that the HCS12 port will get stopped. */
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static void prvSetupTimerInterrupt( void )
|
|
{
|
|
/* Enable hardware RTI timer */
|
|
/* Ignores configTICK_RATE_HZ */
|
|
RTICTL = 0x50; /* 16 MHz xtal: 976.56 Hz, 1024mS */
|
|
CRGINT |= 0x80; /* RTIE */
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
BaseType_t xPortStartScheduler( void )
|
|
{
|
|
/* xPortStartScheduler() does not start the scheduler directly because
|
|
* the header file containing the xPortStartScheduler() prototype is part
|
|
* of the common kernel code, and therefore cannot use the CODE_SEG pragma.
|
|
* Instead it simply calls the locally defined xNearStartScheduler() -
|
|
* which does use the CODE_SEG pragma. */
|
|
|
|
int16_t register d;
|
|
|
|
__asm( "jmp xStartSchedulerNear ; will never return" : "=d" ( d ) );
|
|
return d;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
BaseType_t xStartSchedulerNear( void )
|
|
{
|
|
/* Configure the timer that will generate the RTOS tick. Interrupts are
|
|
* disabled when this function is called. */
|
|
prvSetupTimerInterrupt();
|
|
|
|
/* Restore the context of the first task. */
|
|
portRESTORE_CONTEXT();
|
|
|
|
portISR_TAIL();
|
|
|
|
/* Should not get here! */
|
|
return pdFALSE;
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/*
|
|
* Context switch functions. These are interrupt service routines.
|
|
*/
|
|
|
|
/*
|
|
* Manual context switch forced by calling portYIELD(). This is the SWI
|
|
* handler.
|
|
*/
|
|
void vPortYield( void )
|
|
{
|
|
portISR_HEAD();
|
|
|
|
/* NOTE: This is the trap routine (swi) although not defined as a trap.
|
|
* It will fill the stack the same way as an ISR in order to mix preemtion
|
|
* and cooperative yield. */
|
|
|
|
portSAVE_CONTEXT();
|
|
vTaskSwitchContext();
|
|
portRESTORE_CONTEXT();
|
|
|
|
portISR_TAIL();
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/*
|
|
* RTOS tick interrupt service routine. If the cooperative scheduler is
|
|
* being used then this simply increments the tick count. If the
|
|
* preemptive scheduler is being used a context switch can occur.
|
|
*/
|
|
void vPortTickInterrupt( void )
|
|
{
|
|
portISR_HEAD();
|
|
|
|
/* Clear tick timer flag */
|
|
CRGFLG = 0x80;
|
|
|
|
#if configUSE_PREEMPTION == 1
|
|
{
|
|
/* A context switch might happen so save the context. */
|
|
portSAVE_CONTEXT();
|
|
|
|
/* Increment the tick ... */
|
|
if( xTaskIncrementTick() != pdFALSE )
|
|
{
|
|
/* A context switch is necessary. */
|
|
vTaskSwitchContext();
|
|
}
|
|
|
|
/* Restore the context of a task - which may be a different task
|
|
* to that interrupted. */
|
|
portRESTORE_CONTEXT();
|
|
}
|
|
#else /* if configUSE_PREEMPTION == 1 */
|
|
{
|
|
xTaskIncrementTick();
|
|
}
|
|
#endif /* if configUSE_PREEMPTION == 1 */
|
|
|
|
portISR_TAIL();
|
|
}
|