/* | |
FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd. | |
*************************************************************************** | |
* * | |
* If you are: * | |
* * | |
* + New to FreeRTOS, * | |
* + Wanting to learn FreeRTOS or multitasking in general quickly * | |
* + Looking for basic training, * | |
* + Wanting to improve your FreeRTOS skills and productivity * | |
* * | |
* then take a look at the FreeRTOS books - available as PDF or paperback * | |
* * | |
* "Using the FreeRTOS Real Time Kernel - a Practical Guide" * | |
* http://www.FreeRTOS.org/Documentation * | |
* * | |
* A pdf reference manual is also available. Both are usually delivered * | |
* to your inbox within 20 minutes to two hours when purchased between 8am * | |
* and 8pm GMT (although please allow up to 24 hours in case of * | |
* exceptional circumstances). Thank you for your support! * | |
* * | |
*************************************************************************** | |
This file is part of the FreeRTOS distribution. | |
FreeRTOS is free software; you can redistribute it and/or modify it under | |
the terms of the GNU General Public License (version 2) as published by the | |
Free Software Foundation AND MODIFIED BY the FreeRTOS exception. | |
***NOTE*** The exception to the GPL is included to allow you to distribute | |
a combined work that includes FreeRTOS without being obliged to provide the | |
source code for proprietary components outside of the FreeRTOS kernel. | |
FreeRTOS is distributed in the hope that it will be useful, but WITHOUT | |
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
more details. You should have received a copy of the GNU General Public | |
License and the FreeRTOS license exception along with FreeRTOS; if not it | |
can be viewed here: http://www.freertos.org/a00114.html and also obtained | |
by writing to Richard Barry, contact details for whom are available on the | |
FreeRTOS WEB site. | |
1 tab == 4 spaces! | |
http://www.FreeRTOS.org - Documentation, latest information, license and | |
contact details. | |
http://www.SafeRTOS.com - A version that is certified for use in safety | |
critical systems. | |
http://www.OpenRTOS.com - Commercial support, development, porting, | |
licensing and training services. | |
*/ | |
/*----------------------------------------------------------- | |
* Implementation of functions defined in portable.h for the NIOS2 port. | |
*----------------------------------------------------------*/ | |
/* Standard Includes. */ | |
#include <string.h> | |
#include <errno.h> | |
/* Altera includes. */ | |
#include "sys/alt_irq.h" | |
#include "altera_avalon_timer_regs.h" | |
#include "priv/alt_irq_table.h" | |
/* Scheduler includes. */ | |
#include "FreeRTOS.h" | |
#include "task.h" | |
/* Interrupts are enabled. */ | |
#define portINITIAL_ESTATUS ( portSTACK_TYPE ) 0x01 | |
/*-----------------------------------------------------------*/ | |
/* | |
* Setup the timer to generate the tick interrupts. | |
*/ | |
static void prvSetupTimerInterrupt( void ); | |
/* | |
* Call back for the alarm function. | |
*/ | |
void vPortSysTickHandler( void * context, alt_u32 id ); | |
/*-----------------------------------------------------------*/ | |
void prvReadGp( unsigned long *ulValue ) | |
{ | |
asm( "stw gp, (r4) " ); | |
}; | |
/*-----------------------------------------------------------*/ | |
/* | |
* See header file for description. | |
*/ | |
portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters ) | |
{ | |
portSTACK_TYPE *pxFramePointer = pxTopOfStack - 1; | |
portSTACK_TYPE xGlobalPointer; | |
prvReadGp( &xGlobalPointer ); | |
/* End of stack marker. */ | |
*pxTopOfStack = 0xdeadbeef; | |
pxTopOfStack--; | |
*pxTopOfStack = ( portSTACK_TYPE ) pxFramePointer; | |
pxTopOfStack--; | |
*pxTopOfStack = xGlobalPointer; | |
/* Space for R23 to R16. */ | |
pxTopOfStack -= 9; | |
*pxTopOfStack = ( portSTACK_TYPE ) pxCode; | |
pxTopOfStack--; | |
*pxTopOfStack = portINITIAL_ESTATUS; | |
/* Space for R15 to R5. */ | |
pxTopOfStack -= 12; | |
*pxTopOfStack = ( portSTACK_TYPE ) pvParameters; | |
/* Space for R3 to R1, muldiv and RA. */ | |
pxTopOfStack -= 5; | |
return pxTopOfStack; | |
} | |
/*-----------------------------------------------------------*/ | |
/* | |
* See header file for description. | |
*/ | |
portBASE_TYPE xPortStartScheduler( void ) | |
{ | |
/* Start the timer that generates the tick ISR. Interrupts are disabled | |
here already. */ | |
prvSetupTimerInterrupt(); | |
/* Start the first task. */ | |
asm volatile ( " movia r2, restore_sp_from_pxCurrentTCB \n" | |
" jmp r2 " ); | |
/* Should not get here! */ | |
return 0; | |
} | |
/*-----------------------------------------------------------*/ | |
void vPortEndScheduler( void ) | |
{ | |
/* It is unlikely that the NIOS2 port will require this function as there | |
is nothing to return to. */ | |
} | |
/*-----------------------------------------------------------*/ | |
/* | |
* Setup the systick timer to generate the tick interrupts at the required | |
* frequency. | |
*/ | |
void prvSetupTimerInterrupt( void ) | |
{ | |
/* Try to register the interrupt handler. */ | |
if ( -EINVAL == alt_irq_register( SYS_CLK_IRQ, 0x0, vPortSysTickHandler ) ) | |
{ | |
/* Failed to install the Interrupt Handler. */ | |
asm( "break" ); | |
} | |
else | |
{ | |
/* Configure SysTick to interrupt at the requested rate. */ | |
IOWR_ALTERA_AVALON_TIMER_CONTROL( SYS_CLK_BASE, ALTERA_AVALON_TIMER_CONTROL_STOP_MSK ); | |
IOWR_ALTERA_AVALON_TIMER_PERIODL( SYS_CLK_BASE, ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) & 0xFFFF ); | |
IOWR_ALTERA_AVALON_TIMER_PERIODH( SYS_CLK_BASE, ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) >> 16 ); | |
IOWR_ALTERA_AVALON_TIMER_CONTROL( SYS_CLK_BASE, ALTERA_AVALON_TIMER_CONTROL_CONT_MSK | ALTERA_AVALON_TIMER_CONTROL_START_MSK | ALTERA_AVALON_TIMER_CONTROL_ITO_MSK ); | |
} | |
/* Clear any already pending interrupts generated by the Timer. */ | |
IOWR_ALTERA_AVALON_TIMER_STATUS( SYS_CLK_BASE, ~ALTERA_AVALON_TIMER_STATUS_TO_MSK ); | |
} | |
/*-----------------------------------------------------------*/ | |
void vPortSysTickHandler( void * context, alt_u32 id ) | |
{ | |
/* Increment the Kernel Tick. */ | |
vTaskIncrementTick(); | |
/* If using preemption, also force a context switch. */ | |
#if configUSE_PREEMPTION == 1 | |
vTaskSwitchContext(); | |
#endif | |
/* Clear the interrupt. */ | |
IOWR_ALTERA_AVALON_TIMER_STATUS( SYS_CLK_BASE, ~ALTERA_AVALON_TIMER_STATUS_TO_MSK ); | |
} | |
/*-----------------------------------------------------------*/ | |
/** This function is a re-implementation of the Altera provided function. | |
* The function is re-implemented to prevent it from enabling an interrupt | |
* when it is registered. Interrupts should only be enabled after the FreeRTOS.org | |
* kernel has its scheduler started so that contexts are saved and switched | |
* correctly. | |
*/ | |
int alt_irq_register( alt_u32 id, void* context, void (*handler)(void*, alt_u32) ) | |
{ | |
int rc = -EINVAL; | |
alt_irq_context status; | |
if (id < ALT_NIRQ) | |
{ | |
/* | |
* interrupts are disabled while the handler tables are updated to ensure | |
* that an interrupt doesn't occur while the tables are in an inconsistent | |
* state. | |
*/ | |
status = alt_irq_disable_all (); | |
alt_irq[id].handler = handler; | |
alt_irq[id].context = context; | |
rc = (handler) ? alt_irq_enable (id): alt_irq_disable (id); | |
/* alt_irq_enable_all(status); This line is removed to prevent the interrupt from being immediately enabled. */ | |
} | |
return rc; | |
} | |
/*-----------------------------------------------------------*/ | |