Added new Nios2 port layer.

This commit is contained in:
Richard Barry 2009-08-06 18:23:40 +00:00
parent 3a883a776c
commit 6358344ea1
3 changed files with 515 additions and 0 deletions

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/*
FreeRTOS V5.4.1 - Copyright (C) 2009 Real Time Engineers Ltd.
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.
Alternative commercial license and support terms are also available upon
request. See the licensing section of http://www.FreeRTOS.org for full
license details.
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 along
with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
Temple Place, Suite 330, Boston, MA 02111-1307 USA.
***************************************************************************
* *
* Looking for a quick start? Then check out the FreeRTOS eBook! *
* See http://www.FreeRTOS.org/Documentation for details *
* *
***************************************************************************
1 tab == 4 spaces!
Please ensure to read the configuration and relevant port sections of the
online documentation.
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 portLONG *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 inconsistant
* 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;
}
/*-----------------------------------------------------------*/

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/*
FreeRTOS V5.4.1 - Copyright (C) 2009 Real Time Engineers Ltd.
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.
Alternative commercial license and support terms are also available upon
request. See the licensing section of http://www.FreeRTOS.org for full
license details.
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 along
with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
Temple Place, Suite 330, Boston, MA 02111-1307 USA.
***************************************************************************
* *
* Looking for a quick start? Then check out the FreeRTOS eBook! *
* See http://www.FreeRTOS.org/Documentation for details *
* *
***************************************************************************
1 tab == 4 spaces!
Please ensure to read the configuration and relevant port sections of the
online documentation.
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.
*/
.extern vTaskSwitchContext
.set noat
# Exported to start the first task.
.globl restore_sp_from_pxCurrentTCB
# Entry point for exceptions.
.section .exceptions.entry, "xa"
# Save the entire context of a task.
save_context:
addi ea, ea, -4 # Point to the next instruction.
addi sp, sp, -116 # Create space on the stack.
stw ra, 0(sp)
# Leave a gap for muldiv 0
stw at, 8(sp)
stw r2, 12(sp)
stw r3, 16(sp)
stw r4, 20(sp)
stw r5, 24(sp)
stw r6, 28(sp)
stw r7, 32(sp)
stw r8, 36(sp)
stw r9, 40(sp)
stw r10, 44(sp)
stw r11, 48(sp)
stw r12, 52(sp)
stw r13, 56(sp)
stw r14, 60(sp)
stw r15, 64(sp)
rdctl r5, estatus # Save the eStatus
stw r5, 68(sp)
stw ea, 72(sp) # Save the PC
stw r16, 76(sp) # Save the remaining registers
stw r17, 80(sp)
stw r18, 84(sp)
stw r19, 88(sp)
stw r20, 92(sp)
stw r21, 96(sp)
stw r22, 100(sp)
stw r23, 104(sp)
stw gp, 108(sp)
stw fp, 112(sp)
save_sp_to_pxCurrentTCB:
movia et, pxCurrentTCB # Load the address of the pxCurrentTCB pointer
ldw et, (et) # Load the value of the pxCurrentTCB pointer
stw sp, (et) # Store the stack pointer into the top of the TCB
.section .exceptions.irqtest, "xa"
hw_irq_test:
/*
* Test to see if the exception was a software exception or caused
* by an external interrupt, and vector accordingly.
*/
rdctl r4, ipending # Load the Pending Interrupts indication
rdctl r5, estatus # Load the eStatus (enabled interrupts).
andi r2, r5, 1 # Are interrupts enabled globally.
beq r2, zero, soft_exceptions # Interrupts are not enabled.
beq r4, zero, soft_exceptions # There are no interrupts triggered.
.section .exceptions.irqhandler, "xa"
hw_irq_handler:
call alt_irq_handler # Call the alt_irq_handler to deliver to the registered interrupt handler.
.section .exceptions.irqreturn, "xa"
restore_sp_from_pxCurrentTCB:
movia et, pxCurrentTCB # Load the address of the pxCurrentTCB pointer
ldw et, (et) # Load the value of the pxCurrentTCB pointer
ldw sp, (et) # Load the stack pointer with the top value of the TCB
restore_context:
ldw ra, 0(sp) # Restore the registers.
# Leave a gap for muldiv 0.
ldw at, 8(sp)
ldw r2, 12(sp)
ldw r3, 16(sp)
ldw r4, 20(sp)
ldw r5, 24(sp)
ldw r6, 28(sp)
ldw r7, 32(sp)
ldw r8, 36(sp)
ldw r9, 40(sp)
ldw r10, 44(sp)
ldw r11, 48(sp)
ldw r12, 52(sp)
ldw r13, 56(sp)
ldw r14, 60(sp)
ldw r15, 64(sp)
ldw et, 68(sp) # Load the eStatus
wrctl estatus, et # Write the eStatus
ldw ea, 72(sp) # Load the Program Counter
ldw r16, 76(sp)
ldw r17, 80(sp)
ldw r18, 84(sp)
ldw r19, 88(sp)
ldw r20, 92(sp)
ldw r21, 96(sp)
ldw r22, 100(sp)
ldw r23, 104(sp)
ldw gp, 108(sp)
ldw fp, 112(sp)
addi sp, sp, 116 # Release stack space
eret # Return to address ea, loading eStatus into Status.
.section .exceptions.soft, "xa"
soft_exceptions:
ldw et, 0(ea) # Load the instruction where the interrupt occured.
movhi at, %hi(0x003B683A) # Load the registers with the trap instruction code
ori at, at, %lo(0x003B683A)
cmpne et, et, at # Compare the trap instruction code to the last excuted instruction
beq et, r0, call_scheduler # its a trap so switchcontext
break # This is an un-implemented instruction or muldiv problem.
br restore_context # its something else
call_scheduler:
addi ea, ea, 4 # A trap was called, increment the program counter so it is not called again.
stw ea, 72(sp) # Save the new program counter to the context.
call vTaskSwitchContext # Pick the next context.
br restore_sp_from_pxCurrentTCB # Switch in the task context and restore.

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/*
FreeRTOS V5.4.1 - Copyright (C) 2009 Real Time Engineers Ltd.
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.
Alternative commercial license and support terms are also available upon
request. See the licensing section of http://www.FreeRTOS.org for full
license details.
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 along
with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59
Temple Place, Suite 330, Boston, MA 02111-1307 USA.
***************************************************************************
* *
* Looking for a quick start? Then check out the FreeRTOS eBook! *
* See http://www.FreeRTOS.org/Documentation for details *
* *
***************************************************************************
1 tab == 4 spaces!
Please ensure to read the configuration and relevant port sections of the
online documentation.
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.
*/
#ifndef PORTMACRO_H
#define PORTMACRO_H
#ifdef __cplusplus
extern "C" {
#endif
#include "sys/alt_irq.h"
/*-----------------------------------------------------------
* Port specific definitions.
*
* The settings in this file configure FreeRTOS correctly for the
* given hardware and compiler.
*
* These settings should not be altered.
*-----------------------------------------------------------
*/
/* Type definitions. */
#define portCHAR char
#define portFLOAT float
#define portDOUBLE double
#define portLONG long
#define portSHORT short
#define portSTACK_TYPE unsigned portLONG
#define portBASE_TYPE long
#if( configUSE_16_BIT_TICKS == 1 )
typedef unsigned portSHORT portTickType;
#define portMAX_DELAY ( portTickType ) 0xffff
#else
typedef unsigned portLONG portTickType;
#define portMAX_DELAY ( portTickType ) 0xffffffff
#endif
/*-----------------------------------------------------------*/
/* Architecture specifics. */
#define portSTACK_GROWTH ( -1 )
#define portTICK_RATE_MS ( ( portTickType ) 1000 / configTICK_RATE_HZ )
#define portBYTE_ALIGNMENT 4
#define portNOP() asm volatile ( "NOP" )
#define portCRITICAL_NESTING_IN_TCB 1
/*-----------------------------------------------------------*/
extern void vTaskSwitchContext( void );
#define portYIELD() asm volatile ( "trap" );
#define portEND_SWITCHING_ISR( xSwitchRequired ) if( xSwitchRequired ) vTaskSwitchContext()
/* Include the port_asm.S file where the Context saving/restoring is defined. */
__asm__( "\n\t.globl save_context" );
/*-----------------------------------------------------------*/
extern void vTaskEnterCritical( void );
extern void vTaskExitCritical( void );
#define portDISABLE_INTERRUPTS() alt_irq_disable_all()
#define portENABLE_INTERRUPTS() alt_irq_enable_all( 0x01 );
#define portENTER_CRITICAL() vTaskEnterCritical()
#define portEXIT_CRITICAL() vTaskExitCritical()
/*-----------------------------------------------------------*/
/* Task function macros as described on the FreeRTOS.org WEB site. */
#define portTASK_FUNCTION_PROTO( vFunction, pvParameters ) void vFunction( void *pvParameters )
#define portTASK_FUNCTION( vFunction, pvParameters ) void vFunction( void *pvParameters )
#ifdef __cplusplus
}
#endif
#endif /* PORTMACRO_H */