1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
|
/*
FreeRTOS V8.0.0 - Copyright (C) 2014 Real Time Engineers Ltd.
All rights reserved
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
***************************************************************************
* *
* FreeRTOS provides completely free yet professionally developed, *
* robust, strictly quality controlled, supported, and cross *
* platform software that has become a de facto standard. *
* *
* Help yourself get started quickly and support the FreeRTOS *
* project by purchasing a FreeRTOS tutorial book, reference *
* manual, or both from: http://www.FreeRTOS.org/Documentation *
* *
* Thank you! *
* *
***************************************************************************
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 modification 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. Full license text is available from the following
link: http://www.freertos.org/a00114.html
1 tab == 4 spaces!
***************************************************************************
* *
* Having a problem? Start by reading the FAQ "My application does *
* not run, what could be wrong?" *
* *
* http://www.FreeRTOS.org/FAQHelp.html *
* *
***************************************************************************
http://www.FreeRTOS.org - Documentation, books, training, latest versions,
license and Real Time Engineers Ltd. contact details.
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
including FreeRTOS+Trace - an indispensable productivity tool, a DOS
compatible FAT file system, and our tiny thread aware UDP/IP stack.
http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
licenses offer ticketed support, indemnification and middleware.
http://www.SafeRTOS.com - High Integrity Systems also provide a safety
engineered and independently SIL3 certified version for use in safety and
mission critical applications that require provable dependability.
1 tab == 4 spaces!
*/
/*-----------------------------------------------------------
* 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 ( StackType_t ) 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 );
/*-----------------------------------------------------------*/
static void prvReadGp( uint32_t *ulValue )
{
asm( "stw gp, (%0)" :: "r"(ulValue) );
}
/*-----------------------------------------------------------*/
/*
* See header file for description.
*/
StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
{
StackType_t *pxFramePointer = pxTopOfStack - 1;
StackType_t xGlobalPointer;
prvReadGp( &xGlobalPointer );
/* End of stack marker. */
*pxTopOfStack = 0xdeadbeef;
pxTopOfStack--;
*pxTopOfStack = ( StackType_t ) pxFramePointer;
pxTopOfStack--;
*pxTopOfStack = xGlobalPointer;
/* Space for R23 to R16. */
pxTopOfStack -= 9;
*pxTopOfStack = ( StackType_t ) pxCode;
pxTopOfStack--;
*pxTopOfStack = portINITIAL_ESTATUS;
/* Space for R15 to R5. */
pxTopOfStack -= 12;
*pxTopOfStack = ( StackType_t ) pvParameters;
/* Space for R3 to R1, muldiv and RA. */
pxTopOfStack -= 5;
return pxTopOfStack;
}
/*-----------------------------------------------------------*/
/*
* See header file for description.
*/
BaseType_t 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. */
if( xTaskIncrementTick() != pdFALSE )
{
vTaskSwitchContext();
}
/* 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;
}
/*-----------------------------------------------------------*/
|
