OpenCores
URL https://opencores.org/ocsvn/ao486/ao486/trunk

Subversion Repositories ao486

[/] [ao486/] [trunk/] [syn/] [components/] [sd_card/] [firmware/] [bsp/] [HAL/] [src/] [alt_sbrk.c] - Blame information for rev 8

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 8 alfik
/******************************************************************************
2
*                                                                             *
3
* License Agreement                                                           *
4
*                                                                             *
5
* Copyright (c) 2004 Altera Corporation, San Jose, California, USA.           *
6
* All rights reserved.                                                        *
7
*                                                                             *
8
* Permission is hereby granted, free of charge, to any person obtaining a     *
9
* copy of this software and associated documentation files (the "Software"),  *
10
* to deal in the Software without restriction, including without limitation   *
11
* the rights to use, copy, modify, merge, publish, distribute, sublicense,    *
12
* and/or sell copies of the Software, and to permit persons to whom the       *
13
* Software is furnished to do so, subject to the following conditions:        *
14
*                                                                             *
15
* The above copyright notice and this permission notice shall be included in  *
16
* all copies or substantial portions of the Software.                         *
17
*                                                                             *
18
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR  *
19
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,    *
20
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE *
21
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER      *
22
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING     *
23
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER         *
24
* DEALINGS IN THE SOFTWARE.                                                   *
25
*                                                                             *
26
* This agreement shall be governed in all respects by the laws of the State   *
27
* of California and by the laws of the United States of America.              *
28
*                                                                             *
29
* Altera does not recommend, suggest or require that this reference design    *
30
* file be used in conjunction or combination with any other product.          *
31
******************************************************************************/
32
 
33
#include <sys/types.h>
34
 
35
#include "os/alt_syscall.h"
36
 
37
#include "sys/alt_irq.h"
38
#include "sys/alt_stack.h"
39
 
40
#include "system.h"
41
 
42
/*
43
 * sbrk() is called to dynamically extend the data segment for the application.
44
 * Thie input argument "incr" is the size of the block to allocate.
45
 *
46
 * This simple implementation does not perform any bounds checking. Memory will
47
 * be allocated, even if the request region colides with the stack or overflows
48
 * the available physical memory.
49
 *
50
 * ALT_SBRK is mapped onto the sbrk() system call in alt_syscall.h
51
 *
52
 * This function is called by the profiling code to allocate memory so must be
53
 * safe if called from an interrupt context.  It must also not be instrumented
54
 * because that would lead to an infinate loop.
55
 */
56
 
57
extern char __alt_heap_start[]; /* set by linker */
58
extern char __alt_heap_limit[]; /* set by linker */
59
 
60
static char *heap_end = __alt_heap_start;
61
 
62
#if defined(ALT_EXCEPTION_STACK) && defined(ALT_STACK_CHECK)
63
char * alt_exception_old_stack_limit = NULL;
64
#endif
65
 
66
caddr_t ALT_SBRK (int incr) __attribute__ ((no_instrument_function ));
67
 
68
caddr_t ALT_SBRK (int incr)
69
{
70
  alt_irq_context context;
71
  char *prev_heap_end;
72
 
73
  context = alt_irq_disable_all();
74
 
75
  /* Always return data aligned on a word boundary */
76
  heap_end = (char *)(((unsigned int)heap_end + 3) & ~3);
77
 
78
#ifdef ALT_MAX_HEAP_BYTES
79
  /*
80
   * User specified a maximum heap size.  Return -1 if it would
81
   * be exceeded by this sbrk call.
82
   */
83
  if (((heap_end + incr) - __alt_heap_start) > ALT_MAX_HEAP_BYTES) {
84
    alt_irq_enable_all(context);
85
    return (caddr_t)-1;
86
  }
87
#else
88
  if ((heap_end + incr) > __alt_heap_limit) {
89
    alt_irq_enable_all(context);
90
    return (caddr_t)-1;
91
  }
92
#endif
93
 
94
  prev_heap_end = heap_end;
95
  heap_end += incr;
96
 
97
#ifdef ALT_STACK_CHECK
98
  /*
99
   * If the stack and heap are contiguous then extending the heap reduces the
100
   * space available for the stack.  If we are still using the default stack
101
   * then adjust the stack limit to note this, while checking for stack
102
   * pointer overflow.
103
   * If the stack limit isn't pointing at the top of the heap then the code
104
   * is using a different stack so none of this needs to be done.
105
   */
106
 
107
  if (alt_stack_limit() == prev_heap_end)
108
  {
109
    if (alt_stack_pointer() <= heap_end)
110
      alt_report_stack_overflow();
111
 
112
    alt_set_stack_limit(heap_end);
113
  }
114
 
115
#ifdef ALT_EXCEPTION_STACK
116
  /*
117
   * If we are executing from the exception stack then compare against the
118
   * stack we switched away from as well.  The exception stack is a fixed
119
   * size so doesn't need to be checked.
120
   */
121
 
122
  if (alt_exception_old_stack_limit == prev_heap_end)
123
  {
124
    if (alt_exception_old_stack_limit <= heap_end)
125
      alt_report_stack_overflow();
126
 
127
    alt_exception_old_stack_limit = heap_end;
128
  }
129
#endif
130
 
131
#endif
132
 
133
  alt_irq_enable_all(context);
134
 
135
  return (caddr_t) prev_heap_end;
136
}

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.