1 /**
2 * @file heap.c
3 * @brief System level setup help
4 */
5
6 /*******************************************************************************
7 * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a
10 * copy of this software and associated documentation files (the "Software"),
11 * to deal in the Software without restriction, including without limitation
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13 * and/or sell copies of the Software, and to permit persons to whom the
14 * Software is furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included
17 * in all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
20 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
22 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
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24 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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27 * Except as contained in this notice, the name of Maxim Integrated
28 * Products, Inc. shall not be used except as stated in the Maxim Integrated
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31 * The mere transfer of this software does not imply any licenses
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36 *
37 * $Date: 2018-12-18 15:37:22 -0600 (Tue, 18 Dec 2018) $
38 * $Revision: 40072 $
39 *
40 ******************************************************************************/
41
42 /* **** Includes **** */
43 #include <stdint.h>
44 #include <errno.h>
45 #include <unistd.h>
46
47 /**
48 * @brief sbrk
49 * @detail Increase program data space
50 * @detail Malloc and related functions depend on this
51 */
52
53 /* **** declarations **** */
54 static char *heap_end = 0;
55 extern unsigned int __HeapBase;
56 extern unsigned int __HeapLimit;
57
58 /* **** functions **** */
_sbrk(int incr)59 caddr_t _sbrk(int incr)
60 {
61 char *prev_heap_end;
62
63 if (heap_end == 0) {
64 heap_end = (caddr_t)&__HeapBase;
65 }
66 prev_heap_end = heap_end;
67
68 if ((unsigned int)(heap_end + incr) > (unsigned int)&__HeapLimit) {
69 errno = ENOMEM;
70 return (caddr_t) -1;
71 }
72
73 heap_end += incr;
74
75 return (caddr_t) prev_heap_end;
76 }
77
78