1 /*
2 * Copyright (c) 2020 - 2024 Renesas Electronics Corporation and/or its affiliates
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 /***********************************************************************************************************************
8 * Includes <System Includes> , "Project Includes"
9 **********************************************************************************************************************/
10 #if defined(__GNUC__) && !defined(__ARMCC_VERSION)
11 #include <sys/types.h>
12 #include <errno.h>
13 #include "bsp_api.h"
14
15 /***********************************************************************************************************************
16 * Macro definitions
17 **********************************************************************************************************************/
18
19 /***********************************************************************************************************************
20 * Typedef definitions
21 **********************************************************************************************************************/
22
23 /***********************************************************************************************************************
24 * Private function prototypes
25 **********************************************************************************************************************/
26
27 /***********************************************************************************************************************
28 * Exported global variables (to be accessed by other files)
29 **********************************************************************************************************************/
30
31 /***********************************************************************************************************************
32 * Exported global functions (to be accessed by other files)
33 **********************************************************************************************************************/
34
35 /***********************************************************************************************************************
36 * Private global variables and functions
37 **********************************************************************************************************************/
38 caddr_t _sbrk(int incr);
39
40 /*******************************************************************************************************************//**
41 * @addtogroup BSP_MCU
42 * @{
43 **********************************************************************************************************************/
44
45 /*******************************************************************************************************************//**
46 * FSP implementation of the standard library _sbrk() function.
47 * @param[in] inc The number of bytes being asked for by malloc().
48 *
49 * @note This function overrides the _sbrk version that exists in the newlib library that is linked with.
50 * That version improperly relies on the SP as part of it's allocation strategy. This is bad in general and
51 * worse in an RTOS environment. This version insures that we allocate the byte pool requested by malloc()
52 * only from our allocated HEAP area. Also note that newlib is pre-built and forces the pagesize used by
53 * malloc() to be 4096. That requires that we have a HEAP of at least 4096 if we are to support malloc().
54 * @retval Address of allocated area if successful, -1 otherwise.
55 **********************************************************************************************************************/
_sbrk(int incr)56 caddr_t _sbrk (int incr)
57 {
58 extern char _Heap_Begin __asm("__HeapBase"); ///< Defined by the linker.
59
60 extern char _Heap_Limit __asm("__HeapLimit"); ///< Defined by the linker.
61
62 uint32_t bytes = (uint32_t) incr;
63 static char * current_heap_end = 0;
64 char * current_block_address;
65
66 if (current_heap_end == 0)
67 {
68 current_heap_end = &_Heap_Begin;
69 }
70
71 current_block_address = current_heap_end;
72
73 /* The returned address must be aligned to a word boundary to prevent hard faults on cores that do not support
74 * unaligned access. We assume the heap starts on a word boundary and make sure all allocations are a multiple
75 * of 4. */
76 bytes = (bytes + 3U) & (~3U);
77 if (current_heap_end + bytes > &_Heap_Limit)
78 {
79 /** Heap has overflowed */
80 errno = ENOMEM;
81
82 return (caddr_t) -1;
83 }
84
85 current_heap_end += bytes;
86
87 return (caddr_t) current_block_address;
88 }
89
90 #endif
91
92 /******************************************************************************************************************//**
93 * @} (end addtogroup BSP_MCU)
94 *********************************************************************************************************************/
95
