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 "bsp_api.h"
12 #include <sys/types.h>
13 #include <errno.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 caddr_t _sbrk(int incr);
32
33 /***********************************************************************************************************************
34 * Private global variables and functions
35 **********************************************************************************************************************/
36
37 /*******************************************************************************************************************//**
38 * @addtogroup BSP_MCU
39 * @{
40 **********************************************************************************************************************/
41
42 /*******************************************************************************************************************//**
43 * FSP implementation of the standard library _sbrk() function.
44 * @param[in] inc The number of bytes being asked for by malloc().
45 *
46 * @note This function overrides the _sbrk version that exists in the newlib library that is linked with.
47 * That version improperly relies on the SP as part of it's allocation strategy. This is bad in general and
48 * worse in an RTOS environment. This version insures that we allocate the byte pool requested by malloc()
49 * only from our allocated HEAP area. Also note that newlib is pre-built and forces the pagesize used by
50 * malloc() to be 4096. That requires that we have a HEAP of at least 4096 if we are to support malloc().
51 * @retval Address of allocated area if successful, -1 otherwise.
52 **********************************************************************************************************************/
53
_sbrk(int incr)54 caddr_t _sbrk (int incr)
55 {
56 extern char _Heap_Begin __asm("__HeapBase"); ///< Defined by the linker.
57
58 extern char _Heap_Limit __asm("__HeapLimit"); ///< Defined by the linker.
59
60 uint32_t bytes = (uint32_t) incr;
61 static char * current_heap_end = 0;
62 char * current_block_address;
63
64 if (current_heap_end == 0)
65 {
66 current_heap_end = &_Heap_Begin;
67 }
68
69 current_block_address = current_heap_end;
70
71 /* The returned address must be aligned to a word boundary to prevent hard faults on cores that do not support
72 * unaligned access. We assume the heap starts on a word boundary and make sure all allocations are a multiple
73 * of 4. */
74 bytes = (bytes + 3U) & (~3U);
75 if ((current_heap_end + bytes) > &_Heap_Limit)
76 {
77 /** Heap has overflowed */
78 errno = ENOMEM;
79
80 return (caddr_t) -1;
81 }
82
83 current_heap_end += bytes;
84
85 return (caddr_t) current_block_address;
86 }
87
88 #endif /* defined__GNUC__ && !defined__ARMCC_VERSION */
89
90 /******************************************************************************************************************//**
91 * @} (end addtogroup BSP_MCU)
92 *********************************************************************************************************************/
93
