1 /*
2  * Copyright (c) 2015, Freescale Semiconductor, Inc.
3  * Copyright 2016-2019, 2022 NXP
4  * All rights reserved.
5  *
6  * SPDX-License-Identifier: BSD-3-Clause
7  */
8 #if defined(__GNUC__)
9 #include <stdio.h>
10 #include <errno.h>
11 #include <stdint.h>
12 #include <sys/types.h>
13 #endif
14 
15 #if defined(__GNUC__)
16 /*!
17  * @brief Function to override ARMGCC default function _sbrk
18  *
19  * _sbrk is called by malloc. ARMGCC default _sbrk compares "SP" register and
20  * heap end, if heap end is larger than "SP", then _sbrk returns error and
21  * memory allocation failed. This function changes to compare __HeapLimit with
22  * heap end.
23  */
24 caddr_t _sbrk(int incr);
_sbrk(int incr)25 caddr_t _sbrk(int incr)
26 {
27     extern char end __asm("end");
28     extern char heap_limit __asm("__HeapLimit");
29     static char *heap_end;
30     char *prev_heap_end;
31     caddr_t ret;
32 
33     if (heap_end == NULL)
34     {
35         heap_end = &end;
36     }
37 
38     prev_heap_end = heap_end;
39 
40     if ((uintptr_t)heap_end + (uintptr_t)incr > (uintptr_t)(&heap_limit))
41     {
42         errno = ENOMEM;
43 
44         ret = (caddr_t)-1;
45     }
46     else
47     {
48         heap_end = (char *)((uintptr_t)heap_end + (uintptr_t)incr);
49 
50         ret = (caddr_t)prev_heap_end;
51     }
52 
53     return ret;
54 }
55 #endif
56