43 lines
1.2 KiB
C
43 lines
1.2 KiB
C
/*
|
|
* sbrk.c
|
|
*
|
|
* Copyright (c) 2018 Mentor Graphics
|
|
*
|
|
* The authors hereby grant permission to use, copy, modify, distribute,
|
|
* and license this software and its documentation for any purpose, provided
|
|
* that existing copyright notices are retained in all copies and that this
|
|
* notice is included verbatim in any distributions. No written agreement,
|
|
* license, or royalty fee is required for any of the authorized uses.
|
|
* Modifications to this software may be copyrighted by their authors
|
|
* and need not follow the licensing terms described here, provided that
|
|
* the new terms are clearly indicated on the first page of each file where
|
|
* they apply.
|
|
*/
|
|
|
|
#include <errno.h>
|
|
/*
|
|
* sbrk -- changes heap size size. Get nbytes more
|
|
* RAM. We just increment a pointer in what's
|
|
* left of memory on the board.
|
|
*/
|
|
|
|
/* Provided by the linker script. */
|
|
extern char __heap_start[] __attribute__ ((aligned (8)));
|
|
extern char __heap_end[] __attribute__ ((aligned (8)));
|
|
|
|
void *
|
|
sbrk (int nbytes)
|
|
{
|
|
static char *heap = __heap_start;
|
|
char *base = heap;
|
|
char *new_heap = heap + nbytes;
|
|
|
|
if (nbytes < 0 || new_heap > __heap_end)
|
|
{
|
|
errno = ENOMEM;
|
|
return (void *)-1;
|
|
}
|
|
heap = new_heap;
|
|
return base;
|
|
}
|