newlib-cygwin/libgloss/nios2/sbrk.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;
}