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/* sbrk.c -- allocate memory dynamically.
*
* Copyright (c) 1995,1996 Cygnus Support
*
* 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>
#include "glue.h"
/* just in case, most boards have at least some memory */
#ifndef RAMSIZE
# define RAMSIZE (caddr_t)0x100000
#endif
char *heap_ptr;
/*
* sbrk -- changes heap size size. Get nbytes more
* RAM. We just increment a pointer in what's
* left of memory on the board.
*/
void *
sbrk (ptrdiff_t nbytes)
{
char *base;
if (!heap_ptr)
heap_ptr = (char *)&_end;
base = heap_ptr;
heap_ptr += nbytes;
return base;
/* FIXME: We really want to make sure we don't run out of RAM, but this
* isn't very portable.
*/
#if 0
if ((RAMSIZE - heap_ptr - nbytes) >= 0) {
base = heap_ptr;
heap_ptr += nbytes;
return (base);
} else {
errno = ENOMEM;
return ((char *)-1);
}
#endif
}
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