source: trunk/libs/newlib/src/libgloss/mep/sbrk.c @ 546

Last change on this file since 546 was 444, checked in by satin@…, 6 years ago

add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc

File size: 1.5 KB
Line 
1/*
2 * Copyright (c) 2003  Red Hat, Inc. All rights reserved.
3 *
4 * This copyrighted material is made available to anyone wishing to use, modify,
5 * copy, or redistribute it subject to the terms and conditions of the BSD
6 * License.  This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY expressed or implied, including the implied
8 * warranties of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  A copy
9 * of this license is available at http://www.opensource.org/licenses. Any
10 * Red Hat trademarks that are incorporated in the source code or documentation
11 * are not subject to the BSD License and may only be used or replicated with
12 * the express permission of Red Hat, Inc.
13 */
14
15#include <errno.h>
16
17extern int __heap __far;      /* beginning of heap */
18extern int __heap_end __far;  /* if at address 0, use stack pointer as limit */
19
20static char *the_break = (char *)(& __heap);
21
22int
23is_addr_0 (int address)
24{
25  return address ? 0 : 1;
26}
27
28void *
29sbrk(int inc)
30{
31  char *current_heap_limit = (char *) (& __heap_end);
32
33  /* is_addr_0 avoids optimizing out this block.  */
34  if (is_addr_0 ((int) current_heap_limit))
35    {
36      int something;
37      int margin = 4096;
38      current_heap_limit = (char *) (& something) - margin;
39    }
40
41  if ((the_break + inc) < current_heap_limit)
42    {
43      void *rv = (void *) the_break;
44      the_break += inc;
45      return rv;
46    }
47  else
48    {
49      errno = ENOMEM;
50      return (void *) -1;
51    }
52}
53
54int
55brk (void *ptr)
56{
57  the_break = ptr;
58  return 0;
59}
Note: See TracBrowser for help on using the repository browser.