sysdeps/standalone/brk.c

   1 /* Copyright (C) 1991, 1994, 1995 Free Software Foundation, Inc.
   2    Ported to standalone by Joel Sherrill jsherril@redstone-emh2.army.mil,
   3      On-Line Applications Research Corporation.
   4
   5 This file is part of the GNU C Library.
   6
   7 The GNU C Library is free software; you can redistribute it and/or
   8 modify it under the terms of the GNU Library General Public License as
   9 published by the Free Software Foundation; either version 2 of the
  10 License, or (at your option) any later version.
  11
  12 The GNU C Library is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 Library General Public License for more details.
  16
  17 You should have received a copy of the GNU Library General Public
  18 License along with the GNU C Library; see the file COPYING.LIB.  If
  19 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  20 Cambridge, MA 02139, USA.  */
  21
  22 #include <ansidecl.h>
  23 #include <stdlib.h>
  24
  25 PTR __curbrk;
  26 PTR __rorig;
  27 PTR __rlimit;
  28
  29 int
  30 DEFUN(__brk, (inaddr), PTR inaddr)
  31 {
  32
  33   if ( ( (void *)inaddr > (void *)__rlimit ) ||
  34                         ( (void *)inaddr < (void *)__rorig ) )
  35     return -1;
  36
  37   __curbrk = inaddr;
  38   return 0;
  39 }
  40
  41 /* Initialization Code for Memory Allocation */
  42
  43 PTR __C_heap_start;
  44 int __C_heap_size;
  45
  46 #ifdef HAVE_GNU_LD
  47 static
  48 #endif
  49 void
  50 DEFUN(__NONE_set_memvals, (argc, argv, envp),
  51       int argc AND char **argv AND char **envp)
  52 {
  53
  54   __rorig  =
  55   __curbrk = __C_heap_start;
  56   __rlimit = __curbrk + __C_heap_size;
  57
  58   (void) &__NONE_set_memvals;    /* Avoid "defined but not used" warning.  */
  59 }
  60
  61 #ifdef  HAVE_GNU_LD
  62 text_set_element (__libc_subinit, __NONE_set_memvals);
  63 #endif
  64
  65 weak_alias (__brk, brk)