| /* |
| * Copyright (c) 2003 Red Hat, Inc. All rights reserved. |
| * |
| * This copyrighted material is made available to anyone wishing to use, modify, |
| * copy, or redistribute it subject to the terms and conditions of the BSD |
| * License. This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY expressed or implied, including the implied |
| * warranties of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. A copy |
| * of this license is available at http://www.opensource.org/licenses. Any |
| * Red Hat trademarks that are incorporated in the source code or documentation |
| * are not subject to the BSD License and may only be used or replicated with |
| * the express permission of Red Hat, Inc. |
| */ |
| |
| #include <errno.h> |
| |
| extern int __heap __far; /* beginning of heap */ |
| extern int __heap_end __far; /* if at address 0, use stack pointer as limit */ |
| |
| static char *the_break = (char *)(& __heap); |
| |
| int |
| is_addr_0 (int address) |
| { |
| return address ? 0 : 1; |
| } |
| |
| void * |
| sbrk(int inc) |
| { |
| char *current_heap_limit = (char *) (& __heap_end); |
| |
| /* is_addr_0 avoids optimizing out this block. */ |
| if (is_addr_0 ((int) current_heap_limit)) |
| { |
| int something; |
| int margin = 4096; |
| current_heap_limit = (char *) (& something) - margin; |
| } |
| |
| if ((the_break + inc) < current_heap_limit) |
| { |
| void *rv = (void *) the_break; |
| the_break += inc; |
| return rv; |
| } |
| else |
| { |
| errno = ENOMEM; |
| return (void *) -1; |
| } |
| } |
| |
| int |
| brk (void *ptr) |
| { |
| the_break = ptr; |
| return 0; |
| } |