1/* Native-dependent code for OpenBSD/i386.
2
3   Copyright 2002, 2003, 2004 Free Software Foundation, Inc.
4
5   This file is part of GDB.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 2 of the License, or
10   (at your option) any later version.
11
12   This program 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
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program; if not, write to the Free Software
19   Foundation, Inc., 59 Temple Place - Suite 330,
20   Boston, MA 02111-1307, USA.  */
21
22#include "defs.h"
23
24#include <sys/param.h>
25#include <sys/sysctl.h>
26
27#include "i386-tdep.h"
28
29/* Prevent warning from -Wmissing-prototypes.  */
30void _initialize_i386obsd_nat (void);
31
32void
33_initialize_i386obsd_nat (void)
34{
35  /* OpenBSD provides a vm.psstrings sysctl that we can use to locate
36     the sigtramp.  That way we can still recognize a sigtramp if its
37     location is changed in a new kernel.  This is especially
38     important for OpenBSD, since it uses a different memory layout
39     than NetBSD, yet we cannot distinguish between the two.
40
41     Of course this is still based on the assumption that the sigtramp
42     is placed directly under the location where the program arguments
43     and environment can be found.  */
44#ifdef VM_PSSTRINGS
45  {
46    struct _ps_strings _ps;
47    int mib[2];
48    size_t len;
49
50    mib[0] = CTL_VM;
51    mib[1] = VM_PSSTRINGS;
52    len = sizeof (_ps);
53    if (sysctl (mib, 2, &_ps, &len, NULL, 0) == 0)
54      {
55	i386obsd_sigtramp_start_addr = (CORE_ADDR)_ps.val - 128;
56	i386obsd_sigtramp_end_addr = (CORE_ADDR)_ps.val;
57      }
58  }
59#endif
60}
61