OpenCores
URL https://opencores.org/ocsvn/openrisc_me/openrisc_me/trunk

Subversion Repositories openrisc_me

[/] [openrisc/] [trunk/] [gnu-src/] [gdb-7.1/] [gdb/] [vaxobsd-tdep.c] - Blame information for rev 227

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 227 jeremybenn
/* Target-dependent code for OpenBSD/vax.
2
 
3
   Copyright (C) 2005, 2007, 2008, 2009, 2010 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 3 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, see <http://www.gnu.org/licenses/>.  */
19
 
20
#include "defs.h"
21
#include "arch-utils.h"
22
#include "frame.h"
23
#include "frame-unwind.h"
24
#include "osabi.h"
25
#include "symtab.h"
26
#include "trad-frame.h"
27
 
28
#include "vax-tdep.h"
29
 
30
#include "gdb_string.h"
31
 
32
/* Signal trampolines.  */
33
 
34
/* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page
35
   in virtual memory.  The randomness makes it somewhat tricky to
36
   detect it, but fortunately we can rely on the fact that the start
37
   of the sigtramp routine is page-aligned.  We recognize the
38
   trampoline by looking for the code that invokes the sigreturn
39
   system call.  The offset where we can find that code varies from
40
   release to release.
41
 
42
   By the way, the mapping mentioned above is read-only, so you cannot
43
   place a breakpoint in the signal trampoline.  */
44
 
45
/* Default page size.  */
46
static const int vaxobsd_page_size = 4096;
47
 
48
/* Offset for sigreturn(2).  */
49
static const int vaxobsd_sigreturn_offset = 0x11;
50
 
51
/* Instruction sequence for sigreturn(2).  VAX doesn't have
52
   fixed-length instructions so we include the ensuing exit(2) to
53
   reduce the chance of spurious matches.  */
54
static const gdb_byte vaxobsd_sigreturn[] = {
55
  0xbc, 0x8f, 0x67, 0x00,       /* chmk $SYS_sigreturn */
56
  0xbc, 0x01                    /* chmk $SYS_exit */
57
};
58
 
59
static int
60
vaxobsd_sigtramp_sniffer (const struct frame_unwind *self,
61
                          struct frame_info *this_frame,
62
                          void **this_cache)
63
{
64
  CORE_ADDR pc = get_frame_pc (this_frame);
65
  CORE_ADDR start_pc = (pc & ~(vaxobsd_page_size - 1));
66
  CORE_ADDR sigreturn_addr = start_pc + vaxobsd_sigreturn_offset;
67
  gdb_byte *buf;
68
  char *name;
69
 
70
  find_pc_partial_function (pc, &name, NULL, NULL);
71
  if (name)
72
    return 0;
73
 
74
  buf = alloca(sizeof vaxobsd_sigreturn);
75
  if (!safe_frame_unwind_memory (this_frame, sigreturn_addr,
76
                                 buf, sizeof vaxobsd_sigreturn))
77
    return 0;
78
 
79
  if (memcmp(buf, vaxobsd_sigreturn, sizeof vaxobsd_sigreturn) == 0)
80
    return 1;
81
 
82
  return 0;
83
}
84
 
85
static struct trad_frame_cache *
86
vaxobsd_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache)
87
{
88
  struct trad_frame_cache *cache;
89
  CORE_ADDR addr, base, func;
90
 
91
  if (*this_cache)
92
    return *this_cache;
93
 
94
  cache = trad_frame_cache_zalloc (this_frame);
95
  *this_cache = cache;
96
 
97
  func = get_frame_pc (this_frame);
98
  func &= ~(vaxobsd_page_size - 1);
99
 
100
  base = get_frame_register_unsigned (this_frame, VAX_SP_REGNUM);
101
  addr = get_frame_memory_unsigned (this_frame, base - 4, 4);
102
 
103
  trad_frame_set_reg_addr (cache, VAX_SP_REGNUM, addr + 8);
104
  trad_frame_set_reg_addr (cache, VAX_FP_REGNUM, addr + 12);
105
  trad_frame_set_reg_addr (cache, VAX_AP_REGNUM, addr + 16);
106
  trad_frame_set_reg_addr (cache, VAX_PC_REGNUM, addr + 20);
107
  trad_frame_set_reg_addr (cache, VAX_PS_REGNUM, addr + 24);
108
 
109
  /* Construct the frame ID using the function start.  */
110
  trad_frame_set_id (cache, frame_id_build (base, func));
111
 
112
  return cache;
113
}
114
 
115
static void
116
vaxobsd_sigtramp_frame_this_id (struct frame_info *this_frame,
117
                                void **this_cache, struct frame_id *this_id)
118
{
119
  struct trad_frame_cache *cache =
120
    vaxobsd_sigtramp_frame_cache (this_frame, this_cache);
121
 
122
  trad_frame_get_id (cache, this_id);
123
}
124
 
125
static struct value *
126
vaxobsd_sigtramp_frame_prev_register (struct frame_info *this_frame,
127
                                      void **this_cache, int regnum)
128
{
129
  struct trad_frame_cache *cache =
130
    vaxobsd_sigtramp_frame_cache (this_frame, this_cache);
131
 
132
  return trad_frame_get_register (cache, this_frame, regnum);
133
}
134
 
135
static const struct frame_unwind vaxobsd_sigtramp_frame_unwind = {
136
  SIGTRAMP_FRAME,
137
  vaxobsd_sigtramp_frame_this_id,
138
  vaxobsd_sigtramp_frame_prev_register,
139
  NULL,
140
  vaxobsd_sigtramp_sniffer
141
};
142
 
143
 
144
/* OpenBSD a.out.  */
145
 
146
static void
147
vaxobsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
148
{
149
  frame_unwind_append_unwinder (gdbarch, &vaxobsd_sigtramp_frame_unwind);
150
}
151
 
152
/* FIXME: kettenis/20050821: Since OpenBSD/vax binaries are
153
   indistingushable from NetBSD/vax a.out binaries, building a GDB
154
   that should support both these targets will probably not work as
155
   expected.  */
156
#define GDB_OSABI_OPENBSD_AOUT GDB_OSABI_NETBSD_AOUT
157
 
158
static enum gdb_osabi
159
vaxobsd_aout_osabi_sniffer (bfd *abfd)
160
{
161
  if (strcmp (bfd_get_target (abfd), "a.out-vax-netbsd") == 0)
162
    return GDB_OSABI_OPENBSD_AOUT;
163
 
164
  return GDB_OSABI_UNKNOWN;
165
}
166
 
167
 
168
/* Provide a prototype to silence -Wmissing-prototypes.  */
169
void _initialize_vaxobsd_tdep (void);
170
 
171
void
172
_initialize_vaxobsd_tdep (void)
173
{
174
  gdbarch_register_osabi_sniffer (bfd_arch_vax, bfd_target_aout_flavour,
175
                                  vaxobsd_aout_osabi_sniffer);
176
 
177
  gdbarch_register_osabi (bfd_arch_vax, 0, GDB_OSABI_OPENBSD_AOUT,
178
                          vaxobsd_init_abi);
179
}

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.