fbsd-i386-low.c revision 157572 
1/* GNU/Linux/i386 specific low level interface, for the remote server for GDB.
2   Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002
3   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 "server.h"
23#include "linux-low.h"
24#include "i387-fp.h"
25
26#ifdef HAVE_SYS_REG_H
27#include <sys/reg.h>
28#endif
29
30/* This module only supports access to the general purpose registers.  */
31
32#define i386_num_regs 16
33
34/* This stuff comes from i386-linux-nat.c.  */
35
36/* Mapping between the general-purpose registers in `struct user'
37   format and GDB's register array layout.  */
38static int i386_regmap[] =
39{
40  EAX * 4, ECX * 4, EDX * 4, EBX * 4,
41  UESP * 4, EBP * 4, ESI * 4, EDI * 4,
42  EIP * 4, EFL * 4, CS * 4, SS * 4,
43  DS * 4, ES * 4, FS * 4, GS * 4
44};
45
46static int
47i386_cannot_store_register (int regno)
48{
49  return (regno >= i386_num_regs);
50}
51
52static int
53i386_cannot_fetch_register (int regno)
54{
55  return (regno >= i386_num_regs);
56}
57
58
59#ifdef HAVE_LINUX_REGSETS
60#include <sys/procfs.h>
61#include <sys/ptrace.h>
62
63static void
64i386_fill_gregset (void *buf)
65{
66  int i;
67
68  for (i = 0; i < i386_num_regs; i++)
69    collect_register (i, ((char *) buf) + i386_regmap[i]);
70
71  collect_register_by_name ("orig_eax", ((char *) buf) + ORIG_EAX * 4);
72}
73
74static void
75i386_store_gregset (const void *buf)
76{
77  int i;
78
79  for (i = 0; i < i386_num_regs; i++)
80    supply_register (i, ((char *) buf) + i386_regmap[i]);
81
82  supply_register_by_name ("orig_eax", ((char *) buf) + ORIG_EAX * 4);
83}
84
85static void
86i386_fill_fpregset (void *buf)
87{
88  i387_cache_to_fsave (buf);
89}
90
91static void
92i386_store_fpregset (const void *buf)
93{
94  i387_fsave_to_cache (buf);
95}
96
97static void
98i386_fill_fpxregset (void *buf)
99{
100  i387_cache_to_fxsave (buf);
101}
102
103static void
104i386_store_fpxregset (const void *buf)
105{
106  i387_fxsave_to_cache (buf);
107}
108
109
110struct regset_info target_regsets[] = {
111  { PTRACE_GETREGS, PTRACE_SETREGS, sizeof (elf_gregset_t),
112    GENERAL_REGS,
113    i386_fill_gregset, i386_store_gregset },
114#ifdef HAVE_PTRACE_GETFPXREGS
115  { PTRACE_GETFPXREGS, PTRACE_SETFPXREGS, sizeof (elf_fpxregset_t),
116    EXTENDED_REGS,
117    i386_fill_fpxregset, i386_store_fpxregset },
118#endif
119  { PTRACE_GETFPREGS, PTRACE_SETFPREGS, sizeof (elf_fpregset_t),
120    FP_REGS,
121    i386_fill_fpregset, i386_store_fpregset },
122  { 0, 0, -1, -1, NULL, NULL }
123};
124
125#endif /* HAVE_LINUX_REGSETS */
126
127static const char i386_breakpoint[] = { 0xCC };
128#define i386_breakpoint_len 1
129
130extern int debug_threads;
131
132static CORE_ADDR
133i386_get_pc ()
134{
135  unsigned long pc;
136
137  collect_register_by_name ("eip", &pc);
138
139  if (debug_threads)
140    fprintf (stderr, "stop pc (before any decrement) is %08lx\n", pc);
141  return pc;
142}
143
144static void
145i386_set_pc (CORE_ADDR newpc)
146{
147  if (debug_threads)
148    fprintf (stderr, "set pc to %08lx\n", (long) newpc);
149  supply_register_by_name ("eip", &newpc);
150}
151
152static int
153i386_breakpoint_at (CORE_ADDR pc)
154{
155  unsigned char c;
156
157  read_inferior_memory (pc, &c, 1);
158  if (c == 0xCC)
159    return 1;
160
161  return 0;
162}
163
164struct linux_target_ops the_low_target = {
165  i386_num_regs,
166  i386_regmap,
167  i386_cannot_fetch_register,
168  i386_cannot_store_register,
169  i386_get_pc,
170  i386_set_pc,
171  i386_breakpoint,
172  i386_breakpoint_len,
173  NULL,
174  1,
175  i386_breakpoint_at,
176};
177