fbsd-i386-low.c revision 256281 
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 <sys/cdefs.h>
23__FBSDID("$FreeBSD: stable/10/gnu/usr.bin/gdb/gdbserver/fbsd-i386-low.c 157574 2006-04-06 22:24:01Z jmg $");
24
25#include "server.h"
26#include "fbsd-low.h"
27#include "i387-fp.h"
28
29#ifdef HAVE_SYS_REG_H
30#include <sys/reg.h>
31#else
32#include <machine/reg.h>
33#endif
34
35/* This module only supports access to the general purpose registers.  */
36
37#define i386_num_regs 16
38
39/* This stuff comes from i386-fbsd-nat.c.  */
40
41/* Mapping between the general-purpose registers in `struct user'
42   format and GDB's register array layout.  */
43static int i386_regmap[] =
44{
45  tEAX * 4, tECX * 4, tEDX * 4, tEBX * 4,
46  tESP * 4, tEBP * 4, tESI * 4, tEDI * 4,
47  tEIP * 4, tEFLAGS * 4, tCS * 4, tSS * 4,
48  tDS * 4, tES * 4, tFS * 4, tGS * 4
49};
50
51static int
52i386_cannot_store_register (int regno)
53{
54  return (regno >= i386_num_regs);
55}
56
57static int
58i386_cannot_fetch_register (int regno)
59{
60  return (regno >= i386_num_regs);
61}
62
63
64#include <sys/procfs.h>
65#include <sys/ptrace.h>
66
67static void
68i386_fill_gregset (void *buf)
69{
70  int i;
71
72  for (i = 0; i < i386_num_regs; i++)
73    collect_register (i, ((char *) buf) + i386_regmap[i]);
74
75}
76
77static void
78i386_store_gregset (const void *buf)
79{
80  int i;
81
82  for (i = 0; i < i386_num_regs; i++)
83    supply_register (i, ((char *) buf) + i386_regmap[i]);
84
85}
86
87static void
88i386_fill_fpregset (void *buf)
89{
90  i387_cache_to_fsave (buf);
91}
92
93static void
94i386_store_fpregset (const void *buf)
95{
96  i387_fsave_to_cache (buf);
97}
98
99static void
100i386_fill_fpxregset (void *buf)
101{
102  i387_cache_to_fxsave (buf);
103}
104
105static void
106i386_store_fpxregset (const void *buf)
107{
108  i387_fxsave_to_cache (buf);
109}
110
111
112struct regset_info target_regsets[] = {
113  { PT_GETREGS, PT_SETREGS, sizeof (struct reg),
114    GENERAL_REGS,
115    i386_fill_gregset, i386_store_gregset },
116#ifdef HAVE_PTRACE_GETFPXREGS
117  { PTRACE_GETFPXREGS, PTRACE_SETFPXREGS, sizeof (elf_fpxregset_t),
118    EXTENDED_REGS,
119    i386_fill_fpxregset, i386_store_fpxregset },
120#endif
121  { PT_GETFPREGS, PT_SETFPREGS, sizeof (struct fpreg),
122    FP_REGS,
123    i386_fill_fpregset, i386_store_fpregset },
124  { 0, 0, -1, -1, NULL, NULL }
125};
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 fbsd_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