gdb/gdbserver/linux-i386-low.c

   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.  */
  38 static 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
  46 static int
  47 i386_cannot_store_register (int regno)
  48 {
  49   return (regno >= i386_num_regs);
  50 }
  51
  52 static int
  53 i386_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
  63 static void
  64 i386_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
  74 static void
  75 i386_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
  85 static void
  86 i386_fill_fpregset (void *buf)
  87 {
  88   i387_cache_to_fsave (buf);
  89 }
  90
  91 static void
  92 i386_store_fpregset (const void *buf)
  93 {
  94   i387_fsave_to_cache (buf);
  95 }
  96
  97 static void
  98 i386_fill_fpxregset (void *buf)
  99 {
 100   i387_cache_to_fxsave (buf);
 101 }
 102
 103 static void
 104 i386_store_fpxregset (const void *buf)
 105 {
 106   i387_fxsave_to_cache (buf);
 107 }
 108
 109
 110 struct 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
 127 static const char i386_breakpoint[] = { 0xCC };
 128 #define i386_breakpoint_len 1
 129
 130 extern int debug_threads;
 131
 132 static CORE_ADDR
 133 i386_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
 144 static void
 145 i386_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
 152 static int
 153 i386_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
 164 struct 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 };