gdb/i386bsd-tdep.c

   1 /* Target-dependent code for i386 BSD's.
   2    Copyright 2001, 2002, 2003 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include "defs.h"
  22 #include "arch-utils.h"
  23 #include "frame.h"
  24 #include "gdbcore.h"
  25 #include "regcache.h"
  26 #include "osabi.h"
  27
  28 #include "gdb_string.h"
  29
  30 #include "i386-tdep.h"
  31
  32 /* Support for signal handlers.  */
  33
  34 /* Return whether PC is in a BSD sigtramp routine.  */
  35
  36 static int
  37 i386bsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
  38 {
  39   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
  40
  41   return (pc >= tdep->sigtramp_start && pc < tdep->sigtramp_end);
  42 }
  43
  44 /* Assuming NEXT_FRAME is for a frame following a BSD sigtramp
  45    routine, return the address of the associated sigcontext structure.  */
  46
  47 static CORE_ADDR
  48 i386bsd_sigcontext_addr (struct frame_info *next_frame)
  49 {
  50   char buf[4];
  51   CORE_ADDR sp;
  52
  53   frame_unwind_register (next_frame, I386_ESP_REGNUM, buf);
  54   sp = extract_unsigned_integer (buf, 4);
  55
  56   return read_memory_unsigned_integer (sp + 8, 4);
  57 }
  58
  59 /* Return the start address of the sigtramp routine.  */
  60
  61 CORE_ADDR
  62 i386bsd_sigtramp_start (CORE_ADDR pc)
  63 {
  64   return gdbarch_tdep (current_gdbarch)->sigtramp_start;
  65 }
  66
  67 /* Return the end address of the sigtramp routine.  */
  68
  69 CORE_ADDR
  70 i386bsd_sigtramp_end (CORE_ADDR pc)
  71 {
  72   return gdbarch_tdep (current_gdbarch)->sigtramp_end;
  73 }
  74 \f
  75
  76 /* Support for shared libraries.  */
  77
  78 /* Return non-zero if we are in a shared library trampoline code stub.  */
  79
  80 int
  81 i386bsd_aout_in_solib_call_trampoline (CORE_ADDR pc, char *name)
  82 {
  83   return (name && !strcmp (name, "_DYNAMIC"));
  84 }
  85
  86 /* Traditional BSD (4.3 BSD, still used for BSDI and 386BSD).  */
  87
  88 /* From <machine/signal.h>.  */
  89 int i386bsd_sc_reg_offset[I386_NUM_GREGS] =
  90 {
  91   -1,                           /* %eax */
  92   -1,                           /* %ecx */
  93   -1,                           /* %edx */
  94   -1,                           /* %ebx */
  95   8 + 0 * 4,                    /* %esp */
  96   8 + 1 * 4,                    /* %ebp */
  97   -1,                           /* %esi */
  98   -1,                           /* %edi */
  99   8 + 3 * 4,                    /* %eip */
 100   8 + 4 * 4,                    /* %eflags */
 101   -1,                           /* %cs */
 102   -1,                           /* %ss */
 103   -1,                           /* %ds */
 104   -1,                           /* %es */
 105   -1,                           /* %fs */
 106   -1                            /* %gs */
 107 };
 108
 109 void
 110 i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 111 {
 112   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 113
 114   set_gdbarch_pc_in_sigtramp (gdbarch, i386bsd_pc_in_sigtramp);
 115
 116   /* Allow the recognition of sigtramps as a function named <sigtramp>.  */
 117   set_gdbarch_sigtramp_start (gdbarch, i386bsd_sigtramp_start);
 118   set_gdbarch_sigtramp_end (gdbarch, i386bsd_sigtramp_end);
 119
 120   /* Assume SunOS-style shared libraries.  */
 121   set_gdbarch_in_solib_call_trampoline (gdbarch,
 122                                         i386bsd_aout_in_solib_call_trampoline);
 123
 124   tdep->jb_pc_offset = 0;
 125
 126   tdep->sigtramp_start = 0xfdbfdfc0;
 127   tdep->sigtramp_end = 0xfdbfe000;
 128   tdep->sigcontext_addr = i386bsd_sigcontext_addr;
 129   tdep->sc_reg_offset = i386bsd_sc_reg_offset;
 130   tdep->sc_num_regs = I386_NUM_GREGS;
 131 }
 132
 133 /* FreeBSD 3.0-RELEASE or later.  */
 134
 135 CORE_ADDR i386fbsd_sigtramp_start = 0xbfbfdf20;
 136 CORE_ADDR i386fbsd_sigtramp_end = 0xbfbfdff0;
 137
 138 /* From <machine/signal.h>.  */
 139 int i386fbsd_sc_reg_offset[I386_NUM_GREGS] =
 140 {
 141   8 + 14 * 4,                   /* %eax */
 142   8 + 13 * 4,                   /* %ecx */
 143   8 + 12 * 4,                   /* %edx */
 144   8 + 11 * 4,                   /* %ebx */
 145   8 + 0 * 4,                    /* %esp */
 146   8 + 1 * 4,                    /* %ebp */
 147   8 + 10 * 4,                   /* %esi */
 148   8 + 9 * 4,                    /* %edi */
 149   8 + 3 * 4,                    /* %eip */
 150   8 + 4 * 4,                    /* %eflags */
 151   8 + 7 * 4,                    /* %cs */
 152   8 + 8 * 4,                    /* %ss */
 153   8 + 6 * 4,                    /* %ds */
 154   8 + 5 * 4,                    /* %es */
 155   8 + 15 * 4,                   /* %fs */
 156   8 + 16 * 4                    /* %gs */
 157 };
 158
 159 static void
 160 i386fbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 161 {
 162   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 163
 164   /* Obviously FreeBSD is BSD-based.  */
 165   i386bsd_init_abi (info, gdbarch);
 166
 167   /* FreeBSD uses -freg-struct-return by default.  */
 168   tdep->struct_return = reg_struct_return;
 169
 170   /* FreeBSD uses a different memory layout.  */
 171   tdep->sigtramp_start = i386fbsd_sigtramp_start;
 172   tdep->sigtramp_end = i386fbsd_sigtramp_end;
 173
 174   /* FreeBSD has a more complete `struct sigcontext'.  */
 175   tdep->sc_reg_offset = i386fbsd_sc_reg_offset;
 176   tdep->sc_num_regs = I386_NUM_GREGS;
 177 }
 178
 179 static void
 180 i386fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 181 {
 182   /* It's almost identical to FreeBSD a.out.  */
 183   i386fbsdaout_init_abi (info, gdbarch);
 184
 185   /* Except that it uses ELF.  */
 186   i386_elf_init_abi (info, gdbarch);
 187
 188   /* FreeBSD ELF uses SVR4-style shared libraries.  */
 189   set_gdbarch_in_solib_call_trampoline (gdbarch,
 190                                         generic_in_solib_call_trampoline);
 191 }
 192
 193 /* FreeBSD 4.0-RELEASE or later.  */
 194
 195 /* From <machine/signal.h>.  */
 196 int i386fbsd4_sc_reg_offset[I386_NUM_GREGS] =
 197 {
 198   20 + 11 * 4,                  /* %eax */
 199   20 + 10 * 4,                  /* %ecx */
 200   20 + 9 * 4,                   /* %edx */
 201   20 + 8 * 4,                   /* %ebx */
 202   20 + 17 * 4,                  /* %esp */
 203   20 + 6 * 4,                   /* %ebp */
 204   20 + 5 * 4,                   /* %esi */
 205   20 + 4 * 4,                   /* %edi */
 206   20 + 14 * 4,                  /* %eip */
 207   20 + 16 * 4,                  /* %eflags */
 208   20 + 15 * 4,                  /* %cs */
 209   20 + 18 * 4,                  /* %ss */
 210   20 + 3 * 4,                   /* %ds */
 211   20 + 2 * 4,                   /* %es */
 212   20 + 1 * 4,                   /* %fs */
 213   20 + 0 * 4                    /* %gs */
 214 };
 215
 216 static void
 217 i386fbsd4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 218 {
 219   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 220
 221   /* Inherit stuff from older releases.  We assume that FreeBSD
 222      4.0-RELEASE always uses ELF.  */
 223   i386fbsd_init_abi (info, gdbarch);
 224
 225   /* FreeBSD 4.0 introduced a new `struct sigcontext'.  */
 226   tdep->sc_reg_offset = i386fbsd4_sc_reg_offset;
 227   tdep->sc_num_regs = I386_NUM_GREGS;
 228 }
 229
 230 \f
 231 static enum gdb_osabi
 232 i386bsd_aout_osabi_sniffer (bfd *abfd)
 233 {
 234   if (strcmp (bfd_get_target (abfd), "a.out-i386-netbsd") == 0)
 235     return GDB_OSABI_NETBSD_AOUT;
 236
 237   if (strcmp (bfd_get_target (abfd), "a.out-i386-freebsd") == 0)
 238     return GDB_OSABI_FREEBSD_AOUT;
 239
 240   return GDB_OSABI_UNKNOWN;
 241 }
 242
 243 \f
 244 /* Provide a prototype to silence -Wmissing-prototypes.  */
 245 void _initialize_i386bsd_tdep (void);
 246
 247 void
 248 _initialize_i386bsd_tdep (void)
 249 {
 250   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_aout_flavour,
 251                                   i386bsd_aout_osabi_sniffer);
 252
 253   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_FREEBSD_AOUT,
 254                           i386fbsdaout_init_abi);
 255   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_FREEBSD_ELF,
 256                           i386fbsd4_init_abi);
 257 }