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, SP_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_pc_offset = 20;
  90 int i386bsd_sc_sp_offset = 8;
  91
  92 void
  93 i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
  94 {
  95   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  96
  97   set_gdbarch_pc_in_sigtramp (gdbarch, i386bsd_pc_in_sigtramp);
  98
  99   /* Allow the recognition of sigtramps as a function named <sigtramp>.  */
 100   set_gdbarch_sigtramp_start (gdbarch, i386bsd_sigtramp_start);
 101   set_gdbarch_sigtramp_end (gdbarch, i386bsd_sigtramp_end);
 102
 103   /* Assume SunOS-style shared libraries.  */
 104   set_gdbarch_in_solib_call_trampoline (gdbarch,
 105                                         i386bsd_aout_in_solib_call_trampoline);
 106
 107   tdep->jb_pc_offset = 0;
 108
 109   tdep->sigtramp_start = 0xfdbfdfc0;
 110   tdep->sigtramp_end = 0xfdbfe000;
 111   tdep->sigcontext_addr = i386bsd_sigcontext_addr;
 112   tdep->sc_pc_offset = i386bsd_sc_pc_offset;
 113   tdep->sc_sp_offset = i386bsd_sc_sp_offset;
 114 }
 115
 116 /* FreeBSD 3.0-RELEASE or later.  */
 117
 118 CORE_ADDR i386fbsd_sigtramp_start = 0xbfbfdf20;
 119 CORE_ADDR i386fbsd_sigtramp_end = 0xbfbfdff0;
 120
 121 static void
 122 i386fbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 123 {
 124   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 125
 126   /* Obviously FreeBSD is BSD-based.  */
 127   i386bsd_init_abi (info, gdbarch);
 128
 129   /* FreeBSD uses -freg-struct-return by default.  */
 130   tdep->struct_return = reg_struct_return;
 131
 132   /* FreeBSD uses a different memory layout.  */
 133   tdep->sigtramp_start = i386fbsd_sigtramp_start;
 134   tdep->sigtramp_end = i386fbsd_sigtramp_end;
 135 }
 136
 137 static void
 138 i386fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 139 {
 140   /* It's almost identical to FreeBSD a.out.  */
 141   i386fbsdaout_init_abi (info, gdbarch);
 142
 143   /* Except that it uses ELF.  */
 144   i386_elf_init_abi (info, gdbarch);
 145
 146   /* FreeBSD ELF uses SVR4-style shared libraries.  */
 147   set_gdbarch_in_solib_call_trampoline (gdbarch,
 148                                         generic_in_solib_call_trampoline);
 149 }
 150
 151 /* FreeBSD 4.0-RELEASE or later.  */
 152
 153 /* From <machine/signal.h>.  */
 154 int i386fbsd4_sc_pc_offset = 76;
 155 int i386fbsd4_sc_sp_offset = 88;
 156
 157 static void
 158 i386fbsd4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 159 {
 160   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 161
 162   /* Inherit stuff from older releases.  We assume that FreeBSD
 163      4.0-RELEASE always uses ELF.  */
 164   i386fbsd_init_abi (info, gdbarch);
 165
 166   /* FreeBSD 4.0 introduced a new `struct sigcontext'.  */
 167   tdep->sc_pc_offset = i386fbsd4_sc_pc_offset;
 168   tdep->sc_sp_offset = i386fbsd4_sc_sp_offset;
 169 }
 170
 171 \f
 172 static enum gdb_osabi
 173 i386bsd_aout_osabi_sniffer (bfd *abfd)
 174 {
 175   if (strcmp (bfd_get_target (abfd), "a.out-i386-netbsd") == 0)
 176     return GDB_OSABI_NETBSD_AOUT;
 177
 178   if (strcmp (bfd_get_target (abfd), "a.out-i386-freebsd") == 0)
 179     return GDB_OSABI_FREEBSD_AOUT;
 180
 181   return GDB_OSABI_UNKNOWN;
 182 }
 183
 184 \f
 185 /* Provide a prototype to silence -Wmissing-prototypes.  */
 186 void _initialize_i386bsd_tdep (void);
 187
 188 void
 189 _initialize_i386bsd_tdep (void)
 190 {
 191   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_aout_flavour,
 192                                   i386bsd_aout_osabi_sniffer);
 193
 194   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_FREEBSD_AOUT,
 195                           i386fbsdaout_init_abi);
 196   gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_FREEBSD_ELF,
 197                           i386fbsd4_init_abi);
 198 }