gdb/i386bsd-tdep.c

   1 /* Target-dependent code for i386 BSD's.
   2    Copyright 2001, 2002 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
  27 #include "i386-tdep.h"
  28
  29 /* Support for signal handlers.  */
  30
  31 /* Return whether PC is in a BSD sigtramp routine.  */
  32
  33 static int
  34 i386bsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
  35 {
  36   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
  37
  38   return (pc >= tdep->sigtramp_start && pc < tdep->sigtramp_end);
  39 }
  40
  41 /* Assuming FRAME is for a BSD sigtramp routine, return the address of
  42    the associated sigcontext structure.
  43
  44    Note: This function is used for Solaris 2 too, so don't make it
  45    static.  */
  46
  47 CORE_ADDR
  48 i386bsd_sigcontext_addr (struct frame_info *frame)
  49 {
  50   if (frame->next)
  51     /* If this isn't the top frame, the next frame must be for the
  52        signal handler itself.  A pointer to the sigcontext structure
  53        is passed as the third argument to the signal handler.  */
  54     return read_memory_unsigned_integer (frame->next->frame + 16, 4);
  55
  56   /* This is the top frame.  We'll have to find the address of the
  57      sigcontext structure by looking at the stack pointer.  */
  58   return read_memory_unsigned_integer (read_register (SP_REGNUM) + 8, 4);
  59 }
  60
  61 /* Return the start address of the sigtramp routine.  */
  62
  63 CORE_ADDR
  64 i386bsd_sigtramp_start (CORE_ADDR pc)
  65 {
  66   return gdbarch_tdep (current_gdbarch)->sigtramp_start;
  67 }
  68
  69 /* Return the end address of the sigtramp routine.  */
  70
  71 CORE_ADDR
  72 i386bsd_sigtramp_end (CORE_ADDR pc)
  73 {
  74   return gdbarch_tdep (current_gdbarch)->sigtramp_end;
  75 }
  76 \f
  77
  78 /* Support for shared libraries.  */
  79
  80 /* Return non-zero if we are in a shared library trampoline code stub.  */
  81
  82 int
  83 i386bsd_aout_in_solib_call_trampoline (CORE_ADDR pc, char *name)
  84 {
  85   return (name && !strcmp (name, "_DYNAMIC"));
  86 }
  87
  88 /* Traditional BSD (4.3 BSD, still used for BSDI and 386BSD).  */
  89
  90 /* From <machine/signal.h>.  */
  91 int i386bsd_sc_pc_offset = 20;
  92
  93 static void
  94 i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
  95 {
  96   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  97
  98   set_gdbarch_pc_in_sigtramp (gdbarch, i386bsd_pc_in_sigtramp);
  99
 100   /* Assume SunOS-style shared libraries.  */
 101   set_gdbarch_in_solib_call_trampoline (gdbarch,
 102                                         i386bsd_aout_in_solib_call_trampoline);
 103
 104   tdep->jb_pc_offset = 0;
 105
 106   tdep->sigtramp_start = 0xfdbfdfc0;
 107   tdep->sigtramp_end = 0xfdbfe000;
 108   tdep->sigcontext_addr = i386bsd_sigcontext_addr;
 109   tdep->sc_pc_offset = i386bsd_sc_pc_offset;
 110 }
 111
 112 /* NetBSD 1.0 or later.  */
 113
 114 /* From <machine/signal.h>.  */
 115 int i386nbsd_sc_pc_offset = 44;
 116
 117 static void
 118 i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 119 {
 120   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 121
 122   /* Obviously NetBSD is BSD-based.  */
 123   i386bsd_init_abi (info, gdbarch);
 124
 125   /* NetBSD uses -freg-struct-return by default.  */
 126   tdep->struct_return = reg_struct_return;
 127
 128   /* NetBSD uses a different memory layout.  */
 129   tdep->sigtramp_start = 0xbfbfdf20;
 130   tdep->sigtramp_end = 0xbfbfdff0;
 131
 132   /* NetBSD has a `struct sigcontext' that's different from the
 133      origional 4.3 BSD.  */
 134   tdep->sc_pc_offset = i386nbsd_sc_pc_offset;
 135 }
 136
 137 /* NetBSD ELF.  */
 138 static void
 139 i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 140 {
 141   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 142
 143   /* It's still NetBSD.  */
 144   i386nbsd_init_abi (info, gdbarch);
 145
 146   /* But ELF-based.  */
 147   i386_elf_init_abi (info, gdbarch);
 148
 149   /* NetBSD ELF uses SVR4-style shared libraries.  */
 150   set_gdbarch_in_solib_call_trampoline (gdbarch,
 151                                         generic_in_solib_call_trampoline);
 152
 153   /* NetBSD ELF uses -fpcc-struct-return by default.  */
 154   tdep->struct_return = pcc_struct_return;
 155
 156   /* We support the SSE registers on NetBSD ELF.  */
 157   tdep->num_xmm_regs = I386_NUM_XREGS - 1;
 158   set_gdbarch_num_regs (gdbarch, I386_NUM_GREGS + I386_NUM_FREGS
 159                         + I386_NUM_XREGS);
 160 }
 161
 162 /* FreeBSD 3.0-RELEASE or later.  */
 163
 164 CORE_ADDR i386fbsd_sigtramp_start = 0xbfbfdf20;
 165 CORE_ADDR i386fbsd_sigtramp_end = 0xbfbfdff0;
 166
 167 static void
 168 i386fbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 169 {
 170   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 171
 172   /* Obviously FreeBSD is BSD-based.  */
 173   i386bsd_init_abi (info, gdbarch);
 174
 175   /* FreeBSD uses -freg-struct-return by default.  */
 176   tdep->struct_return = reg_struct_return;
 177
 178   /* FreeBSD uses a different memory layout.  */
 179   tdep->sigtramp_start = i386fbsd_sigtramp_start;
 180   tdep->sigtramp_end = i386fbsd_sigtramp_end;
 181 }
 182
 183 static void
 184 i386fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 185 {
 186   /* It's almost identical to FreeBSD a.out.  */
 187   i386fbsdaout_init_abi (info, gdbarch);
 188
 189   /* Except that it uses ELF.  */
 190   i386_elf_init_abi (info, gdbarch);
 191
 192   /* FreeBSD ELF uses SVR4-style shared libraries.  */
 193   set_gdbarch_in_solib_call_trampoline (gdbarch,
 194                                         generic_in_solib_call_trampoline);
 195 }
 196
 197 /* FreeBSD 4.0-RELEASE or later.  */
 198
 199 /* From <machine/signal.h>.  */
 200 int i386fbsd4_sc_pc_offset = 76;
 201
 202 static void
 203 i386fbsd4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 204 {
 205   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 206
 207   /* Inherit stuff from older releases.  We assume that FreeBSD
 208      4.0-RELEASE always uses ELF.  */
 209   i386fbsd_init_abi (info, gdbarch);
 210
 211   /* FreeBSD 4.0 introduced a new `struct sigcontext'.  */
 212   tdep->sc_pc_offset = i386fbsd4_sc_pc_offset;
 213 }
 214
 215 \f
 216 static enum gdb_osabi
 217 i386bsd_aout_osabi_sniffer (bfd *abfd)
 218 {
 219   if (strcmp (bfd_get_target (abfd), "a.out-i386-netbsd") == 0)
 220     return GDB_OSABI_NETBSD_AOUT;
 221
 222   if (strcmp (bfd_get_target (abfd), "a.out-i386-freebsd") == 0)
 223     return GDB_OSABI_FREEBSD_AOUT;
 224
 225   return GDB_OSABI_UNKNOWN;
 226 }
 227
 228 \f
 229 /* Provide a prototype to silence -Wmissing-prototypes.  */
 230 void _initialize_i386bsd_tdep (void);
 231
 232 void
 233 _initialize_i386bsd_tdep (void)
 234 {
 235   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_aout_flavour,
 236                                   i386bsd_aout_osabi_sniffer);
 237
 238   gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETBSD_AOUT,
 239                           i386nbsd_init_abi);
 240   gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETBSD_ELF,
 241                           i386nbsdelf_init_abi);
 242   gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_FREEBSD_AOUT,
 243                           i386fbsdaout_init_abi);
 244   gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_FREEBSD_ELF,
 245                           i386fbsd4_init_abi);
 246 }