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 int i386bsd_sc_sp_offset = 8;
  93
  94 static void
  95 i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
  96 {
  97   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  98
  99   set_gdbarch_pc_in_sigtramp (gdbarch, i386bsd_pc_in_sigtramp);
 100
 101   /* Assume SunOS-style shared libraries.  */
 102   set_gdbarch_in_solib_call_trampoline (gdbarch,
 103                                         i386bsd_aout_in_solib_call_trampoline);
 104
 105   tdep->jb_pc_offset = 0;
 106
 107   tdep->sigtramp_start = 0xfdbfdfc0;
 108   tdep->sigtramp_end = 0xfdbfe000;
 109   tdep->sigcontext_addr = i386bsd_sigcontext_addr;
 110   tdep->sc_pc_offset = i386bsd_sc_pc_offset;
 111   tdep->sc_sp_offset = i386bsd_sc_sp_offset;
 112 }
 113
 114 /* NetBSD 1.0 or later.  */
 115
 116 CORE_ADDR i386nbsd_sigtramp_start = 0xbfbfdf20;
 117 CORE_ADDR i386nbsd_sigtramp_end = 0xbfbfdff0;
 118
 119 /* From <machine/signal.h>.  */
 120 int i386nbsd_sc_pc_offset = 44;
 121 int i386nbsd_sc_sp_offset = 56;
 122
 123 static void
 124 i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 125 {
 126   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 127
 128   /* Obviously NetBSD is BSD-based.  */
 129   i386bsd_init_abi (info, gdbarch);
 130
 131   /* NetBSD uses -freg-struct-return by default.  */
 132   tdep->struct_return = reg_struct_return;
 133
 134   /* NetBSD uses a different memory layout.  */
 135   tdep->sigtramp_start = i386nbsd_sigtramp_start;
 136   tdep->sigtramp_end = i386nbsd_sigtramp_end;
 137
 138   /* NetBSD has a `struct sigcontext' that's different from the
 139      origional 4.3 BSD.  */
 140   tdep->sc_pc_offset = i386nbsd_sc_pc_offset;
 141   tdep->sc_sp_offset = i386nbsd_sc_sp_offset;
 142 }
 143
 144 /* NetBSD ELF.  */
 145 static void
 146 i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 147 {
 148   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 149
 150   /* It's still NetBSD.  */
 151   i386nbsd_init_abi (info, gdbarch);
 152
 153   /* But ELF-based.  */
 154   i386_elf_init_abi (info, gdbarch);
 155
 156   /* NetBSD ELF uses SVR4-style shared libraries.  */
 157   set_gdbarch_in_solib_call_trampoline (gdbarch,
 158                                         generic_in_solib_call_trampoline);
 159
 160   /* NetBSD ELF uses -fpcc-struct-return by default.  */
 161   tdep->struct_return = pcc_struct_return;
 162
 163   /* We support the SSE registers on NetBSD ELF.  */
 164   tdep->num_xmm_regs = I386_NUM_XREGS - 1;
 165   set_gdbarch_num_regs (gdbarch, I386_NUM_GREGS + I386_NUM_FREGS
 166                         + I386_NUM_XREGS);
 167 }
 168
 169 /* FreeBSD 3.0-RELEASE or later.  */
 170
 171 CORE_ADDR i386fbsd_sigtramp_start = 0xbfbfdf20;
 172 CORE_ADDR i386fbsd_sigtramp_end = 0xbfbfdff0;
 173
 174 static void
 175 i386fbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 176 {
 177   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 178
 179   /* Obviously FreeBSD is BSD-based.  */
 180   i386bsd_init_abi (info, gdbarch);
 181
 182   /* FreeBSD uses -freg-struct-return by default.  */
 183   tdep->struct_return = reg_struct_return;
 184
 185   /* FreeBSD uses a different memory layout.  */
 186   tdep->sigtramp_start = i386fbsd_sigtramp_start;
 187   tdep->sigtramp_end = i386fbsd_sigtramp_end;
 188 }
 189
 190 static void
 191 i386fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 192 {
 193   /* It's almost identical to FreeBSD a.out.  */
 194   i386fbsdaout_init_abi (info, gdbarch);
 195
 196   /* Except that it uses ELF.  */
 197   i386_elf_init_abi (info, gdbarch);
 198
 199   /* FreeBSD ELF uses SVR4-style shared libraries.  */
 200   set_gdbarch_in_solib_call_trampoline (gdbarch,
 201                                         generic_in_solib_call_trampoline);
 202 }
 203
 204 /* FreeBSD 4.0-RELEASE or later.  */
 205
 206 /* From <machine/signal.h>.  */
 207 int i386fbsd4_sc_pc_offset = 76;
 208 int i386fbsd4_sc_sp_offset = 88;
 209
 210 static void
 211 i386fbsd4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 212 {
 213   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 214
 215   /* Inherit stuff from older releases.  We assume that FreeBSD
 216      4.0-RELEASE always uses ELF.  */
 217   i386fbsd_init_abi (info, gdbarch);
 218
 219   /* FreeBSD 4.0 introduced a new `struct sigcontext'.  */
 220   tdep->sc_pc_offset = i386fbsd4_sc_pc_offset;
 221   tdep->sc_sp_offset = i386fbsd4_sc_sp_offset;
 222 }
 223
 224 \f
 225 static enum gdb_osabi
 226 i386bsd_aout_osabi_sniffer (bfd *abfd)
 227 {
 228   if (strcmp (bfd_get_target (abfd), "a.out-i386-netbsd") == 0)
 229     return GDB_OSABI_NETBSD_AOUT;
 230
 231   if (strcmp (bfd_get_target (abfd), "a.out-i386-freebsd") == 0)
 232     return GDB_OSABI_FREEBSD_AOUT;
 233
 234   return GDB_OSABI_UNKNOWN;
 235 }
 236
 237 \f
 238 /* Provide a prototype to silence -Wmissing-prototypes.  */
 239 void _initialize_i386bsd_tdep (void);
 240
 241 void
 242 _initialize_i386bsd_tdep (void)
 243 {
 244   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_aout_flavour,
 245                                   i386bsd_aout_osabi_sniffer);
 246
 247   gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETBSD_AOUT,
 248                           i386nbsd_init_abi);
 249   gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETBSD_ELF,
 250                           i386nbsdelf_init_abi);
 251   gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_FREEBSD_AOUT,
 252                           i386fbsdaout_init_abi);
 253   gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_FREEBSD_ELF,
 254                           i386fbsd4_init_abi);
 255 }