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 "frame.h"
  23 #include "gdbcore.h"
  24 #include "regcache.h"
  25
  26 #include "i386-tdep.h"
  27
  28 /* Support for signal handlers.  */
  29
  30 /* Return whether PC is in a BSD sigtramp routine.  */
  31
  32 static int
  33 i386bsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
  34 {
  35   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
  36
  37   return (pc >= tdep->sigtramp_start && pc < tdep->sigtramp_end);
  38 }
  39
  40 /* Assuming FRAME is for a BSD sigtramp routine, return the address of
  41    the associated sigcontext structure.  */
  42
  43 static CORE_ADDR
  44 i386bsd_sigcontext_addr (struct frame_info *frame)
  45 {
  46   if (frame->next)
  47     /* If this isn't the top frame, the next frame must be for the
  48        signal handler itself.  A pointer to the sigcontext structure
  49        is passed as the third argument to the signal handler.  */
  50     return read_memory_unsigned_integer (frame->next->frame + 16, 4);
  51
  52   /* This is the top frame.  We'll have to find the address of the
  53      sigcontext structure by looking at the stack pointer.  */
  54   return read_memory_unsigned_integer (read_register (SP_REGNUM) + 8, 4);
  55 }
  56
  57 /* Assuming FRAME is for a BSD sigtramp routine, return the saved
  58    program counter.
  59
  60    Note: This function is used for Solaris 2 too, so don't make it
  61    static.  */
  62
  63 CORE_ADDR
  64 i386bsd_sigtramp_saved_pc (struct frame_info *frame)
  65 {
  66   int sc_pc_offset = gdbarch_tdep (current_gdbarch)->sc_pc_offset;
  67   CORE_ADDR addr;
  68
  69   addr = i386bsd_sigcontext_addr (frame);
  70   return read_memory_unsigned_integer (addr + sc_pc_offset, 4);
  71 }
  72
  73 /* Return the saved program counter for FRAME.  */
  74
  75 static CORE_ADDR
  76 i386bsd_frame_saved_pc (struct frame_info *frame)
  77 {
  78   if (frame->signal_handler_caller)
  79     return i386bsd_sigtramp_saved_pc (frame);
  80
  81   return read_memory_unsigned_integer (frame->frame + 4, 4);
  82 }
  83
  84 /* Return the start address of the sigtramp routine.  */
  85
  86 CORE_ADDR
  87 i386bsd_sigtramp_start (CORE_ADDR pc)
  88 {
  89   return gdbarch_tdep (current_gdbarch)->sigtramp_start;
  90 }
  91
  92 /* Return the end address of the sigtramp routine.  */
  93
  94 CORE_ADDR
  95 i386bsd_sigtramp_end (CORE_ADDR pc)
  96 {
  97   return gdbarch_tdep (current_gdbarch)->sigtramp_end;
  98 }
  99 \f
 100
 101 /* Traditional BSD (4.3 BSD, still used for BSDI and 386BSD).  */
 102
 103 /* From <machine/signal.h>.  */
 104 int i386bsd_sc_pc_offset = 20;
 105
 106 static void
 107 i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 108 {
 109   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 110
 111   set_gdbarch_pc_in_sigtramp (gdbarch, i386bsd_pc_in_sigtramp);
 112
 113   tdep->jb_pc_offset = 0;
 114
 115   tdep->sigtramp_saved_pc = i386bsd_sigtramp_saved_pc;
 116   tdep->sigtramp_start = 0xfdbfdfc0;
 117   tdep->sigtramp_end = 0xfdbfe000;
 118   tdep->sc_pc_offset = i386bsd_sc_pc_offset;
 119 }
 120
 121 /* NetBSD 1.0 or later.  */
 122
 123 /* From <machine/signal.h>.  */
 124 int i386nbsd_sc_pc_offset = 44;
 125
 126 static void
 127 i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 128 {
 129   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 130
 131   /* Obviously NetBSD is BSD-based.  */
 132   i386bsd_init_abi (info, gdbarch);
 133
 134   /* NetBSD uses -freg-struct-return by default.  */
 135   tdep->struct_return = reg_struct_return;
 136
 137   /* NetBSD uses a different memory layout.  */
 138   tdep->sigtramp_start = 0xbfbfdf20;
 139   tdep->sigtramp_end = 0xbfbfdff0;
 140
 141   /* NetBSD has a `struct sigcontext' that's different from the
 142      origional 4.3 BSD.  */
 143   tdep->sc_pc_offset = i386nbsd_sc_pc_offset;
 144 }
 145
 146 /* NetBSD ELF.  */
 147 static void
 148 i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 149 {
 150   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 151
 152   /* It's still NetBSD.  */
 153   i386nbsd_init_abi (info, gdbarch);
 154
 155   /* But ELF-based.  */
 156   i386_elf_init_abi (info, gdbarch);
 157
 158   /* NetBSD ELF uses -fpcc-struct-return by default.  */
 159   tdep->struct_return = pcc_struct_return;
 160
 161   /* We support the SSE registers on NetBSD ELF.  */
 162   tdep->num_xmm_regs = I386_NUM_XREGS - 1;
 163   set_gdbarch_num_regs (gdbarch, I386_NUM_GREGS + I386_NUM_FREGS
 164                         + I386_NUM_XREGS);
 165 }
 166
 167 /* FreeBSD 3.0-RELEASE or later.  */
 168
 169 CORE_ADDR i386fbsd_sigtramp_start = 0xbfbfdf20;
 170 CORE_ADDR i386fbsd_sigtramp_end = 0xbfbfdff0;
 171
 172 static void
 173 i386fbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 174 {
 175   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 176
 177   /* Obviously FreeBSD is BSD-based.  */
 178   i386bsd_init_abi (info, gdbarch);
 179
 180   /* FreeBSD uses -freg-struct-return by default.  */
 181   tdep->struct_return = reg_struct_return;
 182
 183   /* FreeBSD uses a different memory layout.  */
 184   tdep->sigtramp_start = i386fbsd_sigtramp_start;
 185   tdep->sigtramp_end = i386fbsd_sigtramp_end;
 186 }
 187
 188 static void
 189 i386fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 190 {
 191   /* It's almost identical to FreeBSD a.out.  */
 192   i386fbsdaout_init_abi (info, gdbarch);
 193
 194   /* Except that it uses ELF.  */
 195   i386_elf_init_abi (info, gdbarch);
 196 }
 197
 198 /* FreeBSD 4.0-RELEASE or later.  */
 199
 200 /* From <machine/signal.h>.  */
 201 int i386fbsd4_sc_pc_offset = 76;
 202
 203 static void
 204 i386fbsd4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 205 {
 206   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 207
 208   /* Inherit stuff from older releases.  We assume that FreeBSD
 209      4.0-RELEASE always uses ELF.  */
 210   i386fbsd_init_abi (info, gdbarch);
 211
 212   /* FreeBSD 4.0 introduced a new `struct sigcontext'.  */
 213   tdep->sc_pc_offset = i386fbsd4_sc_pc_offset;
 214 }
 215
 216 \f
 217 static enum gdb_osabi
 218 i386bsd_aout_osabi_sniffer (bfd *abfd)
 219 {
 220   if (strcmp (bfd_get_target (abfd), "a.out-i386-netbsd") == 0)
 221     return GDB_OSABI_NETBSD_AOUT;
 222
 223   if (strcmp (bfd_get_target (abfd), "a.out-i386-freebsd") == 0)
 224     return GDB_OSABI_FREEBSD_AOUT;
 225
 226   return GDB_OSABI_UNKNOWN;
 227 }
 228
 229 \f
 230 /* Provide a prototype to silence -Wmissing-prototypes.  */
 231 void _initialize_i386bsd_tdep (void);
 232
 233 void
 234 _initialize_i386bsd_tdep (void)
 235 {
 236   gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_aout_flavour,
 237                                   i386bsd_aout_osabi_sniffer);
 238
 239   gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETBSD_AOUT,
 240                           i386nbsd_init_abi);
 241   gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETBSD_ELF,
 242                           i386nbsdelf_init_abi);
 243   gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_FREEBSD_AOUT,
 244                           i386fbsdaout_init_abi);
 245   gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_FREEBSD_ELF,
 246                           i386fbsd4_init_abi);
 247 }