gdb/i386-bsd-tdep.c

   1 /* Target-dependent code for i386 BSD's.
   2
   3    Copyright (C) 2001-2019 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "arch-utils.h"
  22 #include "frame.h"
  23 #include "gdbcore.h"
  24 #include "regcache.h"
  25 #include "osabi.h"
  26
  27 #include "i386-tdep.h"
  28
  29 /* Support for signal handlers.  */
  30
  31 /* Assuming THIS_FRAME is for a BSD sigtramp routine, return the
  32    address of the associated sigcontext structure.  */
  33
  34 static CORE_ADDR
  35 i386bsd_sigcontext_addr (struct frame_info *this_frame)
  36 {
  37   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  38   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  39   gdb_byte buf[4];
  40   CORE_ADDR sp;
  41
  42   get_frame_register (this_frame, I386_ESP_REGNUM, buf);
  43   sp = extract_unsigned_integer (buf, 4, byte_order);
  44
  45   return read_memory_unsigned_integer (sp + 8, 4, byte_order);
  46 }
  47 \f
  48
  49 /* Support for shared libraries.  */
  50
  51 /* Traditional BSD (4.3 BSD, still used for BSDI and 386BSD).  */
  52
  53 /* From <machine/signal.h>.  */
  54 int i386bsd_sc_reg_offset[] =
  55 {
  56   -1,                           /* %eax */
  57   -1,                           /* %ecx */
  58   -1,                           /* %edx */
  59   -1,                           /* %ebx */
  60   8 + 0 * 4,                    /* %esp */
  61   8 + 1 * 4,                    /* %ebp */
  62   -1,                           /* %esi */
  63   -1,                           /* %edi */
  64   8 + 3 * 4,                    /* %eip */
  65   8 + 4 * 4,                    /* %eflags */
  66   -1,                           /* %cs */
  67   -1,                           /* %ss */
  68   -1,                           /* %ds */
  69   -1,                           /* %es */
  70   -1,                           /* %fs */
  71   -1                            /* %gs */
  72 };
  73
  74 void
  75 i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
  76 {
  77   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  78
  79   tdep->jb_pc_offset = 0;
  80
  81   tdep->sigtramp_start = 0xfdbfdfc0;
  82   tdep->sigtramp_end = 0xfdbfe000;
  83   tdep->sigcontext_addr = i386bsd_sigcontext_addr;
  84   tdep->sc_reg_offset = i386bsd_sc_reg_offset;
  85   tdep->sc_num_regs = ARRAY_SIZE (i386bsd_sc_reg_offset);
  86 }
  87
  88 \f