gdb/i386-bsd-tdep.c

/* Target-dependent code for i386 BSD's.

   Copyright (C) 2001-2023 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "arch-utils.h"
#include "frame.h"
#include "gdbcore.h"
#include "regcache.h"
#include "osabi.h"

#include "i386-tdep.h"

/* Support for signal handlers.  */

/* Assuming THIS_FRAME is for a BSD sigtramp routine, return the
   address of the associated sigcontext structure.  */

static CORE_ADDR
i386bsd_sigcontext_addr (frame_info_ptr this_frame)
{
  struct gdbarch *gdbarch = get_frame_arch (this_frame);
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  gdb_byte buf[4];
  CORE_ADDR sp;

  get_frame_register (this_frame, I386_ESP_REGNUM, buf);
  sp = extract_unsigned_integer (buf, 4, byte_order);

  return read_memory_unsigned_integer (sp + 8, 4, byte_order);
}


/* Support for shared libraries.  */

/* Traditional BSD (4.3 BSD, still used for BSDI and 386BSD).  */

/* From <machine/signal.h>.  */
int i386bsd_sc_reg_offset[] =
{
  -1,				/* %eax */
  -1,				/* %ecx */
  -1,				/* %edx */
  -1,				/* %ebx */
  8 + 0 * 4,			/* %esp */
  8 + 1 * 4,			/* %ebp */
  -1,				/* %esi */
  -1,				/* %edi */
  8 + 3 * 4,			/* %eip */
  8 + 4 * 4,			/* %eflags */
  -1,				/* %cs */
  -1,				/* %ss */
  -1,				/* %ds */
  -1,				/* %es */
  -1,				/* %fs */
  -1				/* %gs */
};

void
i386bsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);

  tdep->jb_pc_offset = 0;

  tdep->sigtramp_start = 0xfdbfdfc0;
  tdep->sigtramp_end = 0xfdbfe000;
  tdep->sigcontext_addr = i386bsd_sigcontext_addr;
  tdep->sc_reg_offset = i386bsd_sc_reg_offset;
  tdep->sc_num_regs = ARRAY_SIZE (i386bsd_sc_reg_offset);
}