/* Extract registers from a "standard" core file, for GDB.
   Copyright (C) 1988-1995  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 2 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, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* Typically used on systems that have a.out format executables.
   corefile.c is supposed to contain the more machine-independent
   aspects of reading registers from core files, while this file is
   more machine specific.  */

#include "defs.h"

#ifdef HAVE_PTRACE_H
# include <ptrace.h>
#else
# ifdef HAVE_SYS_PTRACE_H
#  include <sys/ptrace.h>
# endif
#endif

#include <sys/types.h>
#include <sys/param.h>
#include "gdbcore.h"
#include "value.h" /* For supply_register.  */
#include "inferior.h" /* For ARCH_NUM_REGS. */

/* These are needed on various systems to expand REGISTER_U_ADDR.  */
#ifndef USG
#include <sys/dir.h>
#include <sys/file.h>
#include "gdb_stat.h"
#include <sys/user.h>
#endif

#ifndef CORE_REGISTER_ADDR
#define CORE_REGISTER_ADDR(regno, regptr) register_addr(regno, regptr)
#endif /* CORE_REGISTER_ADDR */

#ifdef NEED_SYS_CORE_H
#include <sys/core.h>
#endif

static void fetch_core_registers PARAMS ((char *, unsigned, int, CORE_ADDR));

/* Extract the register values out of the core file and store
   them where `read_register' will find them.

   CORE_REG_SECT points to the register values themselves, read into memory.
   CORE_REG_SIZE is the size of that area.
   WHICH says which set of registers we are handling (0 = int, 2 = float
         on machines where they are discontiguous).
   REG_ADDR is the offset from u.u_ar0 to the register values relative to
            core_reg_sect.  This is used with old-fashioned core files to
	    locate the registers in a large upage-plus-stack ".reg" section.
	    Original upage address X is at location core_reg_sect+x+reg_addr.
 */

static void
fetch_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
     char *core_reg_sect;
     unsigned core_reg_size;
     int which;
     CORE_ADDR reg_addr;
{
  int regno;
  CORE_ADDR addr;
  int bad_reg = -1;
  CORE_ADDR reg_ptr = -reg_addr; /* Original u.u_ar0 is -reg_addr. */
  int numregs = ARCH_NUM_REGS;

  /* If u.u_ar0 was an absolute address in the core file, relativize it now,
     so we can use it as an offset into core_reg_sect.  When we're done,
     "register 0" will be at core_reg_sect+reg_ptr, and we can use
     CORE_REGISTER_ADDR to offset to the other registers.  If this is a modern
     core file without a upage, reg_ptr will be zero and this is all a big
     NOP.  */
  if (reg_ptr > core_reg_size)
    reg_ptr -= KERNEL_U_ADDR;

  for (regno = 0; regno < numregs; regno++)
    {
      addr = CORE_REGISTER_ADDR (regno, reg_ptr);
      if (addr >= core_reg_size
	  && bad_reg < 0)
	bad_reg = regno;
    else
      supply_register (regno, core_reg_sect + addr);
    }

  if (bad_reg >= 0)
    error ("Register %s not found in core file.", reg_names[bad_reg]);
}


#ifdef REGISTER_U_ADDR

/* Return the address in the core dump or inferior of register REGNO.
   BLOCKEND is the address of the end of the user structure.  */

CORE_ADDR
register_addr (regno, blockend)
     int regno;
     CORE_ADDR blockend;
{
  CORE_ADDR addr;

  if (regno < 0 || regno >= ARCH_NUM_REGS)
    error ("Invalid register number %d.", regno);

  REGISTER_U_ADDR (addr, blockend, regno);

  return addr;
}

#endif /* REGISTER_U_ADDR */


/* Register that we are able to handle aout (trad-core) file formats.  */

static struct core_fns aout_core_fns =
{
  bfd_target_unknown_flavour,
  fetch_core_registers,
  NULL
};

void
_initialize_core_aout ()
{
  add_core_fns (&aout_core_fns);
}