/* Intel 386 native support.
   Copyright 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999,
   2000, 2001 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.  */

#include "defs.h"
#include "frame.h"
#include "inferior.h"
#include "language.h"
#include "gdbcore.h"
#include "regcache.h"

#ifdef USG
#include <sys/types.h>
#endif

#include <sys/param.h>
#include <sys/dir.h>
#include <signal.h>
#include <sys/user.h>
#include <sys/ioctl.h>
#include <fcntl.h>

#include <sys/file.h>
#include "gdb_stat.h"

#include <stddef.h>
#include <sys/ptrace.h>

/* Does AIX define this in <errno.h>?  */
extern int errno;

#ifdef HAVE_SYS_REG_H
#include <sys/reg.h>
#endif

#include "floatformat.h"

#include "target.h"

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

/* this table must line up with REGISTER_NAMES in tm-i386v.h */
/* symbols like 'EAX' come from <sys/reg.h> */
static int regmap[] =
{
  EAX, ECX, EDX, EBX,
  USP, EBP, ESI, EDI,
  EIP, EFL, CS, SS,
  DS, ES, FS, GS,
};

/* blockend is the value of u.u_ar0, and points to the
 * place where GS is stored
 */

int
i386_register_u_addr (int blockend, int regnum)
{
#if 0
  /* this will be needed if fp registers are reinstated */
  /* for now, you can look at them with 'info float'
   * sys5 wont let you change them with ptrace anyway
   */
  if (regnum >= FP0_REGNUM && regnum <= FP7_REGNUM)
    {
      int ubase, fpstate;
      struct user u;
      ubase = blockend + 4 * (SS + 1) - KSTKSZ;
      fpstate = ubase + ((char *) &u.u_fpstate - (char *) &u);
      return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM));
    }
  else
#endif
    return (blockend + 4 * regmap[regnum]);

}

/* The code below only work on the aix ps/2 (i386-ibm-aix) -
 * mtranle@paris - Sat Apr 11 10:34:12 1992
 */

struct env387
{
  unsigned short control;
  unsigned short r0;
  unsigned short status;
  unsigned short r1;
  unsigned short tag;
  unsigned short r2;
  unsigned long eip;
  unsigned short code_seg;
  unsigned short opcode;
  unsigned long operand;
  unsigned short operand_seg;
  unsigned short r3;
  unsigned char regs[8][10];
};

static
print_387_status (unsigned short status, struct env387 *ep)
{
  int i;
  int bothstatus;
  int top;
  int fpreg;
  unsigned char *p;

  bothstatus = ((status != 0) && (ep->status != 0));
  if (status != 0)
    {
      if (bothstatus)
	printf_unfiltered ("u: ");
      print_387_status_word (status);
    }

  if (ep->status != 0)
    {
      if (bothstatus)
	printf_unfiltered ("e: ");
      print_387_status_word (ep->status);
    }

  print_387_control_word (ep->control);
  printf_unfiltered ("last exception: ");
  printf_unfiltered ("opcode %s; ", local_hex_string (ep->opcode));
  printf_unfiltered ("pc %s:", local_hex_string (ep->code_seg));
  printf_unfiltered ("%s; ", local_hex_string (ep->eip));
  printf_unfiltered ("operand %s", local_hex_string (ep->operand_seg));
  printf_unfiltered (":%s\n", local_hex_string (ep->operand));

  top = ((ep->status >> 11) & 7);

  printf_unfiltered ("regno  tag  msb              lsb  value\n");
  for (fpreg = 7; fpreg >= 0; fpreg--)
    {
      double val;

      printf_unfiltered ("%s %d: ", fpreg == top ? "=>" : "  ", fpreg);

      switch ((ep->tag >> ((7 - fpreg) * 2)) & 3)
	{
	case 0:
	  printf_unfiltered ("valid ");
	  break;
	case 1:
	  printf_unfiltered ("zero  ");
	  break;
	case 2:
	  printf_unfiltered ("trap  ");
	  break;
	case 3:
	  printf_unfiltered ("empty ");
	  break;
	}
      for (i = 9; i >= 0; i--)
	printf_unfiltered ("%02x", ep->regs[fpreg][i]);

      i387_to_double ((char *) ep->regs[fpreg], (char *) &val);
      printf_unfiltered ("  %#g\n", val);
    }
}

static struct env387 core_env387;

void
i386_float_info (void)
{
  struct env387 fps;
  int fpsaved = 0;
  /* We need to reverse the order of the registers.  Apparently AIX stores
     the highest-numbered ones first.  */
  struct env387 fps_fixed;
  int i;

  if (! ptid_equal (inferior_ptid, null_ptid))
    {
      char buf[10];
      unsigned short status;

      ptrace (PT_READ_FPR, PIDGET (inferior_ptid), buf,
              offsetof (struct env387, status));
      memcpy (&status, buf, sizeof (status));
      fpsaved = status;
    }
  else
    {
      if ((fpsaved = core_env387.status) != 0)
	memcpy (&fps, &core_env387, sizeof (fps));
    }

  if (fpsaved == 0)
    {
      printf_unfiltered ("no floating point status saved\n");
      return;
    }

  if (! ptid_equal (inferior_ptid, null_ptid))
    {
      int offset;
      for (offset = 0; offset < sizeof (fps); offset += 10)
	{
	  char buf[10];
	  ptrace (PT_READ_FPR, PIDGET (inferior_ptid), buf, offset);
	  memcpy ((char *) &fps.control + offset, buf,
		  MIN (10, sizeof (fps) - offset));
	}
    }
  fps_fixed = fps;
  for (i = 0; i < 8; ++i)
    memcpy (fps_fixed.regs[i], fps.regs[7 - i], 10);
  print_387_status (0, &fps_fixed);
}

/* Fetch one register.  */
static void
fetch_register (int regno)
{
  char buf[MAX_REGISTER_RAW_SIZE];
  if (regno < FP0_REGNUM)
    *(int *) buf = ptrace (PT_READ_GPR, PIDGET (inferior_ptid),
			   PT_REG (regmap[regno]), 0, 0);
  else
    ptrace (PT_READ_FPR, PIDGET (inferior_ptid), buf,
	    (regno - FP0_REGNUM) * 10 + offsetof (struct env387, regs));
  supply_register (regno, buf);
}

void
fetch_inferior_registers (int regno)
{
  if (regno < 0)
    for (regno = 0; regno < NUM_REGS; regno++)
      fetch_register (regno);
  else
    fetch_register (regno);
}

/* store one register */
static void
store_register (int regno)
{
  char buf[80];
  errno = 0;
  if (regno < FP0_REGNUM)
    ptrace (PT_WRITE_GPR, PIDGET (inferior_ptid), PT_REG (regmap[regno]),
	    *(int *) &registers[REGISTER_BYTE (regno)], 0);
  else
    ptrace (PT_WRITE_FPR, PIDGET (inferior_ptid),
            &registers[REGISTER_BYTE (regno)],
	    (regno - FP0_REGNUM) * 10 + offsetof (struct env387, regs));

  if (errno != 0)
    {
      sprintf (buf, "writing register number %d", regno);
      perror_with_name (buf);
    }
}

/* Store our register values back into the inferior.
   If REGNO is -1, do this for all registers.
   Otherwise, REGNO specifies which register (so we can save time).  */
void
store_inferior_registers (int regno)
{
  if (regno < 0)
    for (regno = 0; regno < NUM_REGS; regno++)
      store_register (regno);
  else
    store_register (regno);
}

#ifndef CD_AX			/* defined in sys/i386/coredump.h */
#define CD_AX	0
#define CD_BX	1
#define CD_CX	2
#define CD_DX	3
#define CD_SI	4
#define CD_DI	5
#define CD_BP	6
#define CD_SP	7
#define CD_FL	8
#define CD_IP	9
#define CD_CS	10
#define CD_DS	11
#define CD_ES	12
#define CD_FS	13
#define CD_GS	14
#define CD_SS	15
#endif

/*
 * The order here in core_regmap[] has to be the same as in 
 * regmap[] above.
 */
static int core_regmap[] =
{
  CD_AX, CD_CX, CD_DX, CD_BX,
  CD_SP, CD_BP, CD_SI, CD_DI,
  CD_IP, CD_FL, CD_CS, CD_SS,
  CD_DS, CD_ES, CD_FS, CD_GS,
};

/* Provide registers to GDB from a core file.

   CORE_REG_SECT points to an array of bytes, which were obtained from
   a core file which BFD thinks might contain register contents. 
   CORE_REG_SIZE is its size.

   WHICH says which register set corelow suspects this is:
     0 --- the general-purpose register set
     2 --- the floating-point register set

   REG_ADDR isn't used.  */

static void
fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
		      int which, CORE_ADDR reg_addr)
{

  if (which == 0)
    {
      /* Integer registers */

#define cd_regs(n) ((int *)core_reg_sect)[n]
#define regs(n) *((int *) &registers[REGISTER_BYTE (n)])

      int i;
      for (i = 0; i < FP0_REGNUM; i++)
	regs (i) = cd_regs (core_regmap[i]);
    }
  else if (which == 2)
    {
      /* Floating point registers */

      if (core_reg_size >= sizeof (core_env387))
	memcpy (&core_env387, core_reg_sect, core_reg_size);
      else
	fprintf_unfiltered (gdb_stderr, "Couldn't read float regs from core file\n");
    }
}


/* Register that we are able to handle i386aix core file formats.
   FIXME: is this really bfd_target_unknown_flavour? */

static struct core_fns i386aix_core_fns =
{
  bfd_target_unknown_flavour,		/* core_flavour */
  default_check_format,			/* check_format */
  default_core_sniffer,			/* core_sniffer */
  fetch_core_registers,			/* core_read_registers */
  NULL					/* next */
};

void
_initialize_core_i386aix (void)
{
  add_core_fns (&i386aix_core_fns);
}