/* Native-dependent code for SVR4 Unix running on i386's, for GDB.
   Copyright 1988, 1989, 1991, 1992, 1996, 1998 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 "value.h"
#include "inferior.h"

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


#ifdef HAVE_SYS_PROCFS_H

#include <sys/procfs.h>

/* Prototypes for supply_gregset etc. */
#include "gregset.h"

/*  The /proc interface divides the target machine's register set up into
   two different sets, the general register set (gregset) and the floating
   point register set (fpregset).  For each set, there is an ioctl to get
   the current register set and another ioctl to set the current values.

   The actual structure passed through the ioctl interface is, of course,
   naturally machine dependent, and is different for each set of registers.
   For the i386 for example, the general register set is typically defined
   by:

   typedef int gregset_t[19];           (in <sys/regset.h>)

   #define GS   0                       (in <sys/reg.h>)
   #define FS   1
   ...
   #define UESP 17
   #define SS   18

   and the floating point set by:

   typedef struct fpregset
   {
   union
   {
   struct fpchip_state  // fp extension state //
   {
   int state[27];       // 287/387 saved state //
   int status;          // status word saved at exception //
   } fpchip_state;
   struct fp_emul_space // for emulators //
   {
   char fp_emul[246];
   char fp_epad[2];
   } fp_emul_space;
   int f_fpregs[62];    // union of the above //
   } fp_reg_set;
   long f_wregs[33];            // saved weitek state //
   } fpregset_t;

   These routines provide the packing and unpacking of gregset_t and
   fpregset_t formatted data.

 */

#ifdef HAVE_GREGSET_T

/* This is a duplicate of the table in i386-xdep.c. */

static int regmap[] =
{
  EAX, ECX, EDX, EBX,
  UESP, EBP, ESI, EDI,
  EIP, EFL, CS, SS,
  DS, ES, FS, GS,
};

/* Prototypes for local functions */

void fill_gregset (gregset_t *, int);

void supply_gregset (gregset_t *);

void supply_fpregset (fpregset_t *);

void fill_fpregset (fpregset_t *, int);


/*  FIXME:  These routine absolutely depends upon (NUM_REGS - NUM_FREGS)
   being less than or equal to the number of registers that can be stored
   in a gregset_t.  Note that with the current scheme there will typically
   be more registers actually stored in a gregset_t that what we know
   about.  This is bogus and should be fixed. */

/*  Given a pointer to a general register set in /proc format (gregset_t *),
   unpack the register contents and supply them as gdb's idea of the current
   register values. */

void
supply_gregset (gregset_t *gregsetp)
{
  register int regi;
  register greg_t *regp = (greg_t *) gregsetp;
  extern int regmap[];

  for (regi = 0; regi < (NUM_REGS - NUM_FREGS); regi++)
    {
      supply_register (regi, (char *) (regp + regmap[regi]));
    }
}

void
fill_gregset (gregset_t *gregsetp, int regno)
{
  int regi;
  register greg_t *regp = (greg_t *) gregsetp;
  extern int regmap[];

  for (regi = 0; regi < (NUM_REGS - NUM_FREGS); regi++)
    {
      if ((regno == -1) || (regno == regi))
	{
	  *(regp + regmap[regi]) = *(int *) &registers[REGISTER_BYTE (regi)];
	}
    }
}

#endif /* HAVE_GREGSET_T */

#if defined (HAVE_FPREGSET_T)

/*  Given a pointer to a floating point register set in /proc format
   (fpregset_t *), unpack the register contents and supply them as gdb's
   idea of the current floating point register values. */

/* FIXME: Assumes that fpregsetp contains an i387 FSAVE area. */
static const int freg_offset_map[] =
{
#if !defined(FPREGSET_FSAVE_OFFSET)
#define FPREGSET_FSAVE_OFFSET	0
#endif
  FPREGSET_FSAVE_OFFSET + 28 + 0 * 10,
  FPREGSET_FSAVE_OFFSET + 28 + 1 * 10,
  FPREGSET_FSAVE_OFFSET + 28 + 2 * 10,
  FPREGSET_FSAVE_OFFSET + 28 + 3 * 10,
  FPREGSET_FSAVE_OFFSET + 28 + 4 * 10,
  FPREGSET_FSAVE_OFFSET + 28 + 5 * 10,
  FPREGSET_FSAVE_OFFSET + 28 + 6 * 10,
  FPREGSET_FSAVE_OFFSET + 28 + 7 * 10,
  FPREGSET_FSAVE_OFFSET + 0,
  FPREGSET_FSAVE_OFFSET + 4,
  FPREGSET_FSAVE_OFFSET + 8,
  FPREGSET_FSAVE_OFFSET + 16,
  FPREGSET_FSAVE_OFFSET + 12,
  FPREGSET_FSAVE_OFFSET + 24,
  FPREGSET_FSAVE_OFFSET + 20,
  FPREGSET_FSAVE_OFFSET + 16
};

void
supply_fpregset (fpregset_t *fpregsetp)
{
  int regi;
  
  if (NUM_FREGS == 0)
    return;
  for (regi = FP0_REGNUM; regi <= LAST_FPU_CTRL_REGNUM; regi++)
    {
      char tbuf[4];
      ULONGEST tval;
      char *from = (char *) fpregsetp + freg_offset_map[regi - FP0_REGNUM];

      if (regi == FCS_REGNUM)
	{
	  tval = extract_unsigned_integer (from, 4) & 0xffff;
	  store_unsigned_integer (tbuf, 4, tval);
	  supply_register (regi, tbuf);
	}
      else if (regi == FOP_REGNUM)
	{
	  tval = (extract_unsigned_integer (from, 4) >> 16) & ((1 << 11) - 1);
	  store_unsigned_integer (tbuf, 4, tval);
	  supply_register (regi, tbuf);
	}
      else
	supply_register (regi, from);
    }
}

/*  Given a pointer to a floating point register set in /proc format
   (fpregset_t *), update the register specified by REGNO from gdb's idea
   of the current floating point register set.  If REGNO is -1, update
   them all. */

void
fill_fpregset (fpregset_t *fpregsetp, int regno)
{
  int regi;

  if (NUM_FREGS == 0)
    return;
  for (regi = FP0_REGNUM; regi <= LAST_FPU_CTRL_REGNUM; regi++)
    {
      if ((regno == -1) || (regno == regi))
	{
	  char *to = (char *) fpregsetp + freg_offset_map[regi - FP0_REGNUM];
	  char *from = (char *) &registers[REGISTER_BYTE (regi)];
	  ULONGEST valto;
	  ULONGEST valfrom;

	  if (regi == FCS_REGNUM)
	    {
	      valto = extract_unsigned_integer (to, 4);
	      valfrom = extract_unsigned_integer (from, 4);
	      valto = (valto & ~0xffff) | (valfrom & 0xffff);
	      store_unsigned_integer (to, 4, valto);
	    }
	  else if (regi == FOP_REGNUM)
	    {
	      valto = extract_unsigned_integer (to, 4);
	      valfrom = extract_unsigned_integer (from, 4);
	      valto = (valto & 0xffff) | ((valfrom & ((1 << 11) - 1)) << 16);
	      store_unsigned_integer (to, 4, valto);
	    }
	  else
	    {
	      memcpy (to, from, REGISTER_RAW_SIZE (regi));
	    }
	}
    }
}

#endif /* defined (HAVE_FPREGSET_T) */

#endif /* HAVE_SYS_PROCFS_H */
