binutils-gdb/gdb/i386-xdep.c

/* Intel 386 stuff.
   Copyright (C) 1988, 1989, 1991 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include <stdio.h>
#include "defs.h"
#include "param.h"
#include "frame.h"
#include "inferior.h"
#include "language.h"
#include "gdbcore.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 <sys/stat.h>

#include <sys/reg.h>
#include "ieee-float.h"

extern void print_387_control_word ();		/* i387-tdep.h */
extern void print_387_status_word ();

extern struct ext_format ext_format_i387;

/* this table must line up with REGISTER_NAMES in m-i386.h */
/* symbols like 'EAX' come from <sys/reg.h> */
static int regmap[] = 
{
  EAX, ECX, EDX, EBX,
  UESP, 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
 */
i386_register_u_addr (blockend, 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]);
  
}

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 (status, ep)
     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 ("u: ");
      print_387_status_word (status);
    }
  
  if (ep->status != 0) 
    {
      if (bothstatus)
	printf ("e: ");
      print_387_status_word (ep->status);
    }
  
  print_387_control_word (ep->control);
  printf ("last exception: ");
  printf ("opcode %s; ", local_hex_string(ep->opcode));
  printf ("pc %s:", local_hex_string(ep->code_seg));
  printf ("%s; ", local_hex_string(ep->eip));
  printf ("operand %s", local_hex_string(ep->operand_seg));
  printf (":%s\n", local_hex_string(ep->operand));
  
  top = (ep->status >> 11) & 7;
  
  printf ("regno  tag  msb              lsb  value\n");
  for (fpreg = 7; fpreg >= 0; fpreg--) 
    {
      double val;
      
      printf ("%s %d: ", fpreg == top ? "=>" : "  ", fpreg);
      
      switch ((ep->tag >> (fpreg * 2)) & 3) 
	{
	case 0: printf ("valid "); break;
	case 1: printf ("zero  "); break;
	case 2: printf ("trap  "); break;
	case 3: printf ("empty "); break;
	}
      for (i = 9; i >= 0; i--)
	printf ("%02x", ep->regs[fpreg][i]);
      
      ieee_extended_to_double (&ext_format_i387, (char *)ep->regs[fpreg],
			       &val);
      printf ("  %g\n", val);
    }
  if (ep->r0)
    printf ("warning: reserved0 is %s\n", local_hex_string(ep->r0));
  if (ep->r1)
    printf ("warning: reserved1 is %s\n", local_hex_string(ep->r1));
  if (ep->r2)
    printf ("warning: reserved2 is %s\n", local_hex_string(ep->r2));
  if (ep->r3)
    printf ("warning: reserved3 is %s\n", local_hex_string(ep->r3));
}

#ifndef U_FPSTATE
#define U_FPSTATE(u) u.u_fpstate
#endif

i386_float_info ()
{
  struct user u; /* just for address computations */
  int i;
  /* fpstate defined in <sys/user.h> */
  struct fpstate *fpstatep;
  char buf[sizeof (struct fpstate) + 2 * sizeof (int)];
  unsigned int uaddr;
  char fpvalid;
  unsigned int rounded_addr;
  unsigned int rounded_size;
  extern int corechan;
  int skip;
  
  uaddr = (char *)&u.u_fpvalid - (char *)&u;
  if (have_inferior_p()) 
    {
      unsigned int data;
      unsigned int mask;
      
      rounded_addr = uaddr & -sizeof (int);
      data = ptrace (3, inferior_pid, rounded_addr, 0);
      mask = 0xff << ((uaddr - rounded_addr) * 8);
      
      fpvalid = ((data & mask) != 0);
    } 
  else 
    {
      if (lseek (corechan, uaddr, 0) < 0)
	perror ("seek on core file");
      if (myread (corechan, &fpvalid, 1) < 0) 
	perror ("read on core file");
      
    }
  
  if (fpvalid == 0) 
    {
      printf ("no floating point status saved\n");
      return;
    }
  
  uaddr = (char *)&U_FPSTATE(u) - (char *)&u;
  if (have_inferior_p ()) 
    {
      int *ip;
      
      rounded_addr = uaddr & -sizeof (int);
      rounded_size = (((uaddr + sizeof (struct fpstate)) - uaddr) +
		      sizeof (int) - 1) / sizeof (int);
      skip = uaddr - rounded_addr;
      
      ip = (int *)buf;
      for (i = 0; i < rounded_size; i++) 
	{
	  *ip++ = ptrace (3, inferior_pid, rounded_addr, 0);
	  rounded_addr += sizeof (int);
	}
    } 
  else 
    {
      if (lseek (corechan, uaddr, 0) < 0)
	perror_with_name ("seek on core file");
      if (myread (corechan, buf, sizeof (struct fpstate)) < 0) 
	perror_with_name ("read from core file");
      skip = 0;
    }
  
  fpstatep = (struct fpstate *)(buf + skip);
  print_387_status (fpstatep->status, (struct env387 *)fpstatep->state);
}