gdb/i386-xdep.c

   1 /* Intel 386 stuff.
   2    Copyright (C) 1988, 1989, 1991 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #include "defs.h"
  21 #include "frame.h"
  22 #include "inferior.h"
  23 #include "language.h"
  24 #include "gdbcore.h"
  25
  26 #ifdef USG
  27 #include <sys/types.h>
  28 #endif
  29
  30 #include <sys/param.h>
  31 #include <sys/dir.h>
  32 #include <signal.h>
  33 #include <sys/user.h>
  34 #include <sys/ioctl.h>
  35 #include <fcntl.h>
  36
  37 #include <sys/file.h>
  38 #include <sys/stat.h>
  39
  40 #include <sys/reg.h>
  41 #include "ieee-float.h"
  42
  43 #include "target.h"
  44
  45 extern struct ext_format ext_format_i387;
  46 \f
  47 /* this table must line up with REGISTER_NAMES in tm-i386v.h */
  48 /* symbols like 'EAX' come from <sys/reg.h> */
  49 static int regmap[] =
  50 {
  51   EAX, ECX, EDX, EBX,
  52   UESP, EBP, ESI, EDI,
  53   EIP, EFL, CS, SS,
  54   DS, ES, FS, GS,
  55 };
  56
  57 /* blockend is the value of u.u_ar0, and points to the
  58  * place where GS is stored
  59  */
  60
  61 int
  62 i386_register_u_addr (blockend, regnum)
  63      int blockend;
  64      int regnum;
  65 {
  66 #if 0
  67   /* this will be needed if fp registers are reinstated */
  68   /* for now, you can look at them with 'info float'
  69    * sys5 wont let you change them with ptrace anyway
  70    */
  71   if (regnum >= FP0_REGNUM && regnum <= FP7_REGNUM)
  72     {
  73       int ubase, fpstate;
  74       struct user u;
  75       ubase = blockend + 4 * (SS + 1) - KSTKSZ;
  76       fpstate = ubase + ((char *)&u.u_fpstate - (char *)&u);
  77       return (fpstate + 0x1c + 10 * (regnum - FP0_REGNUM));
  78     }
  79   else
  80 #endif
  81     return (blockend + 4 * regmap[regnum]);
  82
  83 }
  84
  85 #if 0
  86 /* mauro@olympus 1991.10.20 -- compiling the following code causes
  87    undefined symbols at link time, specifically: corechan, have_inferior_p */
  88 struct env387
  89 {
  90   unsigned short control;
  91   unsigned short r0;
  92   unsigned short status;
  93   unsigned short r1;
  94   unsigned short tag;
  95   unsigned short r2;
  96   unsigned long eip;
  97   unsigned short code_seg;
  98   unsigned short opcode;
  99   unsigned long operand;
 100   unsigned short operand_seg;
 101   unsigned short r3;
 102   unsigned char regs[8][10];
 103 };
 104
 105 static
 106 print_387_status (status, ep)
 107      unsigned short status;
 108      struct env387 *ep;
 109 {
 110   int i;
 111   int bothstatus;
 112   int top;
 113   int fpreg;
 114   unsigned char *p;
 115
 116   bothstatus = ((status != 0) && (ep->status != 0));
 117   if (status != 0)
 118     {
 119       if (bothstatus)
 120         printf ("u: ");
 121       print_387_status_word (status);
 122     }
 123
 124   if (ep->status != 0)
 125     {
 126       if (bothstatus)
 127         printf ("e: ");
 128       print_387_status_word (ep->status);
 129     }
 130
 131   print_387_control_word (ep->control);
 132   printf ("last exception: ");
 133   printf ("opcode %s; ", local_hex_string(ep->opcode));
 134   printf ("pc %s:", local_hex_string(ep->code_seg));
 135   printf ("%s; ", local_hex_string(ep->eip));
 136   printf ("operand %s", local_hex_string(ep->operand_seg));
 137   printf (":%s\n", local_hex_string(ep->operand));
 138
 139   top = (ep->status >> 11) & 7;
 140
 141   printf ("regno  tag  msb              lsb  value\n");
 142   for (fpreg = 7; fpreg >= 0; fpreg--)
 143     {
 144       double val;
 145
 146       printf ("%s %d: ", fpreg == top ? "=>" : "  ", fpreg);
 147
 148       switch ((ep->tag >> (fpreg * 2)) & 3)
 149         {
 150         case 0: printf ("valid "); break;
 151         case 1: printf ("zero  "); break;
 152         case 2: printf ("trap  "); break;
 153         case 3: printf ("empty "); break;
 154         }
 155       for (i = 9; i >= 0; i--)
 156         printf ("%02x", ep->regs[fpreg][i]);
 157
 158       ieee_extended_to_double (&ext_format_i387, (char *)ep->regs[fpreg],
 159                                &val);
 160       printf ("  %g\n", val);
 161     }
 162   if (ep->r0)
 163     warning ("reserved0 is %s\n", local_hex_string(ep->r0));
 164   if (ep->r1)
 165     warning ("reserved1 is %s\n", local_hex_string(ep->r1));
 166   if (ep->r2)
 167     warning ("reserved2 is %s\n", local_hex_string(ep->r2));
 168   if (ep->r3)
 169     warning ("reserved3 is %s\n", local_hex_string(ep->r3));
 170 }
 171
 172 #ifndef U_FPSTATE
 173 #define U_FPSTATE(u) u.u_fpstate
 174 #endif
 175
 176 i386_float_info ()
 177 {
 178   struct user u; /* just for address computations */
 179   int i;
 180   /* fpstate defined in <sys/user.h> */
 181   struct fpstate *fpstatep;
 182   char buf[sizeof (struct fpstate) + 2 * sizeof (int)];
 183   unsigned int uaddr;
 184   char fpvalid = 0;
 185   unsigned int rounded_addr;
 186   unsigned int rounded_size;
 187   extern int corechan;
 188   int skip;
 189
 190   uaddr = (char *)&u.u_fpvalid - (char *)&u;
 191   if (target_has_execution)
 192     {
 193       unsigned int data;
 194       unsigned int mask;
 195
 196       rounded_addr = uaddr & -sizeof (int);
 197       data = ptrace (3, inferior_pid, (PTRACE_ARG3_TYPE) rounded_addr, 0);
 198       mask = 0xff << ((uaddr - rounded_addr) * 8);
 199
 200       fpvalid = ((data & mask) != 0);
 201     }
 202 #if 0
 203   else
 204     {
 205       if (lseek (corechan, uaddr, 0) < 0)
 206         perror ("seek on core file");
 207       if (myread (corechan, &fpvalid, 1) < 0)
 208         perror ("read on core file");
 209
 210     }
 211 #endif  /* no core support yet */
 212
 213   if (fpvalid == 0)
 214     {
 215       printf ("no floating point status saved\n");
 216       return;
 217     }
 218
 219   uaddr = (char *)&U_FPSTATE(u) - (char *)&u;
 220   if (target_has_execution)
 221     {
 222       int *ip;
 223
 224       rounded_addr = uaddr & -sizeof (int);
 225       rounded_size = (((uaddr + sizeof (struct fpstate)) - uaddr) +
 226                       sizeof (int) - 1) / sizeof (int);
 227       skip = uaddr - rounded_addr;
 228
 229       ip = (int *)buf;
 230       for (i = 0; i < rounded_size; i++)
 231         {
 232           *ip++ = ptrace (3, inferior_pid, (PTRACE_ARG3_TYPE) rounded_addr, 0);
 233           rounded_addr += sizeof (int);
 234         }
 235     }
 236 #if 0
 237   else
 238     {
 239       if (lseek (corechan, uaddr, 0) < 0)
 240         perror_with_name ("seek on core file");
 241       if (myread (corechan, buf, sizeof (struct fpstate)) < 0)
 242         perror_with_name ("read from core file");
 243       skip = 0;
 244     }
 245  #endif /* 0 */
 246
 247   fpstatep = (struct fpstate *)(buf + skip);
 248   print_387_status (fpstatep->status, (struct env387 *)fpstatep->state);
 249 }
 250 #endif /* mauro@olympus 1991.10.20 */