summaryrefslogtreecommitdiffstats
path: root/gdb/m68k-pinsn.c
blob: 17a56bf54af1d51f2ddaf79778389a1cd43182e8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
/* Print Motorola 68k instructions for GDB, the GNU debugger.
   Copyright 1986, 1987, 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 "defs.h"
#include "symtab.h"
#include "opcode/m68k.h"
#include "gdbcore.h"

/* Local function prototypes */

static int
fetch_arg PARAMS ((unsigned char *, int, int));

static void
print_base PARAMS ((int, int, FILE *));

static unsigned char *
print_indexed PARAMS ((int, unsigned char *, CORE_ADDR, FILE *));

static unsigned char *
print_insn_arg PARAMS ((char *, unsigned char *, unsigned char *, CORE_ADDR,
			FILE *));

/* 68k instructions are never longer than this many bytes.  */
#define MAXLEN 22

/* Number of elements in the opcode table.  */
#define NOPCODES (sizeof m68k_opcodes / sizeof m68k_opcodes[0])

extern char *reg_names[];
char *fpcr_names[] = { "", "fpiar", "fpsr", "fpiar/fpsr", "fpcr",
		     "fpiar/fpcr", "fpsr/fpcr", "fpiar-fpcr"};


#define NEXTBYTE(p)  (p += 2, ((char *)p)[-1])

#define NEXTWORD(p)  \
  (p += 2, ((((char *)p)[-2]) << 8) + p[-1])

#define NEXTLONG(p)  \
  (p += 4, (((((p[-4] << 8) + p[-3]) << 8) + p[-2]) << 8) + p[-1])

#define NEXTSINGLE(p) \
  (p += 4, *((float *)(p - 4)))

#define NEXTDOUBLE(p) \
  (p += 8, *((double *)(p - 8)))

#define NEXTEXTEND(p) \
  (p += 12, 0.0)	/* Need a function to convert from extended to double
			   precision... */

#define NEXTPACKED(p) \
  (p += 12, 0.0)	/* Need a function to convert from packed to double
			   precision.   Actually, it's easier to print a
			   packed number than a double anyway, so maybe
			   there should be a special case to handle this... */

/* Print the m68k instruction at address MEMADDR in debugged memory,
   on STREAM.  Returns length of the instruction, in bytes.  */

int
print_insn (memaddr, stream)
     CORE_ADDR memaddr;
     FILE *stream;
{
  unsigned char buffer[MAXLEN];
  register int i;
  register unsigned char *p;
  register char *d;
  register int bestmask;
  int best;

  read_memory (memaddr, (char *) buffer, MAXLEN);

  bestmask = 0;
  best = -1;
  for (i = 0; i < NOPCODES; i++)
    {
      register unsigned int opcode = m68k_opcodes[i].opcode;
      register unsigned int match = m68k_opcodes[i].match;
      if (((0xff & buffer[0] & (match >> 24)) == (0xff & (opcode >> 24)))
	  && ((0xff & buffer[1] & (match >> 16)) == (0xff & (opcode >> 16)))
	  && ((0xff & buffer[2] & (match >> 8)) == (0xff & (opcode >> 8)))
	  && ((0xff & buffer[3] & match) == (0xff & opcode)))
	{
	  /* Don't use for printout the variants of divul and divsl
	     that have the same register number in two places.
	     The more general variants will match instead.  */
	  for (d = m68k_opcodes[i].args; *d; d += 2)
	    if (d[1] == 'D')
	      break;

	  /* Don't use for printout the variants of most floating
	     point coprocessor instructions which use the same
	     register number in two places, as above. */
	  if (*d == 0)
	    for (d = m68k_opcodes[i].args; *d; d += 2)
	      if (d[1] == 't')
		break;

	  if (*d == 0 && match > bestmask)
	    {
	      best = i;
	      bestmask = match;
	    }
	}
    }

  /* Handle undefined instructions.  */
  if (best < 0)
    {
      fprintf_filtered (stream, "0%o", (buffer[0] << 8) + buffer[1]);
      return 2;
    }

  fprintf_filtered (stream, "%s", m68k_opcodes[best].name);

  /* Point at first word of argument data,
     and at descriptor for first argument.  */
  p = buffer + 2;
  
  /* Why do this this way? -MelloN */
  for (d = m68k_opcodes[best].args; *d; d += 2)
    {
      if (d[0] == '#')
	{
	  if (d[1] == 'l' && p - buffer < 6)
	    p = buffer + 6;
	  else if (p - buffer < 4 && d[1] != 'C' && d[1] != '8' )
	    p = buffer + 4;
	}
      if (d[1] >= '1' && d[1] <= '3' && p - buffer < 4)
	p = buffer + 4;
      if (d[1] >= '4' && d[1] <= '6' && p - buffer < 6)
	p = buffer + 6;
      if ((d[0] == 'L' || d[0] == 'l') && d[1] == 'w' && p - buffer < 4)
	p = buffer + 4;
    }

  d = m68k_opcodes[best].args;

  if (*d)
    fputs_filtered (" ", stream);

  while (*d)
    {
      p = print_insn_arg (d, buffer, p, memaddr + p - buffer, stream);
      d += 2;
      if (*d && *(d - 2) != 'I' && *d != 'k')
	fputs_filtered (",", stream);
    }
  return p - buffer;
}

static unsigned char *
print_insn_arg (d, buffer, p, addr, stream)
     char *d;
     unsigned char *buffer;
     register unsigned char *p;
     CORE_ADDR addr;		/* PC for this arg to be relative to */
     FILE *stream;
{
  register int val;
  register int place = d[1];
  int regno;
  register char *regname;
  register unsigned char *p1;
  register double flval;
  int flt_p;

  switch (*d)
    {
    case 'C':
      fprintf_filtered (stream, "ccr");
      break;

    case 'S':
      fprintf_filtered (stream, "sr");
      break;

    case 'U':
      fprintf_filtered (stream, "usp");
      break;

    case 'J':
      {
	static struct { char *name; int value; } names[]
	  = {{"sfc", 0x000}, {"dfc", 0x001}, {"cacr", 0x002},
	     {"usp", 0x800}, {"vbr", 0x801}, {"caar", 0x802},
	     {"msp", 0x803}, {"isp", 0x804}};

	val = fetch_arg (buffer, place, 12);
	for (regno = sizeof names / sizeof names[0] - 1; regno >= 0; regno--)
	  if (names[regno].value == val)
	    {
	      fprintf_filtered (stream, names[regno].name);
	      break;
	    }
	if (regno < 0)
	  fprintf_filtered (stream, "%d", val);
      }
      break;

    case 'Q':
      val = fetch_arg (buffer, place, 3);
      /* 0 means 8, except for the bkpt instruction... */
      if (val == 0 && d[1] != 's')
	val = 8;
      fprintf_filtered (stream, "#%d", val);
      break;

    case 'M':
      val = fetch_arg (buffer, place, 8);
      if (val & 0x80)
	val = val - 0x100;
      fprintf_filtered (stream, "#%d", val);
      break;

    case 'T':
      val = fetch_arg (buffer, place, 4);
      fprintf_filtered (stream, "#%d", val);
      break;

    case 'D':
      fprintf_filtered (stream, "%s", reg_names[fetch_arg (buffer, place, 3)]);
      break;

    case 'A':
      fprintf_filtered (stream, "%s",
			reg_names[fetch_arg (buffer, place, 3) + 010]);
      break;

    case 'R':
      fprintf_filtered (stream, "%s", reg_names[fetch_arg (buffer, place, 4)]);
      break;

    case 'F':
      fprintf_filtered (stream, "fp%d", fetch_arg (buffer, place, 3));
      break;

    case 'O':
      val = fetch_arg (buffer, place, 6);
      if (val & 0x20)
	fprintf_filtered (stream, "%s", reg_names [val & 7]);
      else
	fprintf_filtered (stream, "%d", val);
      break;

    case '+':
      fprintf_filtered (stream, "%s@+",
			reg_names[fetch_arg (buffer, place, 3) + 8]);
      break;

    case '-':
      fprintf_filtered (stream, "%s@-",
	       reg_names[fetch_arg (buffer, place, 3) + 8]);
      break;

    case 'k':
      if (place == 'k')
	fprintf_filtered (stream, "{%s}", reg_names[fetch_arg (buffer, place, 3)]);
      else if (place == 'C')
	{
	  val = fetch_arg (buffer, place, 7);
	  if ( val > 63 )		/* This is a signed constant. */
	    val -= 128;
	  fprintf_filtered (stream, "{#%d}", val);
	}
      else
	error ("Invalid arg format in opcode table: \"%c%c\".",
	       *d, place);
      break;

    case '#':
    case '^':
      p1 = buffer + (*d == '#' ? 2 : 4);
      if (place == 's')
	val = fetch_arg (buffer, place, 4);
      else if (place == 'C')
	val = fetch_arg (buffer, place, 7);
      else if (place == '8')
	val = fetch_arg (buffer, place, 3);
      else if (place == '3')
	val = fetch_arg (buffer, place, 8);
      else if (place == 'b')
	val = NEXTBYTE (p1);
      else if (place == 'w')
	val = NEXTWORD (p1);
      else if (place == 'l')
	val = NEXTLONG (p1);
      else
	error ("Invalid arg format in opcode table: \"%c%c\".",
	       *d, place);
      fprintf_filtered (stream, "#%d", val);
      break;

    case 'B':
      if (place == 'b')
	val = NEXTBYTE (p);
      else if (place == 'B')
	val = ((char *)buffer)[1];
      else if (place == 'w' || place == 'W')
	val = NEXTWORD (p);
      else if (place == 'l' || place == 'L')
	val = NEXTLONG (p);
      else if (place == 'g')
	{
	  val = ((char *)buffer)[1];
	  if (val == 0)
	    val = NEXTWORD (p);
	  else if (val == -1)
	    val = NEXTLONG (p);
	}
      else if (place == 'c')
	{
	  if (buffer[1] & 0x40)		/* If bit six is one, long offset */
	    val = NEXTLONG (p);
	  else
	    val = NEXTWORD (p);
	}
      else
	error ("Invalid arg format in opcode table: \"%c%c\".",
	       *d, place);

      print_address (addr + val, stream);
      break;

    case 'd':
      val = NEXTWORD (p);
      fprintf_filtered (stream, "%s@(%d)",
			reg_names[fetch_arg (buffer, place, 3)], val);
      break;

    case 's':
      fprintf_filtered (stream, "%s",
			fpcr_names[fetch_arg (buffer, place, 3)]);
      break;

    case 'I':
      val = fetch_arg (buffer, 'd', 3);		  /* Get coprocessor ID... */
      if (val != 1)				/* Unusual coprocessor ID? */
	fprintf_filtered (stream, "(cpid=%d) ", val);
      if (place == 'i')
	p += 2;			     /* Skip coprocessor extended operands */
      break;

    case '*':
    case '~':
    case '%':
    case ';':
    case '@':
    case '!':
    case '$':
    case '?':
    case '/':
    case '&':

      if (place == 'd')
	{
	  val = fetch_arg (buffer, 'x', 6);
	  val = ((val & 7) << 3) + ((val >> 3) & 7);
	}
      else
	val = fetch_arg (buffer, 's', 6);

      /* Get register number assuming address register.  */
      regno = (val & 7) + 8;
      regname = reg_names[regno];
      switch (val >> 3)
	{
	case 0:
	  fprintf_filtered (stream, "%s", reg_names[val]);
	  break;

	case 1:
	  fprintf_filtered (stream, "%s", regname);
	  break;

	case 2:
	  fprintf_filtered (stream, "%s@", regname);
	  break;

	case 3:
	  fprintf_filtered (stream, "%s@+", regname);
	  break;

	case 4:
	  fprintf_filtered (stream, "%s@-", regname);
	  break;

	case 5:
	  val = NEXTWORD (p);
	  fprintf_filtered (stream, "%s@(%d)", regname, val);
	  break;

	case 6:
	  p = print_indexed (regno, p, addr, stream);
	  break;

	case 7:
	  switch (val & 7)
	    {
	    case 0:
	      val = NEXTWORD (p);
	      fprintf_filtered (stream, "@#");
	      print_address (val, stream);
	      break;

	    case 1:
	      val = NEXTLONG (p);
	      fprintf_filtered (stream, "@#");
	      print_address (val, stream);
	      break;

	    case 2:
	      val = NEXTWORD (p);
	      print_address (addr + val, stream);
	      break;

	    case 3:
	      p = print_indexed (-1, p, addr, stream);
	      break;

	    case 4:
	      flt_p = 1;	/* Assume it's a float... */
	      switch( place )
	      {
		case 'b':
		  val = NEXTBYTE (p);
		  flt_p = 0;
		  break;

		case 'w':
		  val = NEXTWORD (p);
		  flt_p = 0;
		  break;

		case 'l':
		  val = NEXTLONG (p);
		  flt_p = 0;
		  break;

		case 'f':
		  flval = NEXTSINGLE(p);
		  break;

		case 'F':
		  flval = NEXTDOUBLE(p);
		  break;

		case 'x':
		  flval = NEXTEXTEND(p);
		  break;

		case 'p':
		  flval = NEXTPACKED(p);
		  break;

		default:
		  error ("Invalid arg format in opcode table: \"%c%c\".",
		       *d, place);
	      }
	      if ( flt_p )	/* Print a float? */
		fprintf_filtered (stream, "#%g", flval);
	      else
		fprintf_filtered (stream, "#%d", val);
	      break;

	    default:
	      fprintf_filtered (stream, "<invalid address mode 0%o>", val);
	    }
	}
      break;

    case 'L':
    case 'l':
	if (place == 'w')
	  {
	    char doneany;
	    p1 = buffer + 2;
	    val = NEXTWORD (p1);
	    /* Move the pointer ahead if this point is farther ahead
	       than the last.  */
	    p = p1 > p ? p1 : p;
	    if (val == 0)
	      {
		fputs_filtered ("#0", stream);
		break;
	      }
	    if (*d == 'l')
	      {
		register int newval = 0;
		for (regno = 0; regno < 16; ++regno)
		  if (val & (0x8000 >> regno))
		    newval |= 1 << regno;
		val = newval;
	      }
	    val &= 0xffff;
	    doneany = 0;
	    for (regno = 0; regno < 16; ++regno)
	      if (val & (1 << regno))
		{
		  int first_regno;
		  if (doneany)
		    fputs_filtered ("/", stream);
		  doneany = 1;
		  fprintf_filtered (stream, "%s", reg_names[regno]);
		  first_regno = regno;
		  while (val & (1 << (regno + 1)))
		    ++regno;
		  if (regno > first_regno)
		    fprintf_filtered (stream, "-%s", reg_names[regno]);
		}
	  }
	else if (place == '3')
	  {
	    /* `fmovem' insn.  */
	    char doneany;
	    val = fetch_arg (buffer, place, 8);
	    if (val == 0)
	      {
		fputs_filtered ("#0", stream);
		break;
	      }
	    if (*d == 'l')
	      {
		register int newval = 0;
		for (regno = 0; regno < 8; ++regno)
		  if (val & (0x80 >> regno))
		    newval |= 1 << regno;
		val = newval;
	      }
	    val &= 0xff;
	    doneany = 0;
	    for (regno = 0; regno < 8; ++regno)
	      if (val & (1 << regno))
		{
		  int first_regno;
		  if (doneany)
		    fputs_filtered ("/", stream);
		  doneany = 1;
		  fprintf_filtered (stream, "fp%d", regno);
		  first_regno = regno;
		  while (val & (1 << (regno + 1)))
		    ++regno;
		  if (regno > first_regno)
		    fprintf_filtered (stream, "-fp%d", regno);
		}
	  }
	else
	  abort ();
      break;

    default:
      error ("Invalid arg format in opcode table: \"%c\".", *d);
    }

  return (unsigned char *) p;
}

/* Fetch BITS bits from a position in the instruction specified by CODE.
   CODE is a "place to put an argument", or 'x' for a destination
   that is a general address (mode and register).
   BUFFER contains the instruction.  */

static int
fetch_arg (buffer, code, bits)
     unsigned char *buffer;
     int code;
     int bits;
{
  register int val;
  switch (code)
    {
    case 's':
      val = buffer[1];
      break;

    case 'd':			/* Destination, for register or quick.  */
      val = (buffer[0] << 8) + buffer[1];
      val >>= 9;
      break;

    case 'x':			/* Destination, for general arg */
      val = (buffer[0] << 8) + buffer[1];
      val >>= 6;
      break;

    case 'k':
      val = (buffer[3] >> 4);
      break;

    case 'C':
      val = buffer[3];
      break;

    case '1':
      val = (buffer[2] << 8) + buffer[3];
      val >>= 12;
      break;

    case '2':
      val = (buffer[2] << 8) + buffer[3];
      val >>= 6;
      break;

    case '3':
    case 'j':
      val = (buffer[2] << 8) + buffer[3];
      break;

    case '4':
      val = (buffer[4] << 8) + buffer[5];
      val >>= 12;
      break;

    case '5':
      val = (buffer[4] << 8) + buffer[5];
      val >>= 6;
      break;

    case '6':
      val = (buffer[4] << 8) + buffer[5];
      break;

    case '7':
      val = (buffer[2] << 8) + buffer[3];
      val >>= 7;
      break;
      
    case '8':
      val = (buffer[2] << 8) + buffer[3];
      val >>= 10;
      break;

    default:
      abort ();
    }

  switch (bits)
    {
    case 3:
      return val & 7;
    case 4:
      return val & 017;
    case 5:
      return val & 037;
    case 6:
      return val & 077;
    case 7:
      return val & 0177;
    case 8:
      return val & 0377;
    case 12:
      return val & 07777;
    default:
      abort ();
    }
}

/* Print an indexed argument.  The base register is BASEREG (-1 for pc).
   P points to extension word, in buffer.
   ADDR is the nominal core address of that extension word.  */

static unsigned char *
print_indexed (basereg, p, addr, stream)
     int basereg;
     unsigned char *p;
     CORE_ADDR addr;
     FILE *stream;
{
  register int word;
  static char *scales[] = {"", "*2", "*4", "*8"};
  register int base_disp;
  register int outer_disp;
  char buf[40];

  word = NEXTWORD (p);

  /* Generate the text for the index register.
     Where this will be output is not yet determined.  */
  sprintf (buf, "[%s.%c%s]",
	   reg_names[(word >> 12) & 0xf],
	   (word & 0x800) ? 'l' : 'w',
	   scales[(word >> 9) & 3]);

  /* Handle the 68000 style of indexing.  */

  if ((word & 0x100) == 0)
    {
      print_base (basereg,
		  ((word & 0x80) ? word | 0xff00 : word & 0xff)
		  + ((basereg == -1) ? addr : 0),
		  stream);
      fputs_filtered (buf, stream);
      return p;
    }

  /* Handle the generalized kind.  */
  /* First, compute the displacement to add to the base register.  */

  if (word & 0200)
    basereg = -2;
  if (word & 0100)
    buf[0] = 0;
  base_disp = 0;
  switch ((word >> 4) & 3)
    {
    case 2:
      base_disp = NEXTWORD (p);
      break;
    case 3:
      base_disp = NEXTLONG (p);
    }
  if (basereg == -1)
    base_disp += addr;

  /* Handle single-level case (not indirect) */

  if ((word & 7) == 0)
    {
      print_base (basereg, base_disp, stream);
      fputs_filtered (buf, stream);
      return p;
    }

  /* Two level.  Compute displacement to add after indirection.  */

  outer_disp = 0;
  switch (word & 3)
    {
    case 2:
      outer_disp = NEXTWORD (p);
      break;
    case 3:
      outer_disp = NEXTLONG (p);
    }

  fprintf_filtered (stream, "%d(", outer_disp);
  print_base (basereg, base_disp, stream);

  /* If postindexed, print the closeparen before the index.  */
  if (word & 4)
    fprintf_filtered (stream, ")%s", buf);
  /* If preindexed, print the closeparen after the index.  */
  else
    fprintf_filtered (stream, "%s)", buf);

  return p;
}

/* Print a base register REGNO and displacement DISP, on STREAM.
   REGNO = -1 for pc, -2 for none (suppressed).  */

static void
print_base (regno, disp, stream)
     int regno;
     int disp;
     FILE *stream;
{
  if (regno == -2)
    fprintf_filtered (stream, "%d", disp);
  else if (regno == -1)
    fprintf_filtered (stream, "0x%x", disp);
  else
    fprintf_filtered (stream, "%d(%s)", disp, reg_names[regno]);
}
OpenPOWER on IntegriCloud