OpenCores
URL https://opencores.org/ocsvn/openrisc_2011-10-31/openrisc_2011-10-31/trunk

Subversion Repositories openrisc_2011-10-31

[/] [openrisc/] [trunk/] [gnu-src/] [gdb-7.1/] [gdb/] [m88k-tdep.c] - Blame information for rev 287

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 227 jeremybenn
/* Target-dependent code for the Motorola 88000 series.
2
 
3
   Copyright (C) 2004, 2005, 2007, 2008, 2009, 2010
4
   Free Software Foundation, Inc.
5
 
6
   This file is part of GDB.
7
 
8
   This program is free software; you can redistribute it and/or modify
9
   it under the terms of the GNU General Public License as published by
10
   the Free Software Foundation; either version 3 of the License, or
11
   (at your option) any later version.
12
 
13
   This program is distributed in the hope that it will be useful,
14
   but WITHOUT ANY WARRANTY; without even the implied warranty of
15
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16
   GNU General Public License for more details.
17
 
18
   You should have received a copy of the GNU General Public License
19
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
20
 
21
#include "defs.h"
22
#include "arch-utils.h"
23
#include "dis-asm.h"
24
#include "frame.h"
25
#include "frame-base.h"
26
#include "frame-unwind.h"
27
#include "gdbcore.h"
28
#include "gdbtypes.h"
29
#include "regcache.h"
30
#include "regset.h"
31
#include "symtab.h"
32
#include "trad-frame.h"
33
#include "value.h"
34
 
35
#include "gdb_assert.h"
36
#include "gdb_string.h"
37
 
38
#include "m88k-tdep.h"
39
 
40
/* Fetch the instruction at PC.  */
41
 
42
static unsigned long
43
m88k_fetch_instruction (CORE_ADDR pc, enum bfd_endian byte_order)
44
{
45
  return read_memory_unsigned_integer (pc, 4, byte_order);
46
}
47
 
48
/* Register information.  */
49
 
50
/* Return the name of register REGNUM.  */
51
 
52
static const char *
53
m88k_register_name (struct gdbarch *gdbarch, int regnum)
54
{
55
  static char *register_names[] =
56
  {
57
    "r0",  "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
58
    "r8",  "r9",  "r10", "r11", "r12", "r13", "r14", "r15",
59
    "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
60
    "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
61
    "epsr", "fpsr", "fpcr", "sxip", "snip", "sfip"
62
  };
63
 
64
  if (regnum >= 0 && regnum < ARRAY_SIZE (register_names))
65
    return register_names[regnum];
66
 
67
  return NULL;
68
}
69
 
70
/* Return the GDB type object for the "standard" data type of data in
71
   register REGNUM. */
72
 
73
static struct type *
74
m88k_register_type (struct gdbarch *gdbarch, int regnum)
75
{
76
  /* SXIP, SNIP, SFIP and R1 contain code addresses.  */
77
  if ((regnum >= M88K_SXIP_REGNUM && regnum <= M88K_SFIP_REGNUM)
78
      || regnum == M88K_R1_REGNUM)
79
    return builtin_type (gdbarch)->builtin_func_ptr;
80
 
81
  /* R30 and R31 typically contains data addresses.  */
82
  if (regnum == M88K_R30_REGNUM || regnum == M88K_R31_REGNUM)
83
    return builtin_type (gdbarch)->builtin_data_ptr;
84
 
85
  return builtin_type (gdbarch)->builtin_int32;
86
}
87
 
88
 
89
static CORE_ADDR
90
m88k_addr_bits_remove (struct gdbarch *gdbarch, CORE_ADDR addr)
91
{
92
  /* All instructures are 4-byte aligned.  The lower 2 bits of SXIP,
93
     SNIP and SFIP are used for special purposes: bit 0 is the
94
     exception bit and bit 1 is the valid bit.  */
95
  return addr & ~0x3;
96
}
97
 
98
/* Use the program counter to determine the contents and size of a
99
   breakpoint instruction.  Return a pointer to a string of bytes that
100
   encode a breakpoint instruction, store the length of the string in
101
   *LEN and optionally adjust *PC to point to the correct memory
102
   location for inserting the breakpoint.  */
103
 
104
static const gdb_byte *
105
m88k_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pc, int *len)
106
{
107
  /* tb 0,r0,511 */
108
  static gdb_byte break_insn[] = { 0xf0, 0x00, 0xd1, 0xff };
109
 
110
  *len = sizeof (break_insn);
111
  return break_insn;
112
}
113
 
114
static CORE_ADDR
115
m88k_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
116
{
117
  CORE_ADDR pc;
118
 
119
  pc = frame_unwind_register_unsigned (next_frame, M88K_SXIP_REGNUM);
120
  return m88k_addr_bits_remove (gdbarch, pc);
121
}
122
 
123
static void
124
m88k_write_pc (struct regcache *regcache, CORE_ADDR pc)
125
{
126
  /* According to the MC88100 RISC Microprocessor User's Manual,
127
     section 6.4.3.1.2:
128
 
129
     "... can be made to return to a particular instruction by placing
130
     a valid instruction address in the SNIP and the next sequential
131
     instruction address in the SFIP (with V bits set and E bits
132
     clear).  The rte resumes execution at the instruction pointed to
133
     by the SNIP, then the SFIP."
134
 
135
     The E bit is the least significant bit (bit 0).  The V (valid)
136
     bit is bit 1.  This is why we logical or 2 into the values we are
137
     writing below.  It turns out that SXIP plays no role when
138
     returning from an exception so nothing special has to be done
139
     with it.  We could even (presumably) give it a totally bogus
140
     value.  */
141
 
142
  regcache_cooked_write_unsigned (regcache, M88K_SXIP_REGNUM, pc);
143
  regcache_cooked_write_unsigned (regcache, M88K_SNIP_REGNUM, pc | 2);
144
  regcache_cooked_write_unsigned (regcache, M88K_SFIP_REGNUM, (pc + 4) | 2);
145
}
146
 
147
 
148
/* The functions on this page are intended to be used to classify
149
   function arguments.  */
150
 
151
/* Check whether TYPE is "Integral or Pointer".  */
152
 
153
static int
154
m88k_integral_or_pointer_p (const struct type *type)
155
{
156
  switch (TYPE_CODE (type))
157
    {
158
    case TYPE_CODE_INT:
159
    case TYPE_CODE_BOOL:
160
    case TYPE_CODE_CHAR:
161
    case TYPE_CODE_ENUM:
162
    case TYPE_CODE_RANGE:
163
      {
164
        /* We have byte, half-word, word and extended-word/doubleword
165
           integral types.  */
166
        int len = TYPE_LENGTH (type);
167
        return (len == 1 || len == 2 || len == 4 || len == 8);
168
      }
169
      return 1;
170
    case TYPE_CODE_PTR:
171
    case TYPE_CODE_REF:
172
      {
173
        /* Allow only 32-bit pointers.  */
174
        return (TYPE_LENGTH (type) == 4);
175
      }
176
      return 1;
177
    default:
178
      break;
179
    }
180
 
181
  return 0;
182
}
183
 
184
/* Check whether TYPE is "Floating".  */
185
 
186
static int
187
m88k_floating_p (const struct type *type)
188
{
189
  switch (TYPE_CODE (type))
190
    {
191
    case TYPE_CODE_FLT:
192
      {
193
        int len = TYPE_LENGTH (type);
194
        return (len == 4 || len == 8);
195
      }
196
    default:
197
      break;
198
    }
199
 
200
  return 0;
201
}
202
 
203
/* Check whether TYPE is "Structure or Union".  */
204
 
205
static int
206
m88k_structure_or_union_p (const struct type *type)
207
{
208
  switch (TYPE_CODE (type))
209
    {
210
    case TYPE_CODE_STRUCT:
211
    case TYPE_CODE_UNION:
212
      return 1;
213
    default:
214
      break;
215
    }
216
 
217
  return 0;
218
}
219
 
220
/* Check whether TYPE has 8-byte alignment.  */
221
 
222
static int
223
m88k_8_byte_align_p (struct type *type)
224
{
225
  if (m88k_structure_or_union_p (type))
226
    {
227
      int i;
228
 
229
      for (i = 0; i < TYPE_NFIELDS (type); i++)
230
        {
231
          struct type *subtype = check_typedef (TYPE_FIELD_TYPE (type, i));
232
 
233
          if (m88k_8_byte_align_p (subtype))
234
            return 1;
235
        }
236
    }
237
 
238
  if (m88k_integral_or_pointer_p (type) || m88k_floating_p (type))
239
    return (TYPE_LENGTH (type) == 8);
240
 
241
  return 0;
242
}
243
 
244
/* Check whether TYPE can be passed in a register.  */
245
 
246
static int
247
m88k_in_register_p (struct type *type)
248
{
249
  if (m88k_integral_or_pointer_p (type) || m88k_floating_p (type))
250
    return 1;
251
 
252
  if (m88k_structure_or_union_p (type) && TYPE_LENGTH (type) == 4)
253
    return 1;
254
 
255
  return 0;
256
}
257
 
258
static CORE_ADDR
259
m88k_store_arguments (struct regcache *regcache, int nargs,
260
                      struct value **args, CORE_ADDR sp)
261
{
262
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
263
  int num_register_words = 0;
264
  int num_stack_words = 0;
265
  int i;
266
 
267
  for (i = 0; i < nargs; i++)
268
    {
269
      struct type *type = value_type (args[i]);
270
      int len = TYPE_LENGTH (type);
271
 
272
      if (m88k_integral_or_pointer_p (type) && len < 4)
273
        {
274
          args[i] = value_cast (builtin_type (gdbarch)->builtin_int32,
275
                                args[i]);
276
          type = value_type (args[i]);
277
          len = TYPE_LENGTH (type);
278
        }
279
 
280
      if (m88k_in_register_p (type))
281
        {
282
          int num_words = 0;
283
 
284
          if (num_register_words % 2 == 1 && m88k_8_byte_align_p (type))
285
            num_words++;
286
 
287
          num_words += ((len + 3) / 4);
288
          if (num_register_words + num_words <= 8)
289
            {
290
              num_register_words += num_words;
291
              continue;
292
            }
293
 
294
          /* We've run out of available registers.  Pass the argument
295
             on the stack.  */
296
        }
297
 
298
      if (num_stack_words % 2 == 1 && m88k_8_byte_align_p (type))
299
        num_stack_words++;
300
 
301
      num_stack_words += ((len + 3) / 4);
302
    }
303
 
304
  /* Allocate stack space.  */
305
  sp = align_down (sp - 32 - num_stack_words * 4, 16);
306
  num_stack_words = num_register_words = 0;
307
 
308
  for (i = 0; i < nargs; i++)
309
    {
310
      const bfd_byte *valbuf = value_contents (args[i]);
311
      struct type *type = value_type (args[i]);
312
      int len = TYPE_LENGTH (type);
313
      int stack_word = num_stack_words;
314
 
315
      if (m88k_in_register_p (type))
316
        {
317
          int register_word = num_register_words;
318
 
319
          if (register_word % 2 == 1 && m88k_8_byte_align_p (type))
320
            register_word++;
321
 
322
          gdb_assert (len == 4 || len == 8);
323
 
324
          if (register_word + len / 8 < 8)
325
            {
326
              int regnum = M88K_R2_REGNUM + register_word;
327
 
328
              regcache_raw_write (regcache, regnum, valbuf);
329
              if (len > 4)
330
                regcache_raw_write (regcache, regnum + 1, valbuf + 4);
331
 
332
              num_register_words = (register_word + len / 4);
333
              continue;
334
            }
335
        }
336
 
337
      if (stack_word % 2 == -1 && m88k_8_byte_align_p (type))
338
        stack_word++;
339
 
340
      write_memory (sp + stack_word * 4, valbuf, len);
341
      num_stack_words = (stack_word + (len + 3) / 4);
342
    }
343
 
344
  return sp;
345
}
346
 
347
static CORE_ADDR
348
m88k_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
349
                      struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
350
                      struct value **args, CORE_ADDR sp, int struct_return,
351
                      CORE_ADDR struct_addr)
352
{
353
  /* Set up the function arguments.  */
354
  sp = m88k_store_arguments (regcache, nargs, args, sp);
355
  gdb_assert (sp % 16 == 0);
356
 
357
  /* Store return value address.  */
358
  if (struct_return)
359
    regcache_raw_write_unsigned (regcache, M88K_R12_REGNUM, struct_addr);
360
 
361
  /* Store the stack pointer and return address in the appropriate
362
     registers.  */
363
  regcache_raw_write_unsigned (regcache, M88K_R31_REGNUM, sp);
364
  regcache_raw_write_unsigned (regcache, M88K_R1_REGNUM, bp_addr);
365
 
366
  /* Return the stack pointer.  */
367
  return sp;
368
}
369
 
370
static struct frame_id
371
m88k_dummy_id (struct gdbarch *arch, struct frame_info *this_frame)
372
{
373
  CORE_ADDR sp;
374
 
375
  sp = get_frame_register_unsigned (this_frame, M88K_R31_REGNUM);
376
  return frame_id_build (sp, get_frame_pc (this_frame));
377
}
378
 
379
 
380
/* Determine, for architecture GDBARCH, how a return value of TYPE
381
   should be returned.  If it is supposed to be returned in registers,
382
   and READBUF is non-zero, read the appropriate value from REGCACHE,
383
   and copy it into READBUF.  If WRITEBUF is non-zero, write the value
384
   from WRITEBUF into REGCACHE.  */
385
 
386
static enum return_value_convention
387
m88k_return_value (struct gdbarch *gdbarch, struct type *func_type,
388
                   struct type *type, struct regcache *regcache,
389
                   gdb_byte *readbuf, const gdb_byte *writebuf)
390
{
391
  int len = TYPE_LENGTH (type);
392
  gdb_byte buf[8];
393
 
394
  if (!m88k_integral_or_pointer_p (type) && !m88k_floating_p (type))
395
    return RETURN_VALUE_STRUCT_CONVENTION;
396
 
397
  if (readbuf)
398
    {
399
      /* Read the contents of R2 and (if necessary) R3.  */
400
      regcache_cooked_read (regcache, M88K_R2_REGNUM, buf);
401
      if (len > 4)
402
        {
403
          regcache_cooked_read (regcache, M88K_R3_REGNUM, buf + 4);
404
          gdb_assert (len == 8);
405
          memcpy (readbuf, buf, len);
406
        }
407
      else
408
        {
409
          /* Just stripping off any unused bytes should preserve the
410
             signed-ness just fine.  */
411
          memcpy (readbuf, buf + 4 - len, len);
412
        }
413
    }
414
 
415
  if (writebuf)
416
    {
417
      /* Read the contents to R2 and (if necessary) R3.  */
418
      if (len > 4)
419
        {
420
          gdb_assert (len == 8);
421
          memcpy (buf, writebuf, 8);
422
          regcache_cooked_write (regcache, M88K_R3_REGNUM, buf + 4);
423
        }
424
      else
425
        {
426
          /* ??? Do we need to do any sign-extension here?  */
427
          memcpy (buf + 4 - len, writebuf, len);
428
        }
429
      regcache_cooked_write (regcache, M88K_R2_REGNUM, buf);
430
    }
431
 
432
  return RETURN_VALUE_REGISTER_CONVENTION;
433
}
434
 
435
/* Default frame unwinder.  */
436
 
437
struct m88k_frame_cache
438
{
439
  /* Base address.  */
440
  CORE_ADDR base;
441
  CORE_ADDR pc;
442
 
443
  int sp_offset;
444
  int fp_offset;
445
 
446
  /* Table of saved registers.  */
447
  struct trad_frame_saved_reg *saved_regs;
448
};
449
 
450
/* Prologue analysis.  */
451
 
452
/* Macros for extracting fields from instructions.  */
453
 
454
#define BITMASK(pos, width) (((0x1 << (width)) - 1) << (pos))
455
#define EXTRACT_FIELD(val, pos, width) ((val) >> (pos) & BITMASK (0, width))
456
#define SUBU_OFFSET(x)  ((unsigned)(x & 0xFFFF))
457
#define ST_OFFSET(x)    ((unsigned)((x) & 0xFFFF))
458
#define ST_SRC(x)       EXTRACT_FIELD ((x), 21, 5)
459
#define ADDU_OFFSET(x)  ((unsigned)(x & 0xFFFF))
460
 
461
/* Possible actions to be taken by the prologue analyzer for the
462
   instructions it encounters.  */
463
 
464
enum m88k_prologue_insn_action
465
{
466
  M88K_PIA_SKIP,                /* Ignore.  */
467
  M88K_PIA_NOTE_ST,             /* Note register store.  */
468
  M88K_PIA_NOTE_STD,            /* Note register pair store.  */
469
  M88K_PIA_NOTE_SP_ADJUSTMENT,  /* Note stack pointer adjustment.  */
470
  M88K_PIA_NOTE_FP_ASSIGNMENT,  /* Note frame pointer assignment.  */
471
  M88K_PIA_NOTE_BRANCH,         /* Note branch.  */
472
  M88K_PIA_NOTE_PROLOGUE_END    /* Note end of prologue.  */
473
};
474
 
475
/* Table of instructions that may comprise a function prologue.  */
476
 
477
struct m88k_prologue_insn
478
{
479
  unsigned long insn;
480
  unsigned long mask;
481
  enum m88k_prologue_insn_action action;
482
};
483
 
484
struct m88k_prologue_insn m88k_prologue_insn_table[] =
485
{
486
  /* Various register move instructions.  */
487
  { 0x58000000, 0xf800ffff, M88K_PIA_SKIP },     /* or/or.u with immed of 0 */
488
  { 0xf4005800, 0xfc1fffe0, M88K_PIA_SKIP },     /* or rd,r0,rs */
489
  { 0xf4005800, 0xfc00ffff, M88K_PIA_SKIP },     /* or rd,rs,r0 */
490
 
491
  /* Various other instructions.  */
492
  { 0x58000000, 0xf8000000, M88K_PIA_SKIP },     /* or/or.u */
493
 
494
  /* Stack pointer setup: "subu sp,sp,n" where n is a multiple of 8.  */
495
  { 0x67ff0000, 0xffff0007, M88K_PIA_NOTE_SP_ADJUSTMENT },
496
 
497
  /* Frame pointer assignment: "addu r30,r31,n".  */
498
  { 0x63df0000, 0xffff0000, M88K_PIA_NOTE_FP_ASSIGNMENT },
499
 
500
  /* Store to stack instructions; either "st rx,sp,n" or "st.d rx,sp,n".  */
501
  { 0x241f0000, 0xfc1f0000, M88K_PIA_NOTE_ST },  /* st rx,sp,n */
502
  { 0x201f0000, 0xfc1f0000, M88K_PIA_NOTE_STD }, /* st.d rs,sp,n */
503
 
504
  /* Instructions needed for setting up r25 for pic code.  */
505
  { 0x5f200000, 0xffff0000, M88K_PIA_SKIP },     /* or.u r25,r0,offset_high */
506
  { 0xcc000002, 0xffffffff, M88K_PIA_SKIP },     /* bsr.n Lab */
507
  { 0x5b390000, 0xffff0000, M88K_PIA_SKIP },     /* or r25,r25,offset_low */
508
  { 0xf7396001, 0xffffffff, M88K_PIA_SKIP },     /* Lab: addu r25,r25,r1 */
509
 
510
  /* Various branch or jump instructions which have a delay slot --
511
     these do not form part of the prologue, but the instruction in
512
     the delay slot might be a store instruction which should be
513
     noted.  */
514
  { 0xc4000000, 0xe4000000, M88K_PIA_NOTE_BRANCH },
515
                                      /* br.n, bsr.n, bb0.n, or bb1.n */
516
  { 0xec000000, 0xfc000000, M88K_PIA_NOTE_BRANCH }, /* bcnd.n */
517
  { 0xf400c400, 0xfffff7e0, M88K_PIA_NOTE_BRANCH }, /* jmp.n or jsr.n */
518
 
519
  /* Catch all.  Ends prologue analysis.  */
520
  { 0x00000000, 0x00000000, M88K_PIA_NOTE_PROLOGUE_END }
521
};
522
 
523
/* Do a full analysis of the function prologue at PC and update CACHE
524
   accordingly.  Bail out early if LIMIT is reached.  Return the
525
   address where the analysis stopped.  If LIMIT points beyond the
526
   function prologue, the return address should be the end of the
527
   prologue.  */
528
 
529
static CORE_ADDR
530
m88k_analyze_prologue (struct gdbarch *gdbarch,
531
                       CORE_ADDR pc, CORE_ADDR limit,
532
                       struct m88k_frame_cache *cache)
533
{
534
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
535
  CORE_ADDR end = limit;
536
 
537
  /* Provide a dummy cache if necessary.  */
538
  if (cache == NULL)
539
    {
540
      size_t sizeof_saved_regs =
541
        (M88K_R31_REGNUM + 1) * sizeof (struct trad_frame_saved_reg);
542
 
543
      cache = alloca (sizeof (struct m88k_frame_cache));
544
      cache->saved_regs = alloca (sizeof_saved_regs);
545
 
546
      /* We only initialize the members we care about.  */
547
      cache->saved_regs[M88K_R1_REGNUM].addr = -1;
548
      cache->fp_offset = -1;
549
    }
550
 
551
  while (pc < limit)
552
    {
553
      struct m88k_prologue_insn *pi = m88k_prologue_insn_table;
554
      unsigned long insn = m88k_fetch_instruction (pc, byte_order);
555
 
556
      while ((insn & pi->mask) != pi->insn)
557
        pi++;
558
 
559
      switch (pi->action)
560
        {
561
        case M88K_PIA_SKIP:
562
          /* If we have a frame pointer, and R1 has been saved,
563
             consider this instruction as not being part of the
564
             prologue.  */
565
          if (cache->fp_offset != -1
566
              && cache->saved_regs[M88K_R1_REGNUM].addr != -1)
567
            return min (pc, end);
568
          break;
569
 
570
        case M88K_PIA_NOTE_ST:
571
        case M88K_PIA_NOTE_STD:
572
          /* If no frame has been allocated, the stores aren't part of
573
             the prologue.  */
574
          if (cache->sp_offset == 0)
575
            return min (pc, end);
576
 
577
          /* Record location of saved registers.  */
578
          {
579
            int regnum = ST_SRC (insn) + M88K_R0_REGNUM;
580
            ULONGEST offset = ST_OFFSET (insn);
581
 
582
            cache->saved_regs[regnum].addr = offset;
583
            if (pi->action == M88K_PIA_NOTE_STD && regnum < M88K_R31_REGNUM)
584
              cache->saved_regs[regnum + 1].addr = offset + 4;
585
          }
586
          break;
587
 
588
        case M88K_PIA_NOTE_SP_ADJUSTMENT:
589
          /* A second stack pointer adjustment isn't part of the
590
             prologue.  */
591
          if (cache->sp_offset != 0)
592
            return min (pc, end);
593
 
594
          /* Store stack pointer adjustment.  */
595
          cache->sp_offset = -SUBU_OFFSET (insn);
596
          break;
597
 
598
        case M88K_PIA_NOTE_FP_ASSIGNMENT:
599
          /* A second frame pointer assignment isn't part of the
600
             prologue.  */
601
          if (cache->fp_offset != -1)
602
            return min (pc, end);
603
 
604
          /* Record frame pointer assignment.  */
605
          cache->fp_offset = ADDU_OFFSET (insn);
606
          break;
607
 
608
        case M88K_PIA_NOTE_BRANCH:
609
          /* The branch instruction isn't part of the prologue, but
610
             the instruction in the delay slot might be.  Limit the
611
             prologue analysis to the delay slot and record the branch
612
             instruction as the end of the prologue.  */
613
          limit = min (limit, pc + 2 * M88K_INSN_SIZE);
614
          end = pc;
615
          break;
616
 
617
        case M88K_PIA_NOTE_PROLOGUE_END:
618
          return min (pc, end);
619
        }
620
 
621
      pc += M88K_INSN_SIZE;
622
    }
623
 
624
  return end;
625
}
626
 
627
/* An upper limit to the size of the prologue.  */
628
const int m88k_max_prologue_size = 128 * M88K_INSN_SIZE;
629
 
630
/* Return the address of first real instruction of the function
631
   starting at PC.  */
632
 
633
static CORE_ADDR
634
m88k_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
635
{
636
  struct symtab_and_line sal;
637
  CORE_ADDR func_start, func_end;
638
 
639
  /* This is the preferred method, find the end of the prologue by
640
     using the debugging information.  */
641
  if (find_pc_partial_function (pc, NULL, &func_start, &func_end))
642
    {
643
      sal = find_pc_line (func_start, 0);
644
 
645
      if (sal.end < func_end && pc <= sal.end)
646
        return sal.end;
647
    }
648
 
649
  return m88k_analyze_prologue (gdbarch, pc, pc + m88k_max_prologue_size,
650
                                NULL);
651
}
652
 
653
static struct m88k_frame_cache *
654
m88k_frame_cache (struct frame_info *this_frame, void **this_cache)
655
{
656
  struct gdbarch *gdbarch = get_frame_arch (this_frame);
657
  struct m88k_frame_cache *cache;
658
  CORE_ADDR frame_sp;
659
 
660
  if (*this_cache)
661
    return *this_cache;
662
 
663
  cache = FRAME_OBSTACK_ZALLOC (struct m88k_frame_cache);
664
  cache->saved_regs = trad_frame_alloc_saved_regs (this_frame);
665
  cache->fp_offset = -1;
666
 
667
  cache->pc = get_frame_func (this_frame);
668
  if (cache->pc != 0)
669
    m88k_analyze_prologue (gdbarch, cache->pc, get_frame_pc (this_frame),
670
                           cache);
671
 
672
  /* Calculate the stack pointer used in the prologue.  */
673
  if (cache->fp_offset != -1)
674
    {
675
      CORE_ADDR fp;
676
 
677
      fp = get_frame_register_unsigned (this_frame, M88K_R30_REGNUM);
678
      frame_sp = fp - cache->fp_offset;
679
    }
680
  else
681
    {
682
      /* If we know where the return address is saved, we can take a
683
         solid guess at what the frame pointer should be.  */
684
      if (cache->saved_regs[M88K_R1_REGNUM].addr != -1)
685
        cache->fp_offset = cache->saved_regs[M88K_R1_REGNUM].addr - 4;
686
      frame_sp = get_frame_register_unsigned (this_frame, M88K_R31_REGNUM);
687
    }
688
 
689
  /* Now that we know the stack pointer, adjust the location of the
690
     saved registers.  */
691
  {
692
    int regnum;
693
 
694
    for (regnum = M88K_R0_REGNUM; regnum < M88K_R31_REGNUM; regnum ++)
695
      if (cache->saved_regs[regnum].addr != -1)
696
        cache->saved_regs[regnum].addr += frame_sp;
697
  }
698
 
699
  /* Calculate the frame's base.  */
700
  cache->base = frame_sp - cache->sp_offset;
701
  trad_frame_set_value (cache->saved_regs, M88K_R31_REGNUM, cache->base);
702
 
703
  /* Identify SXIP with the return address in R1.  */
704
  cache->saved_regs[M88K_SXIP_REGNUM] = cache->saved_regs[M88K_R1_REGNUM];
705
 
706
  *this_cache = cache;
707
  return cache;
708
}
709
 
710
static void
711
m88k_frame_this_id (struct frame_info *this_frame, void **this_cache,
712
                    struct frame_id *this_id)
713
{
714
  struct m88k_frame_cache *cache = m88k_frame_cache (this_frame, this_cache);
715
 
716
  /* This marks the outermost frame.  */
717
  if (cache->base == 0)
718
    return;
719
 
720
  (*this_id) = frame_id_build (cache->base, cache->pc);
721
}
722
 
723
static struct value *
724
m88k_frame_prev_register (struct frame_info *this_frame,
725
                          void **this_cache, int regnum)
726
{
727
  struct m88k_frame_cache *cache = m88k_frame_cache (this_frame, this_cache);
728
 
729
  if (regnum == M88K_SNIP_REGNUM || regnum == M88K_SFIP_REGNUM)
730
    {
731
      struct value *value;
732
      CORE_ADDR pc;
733
 
734
      value = trad_frame_get_prev_register (this_frame, cache->saved_regs,
735
                                            M88K_SXIP_REGNUM);
736
      pc = value_as_long (value);
737
      release_value (value);
738
      value_free (value);
739
 
740
      if (regnum == M88K_SFIP_REGNUM)
741
        pc += 4;
742
 
743
      return frame_unwind_got_constant (this_frame, regnum, pc + 4);
744
    }
745
 
746
  return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);
747
}
748
 
749
static const struct frame_unwind m88k_frame_unwind =
750
{
751
  NORMAL_FRAME,
752
  m88k_frame_this_id,
753
  m88k_frame_prev_register,
754
  NULL,
755
  default_frame_sniffer
756
};
757
 
758
 
759
static CORE_ADDR
760
m88k_frame_base_address (struct frame_info *this_frame, void **this_cache)
761
{
762
  struct m88k_frame_cache *cache = m88k_frame_cache (this_frame, this_cache);
763
 
764
  if (cache->fp_offset != -1)
765
    return cache->base + cache->sp_offset + cache->fp_offset;
766
 
767
  return 0;
768
}
769
 
770
static const struct frame_base m88k_frame_base =
771
{
772
  &m88k_frame_unwind,
773
  m88k_frame_base_address,
774
  m88k_frame_base_address,
775
  m88k_frame_base_address
776
};
777
 
778
 
779
/* Core file support.  */
780
 
781
/* Supply register REGNUM from the buffer specified by GREGS and LEN
782
   in the general-purpose register set REGSET to register cache
783
   REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
784
 
785
static void
786
m88k_supply_gregset (const struct regset *regset,
787
                     struct regcache *regcache,
788
                     int regnum, const void *gregs, size_t len)
789
{
790
  const gdb_byte *regs = gregs;
791
  int i;
792
 
793
  for (i = 0; i < M88K_NUM_REGS; i++)
794
    {
795
      if (regnum == i || regnum == -1)
796
        regcache_raw_supply (regcache, i, regs + i * 4);
797
    }
798
}
799
 
800
/* Motorola 88000 register set.  */
801
 
802
static struct regset m88k_gregset =
803
{
804
  NULL,
805
  m88k_supply_gregset
806
};
807
 
808
/* Return the appropriate register set for the core section identified
809
   by SECT_NAME and SECT_SIZE.  */
810
 
811
static const struct regset *
812
m88k_regset_from_core_section (struct gdbarch *gdbarch,
813
                               const char *sect_name, size_t sect_size)
814
{
815
  if (strcmp (sect_name, ".reg") == 0 && sect_size >= M88K_NUM_REGS * 4)
816
    return &m88k_gregset;
817
 
818
  return NULL;
819
}
820
 
821
 
822
static struct gdbarch *
823
m88k_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
824
{
825
  struct gdbarch *gdbarch;
826
 
827
  /* If there is already a candidate, use it.  */
828
  arches = gdbarch_list_lookup_by_info (arches, &info);
829
  if (arches != NULL)
830
    return arches->gdbarch;
831
 
832
  /* Allocate space for the new architecture.  */
833
  gdbarch = gdbarch_alloc (&info, NULL);
834
 
835
  /* There is no real `long double'.  */
836
  set_gdbarch_long_double_bit (gdbarch, 64);
837
  set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
838
 
839
  set_gdbarch_num_regs (gdbarch, M88K_NUM_REGS);
840
  set_gdbarch_register_name (gdbarch, m88k_register_name);
841
  set_gdbarch_register_type (gdbarch, m88k_register_type);
842
 
843
  /* Register numbers of various important registers.  */
844
  set_gdbarch_sp_regnum (gdbarch, M88K_R31_REGNUM);
845
  set_gdbarch_pc_regnum (gdbarch, M88K_SXIP_REGNUM);
846
 
847
  /* Core file support.  */
848
  set_gdbarch_regset_from_core_section
849
    (gdbarch, m88k_regset_from_core_section);
850
 
851
  set_gdbarch_print_insn (gdbarch, print_insn_m88k);
852
 
853
  set_gdbarch_skip_prologue (gdbarch, m88k_skip_prologue);
854
 
855
  /* Stack grows downward.  */
856
  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
857
 
858
  /* Call dummy code.  */
859
  set_gdbarch_push_dummy_call (gdbarch, m88k_push_dummy_call);
860
  set_gdbarch_dummy_id (gdbarch, m88k_dummy_id);
861
 
862
  /* Return value info */
863
  set_gdbarch_return_value (gdbarch, m88k_return_value);
864
 
865
  set_gdbarch_addr_bits_remove (gdbarch, m88k_addr_bits_remove);
866
  set_gdbarch_breakpoint_from_pc (gdbarch, m88k_breakpoint_from_pc);
867
  set_gdbarch_unwind_pc (gdbarch, m88k_unwind_pc);
868
  set_gdbarch_write_pc (gdbarch, m88k_write_pc);
869
 
870
  frame_base_set_default (gdbarch, &m88k_frame_base);
871
  frame_unwind_append_unwinder (gdbarch, &m88k_frame_unwind);
872
 
873
  return gdbarch;
874
}
875
 
876
 
877
/* Provide a prototype to silence -Wmissing-prototypes.  */
878
void _initialize_m88k_tdep (void);
879
 
880
void
881
_initialize_m88k_tdep (void)
882
{
883
  gdbarch_register (bfd_arch_m88k, m88k_gdbarch_init, NULL);
884
}

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.