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[/] [openrisc/] [trunk/] [gnu-src/] [gdb-7.1/] [gdb/] [m32r-tdep.c] - Blame information for rev 452

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1 227 jeremybenn
/* Target-dependent code for Renesas M32R, for GDB.
2
 
3
   Copyright (C) 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007,
4
   2008, 2009, 2010 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 "frame.h"
23
#include "frame-unwind.h"
24
#include "frame-base.h"
25
#include "symtab.h"
26
#include "gdbtypes.h"
27
#include "gdbcmd.h"
28
#include "gdbcore.h"
29
#include "gdb_string.h"
30
#include "value.h"
31
#include "inferior.h"
32
#include "symfile.h"
33
#include "objfiles.h"
34
#include "osabi.h"
35
#include "language.h"
36
#include "arch-utils.h"
37
#include "regcache.h"
38
#include "trad-frame.h"
39
#include "dis-asm.h"
40
 
41
#include "gdb_assert.h"
42
 
43
#include "m32r-tdep.h"
44
 
45
/* Local functions */
46
 
47
extern void _initialize_m32r_tdep (void);
48
 
49
static CORE_ADDR
50
m32r_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp)
51
{
52
  /* Align to the size of an instruction (so that they can safely be
53
     pushed onto the stack.  */
54
  return sp & ~3;
55
}
56
 
57
 
58
/* Breakpoints
59
 
60
   The little endian mode of M32R is unique. In most of architectures,
61
   two 16-bit instructions, A and B, are placed as the following:
62
 
63
   Big endian:
64
   A0 A1 B0 B1
65
 
66
   Little endian:
67
   A1 A0 B1 B0
68
 
69
   In M32R, they are placed like this:
70
 
71
   Big endian:
72
   A0 A1 B0 B1
73
 
74
   Little endian:
75
   B1 B0 A1 A0
76
 
77
   This is because M32R always fetches instructions in 32-bit.
78
 
79
   The following functions take care of this behavior. */
80
 
81
static int
82
m32r_memory_insert_breakpoint (struct gdbarch *gdbarch,
83
                               struct bp_target_info *bp_tgt)
84
{
85
  CORE_ADDR addr = bp_tgt->placed_address;
86
  int val;
87
  gdb_byte buf[4];
88
  gdb_byte *contents_cache = bp_tgt->shadow_contents;
89
  gdb_byte bp_entry[] = { 0x10, 0xf1 }; /* dpt */
90
 
91
  /* Save the memory contents.  */
92
  val = target_read_memory (addr & 0xfffffffc, contents_cache, 4);
93
  if (val != 0)
94
    return val;                 /* return error */
95
 
96
  bp_tgt->placed_size = bp_tgt->shadow_len = 4;
97
 
98
  /* Determine appropriate breakpoint contents and size for this address.  */
99
  if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
100
    {
101
      if ((addr & 3) == 0)
102
        {
103
          buf[0] = bp_entry[0];
104
          buf[1] = bp_entry[1];
105
          buf[2] = contents_cache[2] & 0x7f;
106
          buf[3] = contents_cache[3];
107
        }
108
      else
109
        {
110
          buf[0] = contents_cache[0];
111
          buf[1] = contents_cache[1];
112
          buf[2] = bp_entry[0];
113
          buf[3] = bp_entry[1];
114
        }
115
    }
116
  else                          /* little-endian */
117
    {
118
      if ((addr & 3) == 0)
119
        {
120
          buf[0] = contents_cache[0];
121
          buf[1] = contents_cache[1] & 0x7f;
122
          buf[2] = bp_entry[1];
123
          buf[3] = bp_entry[0];
124
        }
125
      else
126
        {
127
          buf[0] = bp_entry[1];
128
          buf[1] = bp_entry[0];
129
          buf[2] = contents_cache[2];
130
          buf[3] = contents_cache[3];
131
        }
132
    }
133
 
134
  /* Write the breakpoint.  */
135
  val = target_write_memory (addr & 0xfffffffc, buf, 4);
136
  return val;
137
}
138
 
139
static int
140
m32r_memory_remove_breakpoint (struct gdbarch *gdbarch,
141
                               struct bp_target_info *bp_tgt)
142
{
143
  CORE_ADDR addr = bp_tgt->placed_address;
144
  int val;
145
  gdb_byte buf[4];
146
  gdb_byte *contents_cache = bp_tgt->shadow_contents;
147
 
148
  buf[0] = contents_cache[0];
149
  buf[1] = contents_cache[1];
150
  buf[2] = contents_cache[2];
151
  buf[3] = contents_cache[3];
152
 
153
  /* Remove parallel bit.  */
154
  if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
155
    {
156
      if ((buf[0] & 0x80) == 0 && (buf[2] & 0x80) != 0)
157
        buf[2] &= 0x7f;
158
    }
159
  else                          /* little-endian */
160
    {
161
      if ((buf[3] & 0x80) == 0 && (buf[1] & 0x80) != 0)
162
        buf[1] &= 0x7f;
163
    }
164
 
165
  /* Write contents.  */
166
  val = target_write_memory (addr & 0xfffffffc, buf, 4);
167
  return val;
168
}
169
 
170
static const gdb_byte *
171
m32r_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr, int *lenptr)
172
{
173
  static gdb_byte be_bp_entry[] = { 0x10, 0xf1, 0x70, 0x00 };   /* dpt -> nop */
174
  static gdb_byte le_bp_entry[] = { 0x00, 0x70, 0xf1, 0x10 };   /* dpt -> nop */
175
  gdb_byte *bp;
176
 
177
  /* Determine appropriate breakpoint.  */
178
  if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG)
179
    {
180
      if ((*pcptr & 3) == 0)
181
        {
182
          bp = be_bp_entry;
183
          *lenptr = 4;
184
        }
185
      else
186
        {
187
          bp = be_bp_entry;
188
          *lenptr = 2;
189
        }
190
    }
191
  else
192
    {
193
      if ((*pcptr & 3) == 0)
194
        {
195
          bp = le_bp_entry;
196
          *lenptr = 4;
197
        }
198
      else
199
        {
200
          bp = le_bp_entry + 2;
201
          *lenptr = 2;
202
        }
203
    }
204
 
205
  return bp;
206
}
207
 
208
 
209
char *m32r_register_names[] = {
210
  "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
211
  "r8", "r9", "r10", "r11", "r12", "fp", "lr", "sp",
212
  "psw", "cbr", "spi", "spu", "bpc", "pc", "accl", "acch",
213
  "evb"
214
};
215
 
216
static const char *
217
m32r_register_name (struct gdbarch *gdbarch, int reg_nr)
218
{
219
  if (reg_nr < 0)
220
    return NULL;
221
  if (reg_nr >= M32R_NUM_REGS)
222
    return NULL;
223
  return m32r_register_names[reg_nr];
224
}
225
 
226
 
227
/* Return the GDB type object for the "standard" data type
228
   of data in register N.  */
229
 
230
static struct type *
231
m32r_register_type (struct gdbarch *gdbarch, int reg_nr)
232
{
233
  if (reg_nr == M32R_PC_REGNUM)
234
    return builtin_type (gdbarch)->builtin_func_ptr;
235
  else if (reg_nr == M32R_SP_REGNUM || reg_nr == M32R_FP_REGNUM)
236
    return builtin_type (gdbarch)->builtin_data_ptr;
237
  else
238
    return builtin_type (gdbarch)->builtin_int32;
239
}
240
 
241
 
242
/* Write into appropriate registers a function return value
243
   of type TYPE, given in virtual format.
244
 
245
   Things always get returned in RET1_REGNUM, RET2_REGNUM. */
246
 
247
static void
248
m32r_store_return_value (struct type *type, struct regcache *regcache,
249
                         const void *valbuf)
250
{
251
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
252
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
253
  CORE_ADDR regval;
254
  int len = TYPE_LENGTH (type);
255
 
256
  regval = extract_unsigned_integer (valbuf, len > 4 ? 4 : len, byte_order);
257
  regcache_cooked_write_unsigned (regcache, RET1_REGNUM, regval);
258
 
259
  if (len > 4)
260
    {
261
      regval = extract_unsigned_integer ((gdb_byte *) valbuf + 4,
262
                                         len - 4, byte_order);
263
      regcache_cooked_write_unsigned (regcache, RET1_REGNUM + 1, regval);
264
    }
265
}
266
 
267
/* This is required by skip_prologue. The results of decoding a prologue
268
   should be cached because this thrashing is getting nuts.  */
269
 
270
static int
271
decode_prologue (struct gdbarch *gdbarch,
272
                 CORE_ADDR start_pc, CORE_ADDR scan_limit,
273
                 CORE_ADDR *pl_endptr, unsigned long *framelength)
274
{
275
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
276
  unsigned long framesize;
277
  int insn;
278
  int op1;
279
  CORE_ADDR after_prologue = 0;
280
  CORE_ADDR after_push = 0;
281
  CORE_ADDR after_stack_adjust = 0;
282
  CORE_ADDR current_pc;
283
  LONGEST return_value;
284
 
285
  framesize = 0;
286
  after_prologue = 0;
287
 
288
  for (current_pc = start_pc; current_pc < scan_limit; current_pc += 2)
289
    {
290
      /* Check if current pc's location is readable. */
291
      if (!safe_read_memory_integer (current_pc, 2, byte_order, &return_value))
292
        return -1;
293
 
294
      insn = read_memory_unsigned_integer (current_pc, 2, byte_order);
295
 
296
      if (insn == 0x0000)
297
        break;
298
 
299
      /* If this is a 32 bit instruction, we dont want to examine its
300
         immediate data as though it were an instruction */
301
      if (current_pc & 0x02)
302
        {
303
          /* decode this instruction further */
304
          insn &= 0x7fff;
305
        }
306
      else
307
        {
308
          if (insn & 0x8000)
309
            {
310
              if (current_pc == scan_limit)
311
                scan_limit += 2;        /* extend the search */
312
 
313
              current_pc += 2;  /* skip the immediate data */
314
 
315
              /* Check if current pc's location is readable. */
316
              if (!safe_read_memory_integer (current_pc, 2, byte_order,
317
                                             &return_value))
318
                return -1;
319
 
320
              if (insn == 0x8faf)       /* add3 sp, sp, xxxx */
321
                /* add 16 bit sign-extended offset */
322
                {
323
                  framesize +=
324
                    -((short) read_memory_unsigned_integer (current_pc,
325
                                                            2, byte_order));
326
                }
327
              else
328
                {
329
                  if (((insn >> 8) == 0xe4)     /* ld24 r4, xxxxxx; sub sp, r4 */
330
                      && safe_read_memory_integer (current_pc + 2,
331
                                                   2, byte_order,
332
                                                   &return_value)
333
                      && read_memory_unsigned_integer (current_pc + 2,
334
                                                       2, byte_order)
335
                         == 0x0f24)
336
                    /* subtract 24 bit sign-extended negative-offset */
337
                    {
338
                      insn = read_memory_unsigned_integer (current_pc - 2,
339
                                                           4, byte_order);
340
                      if (insn & 0x00800000)    /* sign extend */
341
                        insn |= 0xff000000;     /* negative */
342
                      else
343
                        insn &= 0x00ffffff;     /* positive */
344
                      framesize += insn;
345
                    }
346
                }
347
              after_push = current_pc + 2;
348
              continue;
349
            }
350
        }
351
      op1 = insn & 0xf000;      /* isolate just the first nibble */
352
 
353
      if ((insn & 0xf0ff) == 0x207f)
354
        {                       /* st reg, @-sp */
355
          int regno;
356
          framesize += 4;
357
          regno = ((insn >> 8) & 0xf);
358
          after_prologue = 0;
359
          continue;
360
        }
361
      if ((insn >> 8) == 0x4f)  /* addi sp, xx */
362
        /* add 8 bit sign-extended offset */
363
        {
364
          int stack_adjust = (signed char) (insn & 0xff);
365
 
366
          /* there are probably two of these stack adjustments:
367
             1) A negative one in the prologue, and
368
             2) A positive one in the epilogue.
369
             We are only interested in the first one.  */
370
 
371
          if (stack_adjust < 0)
372
            {
373
              framesize -= stack_adjust;
374
              after_prologue = 0;
375
              /* A frameless function may have no "mv fp, sp".
376
                 In that case, this is the end of the prologue.  */
377
              after_stack_adjust = current_pc + 2;
378
            }
379
          continue;
380
        }
381
      if (insn == 0x1d8f)
382
        {                       /* mv fp, sp */
383
          after_prologue = current_pc + 2;
384
          break;                /* end of stack adjustments */
385
        }
386
 
387
      /* Nop looks like a branch, continue explicitly */
388
      if (insn == 0x7000)
389
        {
390
          after_prologue = current_pc + 2;
391
          continue;             /* nop occurs between pushes */
392
        }
393
      /* End of prolog if any of these are trap instructions */
394
      if ((insn & 0xfff0) == 0x10f0)
395
        {
396
          after_prologue = current_pc;
397
          break;
398
        }
399
      /* End of prolog if any of these are branch instructions */
400
      if ((op1 == 0x7000) || (op1 == 0xb000) || (op1 == 0xf000))
401
        {
402
          after_prologue = current_pc;
403
          continue;
404
        }
405
      /* Some of the branch instructions are mixed with other types */
406
      if (op1 == 0x1000)
407
        {
408
          int subop = insn & 0x0ff0;
409
          if ((subop == 0x0ec0) || (subop == 0x0fc0))
410
            {
411
              after_prologue = current_pc;
412
              continue;         /* jmp , jl */
413
            }
414
        }
415
    }
416
 
417
  if (framelength)
418
    *framelength = framesize;
419
 
420
  if (current_pc >= scan_limit)
421
    {
422
      if (pl_endptr)
423
        {
424
          if (after_stack_adjust != 0)
425
            /* We did not find a "mv fp,sp", but we DID find
426
               a stack_adjust.  Is it safe to use that as the
427
               end of the prologue?  I just don't know. */
428
            {
429
              *pl_endptr = after_stack_adjust;
430
            }
431
          else if (after_push != 0)
432
            /* We did not find a "mv fp,sp", but we DID find
433
               a push.  Is it safe to use that as the
434
               end of the prologue?  I just don't know. */
435
            {
436
              *pl_endptr = after_push;
437
            }
438
          else
439
            /* We reached the end of the loop without finding the end
440
               of the prologue.  No way to win -- we should report failure.
441
               The way we do that is to return the original start_pc.
442
               GDB will set a breakpoint at the start of the function (etc.) */
443
            *pl_endptr = start_pc;
444
        }
445
      return 0;
446
    }
447
 
448
  if (after_prologue == 0)
449
    after_prologue = current_pc;
450
 
451
  if (pl_endptr)
452
    *pl_endptr = after_prologue;
453
 
454
  return 0;
455
}                               /*  decode_prologue */
456
 
457
/* Function: skip_prologue
458
   Find end of function prologue */
459
 
460
#define DEFAULT_SEARCH_LIMIT 128
461
 
462
static CORE_ADDR
463
m32r_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
464
{
465
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
466
  CORE_ADDR func_addr, func_end;
467
  struct symtab_and_line sal;
468
  LONGEST return_value;
469
 
470
  /* See what the symbol table says */
471
 
472
  if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
473
    {
474
      sal = find_pc_line (func_addr, 0);
475
 
476
      if (sal.line != 0 && sal.end <= func_end)
477
        {
478
          func_end = sal.end;
479
        }
480
      else
481
        /* Either there's no line info, or the line after the prologue is after
482
           the end of the function.  In this case, there probably isn't a
483
           prologue.  */
484
        {
485
          func_end = min (func_end, func_addr + DEFAULT_SEARCH_LIMIT);
486
        }
487
    }
488
  else
489
    func_end = pc + DEFAULT_SEARCH_LIMIT;
490
 
491
  /* If pc's location is not readable, just quit. */
492
  if (!safe_read_memory_integer (pc, 4, byte_order, &return_value))
493
    return pc;
494
 
495
  /* Find the end of prologue.  */
496
  if (decode_prologue (gdbarch, pc, func_end, &sal.end, NULL) < 0)
497
    return pc;
498
 
499
  return sal.end;
500
}
501
 
502
struct m32r_unwind_cache
503
{
504
  /* The previous frame's inner most stack address.  Used as this
505
     frame ID's stack_addr.  */
506
  CORE_ADDR prev_sp;
507
  /* The frame's base, optionally used by the high-level debug info.  */
508
  CORE_ADDR base;
509
  int size;
510
  /* How far the SP and r13 (FP) have been offset from the start of
511
     the stack frame (as defined by the previous frame's stack
512
     pointer).  */
513
  LONGEST sp_offset;
514
  LONGEST r13_offset;
515
  int uses_frame;
516
  /* Table indicating the location of each and every register.  */
517
  struct trad_frame_saved_reg *saved_regs;
518
};
519
 
520
/* Put here the code to store, into fi->saved_regs, the addresses of
521
   the saved registers of frame described by FRAME_INFO.  This
522
   includes special registers such as pc and fp saved in special ways
523
   in the stack frame.  sp is even more special: the address we return
524
   for it IS the sp for the next frame. */
525
 
526
static struct m32r_unwind_cache *
527
m32r_frame_unwind_cache (struct frame_info *this_frame,
528
                         void **this_prologue_cache)
529
{
530
  CORE_ADDR pc, scan_limit;
531
  ULONGEST prev_sp;
532
  ULONGEST this_base;
533
  unsigned long op, op2;
534
  int i;
535
  struct m32r_unwind_cache *info;
536
 
537
 
538
  if ((*this_prologue_cache))
539
    return (*this_prologue_cache);
540
 
541
  info = FRAME_OBSTACK_ZALLOC (struct m32r_unwind_cache);
542
  (*this_prologue_cache) = info;
543
  info->saved_regs = trad_frame_alloc_saved_regs (this_frame);
544
 
545
  info->size = 0;
546
  info->sp_offset = 0;
547
  info->uses_frame = 0;
548
 
549
  scan_limit = get_frame_pc (this_frame);
550
  for (pc = get_frame_func (this_frame);
551
       pc > 0 && pc < scan_limit; pc += 2)
552
    {
553
      if ((pc & 2) == 0)
554
        {
555
          op = get_frame_memory_unsigned (this_frame, pc, 4);
556
          if ((op & 0x80000000) == 0x80000000)
557
            {
558
              /* 32-bit instruction */
559
              if ((op & 0xffff0000) == 0x8faf0000)
560
                {
561
                  /* add3 sp,sp,xxxx */
562
                  short n = op & 0xffff;
563
                  info->sp_offset += n;
564
                }
565
              else if (((op >> 8) == 0xe4)
566
                       && get_frame_memory_unsigned (this_frame, pc + 2,
567
                                                     2) == 0x0f24)
568
                {
569
                  /* ld24 r4, xxxxxx; sub sp, r4 */
570
                  unsigned long n = op & 0xffffff;
571
                  info->sp_offset += n;
572
                  pc += 2;      /* skip sub instruction */
573
                }
574
 
575
              if (pc == scan_limit)
576
                scan_limit += 2;        /* extend the search */
577
              pc += 2;          /* skip the immediate data */
578
              continue;
579
            }
580
        }
581
 
582
      /* 16-bit instructions */
583
      op = get_frame_memory_unsigned (this_frame, pc, 2) & 0x7fff;
584
      if ((op & 0xf0ff) == 0x207f)
585
        {
586
          /* st rn, @-sp */
587
          int regno = ((op >> 8) & 0xf);
588
          info->sp_offset -= 4;
589
          info->saved_regs[regno].addr = info->sp_offset;
590
        }
591
      else if ((op & 0xff00) == 0x4f00)
592
        {
593
          /* addi sp, xx */
594
          int n = (signed char) (op & 0xff);
595
          info->sp_offset += n;
596
        }
597
      else if (op == 0x1d8f)
598
        {
599
          /* mv fp, sp */
600
          info->uses_frame = 1;
601
          info->r13_offset = info->sp_offset;
602
          break;                /* end of stack adjustments */
603
        }
604
      else if ((op & 0xfff0) == 0x10f0)
605
        {
606
          /* end of prologue if this is a trap instruction */
607
          break;                /* end of stack adjustments */
608
        }
609
    }
610
 
611
  info->size = -info->sp_offset;
612
 
613
  /* Compute the previous frame's stack pointer (which is also the
614
     frame's ID's stack address), and this frame's base pointer.  */
615
  if (info->uses_frame)
616
    {
617
      /* The SP was moved to the FP.  This indicates that a new frame
618
         was created.  Get THIS frame's FP value by unwinding it from
619
         the next frame.  */
620
      this_base = get_frame_register_unsigned (this_frame, M32R_FP_REGNUM);
621
      /* The FP points at the last saved register.  Adjust the FP back
622
         to before the first saved register giving the SP.  */
623
      prev_sp = this_base + info->size;
624
    }
625
  else
626
    {
627
      /* Assume that the FP is this frame's SP but with that pushed
628
         stack space added back.  */
629
      this_base = get_frame_register_unsigned (this_frame, M32R_SP_REGNUM);
630
      prev_sp = this_base + info->size;
631
    }
632
 
633
  /* Convert that SP/BASE into real addresses.  */
634
  info->prev_sp = prev_sp;
635
  info->base = this_base;
636
 
637
  /* Adjust all the saved registers so that they contain addresses and
638
     not offsets.  */
639
  for (i = 0; i < gdbarch_num_regs (get_frame_arch (this_frame)) - 1; i++)
640
    if (trad_frame_addr_p (info->saved_regs, i))
641
      info->saved_regs[i].addr = (info->prev_sp + info->saved_regs[i].addr);
642
 
643
  /* The call instruction moves the caller's PC in the callee's LR.
644
     Since this is an unwind, do the reverse.  Copy the location of LR
645
     into PC (the address / regnum) so that a request for PC will be
646
     converted into a request for the LR.  */
647
  info->saved_regs[M32R_PC_REGNUM] = info->saved_regs[LR_REGNUM];
648
 
649
  /* The previous frame's SP needed to be computed.  Save the computed
650
     value.  */
651
  trad_frame_set_value (info->saved_regs, M32R_SP_REGNUM, prev_sp);
652
 
653
  return info;
654
}
655
 
656
static CORE_ADDR
657
m32r_read_pc (struct regcache *regcache)
658
{
659
  ULONGEST pc;
660
  regcache_cooked_read_unsigned (regcache, M32R_PC_REGNUM, &pc);
661
  return pc;
662
}
663
 
664
static void
665
m32r_write_pc (struct regcache *regcache, CORE_ADDR val)
666
{
667
  regcache_cooked_write_unsigned (regcache, M32R_PC_REGNUM, val);
668
}
669
 
670
static CORE_ADDR
671
m32r_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame)
672
{
673
  return frame_unwind_register_unsigned (next_frame, M32R_SP_REGNUM);
674
}
675
 
676
 
677
static CORE_ADDR
678
m32r_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
679
                      struct regcache *regcache, CORE_ADDR bp_addr, int nargs,
680
                      struct value **args, CORE_ADDR sp, int struct_return,
681
                      CORE_ADDR struct_addr)
682
{
683
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
684
  int stack_offset, stack_alloc;
685
  int argreg = ARG1_REGNUM;
686
  int argnum;
687
  struct type *type;
688
  enum type_code typecode;
689
  CORE_ADDR regval;
690
  gdb_byte *val;
691
  gdb_byte valbuf[MAX_REGISTER_SIZE];
692
  int len;
693
  int odd_sized_struct;
694
 
695
  /* first force sp to a 4-byte alignment */
696
  sp = sp & ~3;
697
 
698
  /* Set the return address.  For the m32r, the return breakpoint is
699
     always at BP_ADDR.  */
700
  regcache_cooked_write_unsigned (regcache, LR_REGNUM, bp_addr);
701
 
702
  /* If STRUCT_RETURN is true, then the struct return address (in
703
     STRUCT_ADDR) will consume the first argument-passing register.
704
     Both adjust the register count and store that value.  */
705
  if (struct_return)
706
    {
707
      regcache_cooked_write_unsigned (regcache, argreg, struct_addr);
708
      argreg++;
709
    }
710
 
711
  /* Now make sure there's space on the stack */
712
  for (argnum = 0, stack_alloc = 0; argnum < nargs; argnum++)
713
    stack_alloc += ((TYPE_LENGTH (value_type (args[argnum])) + 3) & ~3);
714
  sp -= stack_alloc;            /* make room on stack for args */
715
 
716
  for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++)
717
    {
718
      type = value_type (args[argnum]);
719
      typecode = TYPE_CODE (type);
720
      len = TYPE_LENGTH (type);
721
 
722
      memset (valbuf, 0, sizeof (valbuf));
723
 
724
      /* Passes structures that do not fit in 2 registers by reference.  */
725
      if (len > 8
726
          && (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION))
727
        {
728
          store_unsigned_integer (valbuf, 4, byte_order,
729
                                  value_address (args[argnum]));
730
          typecode = TYPE_CODE_PTR;
731
          len = 4;
732
          val = valbuf;
733
        }
734
      else if (len < 4)
735
        {
736
          /* value gets right-justified in the register or stack word */
737
          memcpy (valbuf + (register_size (gdbarch, argreg) - len),
738
                  (gdb_byte *) value_contents (args[argnum]), len);
739
          val = valbuf;
740
        }
741
      else
742
        val = (gdb_byte *) value_contents (args[argnum]);
743
 
744
      while (len > 0)
745
        {
746
          if (argreg > ARGN_REGNUM)
747
            {
748
              /* must go on the stack */
749
              write_memory (sp + stack_offset, val, 4);
750
              stack_offset += 4;
751
            }
752
          else if (argreg <= ARGN_REGNUM)
753
            {
754
              /* there's room in a register */
755
              regval =
756
                extract_unsigned_integer (val,
757
                                          register_size (gdbarch, argreg),
758
                                          byte_order);
759
              regcache_cooked_write_unsigned (regcache, argreg++, regval);
760
            }
761
 
762
          /* Store the value 4 bytes at a time.  This means that things
763
             larger than 4 bytes may go partly in registers and partly
764
             on the stack.  */
765
          len -= register_size (gdbarch, argreg);
766
          val += register_size (gdbarch, argreg);
767
        }
768
    }
769
 
770
  /* Finally, update the SP register.  */
771
  regcache_cooked_write_unsigned (regcache, M32R_SP_REGNUM, sp);
772
 
773
  return sp;
774
}
775
 
776
 
777
/* Given a return value in `regbuf' with a type `valtype',
778
   extract and copy its value into `valbuf'.  */
779
 
780
static void
781
m32r_extract_return_value (struct type *type, struct regcache *regcache,
782
                           void *dst)
783
{
784
  struct gdbarch *gdbarch = get_regcache_arch (regcache);
785
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
786
  bfd_byte *valbuf = dst;
787
  int len = TYPE_LENGTH (type);
788
  ULONGEST tmp;
789
 
790
  /* By using store_unsigned_integer we avoid having to do
791
     anything special for small big-endian values.  */
792
  regcache_cooked_read_unsigned (regcache, RET1_REGNUM, &tmp);
793
  store_unsigned_integer (valbuf, (len > 4 ? len - 4 : len), byte_order, tmp);
794
 
795
  /* Ignore return values more than 8 bytes in size because the m32r
796
     returns anything more than 8 bytes in the stack. */
797
  if (len > 4)
798
    {
799
      regcache_cooked_read_unsigned (regcache, RET1_REGNUM + 1, &tmp);
800
      store_unsigned_integer (valbuf + len - 4, 4, byte_order, tmp);
801
    }
802
}
803
 
804
static enum return_value_convention
805
m32r_return_value (struct gdbarch *gdbarch, struct type *func_type,
806
                   struct type *valtype, struct regcache *regcache,
807
                   gdb_byte *readbuf, const gdb_byte *writebuf)
808
{
809
  if (TYPE_LENGTH (valtype) > 8)
810
    return RETURN_VALUE_STRUCT_CONVENTION;
811
  else
812
    {
813
      if (readbuf != NULL)
814
        m32r_extract_return_value (valtype, regcache, readbuf);
815
      if (writebuf != NULL)
816
        m32r_store_return_value (valtype, regcache, writebuf);
817
      return RETURN_VALUE_REGISTER_CONVENTION;
818
    }
819
}
820
 
821
 
822
 
823
static CORE_ADDR
824
m32r_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
825
{
826
  return frame_unwind_register_unsigned (next_frame, M32R_PC_REGNUM);
827
}
828
 
829
/* Given a GDB frame, determine the address of the calling function's
830
   frame.  This will be used to create a new GDB frame struct.  */
831
 
832
static void
833
m32r_frame_this_id (struct frame_info *this_frame,
834
                    void **this_prologue_cache, struct frame_id *this_id)
835
{
836
  struct m32r_unwind_cache *info
837
    = m32r_frame_unwind_cache (this_frame, this_prologue_cache);
838
  CORE_ADDR base;
839
  CORE_ADDR func;
840
  struct minimal_symbol *msym_stack;
841
  struct frame_id id;
842
 
843
  /* The FUNC is easy.  */
844
  func = get_frame_func (this_frame);
845
 
846
  /* Check if the stack is empty.  */
847
  msym_stack = lookup_minimal_symbol ("_stack", NULL, NULL);
848
  if (msym_stack && info->base == SYMBOL_VALUE_ADDRESS (msym_stack))
849
    return;
850
 
851
  /* Hopefully the prologue analysis either correctly determined the
852
     frame's base (which is the SP from the previous frame), or set
853
     that base to "NULL".  */
854
  base = info->prev_sp;
855
  if (base == 0)
856
    return;
857
 
858
  id = frame_id_build (base, func);
859
  (*this_id) = id;
860
}
861
 
862
static struct value *
863
m32r_frame_prev_register (struct frame_info *this_frame,
864
                          void **this_prologue_cache, int regnum)
865
{
866
  struct m32r_unwind_cache *info
867
    = m32r_frame_unwind_cache (this_frame, this_prologue_cache);
868
  return trad_frame_get_prev_register (this_frame, info->saved_regs, regnum);
869
}
870
 
871
static const struct frame_unwind m32r_frame_unwind = {
872
  NORMAL_FRAME,
873
  m32r_frame_this_id,
874
  m32r_frame_prev_register,
875
  NULL,
876
  default_frame_sniffer
877
};
878
 
879
static CORE_ADDR
880
m32r_frame_base_address (struct frame_info *this_frame, void **this_cache)
881
{
882
  struct m32r_unwind_cache *info
883
    = m32r_frame_unwind_cache (this_frame, this_cache);
884
  return info->base;
885
}
886
 
887
static const struct frame_base m32r_frame_base = {
888
  &m32r_frame_unwind,
889
  m32r_frame_base_address,
890
  m32r_frame_base_address,
891
  m32r_frame_base_address
892
};
893
 
894
/* Assuming THIS_FRAME is a dummy, return the frame ID of that dummy
895
   frame.  The frame ID's base needs to match the TOS value saved by
896
   save_dummy_frame_tos(), and the PC match the dummy frame's breakpoint.  */
897
 
898
static struct frame_id
899
m32r_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
900
{
901
  CORE_ADDR sp = get_frame_register_unsigned (this_frame, M32R_SP_REGNUM);
902
  return frame_id_build (sp, get_frame_pc (this_frame));
903
}
904
 
905
 
906
static gdbarch_init_ftype m32r_gdbarch_init;
907
 
908
static struct gdbarch *
909
m32r_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
910
{
911
  struct gdbarch *gdbarch;
912
  struct gdbarch_tdep *tdep;
913
 
914
  /* If there is already a candidate, use it.  */
915
  arches = gdbarch_list_lookup_by_info (arches, &info);
916
  if (arches != NULL)
917
    return arches->gdbarch;
918
 
919
  /* Allocate space for the new architecture.  */
920
  tdep = XMALLOC (struct gdbarch_tdep);
921
  gdbarch = gdbarch_alloc (&info, tdep);
922
 
923
  set_gdbarch_read_pc (gdbarch, m32r_read_pc);
924
  set_gdbarch_write_pc (gdbarch, m32r_write_pc);
925
  set_gdbarch_unwind_sp (gdbarch, m32r_unwind_sp);
926
 
927
  set_gdbarch_num_regs (gdbarch, M32R_NUM_REGS);
928
  set_gdbarch_sp_regnum (gdbarch, M32R_SP_REGNUM);
929
  set_gdbarch_register_name (gdbarch, m32r_register_name);
930
  set_gdbarch_register_type (gdbarch, m32r_register_type);
931
 
932
  set_gdbarch_push_dummy_call (gdbarch, m32r_push_dummy_call);
933
  set_gdbarch_return_value (gdbarch, m32r_return_value);
934
 
935
  set_gdbarch_skip_prologue (gdbarch, m32r_skip_prologue);
936
  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
937
  set_gdbarch_breakpoint_from_pc (gdbarch, m32r_breakpoint_from_pc);
938
  set_gdbarch_memory_insert_breakpoint (gdbarch,
939
                                        m32r_memory_insert_breakpoint);
940
  set_gdbarch_memory_remove_breakpoint (gdbarch,
941
                                        m32r_memory_remove_breakpoint);
942
 
943
  set_gdbarch_frame_align (gdbarch, m32r_frame_align);
944
 
945
  frame_base_set_default (gdbarch, &m32r_frame_base);
946
 
947
  /* Methods for saving / extracting a dummy frame's ID.  The ID's
948
     stack address must match the SP value returned by
949
     PUSH_DUMMY_CALL, and saved by generic_save_dummy_frame_tos.  */
950
  set_gdbarch_dummy_id (gdbarch, m32r_dummy_id);
951
 
952
  /* Return the unwound PC value.  */
953
  set_gdbarch_unwind_pc (gdbarch, m32r_unwind_pc);
954
 
955
  set_gdbarch_print_insn (gdbarch, print_insn_m32r);
956
 
957
  /* Hook in ABI-specific overrides, if they have been registered.  */
958
  gdbarch_init_osabi (info, gdbarch);
959
 
960
  /* Hook in the default unwinders.  */
961
  frame_unwind_append_unwinder (gdbarch, &m32r_frame_unwind);
962
 
963
  /* Support simple overlay manager.  */
964
  set_gdbarch_overlay_update (gdbarch, simple_overlay_update);
965
 
966
  return gdbarch;
967
}
968
 
969
void
970
_initialize_m32r_tdep (void)
971
{
972
  register_gdbarch_init (bfd_arch_m32r, m32r_gdbarch_init);
973
}

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