aboutsummaryrefslogtreecommitdiff
path: root/gdb/ft32-tdep.c
blob: 57c1bbba0c4d7c3519846e02abff07d69172f78e (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
/* Target-dependent code for FT32.

   Copyright (C) 2009-2020 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 3 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, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "frame.h"
#include "frame-unwind.h"
#include "frame-base.h"
#include "symtab.h"
#include "gdbtypes.h"
#include "gdbcmd.h"
#include "gdbcore.h"
#include "value.h"
#include "inferior.h"
#include "symfile.h"
#include "objfiles.h"
#include "osabi.h"
#include "language.h"
#include "arch-utils.h"
#include "regcache.h"
#include "trad-frame.h"
#include "dis-asm.h"
#include "record.h"

#include "opcode/ft32.h"

#include "ft32-tdep.h"
#include "gdb/sim-ft32.h"
#include <algorithm>

#define RAM_BIAS  0x800000  /* Bias added to RAM addresses.  */

/* Use an invalid address -1 as 'not available' marker.  */
enum { REG_UNAVAIL = (CORE_ADDR) (-1) };

struct ft32_frame_cache
{
  /* Base address of the frame */
  CORE_ADDR base;
  /* Function this frame belongs to */
  CORE_ADDR pc;
  /* Total size of this frame */
  LONGEST framesize;
  /* Saved registers in this frame */
  CORE_ADDR saved_regs[FT32_NUM_REGS];
  /* Saved SP in this frame */
  CORE_ADDR saved_sp;
  /* Has the new frame been LINKed.  */
  bfd_boolean established;
};

/* Implement the "frame_align" gdbarch method.  */

static CORE_ADDR
ft32_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp)
{
  /* Align to the size of an instruction (so that they can safely be
     pushed onto the stack.  */
  return sp & ~1;
}


constexpr gdb_byte ft32_break_insn[] = { 0x02, 0x00, 0x34, 0x00 };

typedef BP_MANIPULATION (ft32_break_insn) ft32_breakpoint;

/* FT32 register names.  */

static const char *const ft32_register_names[] =
{
    "fp", "sp",
    "r0", "r1", "r2", "r3",  "r4", "r5", "r6", "r7",
    "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
    "r16", "r17", "r18", "r19",  "r20", "r21", "r22", "r23",
    "r24", "r25", "r26", "r27", "r28", "cc",
    "pc"
};

/* Implement the "register_name" gdbarch method.  */

static const char *
ft32_register_name (struct gdbarch *gdbarch, int reg_nr)
{
  if (reg_nr < 0)
    return NULL;
  if (reg_nr >= FT32_NUM_REGS)
    return NULL;
  return ft32_register_names[reg_nr];
}

/* Implement the "register_type" gdbarch method.  */

static struct type *
ft32_register_type (struct gdbarch *gdbarch, int reg_nr)
{
  if (reg_nr == FT32_PC_REGNUM)
    return gdbarch_tdep (gdbarch)->pc_type;
  else if (reg_nr == FT32_SP_REGNUM || reg_nr == FT32_FP_REGNUM)
    return builtin_type (gdbarch)->builtin_data_ptr;
  else
    return builtin_type (gdbarch)->builtin_int32;
}

/* Write into appropriate registers a function return value
   of type TYPE, given in virtual format.  */

static void
ft32_store_return_value (struct type *type, struct regcache *regcache,
			 const gdb_byte *valbuf)
{
  struct gdbarch *gdbarch = regcache->arch ();
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  CORE_ADDR regval;
  int len = TYPE_LENGTH (type);

  /* Things always get returned in RET1_REGNUM, RET2_REGNUM.  */
  regval = extract_unsigned_integer (valbuf, len > 4 ? 4 : len, byte_order);
  regcache_cooked_write_unsigned (regcache, FT32_R0_REGNUM, regval);
  if (len > 4)
    {
      regval = extract_unsigned_integer (valbuf + 4,
					 len - 4, byte_order);
      regcache_cooked_write_unsigned (regcache, FT32_R1_REGNUM, regval);
    }
}

/* Fetch a single 32-bit instruction from address a. If memory contains
   a compressed instruction pair, return the expanded instruction.  */

static ULONGEST
ft32_fetch_instruction (CORE_ADDR a, int *isize,
		        enum bfd_endian byte_order)
{
  unsigned int sc[2];
  ULONGEST inst;

  CORE_ADDR a4 = a & ~3;
  inst = read_code_unsigned_integer (a4, 4, byte_order);
  *isize = ft32_decode_shortcode (a4, inst, sc) ? 2 : 4;
  if (*isize == 2)
    return sc[1 & (a >> 1)];
  else
    return inst;
}

/* Decode the instructions within the given address range.  Decide
   when we must have reached the end of the function prologue.  If a
   frame_info pointer is provided, fill in its saved_regs etc.

   Returns the address of the first instruction after the prologue.  */

static CORE_ADDR
ft32_analyze_prologue (CORE_ADDR start_addr, CORE_ADDR end_addr,
		       struct ft32_frame_cache *cache,
		       struct gdbarch *gdbarch)
{
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  CORE_ADDR next_addr;
  ULONGEST inst;
  int isize = 0;
  int regnum, pushreg;
  struct bound_minimal_symbol msymbol;
  const int first_saved_reg = 13;	/* The first saved register.  */
  /* PROLOGS are addresses of the subroutine prologs, PROLOGS[n]
     is the address of __prolog_$rN.
     __prolog_$rN pushes registers from 13 through n inclusive.
     So for example CALL __prolog_$r15 is equivalent to:
       PUSH $r13 
       PUSH $r14 
       PUSH $r15 
     Note that PROLOGS[0] through PROLOGS[12] are unused.  */
  CORE_ADDR prologs[32];

  cache->saved_regs[FT32_PC_REGNUM] = 0;
  cache->framesize = 0;

  for (regnum = first_saved_reg; regnum < 32; regnum++)
    {
      char prolog_symbol[32];

      snprintf (prolog_symbol, sizeof (prolog_symbol), "__prolog_$r%02d",
		regnum);
      msymbol = lookup_minimal_symbol (prolog_symbol, NULL, NULL);
      if (msymbol.minsym)
	prologs[regnum] = BMSYMBOL_VALUE_ADDRESS (msymbol);
      else
	prologs[regnum] = 0;
    }

  if (start_addr >= end_addr)
    return end_addr;

  cache->established = 0;
  for (next_addr = start_addr; next_addr < end_addr; next_addr += isize)
    {
      inst = ft32_fetch_instruction (next_addr, &isize, byte_order);

      if (FT32_IS_PUSH (inst))
	{
	  pushreg = FT32_PUSH_REG (inst);
	  cache->framesize += 4;
	  cache->saved_regs[FT32_R0_REGNUM + pushreg] = cache->framesize;
	}
      else if (FT32_IS_CALL (inst))
	{
	  for (regnum = first_saved_reg; regnum < 32; regnum++)
	    {
	      if ((4 * (inst & 0x3ffff)) == prologs[regnum])
		{
		  for (pushreg = first_saved_reg; pushreg <= regnum;
		       pushreg++)
		    {
		      cache->framesize += 4;
		      cache->saved_regs[FT32_R0_REGNUM + pushreg] =
			cache->framesize;
		    }
		}
	    }
	  break;
	}
      else
	break;
    }
  for (regnum = FT32_R0_REGNUM; regnum < FT32_PC_REGNUM; regnum++)
    {
      if (cache->saved_regs[regnum] != REG_UNAVAIL)
	cache->saved_regs[regnum] =
	  cache->framesize - cache->saved_regs[regnum];
    }
  cache->saved_regs[FT32_PC_REGNUM] = cache->framesize;

  /* It is a LINK?  */
  if (next_addr < end_addr)
    {
      inst = ft32_fetch_instruction (next_addr, &isize, byte_order);
      if (FT32_IS_LINK (inst))
	{
	  cache->established = 1;
	  for (regnum = FT32_R0_REGNUM; regnum < FT32_PC_REGNUM; regnum++)
	    {
	      if (cache->saved_regs[regnum] != REG_UNAVAIL)
		cache->saved_regs[regnum] += 4;
	    }
	  cache->saved_regs[FT32_PC_REGNUM] = cache->framesize + 4;
	  cache->saved_regs[FT32_FP_REGNUM] = 0;
	  cache->framesize += FT32_LINK_SIZE (inst);
	  next_addr += isize;
	}
    }

  return next_addr;
}

/* Find the end of function prologue.  */

static CORE_ADDR
ft32_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
{
  CORE_ADDR func_addr = 0, func_end = 0;
  const char *func_name;

  /* See if we can determine the end of the prologue via the symbol table.
     If so, then return either PC, or the PC after the prologue, whichever
     is greater.  */
  if (find_pc_partial_function (pc, &func_name, &func_addr, &func_end))
    {
      CORE_ADDR post_prologue_pc
	= skip_prologue_using_sal (gdbarch, func_addr);
      if (post_prologue_pc != 0)
	return std::max (pc, post_prologue_pc);
      else
	{
	  /* Can't determine prologue from the symbol table, need to examine
	     instructions.  */
	  struct symtab_and_line sal;
	  struct symbol *sym;
	  struct ft32_frame_cache cache;
	  CORE_ADDR plg_end;

	  memset (&cache, 0, sizeof cache);

	  plg_end = ft32_analyze_prologue (func_addr,
					   func_end, &cache, gdbarch);
	  /* Found a function.  */
	  sym = lookup_symbol (func_name, NULL, VAR_DOMAIN, NULL).symbol;
	  /* Don't use line number debug info for assembly source files.  */
	  if ((sym != NULL) && sym->language () != language_asm)
	    {
	      sal = find_pc_line (func_addr, 0);
	      if (sal.end && sal.end < func_end)
		{
		  /* Found a line number, use it as end of prologue.  */
		  return sal.end;
		}
	    }
	  /* No useable line symbol.  Use result of prologue parsing method.  */
	  return plg_end;
	}
    }

  /* No function symbol -- just return the PC.  */
  return pc;
}

/* Implementation of `pointer_to_address' gdbarch method.

   On FT32 address space zero is RAM, address space 1 is flash.
   RAM appears at address RAM_BIAS, flash at address 0.  */

static CORE_ADDR
ft32_pointer_to_address (struct gdbarch *gdbarch,
			 struct type *type, const gdb_byte *buf)
{
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  CORE_ADDR addr
    = extract_unsigned_integer (buf, TYPE_LENGTH (type), byte_order);

  if (TYPE_ADDRESS_CLASS_1 (type))
    return addr;
  else
    return addr | RAM_BIAS;
}

/* Implementation of `address_class_type_flags' gdbarch method.

   This method maps DW_AT_address_class attributes to a
   type_instance_flag_value.  */

static type_instance_flags
ft32_address_class_type_flags (int byte_size, int dwarf2_addr_class)
{
  /* The value 1 of the DW_AT_address_class attribute corresponds to the
     __flash__ qualifier, meaning pointer to data in FT32 program memory.
   */
  if (dwarf2_addr_class == 1)
    return TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1;
  return 0;
}

/* Implementation of `address_class_type_flags_to_name' gdbarch method.

   Convert a type_instance_flag_value to an address space qualifier.  */

static const char*
ft32_address_class_type_flags_to_name (struct gdbarch *gdbarch,
				       type_instance_flags type_flags)
{
  if (type_flags & TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1)
    return "flash";
  else
    return NULL;
}

/* Implementation of `address_class_name_to_type_flags' gdbarch method.

   Convert an address space qualifier to a type_instance_flag_value.  */

static bool
ft32_address_class_name_to_type_flags (struct gdbarch *gdbarch,
				       const char* name,
				       type_instance_flags *type_flags_ptr)
{
  if (strcmp (name, "flash") == 0)
    {
      *type_flags_ptr = TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1;
      return true;
    }
  else
    return false;
}

/* Given a return value in `regbuf' with a type `valtype',
   extract and copy its value into `valbuf'.  */

static void
ft32_extract_return_value (struct type *type, struct regcache *regcache,
			   gdb_byte *dst)
{
  struct gdbarch *gdbarch = regcache->arch ();
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  bfd_byte *valbuf = dst;
  int len = TYPE_LENGTH (type);
  ULONGEST tmp;

  /* By using store_unsigned_integer we avoid having to do
     anything special for small big-endian values.  */
  regcache_cooked_read_unsigned (regcache, FT32_R0_REGNUM, &tmp);
  store_unsigned_integer (valbuf, (len > 4 ? len - 4 : len), byte_order, tmp);

  /* Ignore return values more than 8 bytes in size because the ft32
     returns anything more than 8 bytes in the stack.  */
  if (len > 4)
    {
      regcache_cooked_read_unsigned (regcache, FT32_R1_REGNUM, &tmp);
      store_unsigned_integer (valbuf + len - 4, 4, byte_order, tmp);
    }
}

/* Implement the "return_value" gdbarch method.  */

static enum return_value_convention
ft32_return_value (struct gdbarch *gdbarch, struct value *function,
		   struct type *valtype, struct regcache *regcache,
		   gdb_byte *readbuf, const gdb_byte *writebuf)
{
  if (TYPE_LENGTH (valtype) > 8)
    return RETURN_VALUE_STRUCT_CONVENTION;
  else
    {
      if (readbuf != NULL)
	ft32_extract_return_value (valtype, regcache, readbuf);
      if (writebuf != NULL)
	ft32_store_return_value (valtype, regcache, writebuf);
      return RETURN_VALUE_REGISTER_CONVENTION;
    }
}

/* Allocate and initialize a ft32_frame_cache object.  */

static struct ft32_frame_cache *
ft32_alloc_frame_cache (void)
{
  struct ft32_frame_cache *cache;
  int i;

  cache = FRAME_OBSTACK_ZALLOC (struct ft32_frame_cache);

  for (i = 0; i < FT32_NUM_REGS; ++i)
    cache->saved_regs[i] = REG_UNAVAIL;

  return cache;
}

/* Populate a ft32_frame_cache object for this_frame.  */

static struct ft32_frame_cache *
ft32_frame_cache (struct frame_info *this_frame, void **this_cache)
{
  struct ft32_frame_cache *cache;
  CORE_ADDR current_pc;
  int i;

  if (*this_cache)
    return (struct ft32_frame_cache *) *this_cache;

  cache = ft32_alloc_frame_cache ();
  *this_cache = cache;

  cache->base = get_frame_register_unsigned (this_frame, FT32_FP_REGNUM);
  if (cache->base == 0)
    return cache;

  cache->pc = get_frame_func (this_frame);
  current_pc = get_frame_pc (this_frame);
  if (cache->pc)
    {
      struct gdbarch *gdbarch = get_frame_arch (this_frame);

      ft32_analyze_prologue (cache->pc, current_pc, cache, gdbarch);
      if (!cache->established)
	cache->base = get_frame_register_unsigned (this_frame, FT32_SP_REGNUM);
    }

  cache->saved_sp = cache->base - 4;

  for (i = 0; i < FT32_NUM_REGS; ++i)
    if (cache->saved_regs[i] != REG_UNAVAIL)
      cache->saved_regs[i] = cache->base + cache->saved_regs[i];

  return cache;
}

/* Given a GDB frame, determine the address of the calling function's
   frame.  This will be used to create a new GDB frame struct.  */

static void
ft32_frame_this_id (struct frame_info *this_frame,
		    void **this_prologue_cache, struct frame_id *this_id)
{
  struct ft32_frame_cache *cache = ft32_frame_cache (this_frame,
						     this_prologue_cache);

  /* This marks the outermost frame.  */
  if (cache->base == 0)
    return;

  *this_id = frame_id_build (cache->saved_sp, cache->pc);
}

/* Get the value of register regnum in the previous stack frame.  */

static struct value *
ft32_frame_prev_register (struct frame_info *this_frame,
			  void **this_prologue_cache, int regnum)
{
  struct ft32_frame_cache *cache = ft32_frame_cache (this_frame,
						     this_prologue_cache);

  gdb_assert (regnum >= 0);

  if (regnum == FT32_SP_REGNUM && cache->saved_sp)
    return frame_unwind_got_constant (this_frame, regnum, cache->saved_sp);

  if (regnum < FT32_NUM_REGS && cache->saved_regs[regnum] != REG_UNAVAIL)
      return frame_unwind_got_memory (this_frame, regnum,
				      RAM_BIAS | cache->saved_regs[regnum]);

  return frame_unwind_got_register (this_frame, regnum, regnum);
}

static const struct frame_unwind ft32_frame_unwind =
{
  NORMAL_FRAME,
  default_frame_unwind_stop_reason,
  ft32_frame_this_id,
  ft32_frame_prev_register,
  NULL,
  default_frame_sniffer
};

/* Return the base address of this_frame.  */

static CORE_ADDR
ft32_frame_base_address (struct frame_info *this_frame, void **this_cache)
{
  struct ft32_frame_cache *cache = ft32_frame_cache (this_frame,
						     this_cache);

  return cache->base;
}

static const struct frame_base ft32_frame_base =
{
  &ft32_frame_unwind,
  ft32_frame_base_address,
  ft32_frame_base_address,
  ft32_frame_base_address
};

/* Allocate and initialize the ft32 gdbarch object.  */

static struct gdbarch *
ft32_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
{
  struct gdbarch *gdbarch;
  struct gdbarch_tdep *tdep;
  struct type *void_type;
  struct type *func_void_type;

  /* If there is already a candidate, use it.  */
  arches = gdbarch_list_lookup_by_info (arches, &info);
  if (arches != NULL)
    return arches->gdbarch;

  /* Allocate space for the new architecture.  */
  tdep = XCNEW (struct gdbarch_tdep);
  gdbarch = gdbarch_alloc (&info, tdep);

  /* Create a type for PC.  We can't use builtin types here, as they may not
     be defined.  */
  void_type = arch_type (gdbarch, TYPE_CODE_VOID, TARGET_CHAR_BIT, "void");
  func_void_type = make_function_type (void_type, NULL);
  tdep->pc_type = arch_pointer_type (gdbarch, 4 * TARGET_CHAR_BIT, NULL,
				     func_void_type);
  tdep->pc_type->set_instance_flags (tdep->pc_type->instance_flags ()
				     | TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1);

  set_gdbarch_num_regs (gdbarch, FT32_NUM_REGS);
  set_gdbarch_sp_regnum (gdbarch, FT32_SP_REGNUM);
  set_gdbarch_pc_regnum (gdbarch, FT32_PC_REGNUM);
  set_gdbarch_register_name (gdbarch, ft32_register_name);
  set_gdbarch_register_type (gdbarch, ft32_register_type);

  set_gdbarch_return_value (gdbarch, ft32_return_value);

  set_gdbarch_pointer_to_address (gdbarch, ft32_pointer_to_address);

  set_gdbarch_skip_prologue (gdbarch, ft32_skip_prologue);
  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
  set_gdbarch_breakpoint_kind_from_pc (gdbarch, ft32_breakpoint::kind_from_pc);
  set_gdbarch_sw_breakpoint_from_kind (gdbarch, ft32_breakpoint::bp_from_kind);
  set_gdbarch_frame_align (gdbarch, ft32_frame_align);

  frame_base_set_default (gdbarch, &ft32_frame_base);

  /* Hook in ABI-specific overrides, if they have been registered.  */
  gdbarch_init_osabi (info, gdbarch);

  /* Hook in the default unwinders.  */
  frame_unwind_append_unwinder (gdbarch, &ft32_frame_unwind);

  /* Support simple overlay manager.  */
  set_gdbarch_overlay_update (gdbarch, simple_overlay_update);

  set_gdbarch_address_class_type_flags (gdbarch, ft32_address_class_type_flags);
  set_gdbarch_address_class_name_to_type_flags
    (gdbarch, ft32_address_class_name_to_type_flags);
  set_gdbarch_address_class_type_flags_to_name
    (gdbarch, ft32_address_class_type_flags_to_name);

  return gdbarch;
}

/* Register this machine's init routine.  */

void _initialize_ft32_tdep ();
void
_initialize_ft32_tdep ()
{
  register_gdbarch_init (bfd_arch_ft32, ft32_gdbarch_init);
}