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[/] [openrisc/] [trunk/] [gnu-src/] [gdb-6.8/] [gdb/] [avr-tdep.c] - Blame information for rev 157

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1 24 jeremybenn
/* Target-dependent code for Atmel AVR, for GDB.
2
 
3
   Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
4
   2006, 2007, 2008 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
/* Contributed by Theodore A. Roth, troth@openavr.org */
22
 
23
/* Portions of this file were taken from the original gdb-4.18 patch developed
24
   by Denis Chertykov, denisc@overta.ru */
25
 
26
#include "defs.h"
27
#include "frame.h"
28
#include "frame-unwind.h"
29
#include "frame-base.h"
30
#include "trad-frame.h"
31
#include "gdbcmd.h"
32
#include "gdbcore.h"
33
#include "gdbtypes.h"
34
#include "inferior.h"
35
#include "symfile.h"
36
#include "arch-utils.h"
37
#include "regcache.h"
38
#include "gdb_string.h"
39
#include "dis-asm.h"
40
 
41
/* AVR Background:
42
 
43
   (AVR micros are pure Harvard Architecture processors.)
44
 
45
   The AVR family of microcontrollers have three distinctly different memory
46
   spaces: flash, sram and eeprom. The flash is 16 bits wide and is used for
47
   the most part to store program instructions. The sram is 8 bits wide and is
48
   used for the stack and the heap. Some devices lack sram and some can have
49
   an additional external sram added on as a peripheral.
50
 
51
   The eeprom is 8 bits wide and is used to store data when the device is
52
   powered down. Eeprom is not directly accessible, it can only be accessed
53
   via io-registers using a special algorithm. Accessing eeprom via gdb's
54
   remote serial protocol ('m' or 'M' packets) looks difficult to do and is
55
   not included at this time.
56
 
57
   [The eeprom could be read manually via ``x/b <eaddr + AVR_EMEM_START>'' or
58
   written using ``set {unsigned char}<eaddr + AVR_EMEM_START>''.  For this to
59
   work, the remote target must be able to handle eeprom accesses and perform
60
   the address translation.]
61
 
62
   All three memory spaces have physical addresses beginning at 0x0. In
63
   addition, the flash is addressed by gcc/binutils/gdb with respect to 8 bit
64
   bytes instead of the 16 bit wide words used by the real device for the
65
   Program Counter.
66
 
67
   In order for remote targets to work correctly, extra bits must be added to
68
   addresses before they are send to the target or received from the target
69
   via the remote serial protocol. The extra bits are the MSBs and are used to
70
   decode which memory space the address is referring to. */
71
 
72
#undef XMALLOC
73
#define XMALLOC(TYPE) ((TYPE*) xmalloc (sizeof (TYPE)))
74
 
75
#undef EXTRACT_INSN
76
#define EXTRACT_INSN(addr) extract_unsigned_integer(addr,2)
77
 
78
/* Constants: prefixed with AVR_ to avoid name space clashes */
79
 
80
enum
81
{
82
  AVR_REG_W = 24,
83
  AVR_REG_X = 26,
84
  AVR_REG_Y = 28,
85
  AVR_FP_REGNUM = 28,
86
  AVR_REG_Z = 30,
87
 
88
  AVR_SREG_REGNUM = 32,
89
  AVR_SP_REGNUM = 33,
90
  AVR_PC_REGNUM = 34,
91
 
92
  AVR_NUM_REGS = 32 + 1 /*SREG*/ + 1 /*SP*/ + 1 /*PC*/,
93
  AVR_NUM_REG_BYTES = 32 + 1 /*SREG*/ + 2 /*SP*/ + 4 /*PC*/,
94
 
95
  AVR_PC_REG_INDEX = 35,        /* index into array of registers */
96
 
97
  AVR_MAX_PROLOGUE_SIZE = 64,   /* bytes */
98
 
99
  /* Count of pushed registers. From r2 to r17 (inclusively), r28, r29 */
100
  AVR_MAX_PUSHES = 18,
101
 
102
  /* Number of the last pushed register. r17 for current avr-gcc */
103
  AVR_LAST_PUSHED_REGNUM = 17,
104
 
105
  AVR_ARG1_REGNUM = 24,         /* Single byte argument */
106
  AVR_ARGN_REGNUM = 25,         /* Multi byte argments */
107
 
108
  AVR_RET1_REGNUM = 24,         /* Single byte return value */
109
  AVR_RETN_REGNUM = 25,         /* Multi byte return value */
110
 
111
  /* FIXME: TRoth/2002-01-??: Can we shift all these memory masks left 8
112
     bits? Do these have to match the bfd vma values?. It sure would make
113
     things easier in the future if they didn't need to match.
114
 
115
     Note: I chose these values so as to be consistent with bfd vma
116
     addresses.
117
 
118
     TRoth/2002-04-08: There is already a conflict with very large programs
119
     in the mega128. The mega128 has 128K instruction bytes (64K words),
120
     thus the Most Significant Bit is 0x10000 which gets masked off my
121
     AVR_MEM_MASK.
122
 
123
     The problem manifests itself when trying to set a breakpoint in a
124
     function which resides in the upper half of the instruction space and
125
     thus requires a 17-bit address.
126
 
127
     For now, I've just removed the EEPROM mask and changed AVR_MEM_MASK
128
     from 0x00ff0000 to 0x00f00000. Eeprom is not accessible from gdb yet,
129
     but could be for some remote targets by just adding the correct offset
130
     to the address and letting the remote target handle the low-level
131
     details of actually accessing the eeprom. */
132
 
133
  AVR_IMEM_START = 0x00000000,  /* INSN memory */
134
  AVR_SMEM_START = 0x00800000,  /* SRAM memory */
135
#if 1
136
  /* No eeprom mask defined */
137
  AVR_MEM_MASK = 0x00f00000,    /* mask to determine memory space */
138
#else
139
  AVR_EMEM_START = 0x00810000,  /* EEPROM memory */
140
  AVR_MEM_MASK = 0x00ff0000,    /* mask to determine memory space */
141
#endif
142
};
143
 
144
/* Prologue types:
145
 
146
   NORMAL and CALL are the typical types (the -mcall-prologues gcc option
147
   causes the generation of the CALL type prologues).  */
148
 
149
enum {
150
    AVR_PROLOGUE_NONE,              /* No prologue */
151
    AVR_PROLOGUE_NORMAL,
152
    AVR_PROLOGUE_CALL,              /* -mcall-prologues */
153
    AVR_PROLOGUE_MAIN,
154
    AVR_PROLOGUE_INTR,              /* interrupt handler */
155
    AVR_PROLOGUE_SIG,               /* signal handler */
156
};
157
 
158
/* Any function with a frame looks like this
159
   .......    <-SP POINTS HERE
160
   LOCALS1    <-FP POINTS HERE
161
   LOCALS0
162
   SAVED FP
163
   SAVED R3
164
   SAVED R2
165
   RET PC
166
   FIRST ARG
167
   SECOND ARG */
168
 
169
struct avr_unwind_cache
170
{
171
  /* The previous frame's inner most stack address.  Used as this
172
     frame ID's stack_addr.  */
173
  CORE_ADDR prev_sp;
174
  /* The frame's base, optionally used by the high-level debug info.  */
175
  CORE_ADDR base;
176
  int size;
177
  int prologue_type;
178
  /* Table indicating the location of each and every register.  */
179
  struct trad_frame_saved_reg *saved_regs;
180
};
181
 
182
struct gdbarch_tdep
183
{
184
  /* FIXME: TRoth: is there anything to put here? */
185
  int foo;
186
};
187
 
188
/* Lookup the name of a register given it's number. */
189
 
190
static const char *
191
avr_register_name (struct gdbarch *gdbarch, int regnum)
192
{
193
  static char *register_names[] = {
194
    "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
195
    "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
196
    "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
197
    "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
198
    "SREG", "SP", "PC"
199
  };
200
  if (regnum < 0)
201
    return NULL;
202
  if (regnum >= (sizeof (register_names) / sizeof (*register_names)))
203
    return NULL;
204
  return register_names[regnum];
205
}
206
 
207
/* Return the GDB type object for the "standard" data type
208
   of data in register N.  */
209
 
210
static struct type *
211
avr_register_type (struct gdbarch *gdbarch, int reg_nr)
212
{
213
  if (reg_nr == AVR_PC_REGNUM)
214
    return builtin_type_uint32;
215
  if (reg_nr == AVR_SP_REGNUM)
216
    return builtin_type_void_data_ptr;
217
  else
218
    return builtin_type_uint8;
219
}
220
 
221
/* Instruction address checks and convertions. */
222
 
223
static CORE_ADDR
224
avr_make_iaddr (CORE_ADDR x)
225
{
226
  return ((x) | AVR_IMEM_START);
227
}
228
 
229
/* FIXME: TRoth: Really need to use a larger mask for instructions. Some
230
   devices are already up to 128KBytes of flash space.
231
 
232
   TRoth/2002-04-8: See comment above where AVR_IMEM_START is defined. */
233
 
234
static CORE_ADDR
235
avr_convert_iaddr_to_raw (CORE_ADDR x)
236
{
237
  return ((x) & 0xffffffff);
238
}
239
 
240
/* SRAM address checks and convertions. */
241
 
242
static CORE_ADDR
243
avr_make_saddr (CORE_ADDR x)
244
{
245
  return ((x) | AVR_SMEM_START);
246
}
247
 
248
static CORE_ADDR
249
avr_convert_saddr_to_raw (CORE_ADDR x)
250
{
251
  return ((x) & 0xffffffff);
252
}
253
 
254
/* EEPROM address checks and convertions. I don't know if these will ever
255
   actually be used, but I've added them just the same. TRoth */
256
 
257
/* TRoth/2002-04-08: Commented out for now to allow fix for problem with large
258
   programs in the mega128. */
259
 
260
/*  static CORE_ADDR */
261
/*  avr_make_eaddr (CORE_ADDR x) */
262
/*  { */
263
/*    return ((x) | AVR_EMEM_START); */
264
/*  } */
265
 
266
/*  static int */
267
/*  avr_eaddr_p (CORE_ADDR x) */
268
/*  { */
269
/*    return (((x) & AVR_MEM_MASK) == AVR_EMEM_START); */
270
/*  } */
271
 
272
/*  static CORE_ADDR */
273
/*  avr_convert_eaddr_to_raw (CORE_ADDR x) */
274
/*  { */
275
/*    return ((x) & 0xffffffff); */
276
/*  } */
277
 
278
/* Convert from address to pointer and vice-versa. */
279
 
280
static void
281
avr_address_to_pointer (struct type *type, gdb_byte *buf, CORE_ADDR addr)
282
{
283
  /* Is it a code address?  */
284
  if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_FUNC
285
      || TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_METHOD)
286
    {
287
      store_unsigned_integer (buf, TYPE_LENGTH (type),
288
                              avr_convert_iaddr_to_raw (addr >> 1));
289
    }
290
  else
291
    {
292
      /* Strip off any upper segment bits.  */
293
      store_unsigned_integer (buf, TYPE_LENGTH (type),
294
                              avr_convert_saddr_to_raw (addr));
295
    }
296
}
297
 
298
static CORE_ADDR
299
avr_pointer_to_address (struct type *type, const gdb_byte *buf)
300
{
301
  CORE_ADDR addr = extract_unsigned_integer (buf, TYPE_LENGTH (type));
302
 
303
  /* Is it a code address?  */
304
  if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_FUNC
305
      || TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_METHOD
306
      || TYPE_CODE_SPACE (TYPE_TARGET_TYPE (type)))
307
    return avr_make_iaddr (addr << 1);
308
  else
309
    return avr_make_saddr (addr);
310
}
311
 
312
static CORE_ADDR
313
avr_read_pc (struct regcache *regcache)
314
{
315
  ULONGEST pc;
316
  regcache_cooked_read_unsigned (regcache, AVR_PC_REGNUM, &pc);
317
  return avr_make_iaddr (pc);
318
}
319
 
320
static void
321
avr_write_pc (struct regcache *regcache, CORE_ADDR val)
322
{
323
  regcache_cooked_write_unsigned (regcache, AVR_PC_REGNUM,
324
                                  avr_convert_iaddr_to_raw (val));
325
}
326
 
327
static int
328
avr_scan_arg_moves (int vpc, unsigned char *prologue)
329
{
330
  unsigned short insn;
331
 
332
  for (; vpc < AVR_MAX_PROLOGUE_SIZE; vpc += 2)
333
    {
334
      insn = EXTRACT_INSN (&prologue[vpc]);
335
      if ((insn & 0xff00) == 0x0100)    /* movw rXX, rYY */
336
        continue;
337
      else if ((insn & 0xfc00) == 0x2c00) /* mov rXX, rYY */
338
        continue;
339
      else
340
          break;
341
    }
342
 
343
  return vpc;
344
}
345
 
346
/* Function: avr_scan_prologue
347
 
348
   This function decodes an AVR function prologue to determine:
349
     1) the size of the stack frame
350
     2) which registers are saved on it
351
     3) the offsets of saved regs
352
   This information is stored in the avr_unwind_cache structure.
353
 
354
   Some devices lack the sbiw instruction, so on those replace this:
355
        sbiw    r28, XX
356
   with this:
357
        subi    r28,lo8(XX)
358
        sbci    r29,hi8(XX)
359
 
360
   A typical AVR function prologue with a frame pointer might look like this:
361
        push    rXX        ; saved regs
362
        ...
363
        push    r28
364
        push    r29
365
        in      r28,__SP_L__
366
        in      r29,__SP_H__
367
        sbiw    r28,<LOCALS_SIZE>
368
        in      __tmp_reg__,__SREG__
369
        cli
370
        out     __SP_H__,r29
371
        out     __SREG__,__tmp_reg__
372
        out     __SP_L__,r28
373
 
374
   A typical AVR function prologue without a frame pointer might look like
375
   this:
376
        push    rXX        ; saved regs
377
        ...
378
 
379
   A main function prologue looks like this:
380
        ldi     r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>)
381
        ldi     r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>)
382
        out     __SP_H__,r29
383
        out     __SP_L__,r28
384
 
385
   A signal handler prologue looks like this:
386
        push    __zero_reg__
387
        push    __tmp_reg__
388
        in      __tmp_reg__, __SREG__
389
        push    __tmp_reg__
390
        clr     __zero_reg__
391
        push    rXX             ; save registers r18:r27, r30:r31
392
        ...
393
        push    r28             ; save frame pointer
394
        push    r29
395
        in      r28, __SP_L__
396
        in      r29, __SP_H__
397
        sbiw    r28, <LOCALS_SIZE>
398
        out     __SP_H__, r29
399
        out     __SP_L__, r28
400
 
401
   A interrupt handler prologue looks like this:
402
        sei
403
        push    __zero_reg__
404
        push    __tmp_reg__
405
        in      __tmp_reg__, __SREG__
406
        push    __tmp_reg__
407
        clr     __zero_reg__
408
        push    rXX             ; save registers r18:r27, r30:r31
409
        ...
410
        push    r28             ; save frame pointer
411
        push    r29
412
        in      r28, __SP_L__
413
        in      r29, __SP_H__
414
        sbiw    r28, <LOCALS_SIZE>
415
        cli
416
        out     __SP_H__, r29
417
        sei
418
        out     __SP_L__, r28
419
 
420
   A `-mcall-prologues' prologue looks like this (Note that the megas use a
421
   jmp instead of a rjmp, thus the prologue is one word larger since jmp is a
422
   32 bit insn and rjmp is a 16 bit insn):
423
        ldi     r26,lo8(<LOCALS_SIZE>)
424
        ldi     r27,hi8(<LOCALS_SIZE>)
425
        ldi     r30,pm_lo8(.L_foo_body)
426
        ldi     r31,pm_hi8(.L_foo_body)
427
        rjmp    __prologue_saves__+RRR
428
        .L_foo_body:  */
429
 
430
/* Not really part of a prologue, but still need to scan for it, is when a
431
   function prologue moves values passed via registers as arguments to new
432
   registers. In this case, all local variables live in registers, so there
433
   may be some register saves. This is what it looks like:
434
        movw    rMM, rNN
435
        ...
436
 
437
   There could be multiple movw's. If the target doesn't have a movw insn, it
438
   will use two mov insns. This could be done after any of the above prologue
439
   types.  */
440
 
441
static CORE_ADDR
442
avr_scan_prologue (CORE_ADDR pc, struct avr_unwind_cache *info)
443
{
444
  int i;
445
  unsigned short insn;
446
  int scan_stage = 0;
447
  struct minimal_symbol *msymbol;
448
  unsigned char prologue[AVR_MAX_PROLOGUE_SIZE];
449
  int vpc = 0;
450
 
451
  /* FIXME: TRoth/2003-06-11: This could be made more efficient by only
452
     reading in the bytes of the prologue. The problem is that the figuring
453
     out where the end of the prologue is is a bit difficult. The old code
454
     tried to do that, but failed quite often.  */
455
  read_memory (pc, prologue, AVR_MAX_PROLOGUE_SIZE);
456
 
457
  /* Scanning main()'s prologue
458
     ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>)
459
     ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>)
460
     out __SP_H__,r29
461
     out __SP_L__,r28 */
462
 
463
  if (1)
464
    {
465
      CORE_ADDR locals;
466
      unsigned char img[] = {
467
        0xde, 0xbf,             /* out __SP_H__,r29 */
468
        0xcd, 0xbf              /* out __SP_L__,r28 */
469
      };
470
 
471
      insn = EXTRACT_INSN (&prologue[vpc]);
472
      /* ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>) */
473
      if ((insn & 0xf0f0) == 0xe0c0)
474
        {
475
          locals = (insn & 0xf) | ((insn & 0x0f00) >> 4);
476
          insn = EXTRACT_INSN (&prologue[vpc + 2]);
477
          /* ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>) */
478
          if ((insn & 0xf0f0) == 0xe0d0)
479
            {
480
              locals |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8;
481
              if (memcmp (prologue + vpc + 4, img, sizeof (img)) == 0)
482
                {
483
                  info->prologue_type = AVR_PROLOGUE_MAIN;
484
                  info->base = locals;
485
                  return pc + 4;
486
                }
487
            }
488
        }
489
    }
490
 
491
  /* Scanning `-mcall-prologues' prologue
492
     Classic prologue is 10 bytes, mega prologue is a 12 bytes long */
493
 
494
  while (1)     /* Using a while to avoid many goto's */
495
    {
496
      int loc_size;
497
      int body_addr;
498
      unsigned num_pushes;
499
      int pc_offset = 0;
500
 
501
      insn = EXTRACT_INSN (&prologue[vpc]);
502
      /* ldi r26,<LOCALS_SIZE> */
503
      if ((insn & 0xf0f0) != 0xe0a0)
504
        break;
505
      loc_size = (insn & 0xf) | ((insn & 0x0f00) >> 4);
506
      pc_offset += 2;
507
 
508
      insn = EXTRACT_INSN (&prologue[vpc + 2]);
509
      /* ldi r27,<LOCALS_SIZE> / 256 */
510
      if ((insn & 0xf0f0) != 0xe0b0)
511
        break;
512
      loc_size |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8;
513
      pc_offset += 2;
514
 
515
      insn = EXTRACT_INSN (&prologue[vpc + 4]);
516
      /* ldi r30,pm_lo8(.L_foo_body) */
517
      if ((insn & 0xf0f0) != 0xe0e0)
518
        break;
519
      body_addr = (insn & 0xf) | ((insn & 0x0f00) >> 4);
520
      pc_offset += 2;
521
 
522
      insn = EXTRACT_INSN (&prologue[vpc + 6]);
523
      /* ldi r31,pm_hi8(.L_foo_body) */
524
      if ((insn & 0xf0f0) != 0xe0f0)
525
        break;
526
      body_addr |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8;
527
      pc_offset += 2;
528
 
529
      msymbol = lookup_minimal_symbol ("__prologue_saves__", NULL, NULL);
530
      if (!msymbol)
531
        break;
532
 
533
      insn = EXTRACT_INSN (&prologue[vpc + 8]);
534
      /* rjmp __prologue_saves__+RRR */
535
      if ((insn & 0xf000) == 0xc000)
536
        {
537
          /* Extract PC relative offset from RJMP */
538
          i = (insn & 0xfff) | (insn & 0x800 ? (-1 ^ 0xfff) : 0);
539
          /* Convert offset to byte addressable mode */
540
          i *= 2;
541
          /* Destination address */
542
          i += pc + 10;
543
 
544
          if (body_addr != (pc + 10)/2)
545
            break;
546
 
547
          pc_offset += 2;
548
        }
549
      else if ((insn & 0xfe0e) == 0x940c)
550
        {
551
          /* Extract absolute PC address from JMP */
552
          i = (((insn & 0x1) | ((insn & 0x1f0) >> 3) << 16)
553
            | (EXTRACT_INSN (&prologue[vpc + 10]) & 0xffff));
554
          /* Convert address to byte addressable mode */
555
          i *= 2;
556
 
557
          if (body_addr != (pc + 12)/2)
558
            break;
559
 
560
          pc_offset += 4;
561
        }
562
      else
563
        break;
564
 
565
      /* Resolve offset (in words) from __prologue_saves__ symbol.
566
         Which is a pushes count in `-mcall-prologues' mode */
567
      num_pushes = AVR_MAX_PUSHES - (i - SYMBOL_VALUE_ADDRESS (msymbol)) / 2;
568
 
569
      if (num_pushes > AVR_MAX_PUSHES)
570
        {
571
          fprintf_unfiltered (gdb_stderr, _("Num pushes too large: %d\n"),
572
                              num_pushes);
573
          num_pushes = 0;
574
        }
575
 
576
      if (num_pushes)
577
        {
578
          int from;
579
 
580
          info->saved_regs[AVR_FP_REGNUM + 1].addr = num_pushes;
581
          if (num_pushes >= 2)
582
            info->saved_regs[AVR_FP_REGNUM].addr = num_pushes - 1;
583
 
584
          i = 0;
585
          for (from = AVR_LAST_PUSHED_REGNUM + 1 - (num_pushes - 2);
586
               from <= AVR_LAST_PUSHED_REGNUM; ++from)
587
            info->saved_regs [from].addr = ++i;
588
        }
589
      info->size = loc_size + num_pushes;
590
      info->prologue_type = AVR_PROLOGUE_CALL;
591
 
592
      return pc + pc_offset;
593
    }
594
 
595
  /* Scan for the beginning of the prologue for an interrupt or signal
596
     function.  Note that we have to set the prologue type here since the
597
     third stage of the prologue may not be present (e.g. no saved registered
598
     or changing of the SP register).  */
599
 
600
  if (1)
601
    {
602
      unsigned char img[] = {
603
        0x78, 0x94,             /* sei */
604
        0x1f, 0x92,             /* push r1 */
605
        0x0f, 0x92,             /* push r0 */
606
        0x0f, 0xb6,             /* in r0,0x3f SREG */
607
        0x0f, 0x92,             /* push r0 */
608
        0x11, 0x24              /* clr r1 */
609
      };
610
      if (memcmp (prologue, img, sizeof (img)) == 0)
611
        {
612
          info->prologue_type = AVR_PROLOGUE_INTR;
613
          vpc += sizeof (img);
614
          info->saved_regs[AVR_SREG_REGNUM].addr = 3;
615
          info->saved_regs[0].addr = 2;
616
          info->saved_regs[1].addr = 1;
617
          info->size += 3;
618
        }
619
      else if (memcmp (img + 2, prologue, sizeof (img) - 2) == 0)
620
        {
621
          info->prologue_type = AVR_PROLOGUE_SIG;
622
          vpc += sizeof (img) - 2;
623
          info->saved_regs[AVR_SREG_REGNUM].addr = 3;
624
          info->saved_regs[0].addr = 2;
625
          info->saved_regs[1].addr = 1;
626
          info->size += 3;
627
        }
628
    }
629
 
630
  /* First stage of the prologue scanning.
631
     Scan pushes (saved registers) */
632
 
633
  for (; vpc < AVR_MAX_PROLOGUE_SIZE; vpc += 2)
634
    {
635
      insn = EXTRACT_INSN (&prologue[vpc]);
636
      if ((insn & 0xfe0f) == 0x920f)    /* push rXX */
637
        {
638
          /* Bits 4-9 contain a mask for registers R0-R32. */
639
          int regno = (insn & 0x1f0) >> 4;
640
          info->size++;
641
          info->saved_regs[regno].addr = info->size;
642
          scan_stage = 1;
643
        }
644
      else
645
        break;
646
    }
647
 
648
  if (vpc >= AVR_MAX_PROLOGUE_SIZE)
649
     fprintf_unfiltered (gdb_stderr,
650
                         _("Hit end of prologue while scanning pushes\n"));
651
 
652
  /* Second stage of the prologue scanning.
653
     Scan:
654
     in r28,__SP_L__
655
     in r29,__SP_H__ */
656
 
657
  if (scan_stage == 1 && vpc < AVR_MAX_PROLOGUE_SIZE)
658
    {
659
      unsigned char img[] = {
660
        0xcd, 0xb7,             /* in r28,__SP_L__ */
661
        0xde, 0xb7              /* in r29,__SP_H__ */
662
      };
663
      unsigned short insn1;
664
 
665
      if (memcmp (prologue + vpc, img, sizeof (img)) == 0)
666
        {
667
          vpc += 4;
668
          scan_stage = 2;
669
        }
670
    }
671
 
672
  /* Third stage of the prologue scanning. (Really two stages)
673
     Scan for:
674
     sbiw r28,XX or subi r28,lo8(XX)
675
                    sbci r29,hi8(XX)
676
     in __tmp_reg__,__SREG__
677
     cli
678
     out __SP_H__,r29
679
     out __SREG__,__tmp_reg__
680
     out __SP_L__,r28 */
681
 
682
  if (scan_stage == 2 && vpc < AVR_MAX_PROLOGUE_SIZE)
683
    {
684
      int locals_size = 0;
685
      unsigned char img[] = {
686
        0x0f, 0xb6,             /* in r0,0x3f */
687
        0xf8, 0x94,             /* cli */
688
        0xde, 0xbf,             /* out 0x3e,r29 ; SPH */
689
        0x0f, 0xbe,             /* out 0x3f,r0  ; SREG */
690
        0xcd, 0xbf              /* out 0x3d,r28 ; SPL */
691
      };
692
      unsigned char img_sig[] = {
693
        0xde, 0xbf,             /* out 0x3e,r29 ; SPH */
694
        0xcd, 0xbf              /* out 0x3d,r28 ; SPL */
695
      };
696
      unsigned char img_int[] = {
697
        0xf8, 0x94,             /* cli */
698
        0xde, 0xbf,             /* out 0x3e,r29 ; SPH */
699
        0x78, 0x94,             /* sei */
700
        0xcd, 0xbf              /* out 0x3d,r28 ; SPL */
701
      };
702
 
703
      insn = EXTRACT_INSN (&prologue[vpc]);
704
      vpc += 2;
705
      if ((insn & 0xff30) == 0x9720)    /* sbiw r28,XXX */
706
        locals_size = (insn & 0xf) | ((insn & 0xc0) >> 2);
707
      else if ((insn & 0xf0f0) == 0x50c0)       /* subi r28,lo8(XX) */
708
        {
709
          locals_size = (insn & 0xf) | ((insn & 0xf00) >> 4);
710
          insn = EXTRACT_INSN (&prologue[vpc]);
711
          vpc += 2;
712
          locals_size += ((insn & 0xf) | ((insn & 0xf00) >> 4) << 8);
713
        }
714
      else
715
        return pc + vpc;
716
 
717
      /* Scan the last part of the prologue. May not be present for interrupt
718
         or signal handler functions, which is why we set the prologue type
719
         when we saw the beginning of the prologue previously.  */
720
 
721
      if (memcmp (prologue + vpc, img_sig, sizeof (img_sig)) == 0)
722
        {
723
          vpc += sizeof (img_sig);
724
        }
725
      else if (memcmp (prologue + vpc, img_int, sizeof (img_int)) == 0)
726
        {
727
          vpc += sizeof (img_int);
728
        }
729
      if (memcmp (prologue + vpc, img, sizeof (img)) == 0)
730
        {
731
          info->prologue_type = AVR_PROLOGUE_NORMAL;
732
          vpc += sizeof (img);
733
        }
734
 
735
      info->size += locals_size;
736
 
737
      return pc + avr_scan_arg_moves (vpc, prologue);
738
    }
739
 
740
  /* If we got this far, we could not scan the prologue, so just return the pc
741
     of the frame plus an adjustment for argument move insns.  */
742
 
743
  return pc + avr_scan_arg_moves (vpc, prologue);;
744
}
745
 
746
static CORE_ADDR
747
avr_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
748
{
749
  CORE_ADDR func_addr, func_end;
750
  CORE_ADDR prologue_end = pc;
751
 
752
  /* See what the symbol table says */
753
 
754
  if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
755
    {
756
      struct symtab_and_line sal;
757
      struct avr_unwind_cache info = {0};
758
      struct trad_frame_saved_reg saved_regs[AVR_NUM_REGS];
759
 
760
      info.saved_regs = saved_regs;
761
 
762
      /* Need to run the prologue scanner to figure out if the function has a
763
         prologue and possibly skip over moving arguments passed via registers
764
         to other registers.  */
765
 
766
      prologue_end = avr_scan_prologue (pc, &info);
767
 
768
      if (info.prologue_type == AVR_PROLOGUE_NONE)
769
        return pc;
770
      else
771
        {
772
          sal = find_pc_line (func_addr, 0);
773
 
774
          if (sal.line != 0 && sal.end < func_end)
775
            return sal.end;
776
        }
777
    }
778
 
779
/* Either we didn't find the start of this function (nothing we can do),
780
   or there's no line info, or the line after the prologue is after
781
   the end of the function (there probably isn't a prologue). */
782
 
783
  return prologue_end;
784
}
785
 
786
/* Not all avr devices support the BREAK insn. Those that don't should treat
787
   it as a NOP. Thus, it should be ok. Since the avr is currently a remote
788
   only target, this shouldn't be a problem (I hope). TRoth/2003-05-14  */
789
 
790
static const unsigned char *
791
avr_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR * pcptr, int *lenptr)
792
{
793
    static unsigned char avr_break_insn [] = { 0x98, 0x95 };
794
    *lenptr = sizeof (avr_break_insn);
795
    return avr_break_insn;
796
}
797
 
798
/* Given a return value in `regbuf' with a type `valtype',
799
   extract and copy its value into `valbuf'.
800
 
801
   Return values are always passed via registers r25:r24:...  */
802
 
803
static void
804
avr_extract_return_value (struct type *type, struct regcache *regcache,
805
                          gdb_byte *valbuf)
806
{
807
  ULONGEST r24, r25;
808
  ULONGEST c;
809
  int len;
810
  if (TYPE_LENGTH (type) == 1)
811
    {
812
      regcache_cooked_read_unsigned (regcache, 24, &c);
813
      store_unsigned_integer (valbuf, 1, c);
814
    }
815
  else
816
    {
817
      int i;
818
      /* The MSB of the return value is always in r25, calculate which
819
         register holds the LSB.  */
820
      int lsb_reg = 25 - TYPE_LENGTH (type) + 1;
821
 
822
      for (i=0; i< TYPE_LENGTH (type); i++)
823
        {
824
          regcache_cooked_read (regcache, lsb_reg + i,
825
                                (bfd_byte *) valbuf + i);
826
        }
827
    }
828
}
829
 
830
/* Determine, for architecture GDBARCH, how a return value of TYPE
831
   should be returned.  If it is supposed to be returned in registers,
832
   and READBUF is non-zero, read the appropriate value from REGCACHE,
833
   and copy it into READBUF.  If WRITEBUF is non-zero, write the value
834
   from WRITEBUF into REGCACHE.  */
835
 
836
enum return_value_convention
837
avr_return_value (struct gdbarch *gdbarch, struct type *valtype,
838
                  struct regcache *regcache, gdb_byte *readbuf,
839
                  const gdb_byte *writebuf)
840
{
841
  int struct_return = ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
842
                        || TYPE_CODE (valtype) == TYPE_CODE_UNION
843
                        || TYPE_CODE (valtype) == TYPE_CODE_ARRAY)
844
                       && !(TYPE_LENGTH (valtype) == 1
845
                            || TYPE_LENGTH (valtype) == 2
846
                            || TYPE_LENGTH (valtype) == 4
847
                            || TYPE_LENGTH (valtype) == 8));
848
 
849
  if (writebuf != NULL)
850
    {
851
      gdb_assert (!struct_return);
852
      error (_("Cannot store return value."));
853
    }
854
 
855
  if (readbuf != NULL)
856
    {
857
      gdb_assert (!struct_return);
858
      avr_extract_return_value (valtype, regcache, readbuf);
859
    }
860
 
861
  if (struct_return)
862
    return RETURN_VALUE_STRUCT_CONVENTION;
863
  else
864
    return RETURN_VALUE_REGISTER_CONVENTION;
865
}
866
 
867
 
868
/* Put here the code to store, into fi->saved_regs, the addresses of
869
   the saved registers of frame described by FRAME_INFO.  This
870
   includes special registers such as pc and fp saved in special ways
871
   in the stack frame.  sp is even more special: the address we return
872
   for it IS the sp for the next frame. */
873
 
874
struct avr_unwind_cache *
875
avr_frame_unwind_cache (struct frame_info *next_frame,
876
                        void **this_prologue_cache)
877
{
878
  CORE_ADDR pc;
879
  ULONGEST prev_sp;
880
  ULONGEST this_base;
881
  struct avr_unwind_cache *info;
882
  int i;
883
 
884
  if ((*this_prologue_cache))
885
    return (*this_prologue_cache);
886
 
887
  info = FRAME_OBSTACK_ZALLOC (struct avr_unwind_cache);
888
  (*this_prologue_cache) = info;
889
  info->saved_regs = trad_frame_alloc_saved_regs (next_frame);
890
 
891
  info->size = 0;
892
  info->prologue_type = AVR_PROLOGUE_NONE;
893
 
894
  pc = frame_func_unwind (next_frame, NORMAL_FRAME);
895
 
896
  if ((pc > 0) && (pc < frame_pc_unwind (next_frame)))
897
    avr_scan_prologue (pc, info);
898
 
899
  if ((info->prologue_type != AVR_PROLOGUE_NONE)
900
      && (info->prologue_type != AVR_PROLOGUE_MAIN))
901
    {
902
      ULONGEST high_base;       /* High byte of FP */
903
 
904
      /* The SP was moved to the FP.  This indicates that a new frame
905
         was created.  Get THIS frame's FP value by unwinding it from
906
         the next frame.  */
907
      this_base = frame_unwind_register_unsigned (next_frame, AVR_FP_REGNUM);
908
      high_base = frame_unwind_register_unsigned (next_frame, AVR_FP_REGNUM+1);
909
      this_base += (high_base << 8);
910
 
911
      /* The FP points at the last saved register.  Adjust the FP back
912
         to before the first saved register giving the SP.  */
913
      prev_sp = this_base + info->size;
914
   }
915
  else
916
    {
917
      /* Assume that the FP is this frame's SP but with that pushed
918
         stack space added back.  */
919
      this_base = frame_unwind_register_unsigned (next_frame, AVR_SP_REGNUM);
920
      prev_sp = this_base + info->size;
921
    }
922
 
923
  /* Add 1 here to adjust for the post-decrement nature of the push
924
     instruction.*/
925
  info->prev_sp = avr_make_saddr (prev_sp+1);
926
 
927
  info->base = avr_make_saddr (this_base);
928
 
929
  /* Adjust all the saved registers so that they contain addresses and not
930
     offsets.  */
931
  for (i = 0; i < gdbarch_num_regs (get_frame_arch (next_frame)) - 1; i++)
932
    if (info->saved_regs[i].addr)
933
      {
934
        info->saved_regs[i].addr = (info->prev_sp - info->saved_regs[i].addr);
935
      }
936
 
937
  /* Except for the main and startup code, the return PC is always saved on
938
     the stack and is at the base of the frame. */
939
 
940
  if (info->prologue_type != AVR_PROLOGUE_MAIN)
941
    {
942
      info->saved_regs[AVR_PC_REGNUM].addr = info->prev_sp;
943
    }
944
 
945
  /* The previous frame's SP needed to be computed.  Save the computed
946
     value.  */
947
  trad_frame_set_value (info->saved_regs, AVR_SP_REGNUM, info->prev_sp+1);
948
 
949
  return info;
950
}
951
 
952
static CORE_ADDR
953
avr_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
954
{
955
  ULONGEST pc;
956
 
957
  pc = frame_unwind_register_unsigned (next_frame, AVR_PC_REGNUM);
958
 
959
  return avr_make_iaddr (pc);
960
}
961
 
962
static CORE_ADDR
963
avr_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame)
964
{
965
  ULONGEST sp;
966
 
967
  sp = frame_unwind_register_unsigned (next_frame, AVR_SP_REGNUM);
968
 
969
  return avr_make_saddr (sp);
970
}
971
 
972
/* Given a GDB frame, determine the address of the calling function's
973
   frame.  This will be used to create a new GDB frame struct.  */
974
 
975
static void
976
avr_frame_this_id (struct frame_info *next_frame,
977
                   void **this_prologue_cache,
978
                   struct frame_id *this_id)
979
{
980
  struct avr_unwind_cache *info
981
    = avr_frame_unwind_cache (next_frame, this_prologue_cache);
982
  CORE_ADDR base;
983
  CORE_ADDR func;
984
  struct frame_id id;
985
 
986
  /* The FUNC is easy.  */
987
  func = frame_func_unwind (next_frame, NORMAL_FRAME);
988
 
989
  /* Hopefully the prologue analysis either correctly determined the
990
     frame's base (which is the SP from the previous frame), or set
991
     that base to "NULL".  */
992
  base = info->prev_sp;
993
  if (base == 0)
994
    return;
995
 
996
  id = frame_id_build (base, func);
997
  (*this_id) = id;
998
}
999
 
1000
static void
1001
avr_frame_prev_register (struct frame_info *next_frame,
1002
                          void **this_prologue_cache,
1003
                          int regnum, int *optimizedp,
1004
                          enum lval_type *lvalp, CORE_ADDR *addrp,
1005
                          int *realnump, gdb_byte *bufferp)
1006
{
1007
  struct avr_unwind_cache *info
1008
    = avr_frame_unwind_cache (next_frame, this_prologue_cache);
1009
 
1010
  if (regnum == AVR_PC_REGNUM)
1011
    {
1012
      if (trad_frame_addr_p (info->saved_regs, regnum))
1013
        {
1014
          *optimizedp = 0;
1015
          *lvalp = lval_memory;
1016
          *addrp = info->saved_regs[regnum].addr;
1017
          *realnump = -1;
1018
          if (bufferp != NULL)
1019
            {
1020
              /* Reading the return PC from the PC register is slightly
1021
                 abnormal.  register_size(AVR_PC_REGNUM) says it is 4 bytes,
1022
                 but in reality, only two bytes (3 in upcoming mega256) are
1023
                 stored on the stack.
1024
 
1025
                 Also, note that the value on the stack is an addr to a word
1026
                 not a byte, so we will need to multiply it by two at some
1027
                 point.
1028
 
1029
                 And to confuse matters even more, the return address stored
1030
                 on the stack is in big endian byte order, even though most
1031
                 everything else about the avr is little endian. Ick!  */
1032
 
1033
              /* FIXME: number of bytes read here will need updated for the
1034
                 mega256 when it is available.  */
1035
 
1036
              ULONGEST pc;
1037
              unsigned char tmp;
1038
              unsigned char buf[2];
1039
 
1040
              read_memory (info->saved_regs[regnum].addr, buf, 2);
1041
 
1042
              /* Convert the PC read from memory as a big-endian to
1043
                 little-endian order. */
1044
              tmp = buf[0];
1045
              buf[0] = buf[1];
1046
              buf[1] = tmp;
1047
 
1048
              pc = (extract_unsigned_integer (buf, 2) * 2);
1049
              store_unsigned_integer
1050
                (bufferp, register_size (get_frame_arch (next_frame), regnum),
1051
                 pc);
1052
            }
1053
        }
1054
    }
1055
  else
1056
    trad_frame_get_prev_register (next_frame, info->saved_regs, regnum,
1057
                                  optimizedp, lvalp, addrp, realnump, bufferp);
1058
}
1059
 
1060
static const struct frame_unwind avr_frame_unwind = {
1061
  NORMAL_FRAME,
1062
  avr_frame_this_id,
1063
  avr_frame_prev_register
1064
};
1065
 
1066
const struct frame_unwind *
1067
avr_frame_sniffer (struct frame_info *next_frame)
1068
{
1069
  return &avr_frame_unwind;
1070
}
1071
 
1072
static CORE_ADDR
1073
avr_frame_base_address (struct frame_info *next_frame, void **this_cache)
1074
{
1075
  struct avr_unwind_cache *info
1076
    = avr_frame_unwind_cache (next_frame, this_cache);
1077
 
1078
  return info->base;
1079
}
1080
 
1081
static const struct frame_base avr_frame_base = {
1082
  &avr_frame_unwind,
1083
  avr_frame_base_address,
1084
  avr_frame_base_address,
1085
  avr_frame_base_address
1086
};
1087
 
1088
/* Assuming NEXT_FRAME->prev is a dummy, return the frame ID of that
1089
   dummy frame.  The frame ID's base needs to match the TOS value
1090
   saved by save_dummy_frame_tos(), and the PC match the dummy frame's
1091
   breakpoint.  */
1092
 
1093
static struct frame_id
1094
avr_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame)
1095
{
1096
  ULONGEST base;
1097
 
1098
  base = frame_unwind_register_unsigned (next_frame, AVR_SP_REGNUM);
1099
  return frame_id_build (avr_make_saddr (base), frame_pc_unwind (next_frame));
1100
}
1101
 
1102
/* When arguments must be pushed onto the stack, they go on in reverse
1103
   order.  The below implements a FILO (stack) to do this. */
1104
 
1105
struct stack_item
1106
{
1107
  int len;
1108
  struct stack_item *prev;
1109
  void *data;
1110
};
1111
 
1112
static struct stack_item *
1113
push_stack_item (struct stack_item *prev, const bfd_byte *contents, int len)
1114
{
1115
  struct stack_item *si;
1116
  si = xmalloc (sizeof (struct stack_item));
1117
  si->data = xmalloc (len);
1118
  si->len = len;
1119
  si->prev = prev;
1120
  memcpy (si->data, contents, len);
1121
  return si;
1122
}
1123
 
1124
static struct stack_item *pop_stack_item (struct stack_item *si);
1125
static struct stack_item *
1126
pop_stack_item (struct stack_item *si)
1127
{
1128
  struct stack_item *dead = si;
1129
  si = si->prev;
1130
  xfree (dead->data);
1131
  xfree (dead);
1132
  return si;
1133
}
1134
 
1135
/* Setup the function arguments for calling a function in the inferior.
1136
 
1137
   On the AVR architecture, there are 18 registers (R25 to R8) which are
1138
   dedicated for passing function arguments.  Up to the first 18 arguments
1139
   (depending on size) may go into these registers.  The rest go on the stack.
1140
 
1141
   All arguments are aligned to start in even-numbered registers (odd-sized
1142
   arguments, including char, have one free register above them). For example,
1143
   an int in arg1 and a char in arg2 would be passed as such:
1144
 
1145
      arg1 -> r25:r24
1146
      arg2 -> r22
1147
 
1148
   Arguments that are larger than 2 bytes will be split between two or more
1149
   registers as available, but will NOT be split between a register and the
1150
   stack. Arguments that go onto the stack are pushed last arg first (this is
1151
   similar to the d10v).  */
1152
 
1153
/* NOTE: TRoth/2003-06-17: The rest of this comment is old looks to be
1154
   inaccurate.
1155
 
1156
   An exceptional case exists for struct arguments (and possibly other
1157
   aggregates such as arrays) -- if the size is larger than WORDSIZE bytes but
1158
   not a multiple of WORDSIZE bytes.  In this case the argument is never split
1159
   between the registers and the stack, but instead is copied in its entirety
1160
   onto the stack, AND also copied into as many registers as there is room
1161
   for.  In other words, space in registers permitting, two copies of the same
1162
   argument are passed in.  As far as I can tell, only the one on the stack is
1163
   used, although that may be a function of the level of compiler
1164
   optimization.  I suspect this is a compiler bug.  Arguments of these odd
1165
   sizes are left-justified within the word (as opposed to arguments smaller
1166
   than WORDSIZE bytes, which are right-justified).
1167
 
1168
   If the function is to return an aggregate type such as a struct, the caller
1169
   must allocate space into which the callee will copy the return value.  In
1170
   this case, a pointer to the return value location is passed into the callee
1171
   in register R0, which displaces one of the other arguments passed in via
1172
   registers R0 to R2. */
1173
 
1174
static CORE_ADDR
1175
avr_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
1176
                     struct regcache *regcache, CORE_ADDR bp_addr,
1177
                     int nargs, struct value **args, CORE_ADDR sp,
1178
                     int struct_return, CORE_ADDR struct_addr)
1179
{
1180
  int i;
1181
  unsigned char buf[2];
1182
  CORE_ADDR return_pc = avr_convert_iaddr_to_raw (bp_addr);
1183
  int regnum = AVR_ARGN_REGNUM;
1184
  struct stack_item *si = NULL;
1185
 
1186
#if 0
1187
  /* FIXME: TRoth/2003-06-18: Not sure what to do when returning a struct. */
1188
  if (struct_return)
1189
    {
1190
      fprintf_unfiltered (gdb_stderr, "struct_return: 0x%lx\n", struct_addr);
1191
      regcache_cooked_write_unsigned (regcache, argreg--, struct_addr & 0xff);
1192
      regcache_cooked_write_unsigned (regcache, argreg--, (struct_addr >>8) & 0xff);
1193
    }
1194
#endif
1195
 
1196
  for (i = 0; i < nargs; i++)
1197
    {
1198
      int last_regnum;
1199
      int j;
1200
      struct value *arg = args[i];
1201
      struct type *type = check_typedef (value_type (arg));
1202
      const bfd_byte *contents = value_contents (arg);
1203
      int len = TYPE_LENGTH (type);
1204
 
1205
      /* Calculate the potential last register needed. */
1206
      last_regnum = regnum - (len + (len & 1));
1207
 
1208
      /* If there are registers available, use them. Once we start putting
1209
         stuff on the stack, all subsequent args go on stack. */
1210
      if ((si == NULL) && (last_regnum >= 8))
1211
        {
1212
          ULONGEST val;
1213
 
1214
          /* Skip a register for odd length args. */
1215
          if (len & 1)
1216
            regnum--;
1217
 
1218
          val = extract_unsigned_integer (contents, len);
1219
          for (j=0; j<len; j++)
1220
            {
1221
              regcache_cooked_write_unsigned (regcache, regnum--,
1222
                                              val >> (8*(len-j-1)));
1223
            }
1224
        }
1225
      /* No registers available, push the args onto the stack. */
1226
      else
1227
        {
1228
          /* From here on, we don't care about regnum. */
1229
          si = push_stack_item (si, contents, len);
1230
        }
1231
    }
1232
 
1233
  /* Push args onto the stack. */
1234
  while (si)
1235
    {
1236
      sp -= si->len;
1237
      /* Add 1 to sp here to account for post decr nature of pushes. */
1238
      write_memory (sp+1, si->data, si->len);
1239
      si = pop_stack_item (si);
1240
    }
1241
 
1242
  /* Set the return address.  For the avr, the return address is the BP_ADDR.
1243
     Need to push the return address onto the stack noting that it needs to be
1244
     in big-endian order on the stack.  */
1245
  buf[0] = (return_pc >> 8) & 0xff;
1246
  buf[1] = return_pc & 0xff;
1247
 
1248
  sp -= 2;
1249
  write_memory (sp+1, buf, 2);  /* Add one since pushes are post decr ops. */
1250
 
1251
  /* Finally, update the SP register. */
1252
  regcache_cooked_write_unsigned (regcache, AVR_SP_REGNUM,
1253
                                  avr_convert_saddr_to_raw (sp));
1254
 
1255
  return sp;
1256
}
1257
 
1258
/* Initialize the gdbarch structure for the AVR's. */
1259
 
1260
static struct gdbarch *
1261
avr_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1262
{
1263
  struct gdbarch *gdbarch;
1264
  struct gdbarch_tdep *tdep;
1265
 
1266
  /* Find a candidate among the list of pre-declared architectures. */
1267
  arches = gdbarch_list_lookup_by_info (arches, &info);
1268
  if (arches != NULL)
1269
    return arches->gdbarch;
1270
 
1271
  /* None found, create a new architecture from the information provided. */
1272
  tdep = XMALLOC (struct gdbarch_tdep);
1273
  gdbarch = gdbarch_alloc (&info, tdep);
1274
 
1275
  /* If we ever need to differentiate the device types, do it here. */
1276
  switch (info.bfd_arch_info->mach)
1277
    {
1278
    case bfd_mach_avr1:
1279
    case bfd_mach_avr2:
1280
    case bfd_mach_avr3:
1281
    case bfd_mach_avr4:
1282
    case bfd_mach_avr5:
1283
      break;
1284
    }
1285
 
1286
  set_gdbarch_short_bit (gdbarch, 2 * TARGET_CHAR_BIT);
1287
  set_gdbarch_int_bit (gdbarch, 2 * TARGET_CHAR_BIT);
1288
  set_gdbarch_long_bit (gdbarch, 4 * TARGET_CHAR_BIT);
1289
  set_gdbarch_long_long_bit (gdbarch, 8 * TARGET_CHAR_BIT);
1290
  set_gdbarch_ptr_bit (gdbarch, 2 * TARGET_CHAR_BIT);
1291
  set_gdbarch_addr_bit (gdbarch, 32);
1292
 
1293
  set_gdbarch_float_bit (gdbarch, 4 * TARGET_CHAR_BIT);
1294
  set_gdbarch_double_bit (gdbarch, 4 * TARGET_CHAR_BIT);
1295
  set_gdbarch_long_double_bit (gdbarch, 4 * TARGET_CHAR_BIT);
1296
 
1297
  set_gdbarch_float_format (gdbarch, floatformats_ieee_single);
1298
  set_gdbarch_double_format (gdbarch, floatformats_ieee_single);
1299
  set_gdbarch_long_double_format (gdbarch, floatformats_ieee_single);
1300
 
1301
  set_gdbarch_read_pc (gdbarch, avr_read_pc);
1302
  set_gdbarch_write_pc (gdbarch, avr_write_pc);
1303
 
1304
  set_gdbarch_num_regs (gdbarch, AVR_NUM_REGS);
1305
 
1306
  set_gdbarch_sp_regnum (gdbarch, AVR_SP_REGNUM);
1307
  set_gdbarch_pc_regnum (gdbarch, AVR_PC_REGNUM);
1308
 
1309
  set_gdbarch_register_name (gdbarch, avr_register_name);
1310
  set_gdbarch_register_type (gdbarch, avr_register_type);
1311
 
1312
  set_gdbarch_return_value (gdbarch, avr_return_value);
1313
  set_gdbarch_print_insn (gdbarch, print_insn_avr);
1314
 
1315
  set_gdbarch_push_dummy_call (gdbarch, avr_push_dummy_call);
1316
 
1317
  set_gdbarch_address_to_pointer (gdbarch, avr_address_to_pointer);
1318
  set_gdbarch_pointer_to_address (gdbarch, avr_pointer_to_address);
1319
 
1320
  set_gdbarch_skip_prologue (gdbarch, avr_skip_prologue);
1321
  set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
1322
 
1323
  set_gdbarch_breakpoint_from_pc (gdbarch, avr_breakpoint_from_pc);
1324
 
1325
  frame_unwind_append_sniffer (gdbarch, avr_frame_sniffer);
1326
  frame_base_set_default (gdbarch, &avr_frame_base);
1327
 
1328
  set_gdbarch_unwind_dummy_id (gdbarch, avr_unwind_dummy_id);
1329
 
1330
  set_gdbarch_unwind_pc (gdbarch, avr_unwind_pc);
1331
  set_gdbarch_unwind_sp (gdbarch, avr_unwind_sp);
1332
 
1333
  return gdbarch;
1334
}
1335
 
1336
/* Send a query request to the avr remote target asking for values of the io
1337
   registers. If args parameter is not NULL, then the user has requested info
1338
   on a specific io register [This still needs implemented and is ignored for
1339
   now]. The query string should be one of these forms:
1340
 
1341
   "Ravr.io_reg" -> reply is "NN" number of io registers
1342
 
1343
   "Ravr.io_reg:addr,len" where addr is first register and len is number of
1344
   registers to be read. The reply should be "<NAME>,VV;" for each io register
1345
   where, <NAME> is a string, and VV is the hex value of the register.
1346
 
1347
   All io registers are 8-bit. */
1348
 
1349
static void
1350
avr_io_reg_read_command (char *args, int from_tty)
1351
{
1352
  LONGEST bufsiz = 0;
1353
  gdb_byte *buf;
1354
  char query[400];
1355
  char *p;
1356
  unsigned int nreg = 0;
1357
  unsigned int val;
1358
  int i, j, k, step;
1359
 
1360
  /* Find out how many io registers the target has. */
1361
  bufsiz = target_read_alloc (&current_target, TARGET_OBJECT_AVR,
1362
                              "avr.io_reg", &buf);
1363
 
1364
  if (bufsiz <= 0)
1365
    {
1366
      fprintf_unfiltered (gdb_stderr,
1367
                          _("ERR: info io_registers NOT supported "
1368
                            "by current target\n"));
1369
      return;
1370
    }
1371
 
1372
  if (sscanf (buf, "%x", &nreg) != 1)
1373
    {
1374
      fprintf_unfiltered (gdb_stderr,
1375
                          _("Error fetching number of io registers\n"));
1376
      xfree (buf);
1377
      return;
1378
    }
1379
 
1380
  xfree (buf);
1381
 
1382
  reinitialize_more_filter ();
1383
 
1384
  printf_unfiltered (_("Target has %u io registers:\n\n"), nreg);
1385
 
1386
  /* only fetch up to 8 registers at a time to keep the buffer small */
1387
  step = 8;
1388
 
1389
  for (i = 0; i < nreg; i += step)
1390
    {
1391
      /* how many registers this round? */
1392
      j = step;
1393
      if ((i+j) >= nreg)
1394
        j = nreg - i;           /* last block is less than 8 registers */
1395
 
1396
      snprintf (query, sizeof (query) - 1, "avr.io_reg:%x,%x", i, j);
1397
      bufsiz = target_read_alloc (&current_target, TARGET_OBJECT_AVR,
1398
                                  query, &buf);
1399
 
1400
      p = buf;
1401
      for (k = i; k < (i + j); k++)
1402
        {
1403
          if (sscanf (p, "%[^,],%x;", query, &val) == 2)
1404
            {
1405
              printf_filtered ("[%02x] %-15s : %02x\n", k, query, val);
1406
              while ((*p != ';') && (*p != '\0'))
1407
                p++;
1408
              p++;              /* skip over ';' */
1409
              if (*p == '\0')
1410
                break;
1411
            }
1412
        }
1413
 
1414
      xfree (buf);
1415
    }
1416
}
1417
 
1418
extern initialize_file_ftype _initialize_avr_tdep; /* -Wmissing-prototypes */
1419
 
1420
void
1421
_initialize_avr_tdep (void)
1422
{
1423
  register_gdbarch_init (bfd_arch_avr, avr_gdbarch_init);
1424
 
1425
  /* Add a new command to allow the user to query the avr remote target for
1426
     the values of the io space registers in a saner way than just using
1427
     `x/NNNb ADDR`. */
1428
 
1429
  /* FIXME: TRoth/2002-02-18: This should probably be changed to 'info avr
1430
     io_registers' to signify it is not available on other platforms. */
1431
 
1432
  add_cmd ("io_registers", class_info, avr_io_reg_read_command,
1433
           _("query remote avr target for io space register values"),
1434
           &infolist);
1435
}

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