avr-dis.c revision 1.1.1.8 
1/* Disassemble AVR instructions.
2   Copyright (C) 1999-2020 Free Software Foundation, Inc.
3
4   Contributed by Denis Chertykov <denisc@overta.ru>
5
6   This file is part of libopcodes.
7
8   This library 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, or (at your option)
11   any later version.
12
13   It is distributed in the hope that it will be useful, but WITHOUT
14   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
16   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, write to the Free Software
20   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21   MA 02110-1301, USA.  */
22
23#include "sysdep.h"
24#include <assert.h>
25#include "disassemble.h"
26#include "opintl.h"
27#include "libiberty.h"
28#include "bfd_stdint.h"
29
30struct avr_opcodes_s
31{
32  char *name;
33  char *constraints;
34  char *opcode;
35  int insn_size;		/* In words.  */
36  int isa;
37  unsigned int bin_opcode;
38};
39
40#define AVR_INSN(NAME, CONSTR, OPCODE, SIZE, ISA, BIN) \
41{#NAME, CONSTR, OPCODE, SIZE, ISA, BIN},
42
43const struct avr_opcodes_s avr_opcodes[] =
44{
45  #include "opcode/avr.h"
46  {NULL, NULL, NULL, 0, 0, 0}
47};
48
49static const char * comment_start = "0x";
50
51static int
52avr_operand (unsigned int insn, unsigned int insn2, unsigned int pc, int constraint,
53             char *opcode_str, char *buf, char *comment, int regs, int *sym, bfd_vma *sym_addr)
54{
55  int ok = 1;
56  *sym = 0;
57
58  switch (constraint)
59    {
60      /* Any register operand.  */
61    case 'r':
62      if (regs)
63	insn = (insn & 0xf) | ((insn & 0x0200) >> 5); /* Source register.  */
64      else
65	insn = (insn & 0x01f0) >> 4; /* Destination register.  */
66
67      sprintf (buf, "r%d", insn);
68      break;
69
70    case 'd':
71      if (regs)
72	sprintf (buf, "r%d", 16 + (insn & 0xf));
73      else
74	sprintf (buf, "r%d", 16 + ((insn & 0xf0) >> 4));
75      break;
76
77    case 'w':
78      sprintf (buf, "r%d", 24 + ((insn & 0x30) >> 3));
79      break;
80
81    case 'a':
82      if (regs)
83	sprintf (buf, "r%d", 16 + (insn & 7));
84      else
85	sprintf (buf, "r%d", 16 + ((insn >> 4) & 7));
86      break;
87
88    case 'v':
89      if (regs)
90	sprintf (buf, "r%d", (insn & 0xf) * 2);
91      else
92	sprintf (buf, "r%d", ((insn & 0xf0) >> 3));
93      break;
94
95    case 'e':
96      {
97	char *xyz;
98
99	switch (insn & 0x100f)
100	  {
101	    case 0x0000: xyz = "Z";  break;
102	    case 0x1001: xyz = "Z+"; break;
103	    case 0x1002: xyz = "-Z"; break;
104	    case 0x0008: xyz = "Y";  break;
105	    case 0x1009: xyz = "Y+"; break;
106	    case 0x100a: xyz = "-Y"; break;
107	    case 0x100c: xyz = "X";  break;
108	    case 0x100d: xyz = "X+"; break;
109	    case 0x100e: xyz = "-X"; break;
110	    default: xyz = "??"; ok = 0;
111	  }
112	strcpy (buf, xyz);
113
114	if (AVR_UNDEF_P (insn))
115	  sprintf (comment, _("undefined"));
116      }
117      break;
118
119    case 'z':
120      *buf++ = 'Z';
121
122      /* Check for post-increment. */
123      char *s;
124      for (s = opcode_str; *s; ++s)
125        {
126          if (*s == '+')
127            {
128	      if (insn & (1 << (15 - (s - opcode_str))))
129		*buf++ = '+';
130              break;
131            }
132        }
133
134      *buf = '\0';
135      if (AVR_UNDEF_P (insn))
136	sprintf (comment, _("undefined"));
137      break;
138
139    case 'b':
140      {
141	unsigned int x;
142
143	x = (insn & 7);
144	x |= (insn >> 7) & (3 << 3);
145	x |= (insn >> 8) & (1 << 5);
146
147	if (insn & 0x8)
148	  *buf++ = 'Y';
149	else
150	  *buf++ = 'Z';
151	sprintf (buf, "+%d", x);
152	sprintf (comment, "0x%02x", x);
153      }
154      break;
155
156    case 'h':
157      *sym = 1;
158      *sym_addr = ((((insn & 1) | ((insn & 0x1f0) >> 3)) << 16) | insn2) * 2;
159      /* See PR binutils/2454.  Ideally we would like to display the hex
160	 value of the address only once, but this would mean recoding
161	 objdump_print_address() which would affect many targets.  */
162      sprintf (buf, "%#lx", (unsigned long) *sym_addr);
163      strcpy (comment, comment_start);
164      break;
165
166    case 'L':
167      {
168	int rel_addr = (((insn & 0xfff) ^ 0x800) - 0x800) * 2;
169	sprintf (buf, ".%+-8d", rel_addr);
170        *sym = 1;
171        *sym_addr = pc + 2 + rel_addr;
172	strcpy (comment, comment_start);
173      }
174      break;
175
176    case 'l':
177      {
178	int rel_addr = ((((insn >> 3) & 0x7f) ^ 0x40) - 0x40) * 2;
179
180	sprintf (buf, ".%+-8d", rel_addr);
181        *sym = 1;
182        *sym_addr = pc + 2 + rel_addr;
183	strcpy (comment, comment_start);
184      }
185      break;
186
187    case 'i':
188      {
189        unsigned int val = insn2 | 0x800000;
190        *sym = 1;
191        *sym_addr = val;
192        sprintf (buf, "0x%04X", insn2);
193        strcpy (comment, comment_start);
194      }
195      break;
196
197    case 'j':
198      {
199        unsigned int val = ((insn & 0xf) | ((insn & 0x600) >> 5)
200                                         | ((insn & 0x100) >> 2));
201	if ((insn & 0x100) == 0)
202	  val |= 0x80;
203        *sym = 1;
204        *sym_addr = val | 0x800000;
205        sprintf (buf, "0x%02x", val);
206        strcpy (comment, comment_start);
207      }
208      break;
209
210    case 'M':
211      sprintf (buf, "0x%02X", ((insn & 0xf00) >> 4) | (insn & 0xf));
212      sprintf (comment, "%d", ((insn & 0xf00) >> 4) | (insn & 0xf));
213      break;
214
215    case 'n':
216      sprintf (buf, "??");
217      /* xgettext:c-format */
218      opcodes_error_handler (_("internal disassembler error"));
219      ok = 0;
220      break;
221
222    case 'K':
223      {
224	unsigned int x;
225
226	x = (insn & 0xf) | ((insn >> 2) & 0x30);
227	sprintf (buf, "0x%02x", x);
228	sprintf (comment, "%d", x);
229      }
230      break;
231
232    case 's':
233      sprintf (buf, "%d", insn & 7);
234      break;
235
236    case 'S':
237      sprintf (buf, "%d", (insn >> 4) & 7);
238      break;
239
240    case 'P':
241      {
242	unsigned int x;
243
244	x = (insn & 0xf);
245	x |= (insn >> 5) & 0x30;
246	sprintf (buf, "0x%02x", x);
247	sprintf (comment, "%d", x);
248      }
249      break;
250
251    case 'p':
252      {
253	unsigned int x;
254
255	x = (insn >> 3) & 0x1f;
256	sprintf (buf, "0x%02x", x);
257	sprintf (comment, "%d", x);
258      }
259      break;
260
261    case 'E':
262      sprintf (buf, "%d", (insn >> 4) & 15);
263      break;
264
265    case '?':
266      *buf = '\0';
267      break;
268
269    default:
270      sprintf (buf, "??");
271      /* xgettext:c-format */
272      opcodes_error_handler (_("unknown constraint `%c'"), constraint);
273      ok = 0;
274    }
275
276    return ok;
277}
278
279/* Read the opcode from ADDR.  Return 0 in success and save opcode
280   in *INSN, otherwise, return -1.  */
281
282static int
283avrdis_opcode (bfd_vma addr, disassemble_info *info, uint16_t *insn)
284{
285  bfd_byte buffer[2];
286  int status;
287
288  status = info->read_memory_func (addr, buffer, 2, info);
289
290  if (status == 0)
291    {
292      *insn = bfd_getl16 (buffer);
293      return 0;
294    }
295
296  info->memory_error_func (status, addr, info);
297  return -1;
298}
299
300
301int
302print_insn_avr (bfd_vma addr, disassemble_info *info)
303{
304  uint16_t insn, insn2;
305  const struct avr_opcodes_s *opcode;
306  static unsigned int *maskptr;
307  void *stream = info->stream;
308  fprintf_ftype prin = info->fprintf_func;
309  static unsigned int *avr_bin_masks;
310  static int initialized;
311  int cmd_len = 2;
312  int ok = 0;
313  char op1[20], op2[20], comment1[40], comment2[40];
314  int sym_op1 = 0, sym_op2 = 0;
315  bfd_vma sym_addr1, sym_addr2;
316
317
318  if (!initialized)
319    {
320      unsigned int nopcodes;
321
322      /* PR 4045: Try to avoid duplicating the 0x prefix that
323	 objdump_print_addr() will put on addresses when there
324	 is no symbol table available.  */
325      if (info->symtab_size == 0)
326	comment_start = " ";
327
328      nopcodes = sizeof (avr_opcodes) / sizeof (struct avr_opcodes_s);
329
330      avr_bin_masks = xmalloc (nopcodes * sizeof (unsigned int));
331
332      for (opcode = avr_opcodes, maskptr = avr_bin_masks;
333	   opcode->name;
334	   opcode++, maskptr++)
335	{
336	  char * s;
337	  unsigned int bin = 0;
338	  unsigned int mask = 0;
339
340	  for (s = opcode->opcode; *s; ++s)
341	    {
342	      bin <<= 1;
343	      mask <<= 1;
344	      bin |= (*s == '1');
345	      mask |= (*s == '1' || *s == '0');
346	    }
347	  assert (s - opcode->opcode == 16);
348	  assert (opcode->bin_opcode == bin);
349	  *maskptr = mask;
350	}
351
352      initialized = 1;
353    }
354
355  if (avrdis_opcode (addr, info, &insn)  != 0)
356    return -1;
357
358  for (opcode = avr_opcodes, maskptr = avr_bin_masks;
359       opcode->name;
360       opcode++, maskptr++)
361    {
362      if ((opcode->isa == AVR_ISA_TINY) && (info->mach != bfd_mach_avrtiny))
363        continue;
364      if ((insn & *maskptr) == opcode->bin_opcode)
365        break;
366    }
367
368  /* Special case: disassemble `ldd r,b+0' as `ld r,b', and
369     `std b+0,r' as `st b,r' (next entry in the table).  */
370
371  if (AVR_DISP0_P (insn))
372    opcode++;
373
374  op1[0] = 0;
375  op2[0] = 0;
376  comment1[0] = 0;
377  comment2[0] = 0;
378
379  if (opcode->name)
380    {
381      char *constraints = opcode->constraints;
382      char *opcode_str = opcode->opcode;
383
384      insn2 = 0;
385      ok = 1;
386
387      if (opcode->insn_size > 1)
388	{
389	  if (avrdis_opcode (addr + 2, info, &insn2) != 0)
390	    return -1;
391	  cmd_len = 4;
392	}
393
394      if (*constraints && *constraints != '?')
395	{
396	  int regs = REGISTER_P (*constraints);
397
398	  ok = avr_operand (insn, insn2, addr, *constraints, opcode_str, op1, comment1, 0, &sym_op1, &sym_addr1);
399
400	  if (ok && *(++constraints) == ',')
401	    ok = avr_operand (insn, insn2, addr, *(++constraints), opcode_str, op2,
402			      *comment1 ? comment2 : comment1, regs, &sym_op2, &sym_addr2);
403	}
404    }
405
406  if (!ok)
407    {
408      /* Unknown opcode, or invalid combination of operands.  */
409      sprintf (op1, "0x%04x", insn);
410      op2[0] = 0;
411      sprintf (comment1, "????");
412      comment2[0] = 0;
413    }
414
415  (*prin) (stream, "%s", ok ? opcode->name : ".word");
416
417  if (*op1)
418      (*prin) (stream, "\t%s", op1);
419
420  if (*op2)
421    (*prin) (stream, ", %s", op2);
422
423  if (*comment1)
424    (*prin) (stream, "\t; %s", comment1);
425
426  if (sym_op1)
427    info->print_address_func (sym_addr1, info);
428
429  if (*comment2)
430    (*prin) (stream, " %s", comment2);
431
432  if (sym_op2)
433    info->print_address_func (sym_addr2, info);
434
435  return cmd_len;
436}
437