xref: /netbsd-src/external/gpl3/gdb/dist/opcodes/avr-dis.c (revision b757af438b42b93f8c6571f026d8b8ef3eaf5fc9)
1 /* Disassemble AVR instructions.
2    Copyright 1999, 2000, 2002, 2004, 2005, 2006, 2007, 2008
3    Free Software Foundation, Inc.
4 
5    Contributed by Denis Chertykov <denisc@overta.ru>
6 
7    This file is part of libopcodes.
8 
9    This library is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 3, or (at your option)
12    any later version.
13 
14    It is distributed in the hope that it will be useful, but WITHOUT
15    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
17    License for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program; if not, write to the Free Software
21    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22    MA 02110-1301, USA.  */
23 
24 #include <assert.h>
25 #include "sysdep.h"
26 #include "dis-asm.h"
27 #include "opintl.h"
28 #include "libiberty.h"
29 
30 struct 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 
43 const struct avr_opcodes_s avr_opcodes[] =
44 {
45   #include "opcode/avr.h"
46   {NULL, NULL, NULL, 0, 0, 0}
47 };
48 
49 static const char * comment_start = "0x";
50 
51 static int
52 avr_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 	*buf++ = '+';
129               break;
130             }
131         }
132 
133       *buf = '\0';
134       if (AVR_UNDEF_P (insn))
135 	sprintf (comment, _("undefined"));
136       break;
137 
138     case 'b':
139       {
140 	unsigned int x;
141 
142 	x = (insn & 7);
143 	x |= (insn >> 7) & (3 << 3);
144 	x |= (insn >> 8) & (1 << 5);
145 
146 	if (insn & 0x8)
147 	  *buf++ = 'Y';
148 	else
149 	  *buf++ = 'Z';
150 	sprintf (buf, "+%d", x);
151 	sprintf (comment, "0x%02x", x);
152       }
153       break;
154 
155     case 'h':
156       *sym = 1;
157       *sym_addr = ((((insn & 1) | ((insn & 0x1f0) >> 3)) << 16) | insn2) * 2;
158       /* See PR binutils/2454.  Ideally we would like to display the hex
159 	 value of the address only once, but this would mean recoding
160 	 objdump_print_address() which would affect many targets.  */
161       sprintf (buf, "%#lx", (unsigned long) *sym_addr);
162       strcpy (comment, comment_start);
163       break;
164 
165     case 'L':
166       {
167 	int rel_addr = (((insn & 0xfff) ^ 0x800) - 0x800) * 2;
168 	sprintf (buf, ".%+-8d", rel_addr);
169         *sym = 1;
170         *sym_addr = pc + 2 + rel_addr;
171 	strcpy (comment, comment_start);
172       }
173       break;
174 
175     case 'l':
176       {
177 	int rel_addr = ((((insn >> 3) & 0x7f) ^ 0x40) - 0x40) * 2;
178 
179 	sprintf (buf, ".%+-8d", rel_addr);
180         *sym = 1;
181         *sym_addr = pc + 2 + rel_addr;
182 	strcpy (comment, comment_start);
183       }
184       break;
185 
186     case 'i':
187       sprintf (buf, "0x%04X", insn2);
188       break;
189 
190     case 'M':
191       sprintf (buf, "0x%02X", ((insn & 0xf00) >> 4) | (insn & 0xf));
192       sprintf (comment, "%d", ((insn & 0xf00) >> 4) | (insn & 0xf));
193       break;
194 
195     case 'n':
196       sprintf (buf, "??");
197       fprintf (stderr, _("Internal disassembler error"));
198       ok = 0;
199       break;
200 
201     case 'K':
202       {
203 	unsigned int x;
204 
205 	x = (insn & 0xf) | ((insn >> 2) & 0x30);
206 	sprintf (buf, "0x%02x", x);
207 	sprintf (comment, "%d", x);
208       }
209       break;
210 
211     case 's':
212       sprintf (buf, "%d", insn & 7);
213       break;
214 
215     case 'S':
216       sprintf (buf, "%d", (insn >> 4) & 7);
217       break;
218 
219     case 'P':
220       {
221 	unsigned int x;
222 
223 	x = (insn & 0xf);
224 	x |= (insn >> 5) & 0x30;
225 	sprintf (buf, "0x%02x", x);
226 	sprintf (comment, "%d", x);
227       }
228       break;
229 
230     case 'p':
231       {
232 	unsigned int x;
233 
234 	x = (insn >> 3) & 0x1f;
235 	sprintf (buf, "0x%02x", x);
236 	sprintf (comment, "%d", x);
237       }
238       break;
239 
240     case 'E':
241       sprintf (buf, "%d", (insn >> 4) & 15);
242       break;
243 
244     case '?':
245       *buf = '\0';
246       break;
247 
248     default:
249       sprintf (buf, "??");
250       fprintf (stderr, _("unknown constraint `%c'"), constraint);
251       ok = 0;
252     }
253 
254     return ok;
255 }
256 
257 static unsigned short
258 avrdis_opcode (bfd_vma addr, disassemble_info *info)
259 {
260   bfd_byte buffer[2];
261   int status;
262 
263   status = info->read_memory_func (addr, buffer, 2, info);
264 
265   if (status == 0)
266     return bfd_getl16 (buffer);
267 
268   info->memory_error_func (status, addr, info);
269   return -1;
270 }
271 
272 
273 int
274 print_insn_avr (bfd_vma addr, disassemble_info *info)
275 {
276   unsigned int insn, insn2;
277   const struct avr_opcodes_s *opcode;
278   static unsigned int *maskptr;
279   void *stream = info->stream;
280   fprintf_ftype prin = info->fprintf_func;
281   static unsigned int *avr_bin_masks;
282   static int initialized;
283   int cmd_len = 2;
284   int ok = 0;
285   char op1[20], op2[20], comment1[40], comment2[40];
286   int sym_op1 = 0, sym_op2 = 0;
287   bfd_vma sym_addr1, sym_addr2;
288 
289 
290   if (!initialized)
291     {
292       unsigned int nopcodes;
293 
294       /* PR 4045: Try to avoid duplicating the 0x prefix that
295 	 objdump_print_addr() will put on addresses when there
296 	 is no symbol table available.  */
297       if (info->symtab_size == 0)
298 	comment_start = " ";
299 
300       nopcodes = sizeof (avr_opcodes) / sizeof (struct avr_opcodes_s);
301 
302       avr_bin_masks = xmalloc (nopcodes * sizeof (unsigned int));
303 
304       for (opcode = avr_opcodes, maskptr = avr_bin_masks;
305 	   opcode->name;
306 	   opcode++, maskptr++)
307 	{
308 	  char * s;
309 	  unsigned int bin = 0;
310 	  unsigned int mask = 0;
311 
312 	  for (s = opcode->opcode; *s; ++s)
313 	    {
314 	      bin <<= 1;
315 	      mask <<= 1;
316 	      bin |= (*s == '1');
317 	      mask |= (*s == '1' || *s == '0');
318 	    }
319 	  assert (s - opcode->opcode == 16);
320 	  assert (opcode->bin_opcode == bin);
321 	  *maskptr = mask;
322 	}
323 
324       initialized = 1;
325     }
326 
327   insn = avrdis_opcode (addr, info);
328 
329   for (opcode = avr_opcodes, maskptr = avr_bin_masks;
330        opcode->name;
331        opcode++, maskptr++)
332     if ((insn & *maskptr) == opcode->bin_opcode)
333       break;
334 
335   /* Special case: disassemble `ldd r,b+0' as `ld r,b', and
336      `std b+0,r' as `st b,r' (next entry in the table).  */
337 
338   if (AVR_DISP0_P (insn))
339     opcode++;
340 
341   op1[0] = 0;
342   op2[0] = 0;
343   comment1[0] = 0;
344   comment2[0] = 0;
345 
346   if (opcode->name)
347     {
348       char *constraints = opcode->constraints;
349       char *opcode_str = opcode->opcode;
350 
351       insn2 = 0;
352       ok = 1;
353 
354       if (opcode->insn_size > 1)
355 	{
356 	  insn2 = avrdis_opcode (addr + 2, info);
357 	  cmd_len = 4;
358 	}
359 
360       if (*constraints && *constraints != '?')
361 	{
362 	  int regs = REGISTER_P (*constraints);
363 
364 	  ok = avr_operand (insn, insn2, addr, *constraints, opcode_str, op1, comment1, 0, &sym_op1, &sym_addr1);
365 
366 	  if (ok && *(++constraints) == ',')
367 	    ok = avr_operand (insn, insn2, addr, *(++constraints), opcode_str, op2,
368 			      *comment1 ? comment2 : comment1, regs, &sym_op2, &sym_addr2);
369 	}
370     }
371 
372   if (!ok)
373     {
374       /* Unknown opcode, or invalid combination of operands.  */
375       sprintf (op1, "0x%04x", insn);
376       op2[0] = 0;
377       sprintf (comment1, "????");
378       comment2[0] = 0;
379     }
380 
381   (*prin) (stream, "%s", ok ? opcode->name : ".word");
382 
383   if (*op1)
384       (*prin) (stream, "\t%s", op1);
385 
386   if (*op2)
387     (*prin) (stream, ", %s", op2);
388 
389   if (*comment1)
390     (*prin) (stream, "\t; %s", comment1);
391 
392   if (sym_op1)
393     info->print_address_func (sym_addr1, info);
394 
395   if (*comment2)
396     (*prin) (stream, " %s", comment2);
397 
398   if (sym_op2)
399     info->print_address_func (sym_addr2, info);
400 
401   return cmd_len;
402 }
403