1 /* Disassemble AVR instructions.
2    Copyright 1999, 2000, 2002, 2004, 2005, 2006, 2007
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 *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 	sprintf (buf, xyz);
113 
114 	if (AVR_UNDEF_P (insn))
115 	  sprintf (comment, _("undefined"));
116       }
117       break;
118 
119     case 'z':
120       *buf++ = 'Z';
121       if (insn & 0x1)
122 	*buf++ = '+';
123       *buf = '\0';
124       if (AVR_UNDEF_P (insn))
125 	sprintf (comment, _("undefined"));
126       break;
127 
128     case 'b':
129       {
130 	unsigned int x;
131 
132 	x = (insn & 7);
133 	x |= (insn >> 7) & (3 << 3);
134 	x |= (insn >> 8) & (1 << 5);
135 
136 	if (insn & 0x8)
137 	  *buf++ = 'Y';
138 	else
139 	  *buf++ = 'Z';
140 	sprintf (buf, "+%d", x);
141 	sprintf (comment, "0x%02x", x);
142       }
143       break;
144 
145     case 'h':
146       *sym = 1;
147       *sym_addr = ((((insn & 1) | ((insn & 0x1f0) >> 3)) << 16) | insn2) * 2;
148       /* See PR binutils/2454.  Ideally we would like to display the hex
149 	 value of the address only once, but this would mean recoding
150 	 objdump_print_address() which would affect many targets.  */
151       sprintf (buf, "%#lx", (unsigned long) *sym_addr);
152       sprintf (comment, comment_start);
153       break;
154 
155     case 'L':
156       {
157 	int rel_addr = (((insn & 0xfff) ^ 0x800) - 0x800) * 2;
158 	sprintf (buf, ".%+-8d", rel_addr);
159         *sym = 1;
160         *sym_addr = pc + 2 + rel_addr;
161 	sprintf (comment, comment_start);
162       }
163       break;
164 
165     case 'l':
166       {
167 	int rel_addr = ((((insn >> 3) & 0x7f) ^ 0x40) - 0x40) * 2;
168 
169 	sprintf (buf, ".%+-8d", rel_addr);
170         *sym = 1;
171         *sym_addr = pc + 2 + rel_addr;
172 	sprintf (comment, comment_start);
173       }
174       break;
175 
176     case 'i':
177       sprintf (buf, "0x%04X", insn2);
178       break;
179 
180     case 'M':
181       sprintf (buf, "0x%02X", ((insn & 0xf00) >> 4) | (insn & 0xf));
182       sprintf (comment, "%d", ((insn & 0xf00) >> 4) | (insn & 0xf));
183       break;
184 
185     case 'n':
186       sprintf (buf, "??");
187       fprintf (stderr, _("Internal disassembler error"));
188       ok = 0;
189       break;
190 
191     case 'K':
192       {
193 	unsigned int x;
194 
195 	x = (insn & 0xf) | ((insn >> 2) & 0x30);
196 	sprintf (buf, "0x%02x", x);
197 	sprintf (comment, "%d", x);
198       }
199       break;
200 
201     case 's':
202       sprintf (buf, "%d", insn & 7);
203       break;
204 
205     case 'S':
206       sprintf (buf, "%d", (insn >> 4) & 7);
207       break;
208 
209     case 'P':
210       {
211 	unsigned int x;
212 
213 	x = (insn & 0xf);
214 	x |= (insn >> 5) & 0x30;
215 	sprintf (buf, "0x%02x", x);
216 	sprintf (comment, "%d", x);
217       }
218       break;
219 
220     case 'p':
221       {
222 	unsigned int x;
223 
224 	x = (insn >> 3) & 0x1f;
225 	sprintf (buf, "0x%02x", x);
226 	sprintf (comment, "%d", x);
227       }
228       break;
229 
230     case '?':
231       *buf = '\0';
232       break;
233 
234     default:
235       sprintf (buf, "??");
236       fprintf (stderr, _("unknown constraint `%c'"), constraint);
237       ok = 0;
238     }
239 
240     return ok;
241 }
242 
243 static unsigned short
244 avrdis_opcode (bfd_vma addr, disassemble_info *info)
245 {
246   bfd_byte buffer[2];
247   int status;
248 
249   status = info->read_memory_func (addr, buffer, 2, info);
250 
251   if (status == 0)
252     return bfd_getl16 (buffer);
253 
254   info->memory_error_func (status, addr, info);
255   return -1;
256 }
257 
258 
259 int
260 print_insn_avr (bfd_vma addr, disassemble_info *info)
261 {
262   unsigned int insn, insn2;
263   const struct avr_opcodes_s *opcode;
264   static unsigned int *maskptr;
265   void *stream = info->stream;
266   fprintf_ftype prin = info->fprintf_func;
267   static unsigned int *avr_bin_masks;
268   static int initialized;
269   int cmd_len = 2;
270   int ok = 0;
271   char op1[20], op2[20], comment1[40], comment2[40];
272   int sym_op1 = 0, sym_op2 = 0;
273   bfd_vma sym_addr1, sym_addr2;
274 
275 
276   if (!initialized)
277     {
278       unsigned int nopcodes;
279 
280       /* PR 4045: Try to avoid duplicating the 0x prefix that
281 	 objdump_print_addr() will put on addresses when there
282 	 is no symbol table available.  */
283       if (info->symtab_size == 0)
284 	comment_start = " ";
285 
286       nopcodes = sizeof (avr_opcodes) / sizeof (struct avr_opcodes_s);
287 
288       avr_bin_masks = xmalloc (nopcodes * sizeof (unsigned int));
289 
290       for (opcode = avr_opcodes, maskptr = avr_bin_masks;
291 	   opcode->name;
292 	   opcode++, maskptr++)
293 	{
294 	  char * s;
295 	  unsigned int bin = 0;
296 	  unsigned int mask = 0;
297 
298 	  for (s = opcode->opcode; *s; ++s)
299 	    {
300 	      bin <<= 1;
301 	      mask <<= 1;
302 	      bin |= (*s == '1');
303 	      mask |= (*s == '1' || *s == '0');
304 	    }
305 	  assert (s - opcode->opcode == 16);
306 	  assert (opcode->bin_opcode == bin);
307 	  *maskptr = mask;
308 	}
309 
310       initialized = 1;
311     }
312 
313   insn = avrdis_opcode (addr, info);
314 
315   for (opcode = avr_opcodes, maskptr = avr_bin_masks;
316        opcode->name;
317        opcode++, maskptr++)
318     if ((insn & *maskptr) == opcode->bin_opcode)
319       break;
320 
321   /* Special case: disassemble `ldd r,b+0' as `ld r,b', and
322      `std b+0,r' as `st b,r' (next entry in the table).  */
323 
324   if (AVR_DISP0_P (insn))
325     opcode++;
326 
327   op1[0] = 0;
328   op2[0] = 0;
329   comment1[0] = 0;
330   comment2[0] = 0;
331 
332   if (opcode->name)
333     {
334       char *op = opcode->constraints;
335 
336       insn2 = 0;
337       ok = 1;
338 
339       if (opcode->insn_size > 1)
340 	{
341 	  insn2 = avrdis_opcode (addr + 2, info);
342 	  cmd_len = 4;
343 	}
344 
345       if (*op && *op != '?')
346 	{
347 	  int regs = REGISTER_P (*op);
348 
349 	  ok = avr_operand (insn, insn2, addr, *op, op1, comment1, 0, &sym_op1, &sym_addr1);
350 
351 	  if (ok && *(++op) == ',')
352 	    ok = avr_operand (insn, insn2, addr, *(++op), op2,
353 			      *comment1 ? comment2 : comment1, regs, &sym_op2, &sym_addr2);
354 	}
355     }
356 
357   if (!ok)
358     {
359       /* Unknown opcode, or invalid combination of operands.  */
360       sprintf (op1, "0x%04x", insn);
361       op2[0] = 0;
362       sprintf (comment1, "????");
363       comment2[0] = 0;
364     }
365 
366   (*prin) (stream, "%s", ok ? opcode->name : ".word");
367 
368   if (*op1)
369       (*prin) (stream, "\t%s", op1);
370 
371   if (*op2)
372     (*prin) (stream, ", %s", op2);
373 
374   if (*comment1)
375     (*prin) (stream, "\t; %s", comment1);
376 
377   if (sym_op1)
378     info->print_address_func (sym_addr1, info);
379 
380   if (*comment2)
381     (*prin) (stream, " %s", comment2);
382 
383   if (sym_op2)
384     info->print_address_func (sym_addr2, info);
385 
386   return cmd_len;
387 }
388