1 /* Disassemble AVR instructions.
2    Copyright 1999, 2000, 2002, 2004, 2005, 2006, 2007, 2008, 2012
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 "sysdep.h"
25 #include <assert.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
avr_operand(unsigned int insn,unsigned int insn2,unsigned int pc,int constraint,char * opcode_str,char * buf,char * comment,int regs,int * sym,bfd_vma * sym_addr)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 	      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       sprintf (buf, "0x%04X", insn2);
189       break;
190 
191     case 'M':
192       sprintf (buf, "0x%02X", ((insn & 0xf00) >> 4) | (insn & 0xf));
193       sprintf (comment, "%d", ((insn & 0xf00) >> 4) | (insn & 0xf));
194       break;
195 
196     case 'n':
197       sprintf (buf, "??");
198       fprintf (stderr, _("Internal disassembler error"));
199       ok = 0;
200       break;
201 
202     case 'K':
203       {
204 	unsigned int x;
205 
206 	x = (insn & 0xf) | ((insn >> 2) & 0x30);
207 	sprintf (buf, "0x%02x", x);
208 	sprintf (comment, "%d", x);
209       }
210       break;
211 
212     case 's':
213       sprintf (buf, "%d", insn & 7);
214       break;
215 
216     case 'S':
217       sprintf (buf, "%d", (insn >> 4) & 7);
218       break;
219 
220     case 'P':
221       {
222 	unsigned int x;
223 
224 	x = (insn & 0xf);
225 	x |= (insn >> 5) & 0x30;
226 	sprintf (buf, "0x%02x", x);
227 	sprintf (comment, "%d", x);
228       }
229       break;
230 
231     case 'p':
232       {
233 	unsigned int x;
234 
235 	x = (insn >> 3) & 0x1f;
236 	sprintf (buf, "0x%02x", x);
237 	sprintf (comment, "%d", x);
238       }
239       break;
240 
241     case 'E':
242       sprintf (buf, "%d", (insn >> 4) & 15);
243       break;
244 
245     case '?':
246       *buf = '\0';
247       break;
248 
249     default:
250       sprintf (buf, "??");
251       fprintf (stderr, _("unknown constraint `%c'"), constraint);
252       ok = 0;
253     }
254 
255     return ok;
256 }
257 
258 static unsigned short
avrdis_opcode(bfd_vma addr,disassemble_info * info)259 avrdis_opcode (bfd_vma addr, disassemble_info *info)
260 {
261   bfd_byte buffer[2];
262   int status;
263 
264   status = info->read_memory_func (addr, buffer, 2, info);
265 
266   if (status == 0)
267     return bfd_getl16 (buffer);
268 
269   info->memory_error_func (status, addr, info);
270   return -1;
271 }
272 
273 
274 int
print_insn_avr(bfd_vma addr,disassemble_info * info)275 print_insn_avr (bfd_vma addr, disassemble_info *info)
276 {
277   unsigned int insn, insn2;
278   const struct avr_opcodes_s *opcode;
279   static unsigned int *maskptr;
280   void *stream = info->stream;
281   fprintf_ftype prin = info->fprintf_func;
282   static unsigned int *avr_bin_masks;
283   static int initialized;
284   int cmd_len = 2;
285   int ok = 0;
286   char op1[20], op2[20], comment1[40], comment2[40];
287   int sym_op1 = 0, sym_op2 = 0;
288   bfd_vma sym_addr1, sym_addr2;
289 
290 
291   if (!initialized)
292     {
293       unsigned int nopcodes;
294 
295       /* PR 4045: Try to avoid duplicating the 0x prefix that
296 	 objdump_print_addr() will put on addresses when there
297 	 is no symbol table available.  */
298       if (info->symtab_size == 0)
299 	comment_start = " ";
300 
301       nopcodes = sizeof (avr_opcodes) / sizeof (struct avr_opcodes_s);
302 
303       avr_bin_masks = xmalloc (nopcodes * sizeof (unsigned int));
304 
305       for (opcode = avr_opcodes, maskptr = avr_bin_masks;
306 	   opcode->name;
307 	   opcode++, maskptr++)
308 	{
309 	  char * s;
310 	  unsigned int bin = 0;
311 	  unsigned int mask = 0;
312 
313 	  for (s = opcode->opcode; *s; ++s)
314 	    {
315 	      bin <<= 1;
316 	      mask <<= 1;
317 	      bin |= (*s == '1');
318 	      mask |= (*s == '1' || *s == '0');
319 	    }
320 	  assert (s - opcode->opcode == 16);
321 	  assert (opcode->bin_opcode == bin);
322 	  *maskptr = mask;
323 	}
324 
325       initialized = 1;
326     }
327 
328   insn = avrdis_opcode (addr, info);
329 
330   for (opcode = avr_opcodes, maskptr = avr_bin_masks;
331        opcode->name;
332        opcode++, maskptr++)
333     if ((insn & *maskptr) == opcode->bin_opcode)
334       break;
335 
336   /* Special case: disassemble `ldd r,b+0' as `ld r,b', and
337      `std b+0,r' as `st b,r' (next entry in the table).  */
338 
339   if (AVR_DISP0_P (insn))
340     opcode++;
341 
342   op1[0] = 0;
343   op2[0] = 0;
344   comment1[0] = 0;
345   comment2[0] = 0;
346 
347   if (opcode->name)
348     {
349       char *constraints = opcode->constraints;
350       char *opcode_str = opcode->opcode;
351 
352       insn2 = 0;
353       ok = 1;
354 
355       if (opcode->insn_size > 1)
356 	{
357 	  insn2 = avrdis_opcode (addr + 2, info);
358 	  cmd_len = 4;
359 	}
360 
361       if (*constraints && *constraints != '?')
362 	{
363 	  int regs = REGISTER_P (*constraints);
364 
365 	  ok = avr_operand (insn, insn2, addr, *constraints, opcode_str, op1, comment1, 0, &sym_op1, &sym_addr1);
366 
367 	  if (ok && *(++constraints) == ',')
368 	    ok = avr_operand (insn, insn2, addr, *(++constraints), opcode_str, op2,
369 			      *comment1 ? comment2 : comment1, regs, &sym_op2, &sym_addr2);
370 	}
371     }
372 
373   if (!ok)
374     {
375       /* Unknown opcode, or invalid combination of operands.  */
376       sprintf (op1, "0x%04x", insn);
377       op2[0] = 0;
378       sprintf (comment1, "????");
379       comment2[0] = 0;
380     }
381 
382   (*prin) (stream, "%s", ok ? opcode->name : ".word");
383 
384   if (*op1)
385       (*prin) (stream, "\t%s", op1);
386 
387   if (*op2)
388     (*prin) (stream, ", %s", op2);
389 
390   if (*comment1)
391     (*prin) (stream, "\t; %s", comment1);
392 
393   if (sym_op1)
394     info->print_address_func (sym_addr1, info);
395 
396   if (*comment2)
397     (*prin) (stream, " %s", comment2);
398 
399   if (sym_op2)
400     info->print_address_func (sym_addr2, info);
401 
402   return cmd_len;
403 }
404