xref: /openbsd-src/gnu/usr.bin/binutils/opcodes/avr-dis.c (revision db3296cf5c1dd9058ceecc3a29fe4aaa0bd26000)
1 /* Disassemble AVR instructions.
2    Copyright 1999, 2000 Free Software Foundation, Inc.
3 
4    Contributed by Denis Chertykov <denisc@overta.ru>
5 
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
10 
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 GNU General Public License for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
19 
20 #include <assert.h>
21 #include "sysdep.h"
22 #include "dis-asm.h"
23 #include "opintl.h"
24 
25 
26 struct avr_opcodes_s
27 {
28   char *name;
29   char *constraints;
30   char *opcode;
31   int insn_size;		/* in words */
32   int isa;
33   unsigned int bin_opcode;
34   unsigned int bin_mask;
35 };
36 
37 #define AVR_INSN(NAME, CONSTR, OPCODE, SIZE, ISA, BIN) \
38 {#NAME, CONSTR, OPCODE, SIZE, ISA, BIN, 0},
39 
40 struct avr_opcodes_s avr_opcodes[] =
41 {
42   #include "opcode/avr.h"
43   {NULL, NULL, NULL, 0, 0, 0, 0}
44 };
45 
46 static int avr_operand PARAMS ((unsigned int, unsigned int,
47 				unsigned int, int, char *, char *, int));
48 
49 static int
50 avr_operand (insn, insn2, pc, constraint, buf, comment, regs)
51      unsigned int insn;
52      unsigned int insn2;
53      unsigned int pc;
54      int constraint;
55      char *buf;
56      char *comment;
57      int regs;
58 {
59   int ok = 1;
60 
61   switch (constraint)
62     {
63       /* Any register operand.  */
64     case 'r':
65       if (regs)
66 	insn = (insn & 0xf) | ((insn & 0x0200) >> 5); /* source register */
67       else
68 	insn = (insn & 0x01f0) >> 4; /* destination register */
69 
70       sprintf (buf, "r%d", insn);
71       break;
72 
73     case 'd':
74       if (regs)
75 	sprintf (buf, "r%d", 16 + (insn & 0xf));
76       else
77 	sprintf (buf, "r%d", 16 + ((insn & 0xf0) >> 4));
78       break;
79 
80     case 'w':
81       sprintf (buf, "r%d", 24 + ((insn & 0x30) >> 3));
82       break;
83 
84     case 'a':
85       if (regs)
86 	sprintf (buf, "r%d", 16 + (insn & 7));
87       else
88 	sprintf (buf, "r%d", 16 + ((insn >> 4) & 7));
89       break;
90 
91     case 'v':
92       if (regs)
93 	sprintf (buf, "r%d", (insn & 0xf) * 2);
94       else
95 	sprintf (buf, "r%d", ((insn & 0xf0) >> 3));
96       break;
97 
98     case 'e':
99       {
100 	char *xyz;
101 
102 	switch (insn & 0x100f)
103 	  {
104 	    case 0x0000: xyz = "Z";  break;
105 	    case 0x1001: xyz = "Z+"; break;
106 	    case 0x1002: xyz = "-Z"; break;
107 	    case 0x0008: xyz = "Y";  break;
108 	    case 0x1009: xyz = "Y+"; break;
109 	    case 0x100a: xyz = "-Y"; break;
110 	    case 0x100c: xyz = "X";  break;
111 	    case 0x100d: xyz = "X+"; break;
112 	    case 0x100e: xyz = "-X"; break;
113 	    default: xyz = "??"; ok = 0;
114 	  }
115 	sprintf (buf, xyz);
116 
117 	if (AVR_UNDEF_P (insn))
118 	  sprintf (comment, _("undefined"));
119       }
120       break;
121 
122     case 'z':
123       *buf++ = 'Z';
124       if (insn & 0x1)
125 	*buf++ = '+';
126       *buf = '\0';
127       if (AVR_UNDEF_P (insn))
128 	sprintf (comment, _("undefined"));
129       break;
130 
131     case 'b':
132       {
133 	unsigned int x;
134 
135 	x = (insn & 7);
136 	x |= (insn >> 7) & (3 << 3);
137 	x |= (insn >> 8) & (1 << 5);
138 
139 	if (insn & 0x8)
140 	  *buf++ = 'Y';
141 	else
142 	  *buf++ = 'Z';
143 	sprintf (buf, "+%d", x);
144 	sprintf (comment, "0x%02x", x);
145       }
146       break;
147 
148     case 'h':
149       sprintf (buf, "0x%x",
150 	       ((((insn & 1) | ((insn & 0x1f0) >> 3)) << 16) | insn2) * 2);
151       break;
152 
153     case 'L':
154       {
155 	int rel_addr = (((insn & 0xfff) ^ 0x800) - 0x800) * 2;
156 	sprintf (buf, ".%+-8d", rel_addr);
157 	sprintf (comment, "0x%x", pc + 2 + rel_addr);
158       }
159       break;
160 
161     case 'l':
162       {
163 	int rel_addr = ((((insn >> 3) & 0x7f) ^ 0x40) - 0x40) * 2;
164 	sprintf (buf, ".%+-8d", rel_addr);
165 	sprintf (comment, "0x%x", pc + 2 + rel_addr);
166       }
167       break;
168 
169     case 'i':
170       sprintf (buf, "0x%04X", insn2);
171       break;
172 
173     case 'M':
174       sprintf (buf, "0x%02X", ((insn & 0xf00) >> 4) | (insn & 0xf));
175       sprintf (comment, "%d", ((insn & 0xf00) >> 4) | (insn & 0xf));
176       break;
177 
178     case 'n':
179       sprintf (buf, "??");
180       fprintf (stderr, _("Internal disassembler error"));
181       ok = 0;
182       break;
183 
184     case 'K':
185       {
186 	unsigned int x;
187 
188 	x = (insn & 0xf) | ((insn >> 2) & 0x30);
189 	sprintf (buf, "0x%02x", x);
190 	sprintf (comment, "%d", x);
191       }
192       break;
193 
194     case 's':
195       sprintf (buf, "%d", insn & 7);
196       break;
197 
198     case 'S':
199       sprintf (buf, "%d", (insn >> 4) & 7);
200       break;
201 
202     case 'P':
203       {
204 	unsigned int x;
205 	x = (insn & 0xf);
206 	x |= (insn >> 5) & 0x30;
207 	sprintf (buf, "0x%02x", x);
208 	sprintf (comment, "%d", x);
209       }
210       break;
211 
212     case 'p':
213       {
214 	unsigned int x;
215 
216 	x = (insn >> 3) & 0x1f;
217 	sprintf (buf, "0x%02x", x);
218 	sprintf (comment, "%d", x);
219       }
220       break;
221 
222     case '?':
223       *buf = '\0';
224       break;
225 
226     default:
227       sprintf (buf, "??");
228       fprintf (stderr, _("unknown constraint `%c'"), constraint);
229       ok = 0;
230     }
231 
232     return ok;
233 }
234 
235 static unsigned short avrdis_opcode PARAMS ((bfd_vma, disassemble_info *));
236 
237 static unsigned short
238 avrdis_opcode (addr, info)
239      bfd_vma addr;
240      disassemble_info *info;
241 {
242   bfd_byte buffer[2];
243   int status;
244   status = info->read_memory_func(addr, buffer, 2, info);
245   if (status != 0)
246     {
247       info->memory_error_func(status, addr, info);
248       return -1;
249     }
250   return bfd_getl16 (buffer);
251 }
252 
253 
254 int
255 print_insn_avr(addr, info)
256      bfd_vma addr;
257      disassemble_info *info;
258 {
259   unsigned int insn, insn2;
260   struct avr_opcodes_s *opcode;
261   void *stream = info->stream;
262   fprintf_ftype prin = info->fprintf_func;
263   static int initialized;
264   int cmd_len = 2;
265   int ok = 0;
266   char op1[20], op2[20], comment1[40], comment2[40];
267 
268   if (!initialized)
269     {
270       initialized = 1;
271 
272       for (opcode = avr_opcodes; opcode->name; opcode++)
273 	{
274 	  char * s;
275 	  unsigned int bin = 0;
276 	  unsigned int mask = 0;
277 
278 	  for (s = opcode->opcode; *s; ++s)
279 	    {
280 	      bin <<= 1;
281 	      mask <<= 1;
282 	      bin |= (*s == '1');
283 	      mask |= (*s == '1' || *s == '0');
284 	    }
285 	  assert (s - opcode->opcode == 16);
286 	  assert (opcode->bin_opcode == bin);
287 	  opcode->bin_mask = mask;
288 	}
289     }
290 
291   insn = avrdis_opcode (addr, info);
292 
293   for (opcode = avr_opcodes; opcode->name; opcode++)
294     {
295       if ((insn & opcode->bin_mask) == opcode->bin_opcode)
296 	break;
297     }
298 
299   /* Special case: disassemble `ldd r,b+0' as `ld r,b', and
300      `std b+0,r' as `st b,r' (next entry in the table).  */
301 
302   if (AVR_DISP0_P (insn))
303     opcode++;
304 
305   op1[0] = 0;
306   op2[0] = 0;
307   comment1[0] = 0;
308   comment2[0] = 0;
309 
310   if (opcode->name)
311     {
312       char *op = opcode->constraints;
313 
314       insn2 = 0;
315       ok = 1;
316 
317       if (opcode->insn_size > 1)
318 	{
319 	  insn2 = avrdis_opcode (addr + 2, info);
320 	  cmd_len = 4;
321 	}
322 
323       if (*op && *op != '?')
324 	{
325 	  int regs = REGISTER_P (*op);
326 
327 	  ok = avr_operand (insn, insn2, addr, *op, op1, comment1, 0);
328 
329 	  if (ok && *(++op) == ',')
330 	    ok = avr_operand (insn, insn2, addr, *(++op), op2,
331 			      *comment1 ? comment2 : comment1, regs);
332 	}
333     }
334 
335   if (!ok)
336     {
337       /* Unknown opcode, or invalid combination of operands.  */
338       sprintf (op1, "0x%04x", insn);
339       op2[0] = 0;
340       sprintf (comment1, "????");
341       comment2[0] = 0;
342     }
343 
344   (*prin) (stream, "%s", ok ? opcode->name : ".word");
345 
346   if (*op1)
347     (*prin) (stream, "\t%s", op1);
348 
349   if (*op2)
350     (*prin) (stream, ", %s", op2);
351 
352   if (*comment1)
353     (*prin) (stream, "\t; %s", comment1);
354 
355   if (*comment2)
356     (*prin) (stream, " %s", comment2);
357 
358   return cmd_len;
359 }
360