opcodes/avr-dis.c

   1 /* Disassemble AVR instructions.
   2    Copyright (C) 1999-2017 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 "dis-asm.h"
  26 #include "opintl.h"
  27 #include "libiberty.h"
  28 #include "bfd_stdint.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               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         *sym = 1;
 202         *sym_addr = val | 0x800000;
 203         sprintf (buf, "0x%02x", val);
 204         strcpy (comment, comment_start);
 205       }
 206       break;
 207
 208     case 'M':
 209       sprintf (buf, "0x%02X", ((insn & 0xf00) >> 4) | (insn & 0xf));
 210       sprintf (comment, "%d", ((insn & 0xf00) >> 4) | (insn & 0xf));
 211       break;
 212
 213     case 'n':
 214       sprintf (buf, "??");
 215       fprintf (stderr, _("Internal disassembler error"));
 216       ok = 0;
 217       break;
 218
 219     case 'K':
 220       {
 221         unsigned int x;
 222
 223         x = (insn & 0xf) | ((insn >> 2) & 0x30);
 224         sprintf (buf, "0x%02x", x);
 225         sprintf (comment, "%d", x);
 226       }
 227       break;
 228
 229     case 's':
 230       sprintf (buf, "%d", insn & 7);
 231       break;
 232
 233     case 'S':
 234       sprintf (buf, "%d", (insn >> 4) & 7);
 235       break;
 236
 237     case 'P':
 238       {
 239         unsigned int x;
 240
 241         x = (insn & 0xf);
 242         x |= (insn >> 5) & 0x30;
 243         sprintf (buf, "0x%02x", x);
 244         sprintf (comment, "%d", x);
 245       }
 246       break;
 247
 248     case 'p':
 249       {
 250         unsigned int x;
 251
 252         x = (insn >> 3) & 0x1f;
 253         sprintf (buf, "0x%02x", x);
 254         sprintf (comment, "%d", x);
 255       }
 256       break;
 257
 258     case 'E':
 259       sprintf (buf, "%d", (insn >> 4) & 15);
 260       break;
 261
 262     case '?':
 263       *buf = '\0';
 264       break;
 265
 266     default:
 267       sprintf (buf, "??");
 268       fprintf (stderr, _("unknown constraint `%c'"), constraint);
 269       ok = 0;
 270     }
 271
 272     return ok;
 273 }
 274
 275 /* Read the opcode from ADDR.  Return 0 in success and save opcode
 276    in *INSN, otherwise, return -1.  */
 277
 278 static int
 279 avrdis_opcode (bfd_vma addr, disassemble_info *info, uint16_t *insn)
 280 {
 281   bfd_byte buffer[2];
 282   int status;
 283
 284   status = info->read_memory_func (addr, buffer, 2, info);
 285
 286   if (status == 0)
 287     {
 288       *insn = bfd_getl16 (buffer);
 289       return 0;
 290     }
 291
 292   info->memory_error_func (status, addr, info);
 293   return -1;
 294 }
 295
 296
 297 int
 298 print_insn_avr (bfd_vma addr, disassemble_info *info)
 299 {
 300   uint16_t insn, insn2;
 301   const struct avr_opcodes_s *opcode;
 302   static unsigned int *maskptr;
 303   void *stream = info->stream;
 304   fprintf_ftype prin = info->fprintf_func;
 305   static unsigned int *avr_bin_masks;
 306   static int initialized;
 307   int cmd_len = 2;
 308   int ok = 0;
 309   char op1[20], op2[20], comment1[40], comment2[40];
 310   int sym_op1 = 0, sym_op2 = 0;
 311   bfd_vma sym_addr1, sym_addr2;
 312
 313
 314   if (!initialized)
 315     {
 316       unsigned int nopcodes;
 317
 318       /* PR 4045: Try to avoid duplicating the 0x prefix that
 319          objdump_print_addr() will put on addresses when there
 320          is no symbol table available.  */
 321       if (info->symtab_size == 0)
 322         comment_start = " ";
 323
 324       nopcodes = sizeof (avr_opcodes) / sizeof (struct avr_opcodes_s);
 325
 326       avr_bin_masks = xmalloc (nopcodes * sizeof (unsigned int));
 327
 328       for (opcode = avr_opcodes, maskptr = avr_bin_masks;
 329            opcode->name;
 330            opcode++, maskptr++)
 331         {
 332           char * s;
 333           unsigned int bin = 0;
 334           unsigned int mask = 0;
 335
 336           for (s = opcode->opcode; *s; ++s)
 337             {
 338               bin <<= 1;
 339               mask <<= 1;
 340               bin |= (*s == '1');
 341               mask |= (*s == '1' || *s == '0');
 342             }
 343           assert (s - opcode->opcode == 16);
 344           assert (opcode->bin_opcode == bin);
 345           *maskptr = mask;
 346         }
 347
 348       initialized = 1;
 349     }
 350
 351   if (avrdis_opcode (addr, info, &insn)  != 0)
 352     return -1;
 353
 354   for (opcode = avr_opcodes, maskptr = avr_bin_masks;
 355        opcode->name;
 356        opcode++, maskptr++)
 357     {
 358       if ((opcode->isa == AVR_ISA_TINY) && (info->mach != bfd_mach_avrtiny))
 359         continue;
 360       if ((insn & *maskptr) == opcode->bin_opcode)
 361         break;
 362     }
 363
 364   /* Special case: disassemble `ldd r,b+0' as `ld r,b', and
 365      `std b+0,r' as `st b,r' (next entry in the table).  */
 366
 367   if (AVR_DISP0_P (insn))
 368     opcode++;
 369
 370   op1[0] = 0;
 371   op2[0] = 0;
 372   comment1[0] = 0;
 373   comment2[0] = 0;
 374
 375   if (opcode->name)
 376     {
 377       char *constraints = opcode->constraints;
 378       char *opcode_str = opcode->opcode;
 379
 380       insn2 = 0;
 381       ok = 1;
 382
 383       if (opcode->insn_size > 1)
 384         {
 385           if (avrdis_opcode (addr + 2, info, &insn2) != 0)
 386             return -1;
 387           cmd_len = 4;
 388         }
 389
 390       if (*constraints && *constraints != '?')
 391         {
 392           int regs = REGISTER_P (*constraints);
 393
 394           ok = avr_operand (insn, insn2, addr, *constraints, opcode_str, op1, comment1, 0, &sym_op1, &sym_addr1);
 395
 396           if (ok && *(++constraints) == ',')
 397             ok = avr_operand (insn, insn2, addr, *(++constraints), opcode_str, op2,
 398                               *comment1 ? comment2 : comment1, regs, &sym_op2, &sym_addr2);
 399         }
 400     }
 401
 402   if (!ok)
 403     {
 404       /* Unknown opcode, or invalid combination of operands.  */
 405       sprintf (op1, "0x%04x", insn);
 406       op2[0] = 0;
 407       sprintf (comment1, "????");
 408       comment2[0] = 0;
 409     }
 410
 411   (*prin) (stream, "%s", ok ? opcode->name : ".word");
 412
 413   if (*op1)
 414       (*prin) (stream, "\t%s", op1);
 415
 416   if (*op2)
 417     (*prin) (stream, ", %s", op2);
 418
 419   if (*comment1)
 420     (*prin) (stream, "\t; %s", comment1);
 421
 422   if (sym_op1)
 423     info->print_address_func (sym_addr1, info);
 424
 425   if (*comment2)
 426     (*prin) (stream, " %s", comment2);
 427
 428   if (sym_op2)
 429     info->print_address_func (sym_addr2, info);
 430
 431   return cmd_len;
 432 }