opcodes/a29k-dis.c

   1 /* Instruction printing code for the AMD 29000
   2    Copyright 1990, 1993, 1994, 1995, 1998, 2000, 2001
   3    Free Software Foundation, Inc.
   4    Contributed by Cygnus Support.  Written by Jim Kingdon.
   5
   6 This file is part of GDB.
   7
   8 This program 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 2 of the License, or
  11 (at your option) any later version.
  12
  13 This program is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  21
  22 #include "sysdep.h"
  23 #include "dis-asm.h"
  24 #include "opcode/a29k.h"
  25
  26 static void print_general PARAMS ((int, struct disassemble_info *));
  27 static void print_special PARAMS ((unsigned int, struct disassemble_info *));
  28 static int is_delayed_branch PARAMS ((int));
  29 static void find_bytes_little
  30   PARAMS ((char *, unsigned char *, unsigned char *, unsigned char *,
  31            unsigned char *));
  32 static void find_bytes_big
  33   PARAMS ((char *, unsigned char *, unsigned char *, unsigned char *,
  34            unsigned char *));
  35 static int print_insn PARAMS ((bfd_vma, struct disassemble_info *));
  36
  37
  38 /* Print a symbolic representation of a general-purpose
  39    register number NUM on STREAM.
  40    NUM is a number as found in the instruction, not as found in
  41    debugging symbols; it must be in the range 0-255.  */
  42 static void
  43 print_general (num, info)
  44      int num;
  45      struct disassemble_info *info;
  46 {
  47   if (num < 128)
  48     (*info->fprintf_func) (info->stream, "gr%d", num);
  49   else
  50     (*info->fprintf_func) (info->stream, "lr%d", num - 128);
  51 }
  52
  53 /* Like print_general but a special-purpose register.
  54
  55    The mnemonics used by the AMD assembler are not quite the same
  56    as the ones in the User's Manual.  We use the ones that the
  57    assembler uses.  */
  58 static void
  59 print_special (num, info)
  60      unsigned int num;
  61      struct disassemble_info *info;
  62 {
  63   /* Register names of registers 0-SPEC0_NUM-1.  */
  64   static char *spec0_names[] = {
  65     "vab", "ops", "cps", "cfg", "cha", "chd", "chc", "rbp", "tmc", "tmr",
  66     "pc0", "pc1", "pc2", "mmu", "lru", "rsn", "rma0", "rmc0", "rma1", "rmc1",
  67     "spc0", "spc1", "spc2", "iba0", "ibc0", "iba1", "ibc1", "dba", "dbc",
  68     "cir", "cdr"
  69     };
  70 #define SPEC0_NUM ((sizeof spec0_names) / (sizeof spec0_names[0]))
  71
  72   /* Register names of registers 128-128+SPEC128_NUM-1.  */
  73   static char *spec128_names[] = {
  74     "ipc", "ipa", "ipb", "q", "alu", "bp", "fc", "cr"
  75     };
  76 #define SPEC128_NUM ((sizeof spec128_names) / (sizeof spec128_names[0]))
  77
  78   /* Register names of registers 160-160+SPEC160_NUM-1.  */
  79   static char *spec160_names[] = {
  80     "fpe", "inte", "fps", "sr163", "exop"
  81     };
  82 #define SPEC160_NUM ((sizeof spec160_names) / (sizeof spec160_names[0]))
  83
  84   if (num < SPEC0_NUM)
  85     (*info->fprintf_func) (info->stream, spec0_names[num]);
  86   else if (num >= 128 && num < 128 + SPEC128_NUM)
  87     (*info->fprintf_func) (info->stream, spec128_names[num-128]);
  88   else if (num >= 160 && num < 160 + SPEC160_NUM)
  89     (*info->fprintf_func) (info->stream, spec160_names[num-160]);
  90   else
  91     (*info->fprintf_func) (info->stream, "sr%d", num);
  92 }
  93
  94 /* Is an instruction with OPCODE a delayed branch?  */
  95 static int
  96 is_delayed_branch (opcode)
  97      int opcode;
  98 {
  99   return (opcode == 0xa8 || opcode == 0xa9 || opcode == 0xa0 || opcode == 0xa1
 100           || opcode == 0xa4 || opcode == 0xa5
 101           || opcode == 0xb4 || opcode == 0xb5
 102           || opcode == 0xc4 || opcode == 0xc0
 103           || opcode == 0xac || opcode == 0xad
 104           || opcode == 0xcc);
 105 }
 106
 107 /* Now find the four bytes of INSN and put them in *INSN{0,8,16,24}.  */
 108 static void
 109 find_bytes_big (insn, insn0, insn8, insn16, insn24)
 110      char *insn;
 111      unsigned char *insn0;
 112      unsigned char *insn8;
 113      unsigned char *insn16;
 114      unsigned char *insn24;
 115 {
 116   *insn24 = insn[0];
 117   *insn16 = insn[1];
 118   *insn8  = insn[2];
 119   *insn0  = insn[3];
 120 }
 121
 122 static void
 123 find_bytes_little (insn, insn0, insn8, insn16, insn24)
 124      char *insn;
 125      unsigned char *insn0;
 126      unsigned char *insn8;
 127      unsigned char *insn16;
 128      unsigned char *insn24;
 129 {
 130   *insn24 = insn[3];
 131   *insn16 = insn[2];
 132   *insn8 = insn[1];
 133   *insn0 = insn[0];
 134 }
 135
 136 typedef void (*find_byte_func_type)
 137      PARAMS ((char *, unsigned char *, unsigned char *,
 138               unsigned char *, unsigned char *));
 139
 140 /* Print one instruction from MEMADDR on INFO->STREAM.
 141    Return the size of the instruction (always 4 on a29k).  */
 142
 143 static int
 144 print_insn (memaddr, info)
 145      bfd_vma memaddr;
 146      struct disassemble_info *info;
 147 {
 148   /* The raw instruction.  */
 149   char insn[4];
 150
 151   /* The four bytes of the instruction.  */
 152   unsigned char insn24, insn16, insn8, insn0;
 153
 154   find_byte_func_type find_byte_func = (find_byte_func_type)info->private_data;
 155
 156   struct a29k_opcode CONST * opcode;
 157
 158   {
 159     int status =
 160       (*info->read_memory_func) (memaddr, (bfd_byte *) &insn[0], 4, info);
 161     if (status != 0)
 162       {
 163         (*info->memory_error_func) (status, memaddr, info);
 164         return -1;
 165       }
 166   }
 167
 168   (*find_byte_func) (insn, &insn0, &insn8, &insn16, &insn24);
 169
 170   printf ("%02x%02x%02x%02x ", insn24, insn16, insn8, insn0);
 171
 172   /* Handle the nop (aseq 0x40,gr1,gr1) specially */
 173   if ((insn24==0x70) && (insn16==0x40) && (insn8==0x01) && (insn0==0x01)) {
 174     (*info->fprintf_func) (info->stream,"nop");
 175     return 4;
 176   }
 177
 178   /* The opcode is always in insn24.  */
 179   for (opcode = &a29k_opcodes[0];
 180        opcode < &a29k_opcodes[num_opcodes];
 181        ++opcode)
 182     {
 183       if (((unsigned long) insn24 << 24) == opcode->opcode)
 184         {
 185           char *s;
 186
 187           (*info->fprintf_func) (info->stream, "%s ", opcode->name);
 188           for (s = opcode->args; *s != '\0'; ++s)
 189             {
 190               switch (*s)
 191                 {
 192                 case 'a':
 193                   print_general (insn8, info);
 194                   break;
 195
 196                 case 'b':
 197                   print_general (insn0, info);
 198                   break;
 199
 200                 case 'c':
 201                   print_general (insn16, info);
 202                   break;
 203
 204                 case 'i':
 205                   (*info->fprintf_func) (info->stream, "%d", insn0);
 206                   break;
 207
 208                 case 'x':
 209                   (*info->fprintf_func) (info->stream, "0x%x", (insn16 << 8) + insn0);
 210                   break;
 211
 212                 case 'h':
 213                   /* This used to be %x for binutils.  */
 214                   (*info->fprintf_func) (info->stream, "0x%x",
 215                                     (insn16 << 24) + (insn0 << 16));
 216                   break;
 217
 218                 case 'X':
 219                   (*info->fprintf_func) (info->stream, "%d",
 220                                     ((insn16 << 8) + insn0) | 0xffff0000);
 221                   break;
 222
 223                 case 'P':
 224                   /* This output looks just like absolute addressing, but
 225                      maybe that's OK (it's what the GDB m68k and EBMON
 226                      a29k disassemblers do).  */
 227                   /* All the shifting is to sign-extend it.  p*/
 228                   (*info->print_address_func)
 229                     (memaddr +
 230                      (((int)((insn16 << 10) + (insn0 << 2)) << 14) >> 14),
 231                      info);
 232                   break;
 233
 234                 case 'A':
 235                   (*info->print_address_func)
 236                     ((insn16 << 10) + (insn0 << 2), info);
 237                   break;
 238
 239                 case 'e':
 240                   (*info->fprintf_func) (info->stream, "%d", insn16 >> 7);
 241                   break;
 242
 243                 case 'n':
 244                   (*info->fprintf_func) (info->stream, "0x%x", insn16 & 0x7f);
 245                   break;
 246
 247                 case 'v':
 248                   (*info->fprintf_func) (info->stream, "0x%x", insn16);
 249                   break;
 250
 251                 case 's':
 252                   print_special (insn8, info);
 253                   break;
 254
 255                 case 'u':
 256                   (*info->fprintf_func) (info->stream, "%d", insn0 >> 7);
 257                   break;
 258
 259                 case 'r':
 260                   (*info->fprintf_func) (info->stream, "%d", (insn0 >> 4) & 7);
 261                   break;
 262
 263                 case 'I':
 264                   if ((insn16 & 3) != 0)
 265                     (*info->fprintf_func) (info->stream, "%d", insn16 & 3);
 266                   break;
 267
 268                 case 'd':
 269                   (*info->fprintf_func) (info->stream, "%d", (insn0 >> 2) & 3);
 270                   break;
 271
 272                 case 'f':
 273                   (*info->fprintf_func) (info->stream, "%d", insn0 & 3);
 274                   break;
 275
 276                 case 'F':
 277                   (*info->fprintf_func) (info->stream, "%d", (insn16 >> 2) & 15);
 278                   break;
 279
 280                 case 'C':
 281                   (*info->fprintf_func) (info->stream, "%d", insn16 & 3);
 282                   break;
 283
 284                 default:
 285                   (*info->fprintf_func) (info->stream, "%c", *s);
 286                 }
 287             }
 288
 289           /* Now we look for a const,consth pair of instructions,
 290              in which case we try to print the symbolic address.  */
 291           if (insn24 == 2)  /* consth */
 292             {
 293               int errcode;
 294               char prev_insn[4];
 295               unsigned char prev_insn0, prev_insn8, prev_insn16, prev_insn24;
 296
 297               errcode = (*info->read_memory_func) (memaddr - 4,
 298                                                    (bfd_byte *) &prev_insn[0],
 299                                                    4,
 300                                                    info);
 301               if (errcode == 0)
 302                 {
 303                   /* If it is a delayed branch, we need to look at the
 304                      instruction before the delayed brach to handle
 305                      things like
 306
 307                      const _foo
 308                      call _printf
 309                      consth _foo
 310                      */
 311                   (*find_byte_func) (prev_insn, &prev_insn0, &prev_insn8,
 312                                      &prev_insn16, &prev_insn24);
 313                   if (is_delayed_branch (prev_insn24))
 314                     {
 315                       errcode = (*info->read_memory_func)
 316                         (memaddr - 8, (bfd_byte *) &prev_insn[0], 4, info);
 317                       (*find_byte_func) (prev_insn, &prev_insn0, &prev_insn8,
 318                                          &prev_insn16, &prev_insn24);
 319                     }
 320                 }
 321
 322               /* If there was a problem reading memory, then assume
 323                  the previous instruction was not const.  */
 324               if (errcode == 0)
 325                 {
 326                   /* Is it const to the same register?  */
 327                   if (prev_insn24 == 3
 328                       && prev_insn8 == insn8)
 329                     {
 330                       (*info->fprintf_func) (info->stream, "\t; ");
 331                       (*info->print_address_func)
 332                         (((insn16 << 24) + (insn0 << 16)
 333                           + (prev_insn16 << 8) + (prev_insn0)),
 334                          info);
 335                     }
 336                 }
 337             }
 338
 339           return 4;
 340         }
 341     }
 342   /* This used to be %8x for binutils.  */
 343   (*info->fprintf_func)
 344     (info->stream, ".word 0x%08x",
 345      (insn24 << 24) + (insn16 << 16) + (insn8 << 8) + insn0);
 346   return 4;
 347 }
 348
 349 /* Disassemble an big-endian a29k instruction.  */
 350 int
 351 print_insn_big_a29k (memaddr, info)
 352      bfd_vma memaddr;
 353      struct disassemble_info *info;
 354 {
 355   info->private_data = (PTR) find_bytes_big;
 356   return print_insn (memaddr, info);
 357 }
 358
 359 /* Disassemble a little-endian a29k instruction.  */
 360 int
 361 print_insn_little_a29k (memaddr, info)
 362      bfd_vma memaddr;
 363      struct disassemble_info *info;
 364 {
 365   info->private_data = (PTR) find_bytes_little;
 366   return print_insn (memaddr, info);
 367 }