opcodes/xgate-dis.c

   1 /* xgate-dis.c -- Freescale XGATE disassembly
   2    Copyright (C) 2009-2021 Free Software Foundation, Inc.
   3    Written by Sean Keys (skeys@ipdatasys.com)
   4
   5    This file is part of the GNU opcodes library.
   6
   7    This library is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3, or (at your option)
  10    any later version.
  11
  12    It is distributed in the hope that it will be useful, but WITHOUT
  13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  15    License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  20    MA 02110-1301, USA.  */
  21
  22 #include "sysdep.h"
  23 #include <assert.h>
  24 #include "disassemble.h"
  25 #include "opintl.h"
  26 #include "libiberty.h"
  27 #include "ansidecl.h"
  28 #include "opcode/xgate.h"
  29
  30 #define XGATE_TWO_BYTES      0x02
  31 #define XGATE_NINE_BITS      0x1FF
  32 #define XGATE_TEN_BITS       0x3FF
  33 #define XGATE_NINE_SIGNBIT   0x100
  34 #define XGATE_TEN_SIGNBIT    0x200
  35
  36 /* Structures.  */
  37 struct decodeInfo
  38 {
  39   unsigned int operMask;
  40   unsigned int operMasksRegisterBits;
  41   struct xgate_opcode *opcodePTR;
  42 };
  43
  44 /* Prototypes for local functions.  */
  45 static int print_insn (bfd_vma, struct disassemble_info *);
  46 static int read_memory (bfd_vma, bfd_byte*, int, struct disassemble_info *);
  47 static int ripBits (unsigned int *, int,
  48                     struct xgate_opcode *, unsigned int);
  49 static int macro_search (char *, char *);
  50 static struct decodeInfo * find_match (unsigned int);
  51
  52 /* Statics.  */
  53 static struct decodeInfo *decodeTable;
  54 static int initialized;
  55 static char previousOpName[10];
  56 static unsigned int perviousBin;
  57
  58 /* Disassemble one instruction at address 'memaddr'.  Returns the number
  59    of bytes used by that instruction.  */
  60
  61 static int
  62 print_insn (bfd_vma memaddr, struct disassemble_info* info)
  63 {
  64   int status;
  65   unsigned int raw_code;
  66   char *s = 0;
  67   long bytesRead = 0;
  68   int i = 0;
  69   struct xgate_opcode *opcodePTR = (struct xgate_opcode*) xgate_opcodes;
  70   struct decodeInfo *decodeTablePTR = 0;
  71   struct decodeInfo *decodePTR = 0;
  72   unsigned int operandRegisterBits = 0;
  73   signed int relAddr = 0;
  74   signed int operandOne = 0;
  75   signed int operandTwo = 0;
  76   bfd_byte buffer[4];
  77   bfd_vma absAddress;
  78
  79   unsigned int operMaskReg = 0;
  80   /* Initialize our array of opcode masks and check them against our constant
  81      table.  */
  82   if (!initialized)
  83     {
  84       decodeTable = xmalloc (sizeof (struct decodeInfo) * xgate_num_opcodes);
  85       for (i = 0, decodeTablePTR = decodeTable; i < xgate_num_opcodes;
  86           i++, decodeTablePTR++, opcodePTR++)
  87         {
  88           unsigned int bin = 0;
  89           unsigned int mask = 0;
  90           for (s = opcodePTR->format; *s; s++)
  91             {
  92               bin <<= 1;
  93               mask <<= 1;
  94               operandRegisterBits <<= 1;
  95               bin |= (*s == '1');
  96               mask |= (*s == '0' || *s == '1');
  97               operandRegisterBits |= (*s == 'r');
  98             }
  99           /* Asserting will uncover inconsistencies in our table.  */
 100           assert ((s - opcodePTR->format) == 16 || (s - opcodePTR->format) == 32);
 101           assert (opcodePTR->bin_opcode == bin);
 102
 103           decodeTablePTR->operMask = mask;
 104           decodeTablePTR->operMasksRegisterBits = operandRegisterBits;
 105           decodeTablePTR->opcodePTR = opcodePTR;
 106         }
 107       initialized = 1;
 108     }
 109
 110   /* Read 16 bits.  */
 111   bytesRead += XGATE_TWO_BYTES;
 112   status = read_memory (memaddr, buffer, XGATE_TWO_BYTES, info);
 113   if (status == 0)
 114     {
 115       raw_code = buffer[0];
 116       raw_code <<= 8;
 117       raw_code += buffer[1];
 118
 119       decodePTR = find_match (raw_code);
 120       if (decodePTR)
 121         {
 122           operMaskReg = decodePTR->operMasksRegisterBits;
 123           (*info->fprintf_func)(info->stream, "%s", decodePTR->opcodePTR->name);
 124
 125           /* First we compare the shorthand format of the constraints. If we
 126               still are unable to pinpoint the operands
 127               we analyze the opcodes constraint string.  */
 128           if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_MON_R_C))
 129                 {
 130                   (*info->fprintf_func)(info->stream, " R%x, CCR",
 131                           (raw_code >> 8) & 0x7);
 132                 }
 133           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_MON_C_R))
 134             {
 135                   (*info->fprintf_func)(info->stream, " CCR, R%x",
 136                       (raw_code >> 8) & 0x7);
 137             }
 138           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_MON_R_P))
 139             {
 140                   (*info->fprintf_func)(info->stream, " R%x, PC",
 141                       (raw_code >> 8) & 0x7);
 142             }
 143           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_TRI))
 144             {
 145                   (*info->fprintf_func)(info->stream, " R%x, R%x, R%x",
 146                       (raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7,
 147                       (raw_code >> 2) & 0x7);
 148             }
 149           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IDR))
 150             {
 151                   if (raw_code & 0x01)
 152                     {
 153                       (*info->fprintf_func)(info->stream, " R%x, (R%x, R%x+)",
 154                           (raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7,
 155                           (raw_code >> 2) & 0x7);
 156                     }
 157                    else if (raw_code & 0x02)
 158                           {
 159                             (*info->fprintf_func)(info->stream, " R%x, (R%x, -R%x)",
 160                                 (raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7,
 161                                 (raw_code >> 2) & 0x7);
 162                           }
 163                    else
 164                      {
 165                        (*info->fprintf_func)(info->stream, " R%x, (R%x, R%x)",
 166                            (raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7,
 167                            (raw_code >> 2) & 0x7);
 168                      }
 169             }
 170           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_DYA))
 171             {
 172                   operandOne = ripBits (&operMaskReg, 3, decodePTR->opcodePTR, raw_code);
 173                   operandTwo = ripBits (&operMaskReg, 3, decodePTR->opcodePTR, raw_code);
 174                  ( *info->fprintf_func)(info->stream, " R%x, R%x", operandOne,
 175                       operandTwo);
 176             }
 177           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IDO5))
 178             {
 179                   (*info->fprintf_func)(info->stream, " R%x, (R%x, #0x%x)",
 180                       (raw_code >> 8) & 0x7, (raw_code >> 5) & 0x7, raw_code & 0x1f);
 181             }
 182           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_MON))
 183             {
 184                   operandOne = ripBits (&operMaskReg, 3, decodePTR->opcodePTR,
 185                      raw_code);
 186                  (*info->fprintf_func)(info->stream, " R%x", operandOne);
 187             }
 188           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_REL9))
 189             {
 190               /* If address is negative handle it accordingly.  */
 191               if (raw_code & XGATE_NINE_SIGNBIT)
 192                 {
 193                   relAddr = XGATE_NINE_BITS >> 1; /* Clip sign bit.  */
 194                   relAddr = ~relAddr; /* Make signed.  */
 195                   relAddr |= (raw_code & 0xFF) + 1; /* Apply our value.  */
 196                   relAddr *= 2; /* Multiply by two as per processor docs.  */
 197                 }
 198               else
 199                 {
 200                   relAddr = raw_code & 0xff;
 201                   relAddr = relAddr * 2 + 2;
 202                 }
 203              (*info->fprintf_func)(info->stream, " *%d", relAddr);
 204              (*info->fprintf_func)(info->stream, "  Abs* 0x");
 205              (*info->print_address_func)(memaddr + relAddr, info);
 206            }
 207           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_REL10))
 208             {
 209               /* If address is negative handle it accordingly.  */
 210               if (raw_code & XGATE_TEN_SIGNBIT)
 211                 {
 212                   relAddr = XGATE_TEN_BITS >> 1; /* Clip sign bit.  */
 213                   relAddr = ~relAddr; /* Make signed.  */
 214                   relAddr |= (raw_code & 0x1FF) + 1; /* Apply our value.  */
 215                   relAddr *= 2; /* Multiply by two as per processor docs.  */
 216                 }
 217               else
 218                 {
 219                   relAddr = raw_code & 0x1FF;
 220                   relAddr = relAddr * 2 + 2;
 221                 }
 222               (*info->fprintf_func)(info->stream, " *%d", relAddr);
 223               (*info->fprintf_func)(info->stream, "  Abs* 0x");
 224               (*info->print_address_func)(memaddr + relAddr, info);
 225             }
 226           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IMM4))
 227             {
 228               (*info->fprintf_func)(info->stream, " R%x, #0x%02x",
 229               (raw_code >> 8) & 0x7, (raw_code >> 4) & 0xF);
 230             }
 231           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IMM8))
 232             {
 233               if (macro_search (decodePTR->opcodePTR->name, previousOpName) &&
 234                  previousOpName[0])
 235                {
 236                  absAddress = (0xFF & raw_code) << 8;
 237                  absAddress |= perviousBin & 0xFF;
 238                  (*info->fprintf_func)(info->stream, " R%x, #0x%02x Abs* 0x",
 239                      (raw_code >> 8) & 0x7, raw_code & 0xff);
 240                  (*info->print_address_func)(absAddress, info);
 241                  previousOpName[0] = 0;
 242                }
 243               else
 244                {
 245                  strcpy (previousOpName, decodePTR->opcodePTR->name);
 246                  (*info->fprintf_func)(info->stream, " R%x, #0x%02x",
 247                      (raw_code >> 8) & 0x7, raw_code & 0xff);
 248                }
 249             }
 250           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_IMM3))
 251             {
 252                   (*info->fprintf_func)(info->stream, " #0x%x",
 253                      (raw_code >> 8) & 0x7);
 254             }
 255           else if (!strcmp (decodePTR->opcodePTR->constraints, XGATE_OP_INH))
 256             {
 257             }
 258           else
 259             {
 260               (*info->fprintf_func)(info->stream, " unhandled mode %s",
 261                                     decodePTR->opcodePTR->constraints);
 262             }
 263           perviousBin = raw_code;
 264         }
 265       else
 266         {
 267           (*info->fprintf_func)(info->stream,
 268                                 " unable to find opcode match #0%x", raw_code);
 269         }
 270     }
 271   return bytesRead;
 272 }
 273
 274 int
 275 print_insn_xgate (bfd_vma memaddr, struct disassemble_info* info)
 276 {
 277   return print_insn (memaddr, info);
 278 }
 279
 280 static int
 281 read_memory (bfd_vma memaddr, bfd_byte* buffer, int size,
 282     struct disassemble_info* info)
 283 {
 284   int status;
 285   status = (*info->read_memory_func) (memaddr, buffer, size, info);
 286   if (status != 0)
 287     {
 288       (*info->memory_error_func) (status, memaddr, info);
 289       return -1;
 290     }
 291   return 0;
 292 }
 293
 294 static int
 295 ripBits (unsigned int *operandBitsRemaining,
 296          int numBitsRequested,
 297          struct xgate_opcode *opcodePTR,
 298          unsigned int memory)
 299 {
 300   unsigned int currentBit;
 301   unsigned int operand = 0;
 302   int numBitsFound;
 303
 304   for (numBitsFound = 0, currentBit = 1u << ((opcodePTR->size * 8) - 1);
 305        numBitsFound < numBitsRequested && currentBit != 0;
 306        currentBit >>= 1)
 307     {
 308       if (currentBit & *operandBitsRemaining)
 309         {
 310           *operandBitsRemaining &= ~(currentBit); /* Consume the current bit.  */
 311           operand <<= 1; /* Make room for our next bit.  */
 312           numBitsFound++;
 313           operand |= (currentBit & memory) > 0;
 314         }
 315     }
 316   return operand;
 317 }
 318
 319 static int
 320 macro_search (char *currentName, char *lastName)
 321 {
 322   int i;
 323   int length = 0;
 324   char *where;
 325
 326   for (i = 0; i < xgate_num_opcodes; i++)
 327     {
 328       where = strstr (xgate_opcodes[i].constraints, lastName);
 329
 330       if (where)
 331         {
 332           length = strlen (where);
 333         }
 334       if (length)
 335         {
 336           where = strstr (xgate_opcodes[i].constraints, currentName);
 337           if (where)
 338             {
 339               length = strlen (where);
 340               return 1;
 341             }
 342         }
 343     }
 344   return 0;
 345 }
 346
 347 static struct decodeInfo *
 348 find_match (unsigned int raw_code)
 349 {
 350   struct decodeInfo *decodeTablePTR = 0;
 351   int i;
 352
 353   for (i = 0, decodeTablePTR = decodeTable; i < xgate_num_opcodes;
 354       i++, decodeTablePTR++)
 355     {
 356       if ((raw_code & decodeTablePTR->operMask)
 357           == decodeTablePTR->opcodePTR->bin_opcode)
 358         {
 359           /* Make sure we didn't run into a macro or alias.  */
 360           if (decodeTablePTR->opcodePTR->cycles_min != 0)
 361             {
 362               return decodeTablePTR;
 363               break;
 364             }
 365           else
 366             continue;
 367         }
 368     }
 369   return 0;
 370 }