| 1 | /* Print VAX instructions. |
| 2 | Copyright 1995, 1998, 2000, 2001, 2002, 2005, 2007 |
| 3 | Free Software Foundation, Inc. |
| 4 | Contributed by Pauline Middelink <middelin@polyware.iaf.nl> |
| 5 | |
| 6 | This file is part of the GNU opcodes library. |
| 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 <setjmp.h> |
| 24 | #include <string.h> |
| 25 | #include "sysdep.h" |
| 26 | #include "opcode/vax.h" |
| 27 | #include "dis-asm.h" |
| 28 | |
| 29 | static char *reg_names[] = |
| 30 | { |
| 31 | "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", |
| 32 | "r8", "r9", "r10", "r11", "ap", "fp", "sp", "pc" |
| 33 | }; |
| 34 | |
| 35 | /* Definitions for the function entry mask bits. */ |
| 36 | static char *entry_mask_bit[] = |
| 37 | { |
| 38 | /* Registers 0 and 1 shall not be saved, since they're used to pass back |
| 39 | a function's result to its caller... */ |
| 40 | "~r0~", "~r1~", |
| 41 | /* Registers 2 .. 11 are normal registers. */ |
| 42 | "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", |
| 43 | /* Registers 12 and 13 are argument and frame pointer and must not |
| 44 | be saved by using the entry mask. */ |
| 45 | "~ap~", "~fp~", |
| 46 | /* Bits 14 and 15 control integer and decimal overflow. */ |
| 47 | "IntOvfl", "DecOvfl", |
| 48 | }; |
| 49 | |
| 50 | /* Sign-extend an (unsigned char). */ |
| 51 | #define COERCE_SIGNED_CHAR(ch) ((signed char)(ch)) |
| 52 | |
| 53 | /* Get a 1 byte signed integer. */ |
| 54 | #define NEXTBYTE(p) \ |
| 55 | (p += 1, FETCH_DATA (info, p), \ |
| 56 | COERCE_SIGNED_CHAR(p[-1])) |
| 57 | |
| 58 | /* Get a 2 byte signed integer. */ |
| 59 | #define COERCE16(x) ((int) (((x) ^ 0x8000) - 0x8000)) |
| 60 | #define NEXTWORD(p) \ |
| 61 | (p += 2, FETCH_DATA (info, p), \ |
| 62 | COERCE16 ((p[-1] << 8) + p[-2])) |
| 63 | |
| 64 | /* Get a 4 byte signed integer. */ |
| 65 | #define COERCE32(x) ((int) (((x) ^ 0x80000000) - 0x80000000)) |
| 66 | #define NEXTLONG(p) \ |
| 67 | (p += 4, FETCH_DATA (info, p), \ |
| 68 | (COERCE32 ((((((p[-1] << 8) + p[-2]) << 8) + p[-3]) << 8) + p[-4]))) |
| 69 | |
| 70 | /* Maximum length of an instruction. */ |
| 71 | #define MAXLEN 25 |
| 72 | |
| 73 | struct private |
| 74 | { |
| 75 | /* Points to first byte not fetched. */ |
| 76 | bfd_byte * max_fetched; |
| 77 | bfd_byte the_buffer[MAXLEN]; |
| 78 | bfd_vma insn_start; |
| 79 | jmp_buf bailout; |
| 80 | }; |
| 81 | |
| 82 | /* Make sure that bytes from INFO->PRIVATE_DATA->BUFFER (inclusive) |
| 83 | to ADDR (exclusive) are valid. Returns 1 for success, longjmps |
| 84 | on error. */ |
| 85 | #define FETCH_DATA(info, addr) \ |
| 86 | ((addr) <= ((struct private *)(info->private_data))->max_fetched \ |
| 87 | ? 1 : fetch_data ((info), (addr))) |
| 88 | |
| 89 | static int |
| 90 | fetch_data (struct disassemble_info *info, bfd_byte *addr) |
| 91 | { |
| 92 | int status; |
| 93 | struct private *priv = (struct private *) info->private_data; |
| 94 | bfd_vma start = priv->insn_start + (priv->max_fetched - priv->the_buffer); |
| 95 | |
| 96 | status = (*info->read_memory_func) (start, |
| 97 | priv->max_fetched, |
| 98 | addr - priv->max_fetched, |
| 99 | info); |
| 100 | if (status != 0) |
| 101 | { |
| 102 | (*info->memory_error_func) (status, start, info); |
| 103 | longjmp (priv->bailout, 1); |
| 104 | } |
| 105 | else |
| 106 | priv->max_fetched = addr; |
| 107 | |
| 108 | return 1; |
| 109 | } |
| 110 | |
| 111 | /* Entry mask handling. */ |
| 112 | static unsigned int entry_addr_occupied_slots = 0; |
| 113 | static unsigned int entry_addr_total_slots = 0; |
| 114 | static bfd_vma * entry_addr = NULL; |
| 115 | |
| 116 | /* Parse the VAX specific disassembler options. These contain function |
| 117 | entry addresses, which can be useful to disassemble ROM images, since |
| 118 | there's no symbol table. Returns TRUE upon success, FALSE otherwise. */ |
| 119 | |
| 120 | static bfd_boolean |
| 121 | parse_disassembler_options (char * options) |
| 122 | { |
| 123 | const char * entry_switch = "entry:"; |
| 124 | |
| 125 | while ((options = strstr (options, entry_switch))) |
| 126 | { |
| 127 | options += strlen (entry_switch); |
| 128 | |
| 129 | /* The greater-than part of the test below is paranoia. */ |
| 130 | if (entry_addr_occupied_slots >= entry_addr_total_slots) |
| 131 | { |
| 132 | /* A guesstimate of the number of entries we will have to create. */ |
| 133 | entry_addr_total_slots += |
| 134 | strlen (options) / (strlen (entry_switch) + 5); |
| 135 | |
| 136 | entry_addr = realloc (entry_addr, sizeof (bfd_vma) |
| 137 | * entry_addr_total_slots); |
| 138 | } |
| 139 | |
| 140 | if (entry_addr == NULL) |
| 141 | return FALSE; |
| 142 | |
| 143 | entry_addr[entry_addr_occupied_slots] = bfd_scan_vma (options, NULL, 0); |
| 144 | entry_addr_occupied_slots ++; |
| 145 | } |
| 146 | |
| 147 | return TRUE; |
| 148 | } |
| 149 | |
| 150 | #if 0 /* FIXME: Ideally the disassembler should have target specific |
| 151 | initialisation and termination function pointers. Then |
| 152 | parse_disassembler_options could be the init function and |
| 153 | free_entry_array (below) could be the termination routine. |
| 154 | Until then there is no way for the disassembler to tell us |
| 155 | that it has finished and that we no longer need the entry |
| 156 | array, so this routine is suppressed for now. It does mean |
| 157 | that we leak memory, but only to the extent that we do not |
| 158 | free it just before the disassembler is about to terminate |
| 159 | anyway. */ |
| 160 | |
| 161 | /* Free memory allocated to our entry array. */ |
| 162 | |
| 163 | static void |
| 164 | free_entry_array (void) |
| 165 | { |
| 166 | if (entry_addr) |
| 167 | { |
| 168 | free (entry_addr); |
| 169 | entry_addr = NULL; |
| 170 | entry_addr_occupied_slots = entry_addr_total_slots = 0; |
| 171 | } |
| 172 | } |
| 173 | #endif |
| 174 | /* Check if the given address is a known function entry. Either there must |
| 175 | be a symbol of function type at this address, or the address must be |
| 176 | a forced entry point. The later helps in disassembling ROM images, because |
| 177 | there's no symbol table at all. Forced entry points can be given by |
| 178 | supplying several -M options to objdump: -M entry:0xffbb7730. */ |
| 179 | |
| 180 | static bfd_boolean |
| 181 | is_function_entry (struct disassemble_info *info, bfd_vma addr) |
| 182 | { |
| 183 | unsigned int i; |
| 184 | |
| 185 | /* Check if there's a BSF_FUNCTION symbol at our address. */ |
| 186 | if (info->symbols |
| 187 | && info->symbols[0] |
| 188 | && (info->symbols[0]->flags & BSF_FUNCTION) |
| 189 | && addr == bfd_asymbol_value (info->symbols[0])) |
| 190 | return TRUE; |
| 191 | |
| 192 | /* Check for forced function entry address. */ |
| 193 | for (i = entry_addr_occupied_slots; i--;) |
| 194 | if (entry_addr[i] == addr) |
| 195 | return TRUE; |
| 196 | |
| 197 | return FALSE; |
| 198 | } |
| 199 | |
| 200 | static int |
| 201 | print_insn_mode (const char *d, |
| 202 | int size, |
| 203 | unsigned char *p0, |
| 204 | bfd_vma addr, /* PC for this arg to be relative to. */ |
| 205 | disassemble_info *info) |
| 206 | { |
| 207 | unsigned char *p = p0; |
| 208 | unsigned char mode, reg; |
| 209 | |
| 210 | /* Fetch and interpret mode byte. */ |
| 211 | mode = (unsigned char) NEXTBYTE (p); |
| 212 | reg = mode & 0xF; |
| 213 | switch (mode & 0xF0) |
| 214 | { |
| 215 | case 0x00: |
| 216 | case 0x10: |
| 217 | case 0x20: |
| 218 | case 0x30: /* Literal mode $number. */ |
| 219 | if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h') |
| 220 | (*info->fprintf_func) (info->stream, "$0x%x [%c-float]", mode, d[1]); |
| 221 | else |
| 222 | (*info->fprintf_func) (info->stream, "$0x%x", mode); |
| 223 | break; |
| 224 | case 0x40: /* Index: base-addr[Rn] */ |
| 225 | p += print_insn_mode (d, size, p0 + 1, addr + 1, info); |
| 226 | (*info->fprintf_func) (info->stream, "[%s]", reg_names[reg]); |
| 227 | break; |
| 228 | case 0x50: /* Register: Rn */ |
| 229 | (*info->fprintf_func) (info->stream, "%s", reg_names[reg]); |
| 230 | break; |
| 231 | case 0x60: /* Register deferred: (Rn) */ |
| 232 | (*info->fprintf_func) (info->stream, "(%s)", reg_names[reg]); |
| 233 | break; |
| 234 | case 0x70: /* Autodecrement: -(Rn) */ |
| 235 | (*info->fprintf_func) (info->stream, "-(%s)", reg_names[reg]); |
| 236 | break; |
| 237 | case 0x80: /* Autoincrement: (Rn)+ */ |
| 238 | if (reg == 0xF) |
| 239 | { /* Immediate? */ |
| 240 | int i; |
| 241 | |
| 242 | FETCH_DATA (info, p + size); |
| 243 | (*info->fprintf_func) (info->stream, "$0x"); |
| 244 | if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h') |
| 245 | { |
| 246 | int float_word; |
| 247 | |
| 248 | float_word = p[0] | (p[1] << 8); |
| 249 | if ((d[1] == 'd' || d[1] == 'f') |
| 250 | && (float_word & 0xff80) == 0x8000) |
| 251 | { |
| 252 | (*info->fprintf_func) (info->stream, "[invalid %c-float]", |
| 253 | d[1]); |
| 254 | } |
| 255 | else |
| 256 | { |
| 257 | for (i = 0; i < size; i++) |
| 258 | (*info->fprintf_func) (info->stream, "%02x", |
| 259 | p[size - i - 1]); |
| 260 | (*info->fprintf_func) (info->stream, " [%c-float]", d[1]); |
| 261 | } |
| 262 | } |
| 263 | else |
| 264 | { |
| 265 | for (i = 0; i < size; i++) |
| 266 | (*info->fprintf_func) (info->stream, "%02x", p[size - i - 1]); |
| 267 | } |
| 268 | p += size; |
| 269 | } |
| 270 | else |
| 271 | (*info->fprintf_func) (info->stream, "(%s)+", reg_names[reg]); |
| 272 | break; |
| 273 | case 0x90: /* Autoincrement deferred: @(Rn)+ */ |
| 274 | if (reg == 0xF) |
| 275 | (*info->fprintf_func) (info->stream, "*0x%x", NEXTLONG (p)); |
| 276 | else |
| 277 | (*info->fprintf_func) (info->stream, "@(%s)+", reg_names[reg]); |
| 278 | break; |
| 279 | case 0xB0: /* Displacement byte deferred: *displ(Rn). */ |
| 280 | (*info->fprintf_func) (info->stream, "*"); |
| 281 | case 0xA0: /* Displacement byte: displ(Rn). */ |
| 282 | if (reg == 0xF) |
| 283 | (*info->print_address_func) (addr + 2 + NEXTBYTE (p), info); |
| 284 | else |
| 285 | (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTBYTE (p), |
| 286 | reg_names[reg]); |
| 287 | break; |
| 288 | case 0xD0: /* Displacement word deferred: *displ(Rn). */ |
| 289 | (*info->fprintf_func) (info->stream, "*"); |
| 290 | case 0xC0: /* Displacement word: displ(Rn). */ |
| 291 | if (reg == 0xF) |
| 292 | (*info->print_address_func) (addr + 3 + NEXTWORD (p), info); |
| 293 | else |
| 294 | (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTWORD (p), |
| 295 | reg_names[reg]); |
| 296 | break; |
| 297 | case 0xF0: /* Displacement long deferred: *displ(Rn). */ |
| 298 | (*info->fprintf_func) (info->stream, "*"); |
| 299 | case 0xE0: /* Displacement long: displ(Rn). */ |
| 300 | if (reg == 0xF) |
| 301 | (*info->print_address_func) (addr + 5 + NEXTLONG (p), info); |
| 302 | else |
| 303 | (*info->fprintf_func) (info->stream, "0x%x(%s)", NEXTLONG (p), |
| 304 | reg_names[reg]); |
| 305 | break; |
| 306 | } |
| 307 | |
| 308 | return p - p0; |
| 309 | } |
| 310 | |
| 311 | /* Returns number of bytes "eaten" by the operand, or return -1 if an |
| 312 | invalid operand was found, or -2 if an opcode tabel error was |
| 313 | found. */ |
| 314 | |
| 315 | static int |
| 316 | print_insn_arg (const char *d, |
| 317 | unsigned char *p0, |
| 318 | bfd_vma addr, /* PC for this arg to be relative to. */ |
| 319 | disassemble_info *info) |
| 320 | { |
| 321 | int arg_len; |
| 322 | |
| 323 | /* Check validity of addressing length. */ |
| 324 | switch (d[1]) |
| 325 | { |
| 326 | case 'b' : arg_len = 1; break; |
| 327 | case 'd' : arg_len = 8; break; |
| 328 | case 'f' : arg_len = 4; break; |
| 329 | case 'g' : arg_len = 8; break; |
| 330 | case 'h' : arg_len = 16; break; |
| 331 | case 'l' : arg_len = 4; break; |
| 332 | case 'o' : arg_len = 16; break; |
| 333 | case 'w' : arg_len = 2; break; |
| 334 | case 'q' : arg_len = 8; break; |
| 335 | default : abort (); |
| 336 | } |
| 337 | |
| 338 | /* Branches have no mode byte. */ |
| 339 | if (d[0] == 'b') |
| 340 | { |
| 341 | unsigned char *p = p0; |
| 342 | |
| 343 | if (arg_len == 1) |
| 344 | (*info->print_address_func) (addr + 1 + NEXTBYTE (p), info); |
| 345 | else |
| 346 | (*info->print_address_func) (addr + 2 + NEXTWORD (p), info); |
| 347 | |
| 348 | return p - p0; |
| 349 | } |
| 350 | |
| 351 | return print_insn_mode (d, arg_len, p0, addr, info); |
| 352 | } |
| 353 | |
| 354 | /* Print the vax instruction at address MEMADDR in debugged memory, |
| 355 | on INFO->STREAM. Returns length of the instruction, in bytes. */ |
| 356 | |
| 357 | int |
| 358 | print_insn_vax (bfd_vma memaddr, disassemble_info *info) |
| 359 | { |
| 360 | static bfd_boolean parsed_disassembler_options = FALSE; |
| 361 | const struct vot *votp; |
| 362 | const char *argp; |
| 363 | unsigned char *arg; |
| 364 | struct private priv; |
| 365 | bfd_byte *buffer = priv.the_buffer; |
| 366 | |
| 367 | info->private_data = & priv; |
| 368 | priv.max_fetched = priv.the_buffer; |
| 369 | priv.insn_start = memaddr; |
| 370 | |
| 371 | if (! parsed_disassembler_options |
| 372 | && info->disassembler_options != NULL) |
| 373 | { |
| 374 | parse_disassembler_options (info->disassembler_options); |
| 375 | |
| 376 | /* To avoid repeated parsing of these options. */ |
| 377 | parsed_disassembler_options = TRUE; |
| 378 | } |
| 379 | |
| 380 | if (setjmp (priv.bailout) != 0) |
| 381 | /* Error return. */ |
| 382 | return -1; |
| 383 | |
| 384 | argp = NULL; |
| 385 | /* Check if the info buffer has more than one byte left since |
| 386 | the last opcode might be a single byte with no argument data. */ |
| 387 | if (info->buffer_length - (memaddr - info->buffer_vma) > 1) |
| 388 | { |
| 389 | FETCH_DATA (info, buffer + 2); |
| 390 | } |
| 391 | else |
| 392 | { |
| 393 | FETCH_DATA (info, buffer + 1); |
| 394 | buffer[1] = 0; |
| 395 | } |
| 396 | |
| 397 | /* Decode function entry mask. */ |
| 398 | if (is_function_entry (info, memaddr)) |
| 399 | { |
| 400 | int i = 0; |
| 401 | int register_mask = buffer[1] << 8 | buffer[0]; |
| 402 | |
| 403 | (*info->fprintf_func) (info->stream, ".word 0x%04x # Entry mask: <", |
| 404 | register_mask); |
| 405 | |
| 406 | for (i = 15; i >= 0; i--) |
| 407 | if (register_mask & (1 << i)) |
| 408 | (*info->fprintf_func) (info->stream, " %s", entry_mask_bit[i]); |
| 409 | |
| 410 | (*info->fprintf_func) (info->stream, " >"); |
| 411 | |
| 412 | return 2; |
| 413 | } |
| 414 | |
| 415 | for (votp = &votstrs[0]; votp->name[0]; votp++) |
| 416 | { |
| 417 | vax_opcodeT opcode = votp->detail.code; |
| 418 | |
| 419 | /* 2 byte codes match 2 buffer pos. */ |
| 420 | if ((bfd_byte) opcode == buffer[0] |
| 421 | && (opcode >> 8 == 0 || opcode >> 8 == buffer[1])) |
| 422 | { |
| 423 | argp = votp->detail.args; |
| 424 | break; |
| 425 | } |
| 426 | } |
| 427 | if (argp == NULL) |
| 428 | { |
| 429 | /* Handle undefined instructions. */ |
| 430 | (*info->fprintf_func) (info->stream, ".word 0x%x", |
| 431 | (buffer[0] << 8) + buffer[1]); |
| 432 | return 2; |
| 433 | } |
| 434 | |
| 435 | /* Point at first byte of argument data, and at descriptor for first |
| 436 | argument. */ |
| 437 | arg = buffer + ((votp->detail.code >> 8) ? 2 : 1); |
| 438 | |
| 439 | /* Make sure we have it in mem */ |
| 440 | FETCH_DATA (info, arg); |
| 441 | |
| 442 | (*info->fprintf_func) (info->stream, "%s", votp->name); |
| 443 | if (*argp) |
| 444 | (*info->fprintf_func) (info->stream, " "); |
| 445 | |
| 446 | while (*argp) |
| 447 | { |
| 448 | arg += print_insn_arg (argp, arg, memaddr + arg - buffer, info); |
| 449 | argp += 2; |
| 450 | if (*argp) |
| 451 | (*info->fprintf_func) (info->stream, ","); |
| 452 | } |
| 453 | |
| 454 | return arg - buffer; |
| 455 | } |
| 456 | |