| 1 | /* Print National Semiconductor 32000 instructions for GDB, the GNU debugger. |
| 2 | Copyright 1986, 1988, 1991, 1992 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "symtab.h" |
| 22 | #include "ns32k-opcode.h" |
| 23 | #include "gdbcore.h" |
| 24 | |
| 25 | /* 32000 instructions are never longer than this. */ |
| 26 | #define MAXLEN 62 |
| 27 | |
| 28 | /* Number of elements in the opcode table. */ |
| 29 | #define NOPCODES (sizeof notstrs / sizeof notstrs[0]) |
| 30 | |
| 31 | #define NEXT_IS_ADDR '|' |
| 32 | |
| 33 | /* |
| 34 | * extract "count" bits starting "offset" bits |
| 35 | * into buffer |
| 36 | */ |
| 37 | |
| 38 | int |
| 39 | bit_extract (buffer, offset, count) |
| 40 | char *buffer; |
| 41 | int offset; |
| 42 | int count; |
| 43 | { |
| 44 | int result; |
| 45 | int mask; |
| 46 | int bit; |
| 47 | |
| 48 | buffer += offset >> 3; |
| 49 | offset &= 7; |
| 50 | bit = 1; |
| 51 | result = 0; |
| 52 | while (count--) |
| 53 | { |
| 54 | if ((*buffer & (1 << offset))) |
| 55 | result |= bit; |
| 56 | if (++offset == 8) |
| 57 | { |
| 58 | offset = 0; |
| 59 | buffer++; |
| 60 | } |
| 61 | bit <<= 1; |
| 62 | } |
| 63 | return result; |
| 64 | } |
| 65 | |
| 66 | float |
| 67 | fbit_extract (buffer, offset, count) |
| 68 | { |
| 69 | union { |
| 70 | int ival; |
| 71 | float fval; |
| 72 | } foo; |
| 73 | |
| 74 | foo.ival = bit_extract (buffer, offset, 32); |
| 75 | return foo.fval; |
| 76 | } |
| 77 | |
| 78 | double |
| 79 | dbit_extract (buffer, offset, count) |
| 80 | { |
| 81 | union { |
| 82 | struct {int low, high; } ival; |
| 83 | double dval; |
| 84 | } foo; |
| 85 | |
| 86 | foo.ival.low = bit_extract (buffer, offset, 32); |
| 87 | foo.ival.high = bit_extract (buffer, offset+32, 32); |
| 88 | return foo.dval; |
| 89 | } |
| 90 | |
| 91 | sign_extend (value, bits) |
| 92 | { |
| 93 | value = value & ((1 << bits) - 1); |
| 94 | return (value & (1 << (bits-1)) |
| 95 | ? value | (~((1 << bits) - 1)) |
| 96 | : value); |
| 97 | } |
| 98 | |
| 99 | flip_bytes (ptr, count) |
| 100 | char *ptr; |
| 101 | int count; |
| 102 | { |
| 103 | char tmp; |
| 104 | |
| 105 | while (count > 0) |
| 106 | { |
| 107 | tmp = *ptr; |
| 108 | ptr[0] = ptr[count-1]; |
| 109 | ptr[count-1] = tmp; |
| 110 | ptr++; |
| 111 | count -= 2; |
| 112 | } |
| 113 | } |
| 114 | \f |
| 115 | /* Given a character C, does it represent a general addressing mode? */ |
| 116 | #define Is_gen(c) \ |
| 117 | ((c) == 'F' || (c) == 'L' || (c) == 'B' \ |
| 118 | || (c) == 'W' || (c) == 'D' || (c) == 'A') |
| 119 | |
| 120 | /* Adressing modes. */ |
| 121 | #define Adrmod_index_byte 0x1c |
| 122 | #define Adrmod_index_word 0x1d |
| 123 | #define Adrmod_index_doubleword 0x1e |
| 124 | #define Adrmod_index_quadword 0x1f |
| 125 | |
| 126 | /* Is MODE an indexed addressing mode? */ |
| 127 | #define Adrmod_is_index(mode) \ |
| 128 | (mode == Adrmod_index_byte \ |
| 129 | || mode == Adrmod_index_word \ |
| 130 | || mode == Adrmod_index_doubleword \ |
| 131 | || mode == Adrmod_index_quadword) |
| 132 | |
| 133 | \f |
| 134 | /* Print the 32000 instruction at address MEMADDR in debugged memory, |
| 135 | on STREAM. Returns length of the instruction, in bytes. */ |
| 136 | |
| 137 | int |
| 138 | print_insn (memaddr, stream) |
| 139 | CORE_ADDR memaddr; |
| 140 | FILE *stream; |
| 141 | { |
| 142 | unsigned char buffer[MAXLEN]; |
| 143 | register int i; |
| 144 | register unsigned char *p; |
| 145 | register char *d; |
| 146 | unsigned short first_word; |
| 147 | int gen, disp; |
| 148 | int ioffset; /* bits into instruction */ |
| 149 | int aoffset; /* bits into arguments */ |
| 150 | char arg_bufs[MAX_ARGS+1][ARG_LEN]; |
| 151 | int argnum; |
| 152 | int maxarg; |
| 153 | |
| 154 | read_memory (memaddr, buffer, MAXLEN); |
| 155 | |
| 156 | first_word = *(unsigned short *) buffer; |
| 157 | for (i = 0; i < NOPCODES; i++) |
| 158 | if ((first_word & ((1 << notstrs[i].detail.obits) - 1)) |
| 159 | == notstrs[i].detail.code) |
| 160 | break; |
| 161 | |
| 162 | /* Handle undefined instructions. */ |
| 163 | if (i == NOPCODES) |
| 164 | { |
| 165 | fprintf (stream, "0%o", buffer[0]); |
| 166 | return 1; |
| 167 | } |
| 168 | |
| 169 | fprintf (stream, "%s", notstrs[i].name); |
| 170 | |
| 171 | ioffset = notstrs[i].detail.ibits; |
| 172 | aoffset = notstrs[i].detail.ibits; |
| 173 | d = notstrs[i].detail.args; |
| 174 | |
| 175 | if (*d) |
| 176 | { |
| 177 | /* Offset in bits of the first thing beyond each index byte. |
| 178 | Element 0 is for operand A and element 1 is for operand B. |
| 179 | The rest are irrelevant, but we put them here so we don't |
| 180 | index outside the array. */ |
| 181 | int index_offset[MAX_ARGS]; |
| 182 | |
| 183 | /* 0 for operand A, 1 for operand B, greater for other args. */ |
| 184 | int whicharg = 0; |
| 185 | |
| 186 | fputc ('\t', stream); |
| 187 | |
| 188 | maxarg = 0; |
| 189 | |
| 190 | /* First we have to find and keep track of the index bytes, |
| 191 | if we are using scaled indexed addressing mode, since the index |
| 192 | bytes occur right after the basic instruction, not as part |
| 193 | of the addressing extension. */ |
| 194 | if (Is_gen(d[1])) |
| 195 | { |
| 196 | int addr_mode = bit_extract (buffer, ioffset - 5, 5); |
| 197 | |
| 198 | if (Adrmod_is_index (addr_mode)) |
| 199 | { |
| 200 | aoffset += 8; |
| 201 | index_offset[0] = aoffset; |
| 202 | } |
| 203 | } |
| 204 | if (d[2] && Is_gen(d[3])) |
| 205 | { |
| 206 | int addr_mode = bit_extract (buffer, ioffset - 10, 5); |
| 207 | |
| 208 | if (Adrmod_is_index (addr_mode)) |
| 209 | { |
| 210 | aoffset += 8; |
| 211 | index_offset[1] = aoffset; |
| 212 | } |
| 213 | } |
| 214 | |
| 215 | while (*d) |
| 216 | { |
| 217 | argnum = *d - '1'; |
| 218 | d++; |
| 219 | if (argnum > maxarg && argnum < MAX_ARGS) |
| 220 | maxarg = argnum; |
| 221 | ioffset = print_insn_arg (*d, ioffset, &aoffset, buffer, |
| 222 | memaddr, arg_bufs[argnum], |
| 223 | index_offset[whicharg]); |
| 224 | d++; |
| 225 | whicharg++; |
| 226 | } |
| 227 | for (argnum = 0; argnum <= maxarg; argnum++) |
| 228 | { |
| 229 | CORE_ADDR addr; |
| 230 | char *ch; |
| 231 | for (ch = arg_bufs[argnum]; *ch;) |
| 232 | { |
| 233 | if (*ch == NEXT_IS_ADDR) |
| 234 | { |
| 235 | ++ch; |
| 236 | addr = atoi (ch); |
| 237 | print_address (addr, stream); |
| 238 | while (*ch && *ch != NEXT_IS_ADDR) |
| 239 | ++ch; |
| 240 | if (*ch) |
| 241 | ++ch; |
| 242 | } |
| 243 | else |
| 244 | putc (*ch++, stream); |
| 245 | } |
| 246 | if (argnum < maxarg) |
| 247 | fprintf (stream, ", "); |
| 248 | } |
| 249 | } |
| 250 | return aoffset / 8; |
| 251 | } |
| 252 | |
| 253 | /* Print an instruction operand of category given by d. IOFFSET is |
| 254 | the bit position below which small (<1 byte) parts of the operand can |
| 255 | be found (usually in the basic instruction, but for indexed |
| 256 | addressing it can be in the index byte). AOFFSETP is a pointer to the |
| 257 | bit position of the addressing extension. BUFFER contains the |
| 258 | instruction. ADDR is where BUFFER was read from. Put the disassembled |
| 259 | version of the operand in RESULT. INDEX_OFFSET is the bit position |
| 260 | of the index byte (it contains garbage if this operand is not a |
| 261 | general operand using scaled indexed addressing mode). */ |
| 262 | |
| 263 | print_insn_arg (d, ioffset, aoffsetp, buffer, addr, result, index_offset) |
| 264 | char d; |
| 265 | int ioffset, *aoffsetp; |
| 266 | char *buffer; |
| 267 | CORE_ADDR addr; |
| 268 | char *result; |
| 269 | int index_offset; |
| 270 | { |
| 271 | int addr_mode; |
| 272 | float Fvalue; |
| 273 | double Lvalue; |
| 274 | int Ivalue; |
| 275 | int disp1, disp2; |
| 276 | int index; |
| 277 | |
| 278 | switch (d) |
| 279 | { |
| 280 | case 'F': |
| 281 | case 'L': |
| 282 | case 'B': |
| 283 | case 'W': |
| 284 | case 'D': |
| 285 | case 'A': |
| 286 | addr_mode = bit_extract (buffer, ioffset-5, 5); |
| 287 | ioffset -= 5; |
| 288 | switch (addr_mode) |
| 289 | { |
| 290 | case 0x0: case 0x1: case 0x2: case 0x3: |
| 291 | case 0x4: case 0x5: case 0x6: case 0x7: |
| 292 | switch (d) |
| 293 | { |
| 294 | case 'F': |
| 295 | case 'L': |
| 296 | sprintf (result, "f%d", addr_mode); |
| 297 | break; |
| 298 | default: |
| 299 | sprintf (result, "r%d", addr_mode); |
| 300 | } |
| 301 | break; |
| 302 | case 0x8: case 0x9: case 0xa: case 0xb: |
| 303 | case 0xc: case 0xd: case 0xe: case 0xf: |
| 304 | disp1 = get_displacement (buffer, aoffsetp); |
| 305 | sprintf (result, "%d(r%d)", disp1, addr_mode & 7); |
| 306 | break; |
| 307 | case 0x10: |
| 308 | case 0x11: |
| 309 | case 0x12: |
| 310 | disp1 = get_displacement (buffer, aoffsetp); |
| 311 | disp2 = get_displacement (buffer, aoffsetp); |
| 312 | sprintf (result, "%d(%d(%s))", disp2, disp1, |
| 313 | addr_mode==0x10?"fp":addr_mode==0x11?"sp":"sb"); |
| 314 | break; |
| 315 | case 0x13: |
| 316 | sprintf (result, "reserved"); |
| 317 | break; |
| 318 | case 0x14: |
| 319 | switch (d) |
| 320 | { |
| 321 | case 'B': |
| 322 | Ivalue = bit_extract (buffer, *aoffsetp, 8); |
| 323 | Ivalue = sign_extend (Ivalue, 8); |
| 324 | *aoffsetp += 8; |
| 325 | sprintf (result, "$%d", Ivalue); |
| 326 | break; |
| 327 | case 'W': |
| 328 | Ivalue = bit_extract (buffer, *aoffsetp, 16); |
| 329 | flip_bytes (&Ivalue, 2); |
| 330 | *aoffsetp += 16; |
| 331 | Ivalue = sign_extend (Ivalue, 16); |
| 332 | sprintf (result, "$%d", Ivalue); |
| 333 | break; |
| 334 | case 'D': |
| 335 | Ivalue = bit_extract (buffer, *aoffsetp, 32); |
| 336 | flip_bytes (&Ivalue, 4); |
| 337 | *aoffsetp += 32; |
| 338 | sprintf (result, "$%d", Ivalue); |
| 339 | break; |
| 340 | case 'A': |
| 341 | Ivalue = bit_extract (buffer, *aoffsetp, 32); |
| 342 | flip_bytes (&Ivalue, 4); |
| 343 | *aoffsetp += 32; |
| 344 | sprintf (result, "$|%d|", Ivalue); |
| 345 | break; |
| 346 | case 'F': |
| 347 | Fvalue = fbit_extract (buffer, *aoffsetp, 32); |
| 348 | flip_bytes (&Fvalue, 4); |
| 349 | *aoffsetp += 32; |
| 350 | sprintf (result, "$%g", Fvalue); |
| 351 | break; |
| 352 | case 'L': |
| 353 | Lvalue = dbit_extract (buffer, *aoffsetp, 64); |
| 354 | flip_bytes (&Lvalue, 8); |
| 355 | *aoffsetp += 64; |
| 356 | sprintf (result, "$%g", Lvalue); |
| 357 | break; |
| 358 | } |
| 359 | break; |
| 360 | case 0x15: |
| 361 | disp1 = get_displacement (buffer, aoffsetp); |
| 362 | sprintf (result, "@|%d|", disp1); |
| 363 | break; |
| 364 | case 0x16: |
| 365 | disp1 = get_displacement (buffer, aoffsetp); |
| 366 | disp2 = get_displacement (buffer, aoffsetp); |
| 367 | sprintf (result, "EXT(%d) + %d", disp1, disp2); |
| 368 | break; |
| 369 | case 0x17: |
| 370 | sprintf (result, "tos"); |
| 371 | break; |
| 372 | case 0x18: |
| 373 | disp1 = get_displacement (buffer, aoffsetp); |
| 374 | sprintf (result, "%d(fp)", disp1); |
| 375 | break; |
| 376 | case 0x19: |
| 377 | disp1 = get_displacement (buffer, aoffsetp); |
| 378 | sprintf (result, "%d(sp)", disp1); |
| 379 | break; |
| 380 | case 0x1a: |
| 381 | disp1 = get_displacement (buffer, aoffsetp); |
| 382 | sprintf (result, "%d(sb)", disp1); |
| 383 | break; |
| 384 | case 0x1b: |
| 385 | disp1 = get_displacement (buffer, aoffsetp); |
| 386 | sprintf (result, "|%d|", addr + disp1); |
| 387 | break; |
| 388 | case 0x1c: |
| 389 | case 0x1d: |
| 390 | case 0x1e: |
| 391 | case 0x1f: |
| 392 | index = bit_extract (buffer, index_offset - 8, 3); |
| 393 | print_insn_arg (d, index_offset, aoffsetp, buffer, addr, |
| 394 | result, 0); |
| 395 | { |
| 396 | static char *ind[] = {"b", "w", "d", "q"}; |
| 397 | char *off; |
| 398 | |
| 399 | off = result + strlen (result); |
| 400 | sprintf (off, "[r%d:%s]", index, |
| 401 | ind[addr_mode & 3]); |
| 402 | } |
| 403 | break; |
| 404 | } |
| 405 | break; |
| 406 | case 'q': |
| 407 | Ivalue = bit_extract (buffer, ioffset-4, 4); |
| 408 | Ivalue = sign_extend (Ivalue, 4); |
| 409 | sprintf (result, "%d", Ivalue); |
| 410 | ioffset -= 4; |
| 411 | break; |
| 412 | case 'r': |
| 413 | Ivalue = bit_extract (buffer, ioffset-3, 3); |
| 414 | sprintf (result, "r%d", Ivalue&7); |
| 415 | ioffset -= 3; |
| 416 | break; |
| 417 | case 'd': |
| 418 | sprintf (result, "%d", get_displacement (buffer, aoffsetp)); |
| 419 | break; |
| 420 | case 'p': |
| 421 | sprintf (result, "%c%d%c", NEXT_IS_ADDR, |
| 422 | addr + get_displacement (buffer, aoffsetp), |
| 423 | NEXT_IS_ADDR); |
| 424 | break; |
| 425 | case 'i': |
| 426 | Ivalue = bit_extract (buffer, *aoffsetp, 8); |
| 427 | *aoffsetp += 8; |
| 428 | sprintf (result, "0x%x", Ivalue); |
| 429 | break; |
| 430 | } |
| 431 | return ioffset; |
| 432 | } |
| 433 | |
| 434 | get_displacement (buffer, aoffsetp) |
| 435 | char *buffer; |
| 436 | int *aoffsetp; |
| 437 | { |
| 438 | int Ivalue; |
| 439 | |
| 440 | Ivalue = bit_extract (buffer, *aoffsetp, 8); |
| 441 | switch (Ivalue & 0xc0) |
| 442 | { |
| 443 | case 0x00: |
| 444 | case 0x40: |
| 445 | Ivalue = sign_extend (Ivalue, 7); |
| 446 | *aoffsetp += 8; |
| 447 | break; |
| 448 | case 0x80: |
| 449 | Ivalue = bit_extract (buffer, *aoffsetp, 16); |
| 450 | flip_bytes (&Ivalue, 2); |
| 451 | Ivalue = sign_extend (Ivalue, 14); |
| 452 | *aoffsetp += 16; |
| 453 | break; |
| 454 | case 0xc0: |
| 455 | Ivalue = bit_extract (buffer, *aoffsetp, 32); |
| 456 | flip_bytes (&Ivalue, 4); |
| 457 | Ivalue = sign_extend (Ivalue, 30); |
| 458 | *aoffsetp += 32; |
| 459 | break; |
| 460 | } |
| 461 | return Ivalue; |
| 462 | } |
| 463 | \f |
| 464 | /* Return the number of locals in the current frame given a pc |
| 465 | pointing to the enter instruction. This is used in the macro |
| 466 | FRAME_FIND_SAVED_REGS. */ |
| 467 | |
| 468 | ns32k_localcount (enter_pc) |
| 469 | CORE_ADDR enter_pc; |
| 470 | { |
| 471 | unsigned char localtype; |
| 472 | int localcount; |
| 473 | |
| 474 | localtype = read_memory_integer (enter_pc+2, 1); |
| 475 | if ((localtype & 0x80) == 0) |
| 476 | localcount = localtype; |
| 477 | else if ((localtype & 0xc0) == 0x80) |
| 478 | localcount = (((localtype & 0x3f) << 8) |
| 479 | | (read_memory_integer (enter_pc+3, 1) & 0xff)); |
| 480 | else |
| 481 | localcount = (((localtype & 0x3f) << 24) |
| 482 | | ((read_memory_integer (enter_pc+3, 1) & 0xff) << 16) |
| 483 | | ((read_memory_integer (enter_pc+4, 1) & 0xff) << 8 ) |
| 484 | | (read_memory_integer (enter_pc+5, 1) & 0xff)); |
| 485 | return localcount; |
| 486 | } |
| 487 | |
| 488 | /* |
| 489 | * Get the address of the enter opcode for the function |
| 490 | * containing PC, if there is an enter for the function, |
| 491 | * and if the pc is between the enter and exit. |
| 492 | * Returns positive address if pc is between enter/exit, |
| 493 | * 1 if pc before enter or after exit, 0 otherwise. |
| 494 | */ |
| 495 | |
| 496 | CORE_ADDR |
| 497 | ns32k_get_enter_addr (pc) |
| 498 | CORE_ADDR pc; |
| 499 | { |
| 500 | CORE_ADDR enter_addr; |
| 501 | unsigned char op; |
| 502 | |
| 503 | if (ABOUT_TO_RETURN (pc)) |
| 504 | return 1; /* after exit */ |
| 505 | |
| 506 | enter_addr = get_pc_function_start (pc); |
| 507 | |
| 508 | if (pc == enter_addr) |
| 509 | return 1; /* before enter */ |
| 510 | |
| 511 | op = read_memory_integer (enter_addr, 1); |
| 512 | |
| 513 | if (op != 0x82) |
| 514 | return 0; /* function has no enter/exit */ |
| 515 | |
| 516 | return enter_addr; /* pc is between enter and exit */ |
| 517 | } |