1 /* -*- c -*- */ 2 /* Copyright (C) 2013-2014 Free Software Foundation, Inc. 3 Contributed by Red Hat. 4 Written by DJ Delorie. 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 "sysdep.h" 24 #include <stdio.h> 25 #include <stdlib.h> 26 #include <string.h> 27 #include "ansidecl.h" 28 #include "opcode/msp430-decode.h" 29 30 static int trace = 0; 31 32 typedef struct 33 { 34 MSP430_Opcode_Decoded *msp430; 35 int (*getbyte)(void *); 36 void *ptr; 37 unsigned char *op; 38 int op_ptr; 39 int pc; 40 } LocalData; 41 42 #define AU ATTRIBUTE_UNUSED 43 #define GETBYTE() getbyte_swapped (ld) 44 #define B ((unsigned long) GETBYTE ()) 45 46 static int 47 getbyte_swapped (LocalData *ld) 48 { 49 int b; 50 51 if (ld->op_ptr == ld->msp430->n_bytes) 52 { 53 do 54 { 55 b = ld->getbyte (ld->ptr); 56 ld->op [(ld->msp430->n_bytes++)^1] = b; 57 } 58 while (ld->msp430->n_bytes & 1); 59 } 60 return ld->op[ld->op_ptr++]; 61 } 62 63 #define ID(x) msp430->id = x 64 65 #define OP(n, t, r, a) (msp430->op[n].type = t, \ 66 msp430->op[n].reg = r, \ 67 msp430->op[n].addend = a) 68 69 #define OPX(n, t, r1, r2, a) \ 70 (msp430->op[n].type = t, \ 71 msp430->op[n].reg = r1, \ 72 msp430->op[n].reg2 = r2, \ 73 msp430->op[n].addend = a) 74 75 #define SYNTAX(x) msp430->syntax = x 76 #define UNSUPPORTED() msp430->syntax = "*unknown*" 77 78 #define DC(c) OP (0, MSP430_Operand_Immediate, 0, c) 79 #define DR(r) OP (0, MSP430_Operand_Register, r, 0) 80 #define DM(r, a) OP (0, MSP430_Operand_Indirect, r, a) 81 #define DA(a) OP (0, MSP430_Operand_Indirect, MSR_None, a) 82 #define AD(r, ad) encode_ad (r, ad, ld, 0) 83 #define ADX(r, ad, x) encode_ad (r, ad, ld, x) 84 85 #define SC(c) OP (1, MSP430_Operand_Immediate, 0, c) 86 #define SR(r) OP (1, MSP430_Operand_Register, r, 0) 87 #define SM(r, a) OP (1, MSP430_Operand_Indirect, r, a) 88 #define SA(a) OP (1, MSP430_Operand_Indirect, MSR_None, a) 89 #define SI(r) OP (1, MSP430_Operand_Indirect_Postinc, r, 0) 90 #define AS(r, as) encode_as (r, as, ld, 0) 91 #define ASX(r, as, x) encode_as (r, as, ld, x) 92 93 #define BW(x) msp430->size = (x ? 8 : 16) 94 /* The last 20 is for SWPBX.Z and SXTX.A. */ 95 #define ABW(a,x) msp430->size = (a ? ((x ? 8 : 16)) : (x ? 20 : 20)) 96 97 #define IMMU(bytes) immediate (bytes, 0, ld) 98 #define IMMS(bytes) immediate (bytes, 1, ld) 99 100 /* Helper macros for known status bits settings. */ 101 #define F_____ msp430->flags_1 = msp430->flags_0 = 0; msp430->flags_set = 0 102 #define F_VNZC msp430->flags_1 = msp430->flags_0 = 0; msp430->flags_set = 0x87 103 #define F_0NZC msp430->flags_1 = 0; msp430->flags_0 = 0x80; msp430->flags_set = 0x07 104 105 106 /* The chip is little-endian, but GETBYTE byte-swaps words because the 107 decoder is based on 16-bit "words" so *this* logic is big-endian. */ 108 109 static int 110 immediate (int bytes, int sign_extend, LocalData *ld) 111 { 112 unsigned long i = 0; 113 114 switch (bytes) 115 { 116 case 1: 117 i |= B; 118 if (sign_extend && (i & 0x80)) 119 i -= 0x100; 120 break; 121 case 2: 122 i |= B << 8; 123 i |= B; 124 if (sign_extend && (i & 0x8000)) 125 i -= 0x10000; 126 break; 127 case 3: 128 i |= B << 16; 129 i |= B << 8; 130 i |= B; 131 if (sign_extend && (i & 0x800000)) 132 i -= 0x1000000; 133 break; 134 case 4: 135 i |= B << 24; 136 i |= B << 16; 137 i |= B << 8; 138 i |= B; 139 if (sign_extend && (i & 0x80000000ULL)) 140 i -= 0x100000000ULL; 141 break; 142 default: 143 fprintf (stderr, 144 "Programmer error: immediate() called with invalid byte count %d\n", 145 bytes); 146 abort (); 147 } 148 return i; 149 } 150 151 /* 152 PC SP SR CG 153 As 154 00 Rn - - R2 #0 155 01 X(Rn) Sym - X(abs) #1 156 10 (Rn) - - #4 #2 157 11 (Rn++) #imm - #8 #-1 158 159 Ad 160 0 Rn - - - - 161 1 X(Rn) Sym - X(abs) - */ 162 163 static void 164 encode_ad (int reg, int ad, LocalData *ld, int ext) 165 { 166 MSP430_Opcode_Decoded *msp430 = ld->msp430; 167 168 if (ad) 169 { 170 int x = IMMU(2) | (ext << 16); 171 switch (reg) 172 { 173 case 0: /* (PC) -> Symbolic. */ 174 DA (x + ld->pc + ld->op_ptr - 2); 175 break; 176 case 2: /* (SR) -> Absolute. */ 177 DA (x); 178 break; 179 default: 180 DM (reg, x); 181 break; 182 } 183 } 184 else 185 { 186 DR (reg); 187 } 188 } 189 190 static void 191 encode_as (int reg, int as, LocalData *ld, int ext) 192 { 193 MSP430_Opcode_Decoded *msp430 = ld->msp430; 194 int x; 195 196 switch (as) 197 { 198 case 0: 199 switch (reg) 200 { 201 case 3: 202 SC (0); 203 break; 204 default: 205 SR (reg); 206 break; 207 } 208 break; 209 case 1: 210 switch (reg) 211 { 212 case 0: /* PC -> Symbolic. */ 213 x = IMMU(2) | (ext << 16); 214 SA (x + ld->pc + ld->op_ptr - 2); 215 break; 216 case 2: /* SR -> Absolute. */ 217 x = IMMU(2) | (ext << 16); 218 SA (x); 219 break; 220 case 3: 221 SC (1); 222 break; 223 default: 224 x = IMMU(2) | (ext << 16); 225 SM (reg, x); 226 break; 227 } 228 break; 229 case 2: 230 switch (reg) 231 { 232 case 2: 233 SC (4); 234 break; 235 case 3: 236 SC (2); 237 break; 238 case MSR_None: 239 SA (0); 240 default: 241 SM (reg, 0); 242 break; 243 } 244 break; 245 case 3: 246 switch (reg) 247 { 248 case 0: 249 { 250 /* This fetch *is* the *PC++ that the opcode encodes :-) */ 251 x = IMMU(2) | (ext << 16); 252 SC (x); 253 } 254 break; 255 case 2: 256 SC (8); 257 break; 258 case 3: 259 SC (-1); 260 break; 261 default: 262 SI (reg); 263 break; 264 } 265 break; 266 } 267 } 268 269 static void 270 encode_rep_zc (int srxt, int dsxt, LocalData *ld) 271 { 272 MSP430_Opcode_Decoded *msp430 = ld->msp430; 273 274 msp430->repeat_reg = srxt & 1; 275 msp430->repeats = dsxt; 276 msp430->zc = (srxt & 2) ? 1 : 0; 277 } 278 279 #define REPZC(s,d) encode_rep_zc (s, d, ld) 280 281 static int 282 dopc_to_id (int dopc) 283 { 284 switch (dopc) 285 { 286 case 4: return MSO_mov; 287 case 5: return MSO_add; 288 case 6: return MSO_addc; 289 case 7: return MSO_subc; 290 case 8: return MSO_sub; 291 case 9: return MSO_cmp; 292 case 10: return MSO_dadd; 293 case 11: return MSO_bit; 294 case 12: return MSO_bic; 295 case 13: return MSO_bis; 296 case 14: return MSO_xor; 297 case 15: return MSO_and; 298 default: return MSO_unknown; 299 } 300 } 301 302 static int 303 sopc_to_id (int sop, int c) 304 { 305 switch (sop * 2 + c) 306 { 307 case 0: return MSO_rrc; 308 case 1: return MSO_swpb; 309 case 2: return MSO_rra; 310 case 3: return MSO_sxt; 311 case 4: return MSO_push; 312 case 5: return MSO_call; 313 case 6: return MSO_reti; 314 default: return MSO_unknown; 315 } 316 } 317 318 int 319 msp430_decode_opcode (unsigned long pc, 320 MSP430_Opcode_Decoded *msp430, 321 int (*getbyte)(void *), 322 void *ptr) 323 { 324 LocalData lds, *ld = &lds; 325 unsigned char op_buf[20] = {0}; 326 unsigned char *op = op_buf; 327 int raddr; 328 int al_bit; 329 int srxt_bits, dsxt_bits; 330 331 lds.msp430 = msp430; 332 lds.getbyte = getbyte; 333 lds.ptr = ptr; 334 lds.op = op; 335 lds.op_ptr = 0; 336 lds.pc = pc; 337 338 memset (msp430, 0, sizeof (*msp430)); 339 340 /* These are overridden by an extension word. */ 341 al_bit = 1; 342 srxt_bits = 0; 343 dsxt_bits = 0; 344 345 post_extension_word: 346 ; 347 348 /* 430X extention word. */ 349 /** 0001 1srx t l 00 dsxt 430x */ 350 351 al_bit = l; 352 srxt_bits = srx * 2 + t; 353 dsxt_bits = dsxt; 354 op = op_buf + lds.op_ptr; 355 msp430->ofs_430x = 1; 356 goto post_extension_word; 357 358 /* double-op insns: 359 opcode:4 sreg:4 Ad:1 BW:1 As:2 Dreg:4 360 361 single-op insn: 362 opcode:9 BW:1 Ad:2 DSreg:4 363 364 jumps: 365 opcode:3 Cond:3 pcrel:10. */ 366 367 /* Double-Operand "opcode" fields. */ 368 /** VARY dopc 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111 */ 369 370 /** dopc sreg a b as dreg %D%b %1,%0 */ 371 372 ID (dopc_to_id (dopc)); ASX (sreg, as, srxt_bits); ADX (dreg, a, dsxt_bits); ABW (al_bit, b); 373 if (a == 0 && as == 0) 374 REPZC (srxt_bits, dsxt_bits); 375 376 switch (msp430->id) 377 { 378 case MSO_mov: F_____; break; 379 case MSO_add: F_VNZC; break; 380 case MSO_addc: F_VNZC; break; 381 case MSO_subc: F_VNZC; break; 382 case MSO_sub: F_VNZC; break; 383 case MSO_cmp: F_VNZC; break; 384 case MSO_dadd: F_VNZC; break; 385 case MSO_bit: F_0NZC; break; 386 case MSO_bic: F_____; break; 387 case MSO_bis: F_____; break; 388 case MSO_xor: F_VNZC; break; 389 case MSO_and: F_0NZC; break; 390 default: break; 391 } 392 393 /** 0001 00so c b ad dreg %S%b %1 */ 394 395 ID (sopc_to_id (so,c)); ASX (dreg, ad, srxt_bits); ABW (al_bit, b); 396 397 if (ad == 0) 398 REPZC (srxt_bits, dsxt_bits); 399 400 /* The helper functions encode for source, but it's 401 both source and dest, with a few documented exceptions. */ 402 msp430->op[0] = msp430->op[1]; 403 404 /* RETI ignores the operand. */ 405 if (msp430->id == MSO_reti) 406 msp430->syntax = "%S"; 407 408 switch (msp430->id) 409 { 410 case MSO_rrc: F_VNZC; break; 411 case MSO_swpb: F_____; break; 412 case MSO_rra: F_0NZC; break; 413 case MSO_sxt: F_0NZC; break; 414 case MSO_push: F_____; break; 415 case MSO_call: F_____; break; 416 case MSO_reti: F_VNZC; break; 417 default: break; 418 } 419 420 /* 20xx 0010 0000 ---- ---- 421 3cxx 0011 1100 ---- ---- 422 001j mp-- ---- ----. */ 423 /** 001jmp aa addrlsbs %J %1 */ 424 425 raddr = (aa << 9) | (addrlsbs << 1); 426 if (raddr & 0x400) 427 raddr = raddr - 0x800; 428 /* This is a pc-relative jump, but we don't use SM because that 429 would load the target address from the memory at X(PC), not use 430 PC+X *as* the address. So we use SC to use the address, not the 431 data at that address. */ 432 ID (MSO_jmp); SC (pc + raddr + msp430->n_bytes); 433 msp430->cond = jmp; 434 435 /* Extended instructions. */ 436 437 /** 0000 srcr 0000 dstr MOVA @%1, %0 */ 438 ID (MSO_mov); SM (srcr, 0); DR (dstr); 439 msp430->size = 20; 440 msp430->ofs_430x = 1; 441 442 /** 0000 srcr 0001 dstr MOVA @%1+, %0 */ 443 ID (MSO_mov); SI (srcr); DR (dstr); 444 msp430->size = 20; 445 msp430->ofs_430x = 1; 446 447 /** 0000 srcr 0010 dstr MOVA &%1, %0 */ 448 ID (MSO_mov); SA ((srcr << 16) + IMMU(2)); DR (dstr); 449 msp430->size = 20; 450 msp430->ofs_430x = 1; 451 452 /** 0000 srcr 0011 dstr MOVA %1, %0 */ 453 ID (MSO_mov); SM (srcr, IMMS(2)); DR (dstr); 454 msp430->size = 20; 455 msp430->ofs_430x = 1; 456 457 /** 0000 srcr 0110 dstr MOVA %1, &%0 */ 458 ID (MSO_mov); SR (srcr); DA ((dstr << 16) + IMMU(2)); 459 msp430->size = 20; 460 msp430->ofs_430x = 1; 461 462 /** 0000 srcr 0111 dstr MOVA %1, &%0 */ 463 ID (MSO_mov); SR (srcr); DM (dstr, IMMS(2)); 464 msp430->size = 20; 465 msp430->ofs_430x = 1; 466 467 /** 0000 srcr 1000 dstr MOVA %1, %0 */ 468 ID (MSO_mov); SC ((srcr << 16) + IMMU(2)); DR (dstr); 469 msp430->size = 20; 470 msp430->ofs_430x = 1; 471 472 /** 0000 srcr 1001 dstr CMPA %1, %0 */ 473 ID (MSO_cmp); SC ((srcr << 16) + IMMU(2)); DR (dstr); 474 msp430->size = 20; 475 msp430->ofs_430x = 1; 476 F_VNZC; 477 478 /** 0000 srcr 1010 dstr ADDA %1, %0 */ 479 ID (MSO_add); SC ((srcr << 16) + IMMU(2)); DR (dstr); 480 msp430->size = 20; 481 msp430->ofs_430x = 1; 482 F_VNZC; 483 484 /** 0000 srcr 1011 dstr SUBA %1, %0 */ 485 ID (MSO_sub); SC ((srcr << 16) + IMMU(2)); DR (dstr); 486 msp430->size = 20; 487 msp430->ofs_430x = 1; 488 F_VNZC; 489 490 /** 0000 srcr 1011 dstr SUBA %1, %0 */ 491 ID (MSO_sub); SC ((srcr << 16) + IMMU(2)); DR (dstr); 492 msp430->size = 20; 493 msp430->ofs_430x = 1; 494 F_VNZC; 495 496 /** 0000 srcr 1100 dstr MOVA %1, %0 */ 497 ID (MSO_mov); SR (srcr); DR (dstr); 498 msp430->size = 20; 499 msp430->ofs_430x = 1; 500 501 /** 0000 srcr 1101 dstr CMPA %1, %0 */ 502 ID (MSO_cmp); SR (srcr); DR (dstr); 503 msp430->size = 20; 504 msp430->ofs_430x = 1; 505 F_VNZC; 506 507 /** 0000 srcr 1110 dstr ADDA %1, %0 */ 508 ID (MSO_add); SR (srcr); DR (dstr); 509 msp430->size = 20; 510 msp430->ofs_430x = 1; 511 F_VNZC; 512 513 /** 0000 srcr 1111 dstr SUBA %1, %0 */ 514 ID (MSO_sub); SR (srcr); DR (dstr); 515 msp430->size = 20; 516 msp430->ofs_430x = 1; 517 F_VNZC; 518 519 /** 0000 bt00 010w dstr RRCM.A %c, %0 */ 520 ID (MSO_rrc); DR (dstr); SR (dstr); 521 msp430->repeats = bt; 522 msp430->size = w ? 16 : 20; 523 msp430->ofs_430x = 1; 524 F_0NZC; 525 526 /** 0000 bt01 010w dstr RRAM.A %c, %0 */ 527 ID (MSO_rra); DR (dstr); SR (dstr); 528 msp430->repeats = bt; 529 msp430->size = w ? 16 : 20; 530 msp430->ofs_430x = 1; 531 F_0NZC; 532 533 /** 0000 bt10 010w dstr RLAM.A %c, %0 */ 534 ID (MSO_add); DR (dstr); SR (dstr); 535 msp430->repeats = bt; 536 msp430->size = w ? 16 : 20; 537 msp430->ofs_430x = 1; 538 F_0NZC; 539 540 /** 0000 bt11 010w dstr RRUM.A %c, %0 */ 541 ID (MSO_rru); DR (dstr); SR (dstr); 542 msp430->repeats = bt; 543 msp430->size = w ? 16 : 20; 544 msp430->ofs_430x = 1; 545 F_0NZC; 546 547 /** 0001 0011 0000 0000 RETI */ 548 ID (MSO_reti); 549 msp430->size = 20; 550 msp430->ofs_430x = 1; 551 552 /** 0001 0011 01as dstr CALLA %0 */ 553 ID (MSO_call); AS (dstr, as); 554 msp430->size = 20; 555 msp430->ofs_430x = 1; 556 557 /** 0001 0011 1000 extb CALLA %0 */ 558 ID (MSO_call); SA (IMMU(2) | (extb << 16)); 559 msp430->size = 20; 560 msp430->ofs_430x = 1; 561 562 /** 0001 0011 1001 extb CALLA %0 */ 563 raddr = IMMU(2) | (extb << 16); 564 if (raddr & 0x80000) 565 raddr -= 0x100000; 566 ID (MSO_call); SA (pc + raddr + msp430->n_bytes); 567 msp430->size = 20; 568 msp430->ofs_430x = 1; 569 570 /** 0001 0011 1011 extb CALLA %0 */ 571 ID (MSO_call); SC (IMMU(2) | (extb << 16)); 572 msp430->size = 20; 573 msp430->ofs_430x = 1; 574 575 /** 0001 010w bits srcr PUSHM.A %0 */ 576 ID (MSO_push); SR (srcr); 577 msp430->size = w ? 16 : 20; 578 msp430->repeats = bits; 579 msp430->ofs_430x = 1; 580 581 /** 0001 011w bits dstr POPM.A %0 */ 582 ID (MSO_pop); DR (dstr); 583 msp430->size = w ? 16 : 20; 584 msp430->repeats = bits; 585 msp430->ofs_430x = 1; 586 587 /** */ 588 589 return msp430->n_bytes; 590 } 591
