1/* -*- c -*- */ 2/* Copyright (C) 2013-2017 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 30static int trace = 0; 31 32typedef 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 46static int 47getbyte_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 109static int 110immediate (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 163static void 164encode_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 190static void 191encode_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 break; 241 default: 242 SM (reg, 0); 243 break; 244 } 245 break; 246 case 3: 247 switch (reg) 248 { 249 case 0: 250 { 251 /* This fetch *is* the *PC++ that the opcode encodes :-) */ 252 x = IMMU(2) | (ext << 16); 253 SC (x); 254 } 255 break; 256 case 2: 257 SC (8); 258 break; 259 case 3: 260 SC (-1); 261 break; 262 default: 263 SI (reg); 264 break; 265 } 266 break; 267 } 268} 269 270static void 271encode_rep_zc (int srxt, int dsxt, LocalData *ld) 272{ 273 MSP430_Opcode_Decoded *msp430 = ld->msp430; 274 275 msp430->repeat_reg = srxt & 1; 276 msp430->repeats = dsxt; 277 msp430->zc = (srxt & 2) ? 1 : 0; 278} 279 280#define REPZC(s,d) encode_rep_zc (s, d, ld) 281 282static int 283dopc_to_id (int dopc) 284{ 285 switch (dopc) 286 { 287 case 4: return MSO_mov; 288 case 5: return MSO_add; 289 case 6: return MSO_addc; 290 case 7: return MSO_subc; 291 case 8: return MSO_sub; 292 case 9: return MSO_cmp; 293 case 10: return MSO_dadd; 294 case 11: return MSO_bit; 295 case 12: return MSO_bic; 296 case 13: return MSO_bis; 297 case 14: return MSO_xor; 298 case 15: return MSO_and; 299 default: return MSO_unknown; 300 } 301} 302 303static int 304sopc_to_id (int sop, int c) 305{ 306 switch (sop * 2 + c) 307 { 308 case 0: return MSO_rrc; 309 case 1: return MSO_swpb; 310 case 2: return MSO_rra; 311 case 3: return MSO_sxt; 312 case 4: return MSO_push; 313 case 5: return MSO_call; 314 case 6: return MSO_reti; 315 default: return MSO_unknown; 316 } 317} 318 319int 320msp430_decode_opcode (unsigned long pc, 321 MSP430_Opcode_Decoded *msp430, 322 int (*getbyte)(void *), 323 void *ptr) 324{ 325 LocalData lds, *ld = &lds; 326 unsigned char op_buf[20] = {0}; 327 unsigned char *op = op_buf; 328 int raddr; 329 int al_bit; 330 int srxt_bits, dsxt_bits; 331 332 lds.msp430 = msp430; 333 lds.getbyte = getbyte; 334 lds.ptr = ptr; 335 lds.op = op; 336 lds.op_ptr = 0; 337 lds.pc = pc; 338 339 memset (msp430, 0, sizeof (*msp430)); 340 341 /* These are overridden by an extension word. */ 342 al_bit = 1; 343 srxt_bits = 0; 344 dsxt_bits = 0; 345 346 post_extension_word: 347 ; 348 349 /* 430X extention word. */ 350/** 0001 1srx t l 00 dsxt 430x */ 351 352 al_bit = l; 353 srxt_bits = srx * 2 + t; 354 dsxt_bits = dsxt; 355 op = op_buf + lds.op_ptr; 356 msp430->ofs_430x = 1; 357 goto post_extension_word; 358 359/* double-op insns: 360 opcode:4 sreg:4 Ad:1 BW:1 As:2 Dreg:4 361 362 single-op insn: 363 opcode:9 BW:1 Ad:2 DSreg:4 364 365 jumps: 366 opcode:3 Cond:3 pcrel:10. */ 367 368/* Double-Operand "opcode" fields. */ 369/** VARY dopc 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111 */ 370 371/** dopc sreg a b as dreg %D%b %1,%0 */ 372 373 ID (dopc_to_id (dopc)); ASX (sreg, as, srxt_bits); ADX (dreg, a, dsxt_bits); ABW (al_bit, b); 374 if (a == 0 && as == 0) 375 REPZC (srxt_bits, dsxt_bits); 376 377 switch (msp430->id) 378 { 379 case MSO_mov: F_____; break; 380 case MSO_add: F_VNZC; break; 381 case MSO_addc: F_VNZC; break; 382 case MSO_subc: F_VNZC; break; 383 case MSO_sub: F_VNZC; break; 384 case MSO_cmp: F_VNZC; break; 385 case MSO_dadd: F_VNZC; break; 386 case MSO_bit: F_0NZC; break; 387 case MSO_bic: F_____; break; 388 case MSO_bis: F_____; break; 389 case MSO_xor: F_VNZC; break; 390 case MSO_and: F_0NZC; break; 391 default: break; 392 } 393 394/** 0001 00so c b ad dreg %S%b %1 */ 395 396 ID (sopc_to_id (so,c)); ASX (dreg, ad, srxt_bits); ABW (al_bit, b); 397 398 if (ad == 0) 399 REPZC (srxt_bits, dsxt_bits); 400 401 /* The helper functions encode for source, but it's 402 both source and dest, with a few documented exceptions. */ 403 msp430->op[0] = msp430->op[1]; 404 405 /* RETI ignores the operand. */ 406 if (msp430->id == MSO_reti) 407 msp430->syntax = "%S"; 408 409 switch (msp430->id) 410 { 411 case MSO_rrc: F_VNZC; break; 412 case MSO_swpb: F_____; break; 413 case MSO_rra: F_0NZC; break; 414 case MSO_sxt: F_0NZC; break; 415 case MSO_push: F_____; break; 416 case MSO_call: F_____; break; 417 case MSO_reti: F_VNZC; break; 418 default: break; 419 } 420 421 /* 20xx 0010 0000 ---- ---- 422 3cxx 0011 1100 ---- ---- 423 001j mp-- ---- ----. */ 424/** 001jmp aa addrlsbs %J %1 */ 425 426 raddr = (aa << 9) | (addrlsbs << 1); 427 if (raddr & 0x400) 428 raddr = raddr - 0x800; 429 /* This is a pc-relative jump, but we don't use SM because that 430 would load the target address from the memory at X(PC), not use 431 PC+X *as* the address. So we use SC to use the address, not the 432 data at that address. */ 433 ID (MSO_jmp); SC (pc + raddr + msp430->n_bytes); 434 msp430->cond = jmp; 435 436 /* Extended instructions. */ 437 438/** 0000 srcr 0000 dstr MOVA @%1, %0 */ 439 ID (MSO_mov); SM (srcr, 0); DR (dstr); 440 msp430->size = 20; 441 msp430->ofs_430x = 1; 442 443/** 0000 srcr 0001 dstr MOVA @%1+, %0 */ 444 ID (MSO_mov); SI (srcr); DR (dstr); 445 msp430->size = 20; 446 msp430->ofs_430x = 1; 447 448/** 0000 srcr 0010 dstr MOVA &%1, %0 */ 449 ID (MSO_mov); SA ((srcr << 16) + IMMU(2)); DR (dstr); 450 msp430->size = 20; 451 msp430->ofs_430x = 1; 452 453/** 0000 srcr 0011 dstr MOVA %1, %0 */ 454 ID (MSO_mov); SM (srcr, IMMS(2)); DR (dstr); 455 msp430->size = 20; 456 msp430->ofs_430x = 1; 457 458/** 0000 srcr 0110 dstr MOVA %1, &%0 */ 459 ID (MSO_mov); SR (srcr); DA ((dstr << 16) + IMMU(2)); 460 msp430->size = 20; 461 msp430->ofs_430x = 1; 462 463/** 0000 srcr 0111 dstr MOVA %1, &%0 */ 464 ID (MSO_mov); SR (srcr); DM (dstr, IMMS(2)); 465 msp430->size = 20; 466 msp430->ofs_430x = 1; 467 468/** 0000 srcr 1000 dstr MOVA %1, %0 */ 469 ID (MSO_mov); SC ((srcr << 16) + IMMU(2)); DR (dstr); 470 msp430->size = 20; 471 msp430->ofs_430x = 1; 472 473/** 0000 srcr 1001 dstr CMPA %1, %0 */ 474 ID (MSO_cmp); SC ((srcr << 16) + IMMU(2)); DR (dstr); 475 msp430->size = 20; 476 msp430->ofs_430x = 1; 477 F_VNZC; 478 479/** 0000 srcr 1010 dstr ADDA %1, %0 */ 480 ID (MSO_add); SC ((srcr << 16) + IMMU(2)); DR (dstr); 481 msp430->size = 20; 482 msp430->ofs_430x = 1; 483 F_VNZC; 484 485/** 0000 srcr 1011 dstr SUBA %1, %0 */ 486 ID (MSO_sub); SC ((srcr << 16) + IMMU(2)); DR (dstr); 487 msp430->size = 20; 488 msp430->ofs_430x = 1; 489 F_VNZC; 490 491/** 0000 srcr 1011 dstr SUBA %1, %0 */ 492 ID (MSO_sub); SC ((srcr << 16) + IMMU(2)); DR (dstr); 493 msp430->size = 20; 494 msp430->ofs_430x = 1; 495 F_VNZC; 496 497/** 0000 srcr 1100 dstr MOVA %1, %0 */ 498 ID (MSO_mov); SR (srcr); DR (dstr); 499 msp430->size = 20; 500 msp430->ofs_430x = 1; 501 502/** 0000 srcr 1101 dstr CMPA %1, %0 */ 503 ID (MSO_cmp); SR (srcr); DR (dstr); 504 msp430->size = 20; 505 msp430->ofs_430x = 1; 506 F_VNZC; 507 508/** 0000 srcr 1110 dstr ADDA %1, %0 */ 509 ID (MSO_add); SR (srcr); DR (dstr); 510 msp430->size = 20; 511 msp430->ofs_430x = 1; 512 F_VNZC; 513 514/** 0000 srcr 1111 dstr SUBA %1, %0 */ 515 ID (MSO_sub); SR (srcr); DR (dstr); 516 msp430->size = 20; 517 msp430->ofs_430x = 1; 518 F_VNZC; 519 520/** 0000 bt00 010w dstr RRCM.A %c, %0 */ 521 ID (MSO_rrc); DR (dstr); SR (dstr); 522 msp430->repeats = bt; 523 msp430->size = w ? 16 : 20; 524 msp430->ofs_430x = 1; 525 F_0NZC; 526 527/** 0000 bt01 010w dstr RRAM.A %c, %0 */ 528 ID (MSO_rra); DR (dstr); SR (dstr); 529 msp430->repeats = bt; 530 msp430->size = w ? 16 : 20; 531 msp430->ofs_430x = 1; 532 F_0NZC; 533 534/** 0000 bt10 010w dstr RLAM.A %c, %0 */ 535 ID (MSO_add); DR (dstr); SR (dstr); 536 msp430->repeats = bt; 537 msp430->size = w ? 16 : 20; 538 msp430->ofs_430x = 1; 539 F_0NZC; 540 541/** 0000 bt11 010w dstr RRUM.A %c, %0 */ 542 ID (MSO_rru); DR (dstr); SR (dstr); 543 msp430->repeats = bt; 544 msp430->size = w ? 16 : 20; 545 msp430->ofs_430x = 1; 546 F_0NZC; 547 548/** 0001 0011 0000 0000 RETI */ 549 ID (MSO_reti); 550 msp430->size = 20; 551 msp430->ofs_430x = 1; 552 553/** 0001 0011 01as dstr CALLA %0 */ 554 ID (MSO_call); AS (dstr, as); 555 msp430->size = 20; 556 msp430->ofs_430x = 1; 557 558/** 0001 0011 1000 extb CALLA %0 */ 559 ID (MSO_call); SA (IMMU(2) | (extb << 16)); 560 msp430->size = 20; 561 msp430->ofs_430x = 1; 562 563/** 0001 0011 1001 extb CALLA %0 */ 564 raddr = IMMU(2) | (extb << 16); 565 if (raddr & 0x80000) 566 raddr -= 0x100000; 567 ID (MSO_call); SA (pc + raddr + msp430->n_bytes); 568 msp430->size = 20; 569 msp430->ofs_430x = 1; 570 571/** 0001 0011 1011 extb CALLA %0 */ 572 ID (MSO_call); SC (IMMU(2) | (extb << 16)); 573 msp430->size = 20; 574 msp430->ofs_430x = 1; 575 576/** 0001 010w bits srcr PUSHM.A %0 */ 577 ID (MSO_push); SR (srcr); 578 msp430->size = w ? 16 : 20; 579 msp430->repeats = bits; 580 msp430->ofs_430x = 1; 581 582/** 0001 011w bits dstr POPM.A %0 */ 583 ID (MSO_pop); DR (dstr); 584 msp430->size = w ? 16 : 20; 585 msp430->repeats = bits; 586 msp430->ofs_430x = 1; 587 588/** */ 589 590 return msp430->n_bytes; 591} 592