deps/lightrec/disassembler.c

   1 // SPDX-License-Identifier: LGPL-2.1-or-later
   2 /*
   3  * Copyright (C) 2014-2021 Paul Cercueil <paul@crapouillou.net>
   4  */
   5
   6 #include <stdbool.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10
  11 #include "lightrec-private.h"
  12 #include "regcache.h"
  13
  14 static const char * const std_opcodes[] = {
  15         [OP_J]                  = "j       ",
  16         [OP_JAL]                = "jal     ",
  17         [OP_BEQ]                = "beq     ",
  18         [OP_BNE]                = "bne     ",
  19         [OP_BLEZ]               = "blez    ",
  20         [OP_BGTZ]               = "bgtz    ",
  21         [OP_ADDI]               = "addi    ",
  22         [OP_ADDIU]              = "addiu   ",
  23         [OP_SLTI]               = "slti    ",
  24         [OP_SLTIU]              = "sltiu   ",
  25         [OP_ANDI]               = "andi    ",
  26         [OP_ORI]                = "ori     ",
  27         [OP_XORI]               = "xori    ",
  28         [OP_LUI]                = "lui     ",
  29         [OP_LB]                 = "lb      ",
  30         [OP_LH]                 = "lh      ",
  31         [OP_LWL]                = "lwl     ",
  32         [OP_LW]                 = "lw      ",
  33         [OP_LBU]                = "lbu     ",
  34         [OP_LHU]                = "lhu     ",
  35         [OP_LWR]                = "lwr     ",
  36         [OP_SB]                 = "sb      ",
  37         [OP_SH]                 = "sh      ",
  38         [OP_SWL]                = "swl     ",
  39         [OP_SW]                 = "sw      ",
  40         [OP_SWR]                = "swr     ",
  41         [OP_LWC2]               = "lwc2    ",
  42         [OP_SWC2]               = "swc2    ",
  43 };
  44
  45 static const char * const special_opcodes[] = {
  46         [OP_SPECIAL_SLL]        = "sll     ",
  47         [OP_SPECIAL_SRL]        = "srl     ",
  48         [OP_SPECIAL_SRA]        = "sra     ",
  49         [OP_SPECIAL_SLLV]       = "sllv    ",
  50         [OP_SPECIAL_SRLV]       = "srlv    ",
  51         [OP_SPECIAL_SRAV]       = "srav    ",
  52         [OP_SPECIAL_JR]         = "jr      ",
  53         [OP_SPECIAL_JALR]       = "jalr    ",
  54         [OP_SPECIAL_SYSCALL]    = "syscall ",
  55         [OP_SPECIAL_BREAK]      = "break   ",
  56         [OP_SPECIAL_MFHI]       = "mfhi    ",
  57         [OP_SPECIAL_MTHI]       = "mthi    ",
  58         [OP_SPECIAL_MFLO]       = "mflo    ",
  59         [OP_SPECIAL_MTLO]       = "mtlo    ",
  60         [OP_SPECIAL_MULT]       = "mult    ",
  61         [OP_SPECIAL_MULTU]      = "multu   ",
  62         [OP_SPECIAL_DIV]        = "div     ",
  63         [OP_SPECIAL_DIVU]       = "divu    ",
  64         [OP_SPECIAL_ADD]        = "add     ",
  65         [OP_SPECIAL_ADDU]       = "addu    ",
  66         [OP_SPECIAL_SUB]        = "sub     ",
  67         [OP_SPECIAL_SUBU]       = "subu    ",
  68         [OP_SPECIAL_AND]        = "and     ",
  69         [OP_SPECIAL_OR]         = "or      ",
  70         [OP_SPECIAL_XOR]        = "xor     ",
  71         [OP_SPECIAL_NOR]        = "nor     ",
  72         [OP_SPECIAL_SLT]        = "slt     ",
  73         [OP_SPECIAL_SLTU]       = "sltu    ",
  74 };
  75
  76 static const char * const regimm_opcodes[] = {
  77         [OP_REGIMM_BLTZ]        = "bltz    ",
  78         [OP_REGIMM_BGEZ]        = "bgez    ",
  79         [OP_REGIMM_BLTZAL]      = "bltzal  ",
  80         [OP_REGIMM_BGEZAL]      = "bgezal  ",
  81 };
  82
  83 static const char * const cp0_opcodes[] = {
  84         [OP_CP0_MFC0]           = "mfc0    ",
  85         [OP_CP0_CFC0]           = "cfc0    ",
  86         [OP_CP0_MTC0]           = "mtc0    ",
  87         [OP_CP0_CTC0]           = "ctc0    ",
  88         [OP_CP0_RFE]            = "rfe",
  89 };
  90
  91 static const char * const cp2_basic_opcodes[] = {
  92         [OP_CP2_BASIC_MFC2]     = "mfc2    ",
  93         [OP_CP2_BASIC_CFC2]     = "cfc2    ",
  94         [OP_CP2_BASIC_MTC2]     = "mtc2    ",
  95         [OP_CP2_BASIC_CTC2]     = "ctc2    ",
  96 };
  97
  98 static const char * const cp2_opcodes[] = {
  99         [OP_CP2_RTPS]           = "rtps    ",
 100         [OP_CP2_NCLIP]          = "nclip   ",
 101         [OP_CP2_OP]             = "op      ",
 102         [OP_CP2_DPCS]           = "dpcs    ",
 103         [OP_CP2_INTPL]          = "intpl   ",
 104         [OP_CP2_MVMVA]          = "mvmva   ",
 105         [OP_CP2_NCDS]           = "ncds    ",
 106         [OP_CP2_CDP]            = "cdp     ",
 107         [OP_CP2_NCDT]           = "ncdt    ",
 108         [OP_CP2_NCCS]           = "nccs    ",
 109         [OP_CP2_CC]             = "cc      ",
 110         [OP_CP2_NCS]            = "ncs     ",
 111         [OP_CP2_NCT]            = "nct     ",
 112         [OP_CP2_SQR]            = "sqr     ",
 113         [OP_CP2_DCPL]           = "dcpl    ",
 114         [OP_CP2_DPCT]           = "dpct    ",
 115         [OP_CP2_AVSZ3]          = "avsz3   ",
 116         [OP_CP2_AVSZ4]          = "avsz4   ",
 117         [OP_CP2_RTPT]           = "rtpt    ",
 118         [OP_CP2_GPF]            = "gpf     ",
 119         [OP_CP2_GPL]            = "gpl     ",
 120         [OP_CP2_NCCT]           = "ncct    ",
 121 };
 122
 123 static const char * const mult2_opcodes[] = {
 124         "mult2   ", "multu2  ",
 125 };
 126
 127 static const char * const opcode_flags[] = {
 128         "switched branch/DS",
 129         "sync point",
 130 };
 131
 132 static const char * const opcode_io_flags[] = {
 133         "self-modifying code",
 134         "no invalidation",
 135         "no mask",
 136 };
 137
 138 static const char * const opcode_io_modes[] = {
 139         "Memory access",
 140         "I/O access",
 141         "RAM access",
 142         "BIOS access",
 143         "Scratchpad access",
 144         "Mapped I/O access"
 145 };
 146
 147 static const char * const opcode_branch_flags[] = {
 148         "emulate branch",
 149         "local branch",
 150 };
 151
 152 static const char * const opcode_multdiv_flags[] = {
 153         "No LO",
 154         "No HI",
 155         "No div check",
 156 };
 157
 158 static size_t do_snprintf(char *buf, size_t len, bool *first,
 159                           const char *arg1, const char *arg2)
 160 {
 161         size_t bytes;
 162
 163         if (*first)
 164                 bytes = snprintf(buf, len, "(%s%s", arg1, arg2);
 165         else
 166                 bytes = snprintf(buf, len, ", %s%s", arg1, arg2);
 167
 168         *first = false;
 169
 170         return bytes;
 171 }
 172
 173 static const char * const reg_op_token[3] = {
 174         "-", "*", "~",
 175 };
 176
 177 static int print_flags(char *buf, size_t len, const struct opcode *op,
 178                        const char * const *array, size_t array_size,
 179                        bool is_io)
 180 {
 181         const char *flag_name, *io_mode_name;
 182         unsigned int i, io_mode;
 183         size_t count = 0, bytes;
 184         bool first = true;
 185         u32 flags = op->flags;
 186         unsigned int reg_op;
 187
 188         for (i = 0; i < array_size + ARRAY_SIZE(opcode_flags); i++) {
 189                 if (!(flags & BIT(i)))
 190                         continue;
 191
 192                 if (i < ARRAY_SIZE(opcode_flags))
 193                         flag_name = opcode_flags[i];
 194                 else
 195                         flag_name = array[i - ARRAY_SIZE(opcode_flags)];
 196
 197                 bytes = do_snprintf(buf, len, &first, "", flag_name);
 198                 buf += bytes;
 199                 len -= bytes;
 200                 count += bytes;
 201         }
 202
 203         if (is_io) {
 204                 io_mode = LIGHTREC_FLAGS_GET_IO_MODE(flags);
 205                 if (io_mode > 0) {
 206                         io_mode_name = opcode_io_modes[io_mode - 1];
 207
 208                         bytes = do_snprintf(buf, len, &first, "", io_mode_name);
 209                         buf += bytes;
 210                         len -= bytes;
 211                         count += bytes;
 212                 }
 213         }
 214
 215         if (OPT_EARLY_UNLOAD) {
 216                 reg_op = LIGHTREC_FLAGS_GET_RS(flags);
 217                 if (reg_op) {
 218                         bytes = do_snprintf(buf, len, &first,
 219                                             reg_op_token[reg_op - 1],
 220                                             lightrec_reg_name(op->i.rs));
 221                         buf += bytes;
 222                         len -= bytes;
 223                         count += bytes;
 224                 }
 225
 226                 reg_op = LIGHTREC_FLAGS_GET_RT(flags);
 227                 if (reg_op) {
 228                         bytes = do_snprintf(buf, len, &first,
 229                                             reg_op_token[reg_op - 1],
 230                                             lightrec_reg_name(op->i.rt));
 231                         buf += bytes;
 232                         len -= bytes;
 233                         count += bytes;
 234                 }
 235
 236                 reg_op = LIGHTREC_FLAGS_GET_RD(flags);
 237                 if (reg_op) {
 238                         bytes = do_snprintf(buf, len, &first,
 239                                             reg_op_token[reg_op - 1],
 240                                             lightrec_reg_name(op->r.rd));
 241                         buf += bytes;
 242                         len -= bytes;
 243                         count += bytes;
 244                 }
 245         }
 246
 247         if (!first)
 248                 count += snprintf(buf, len, ")");
 249         else
 250                 *buf = '\0';
 251
 252         return count;
 253 }
 254
 255 static int print_op_special(union code c, char *buf, size_t len,
 256                             const char * const **flags_ptr, size_t *nb_flags)
 257 {
 258         switch (c.r.op) {
 259         case OP_SPECIAL_SLL:
 260         case OP_SPECIAL_SRL:
 261         case OP_SPECIAL_SRA:
 262                 return snprintf(buf, len, "%s%s,%s,%u",
 263                                 special_opcodes[c.r.op],
 264                                 lightrec_reg_name(c.r.rd),
 265                                 lightrec_reg_name(c.r.rt),
 266                                 c.r.imm);
 267         case OP_SPECIAL_SLLV:
 268         case OP_SPECIAL_SRLV:
 269         case OP_SPECIAL_SRAV:
 270         case OP_SPECIAL_ADD:
 271         case OP_SPECIAL_ADDU:
 272         case OP_SPECIAL_SUB:
 273         case OP_SPECIAL_SUBU:
 274         case OP_SPECIAL_AND:
 275         case OP_SPECIAL_OR:
 276         case OP_SPECIAL_XOR:
 277         case OP_SPECIAL_NOR:
 278         case OP_SPECIAL_SLT:
 279         case OP_SPECIAL_SLTU:
 280                 return snprintf(buf, len, "%s%s,%s,%s",
 281                                 special_opcodes[c.r.op],
 282                                 lightrec_reg_name(c.r.rd),
 283                                 lightrec_reg_name(c.r.rt),
 284                                 lightrec_reg_name(c.r.rs));
 285         case OP_SPECIAL_JR:
 286                 *flags_ptr = opcode_branch_flags;
 287                 *nb_flags = ARRAY_SIZE(opcode_branch_flags);
 288                 fallthrough;
 289         case OP_SPECIAL_MTHI:
 290         case OP_SPECIAL_MTLO:
 291                 return snprintf(buf, len, "%s%s",
 292                                 special_opcodes[c.r.op],
 293                                 lightrec_reg_name(c.r.rs));
 294         case OP_SPECIAL_JALR:
 295                 return snprintf(buf, len, "%s%s,%s",
 296                                 special_opcodes[c.r.op],
 297                                 lightrec_reg_name(c.r.rd),
 298                                 lightrec_reg_name(c.r.rt));
 299         case OP_SPECIAL_SYSCALL:
 300         case OP_SPECIAL_BREAK:
 301                 return snprintf(buf, len, "%s", special_opcodes[c.r.op]);
 302         case OP_SPECIAL_MFHI:
 303         case OP_SPECIAL_MFLO:
 304                 return snprintf(buf, len, "%s%s",
 305                                 special_opcodes[c.r.op],
 306                                 lightrec_reg_name(c.r.rd));
 307         case OP_SPECIAL_MULT:
 308         case OP_SPECIAL_MULTU:
 309         case OP_SPECIAL_DIV:
 310         case OP_SPECIAL_DIVU:
 311                 *flags_ptr = opcode_multdiv_flags;
 312                 *nb_flags = ARRAY_SIZE(opcode_multdiv_flags);
 313                 return snprintf(buf, len, "%s%s,%s,%s,%s",
 314                                 special_opcodes[c.r.op],
 315                                 lightrec_reg_name(get_mult_div_hi(c)),
 316                                 lightrec_reg_name(get_mult_div_lo(c)),
 317                                 lightrec_reg_name(c.r.rs),
 318                                 lightrec_reg_name(c.r.rt));
 319         default:
 320                 return snprintf(buf, len, "unknown (0x%08x)", c.opcode);
 321         }
 322 }
 323
 324 static int print_op_cp(union code c, char *buf, size_t len, unsigned int cp)
 325 {
 326         if (cp == 2) {
 327                 switch (c.r.op) {
 328                 case OP_CP2_BASIC:
 329                         return snprintf(buf, len, "%s%s,%u",
 330                                         cp2_basic_opcodes[c.i.rs],
 331                                         lightrec_reg_name(c.i.rt),
 332                                         c.r.rd);
 333                 default:
 334                         return snprintf(buf, len, "%s", cp2_opcodes[c.r.op]);
 335                 }
 336         } else {
 337                 switch (c.i.rs) {
 338                 case OP_CP0_MFC0:
 339                 case OP_CP0_CFC0:
 340                 case OP_CP0_MTC0:
 341                 case OP_CP0_CTC0:
 342                         return snprintf(buf, len, "%s%s,%u",
 343                                         cp0_opcodes[c.i.rs],
 344                                         lightrec_reg_name(c.i.rt),
 345                                         c.r.rd);
 346                 case OP_CP0_RFE:
 347                         return snprintf(buf, len, "rfe     ");
 348                 default:
 349                         return snprintf(buf, len, "unknown (0x%08x)", c.opcode);
 350                 }
 351         }
 352 }
 353
 354 static int print_op(union code c, u32 pc, char *buf, size_t len,
 355                     const char * const **flags_ptr, size_t *nb_flags,
 356                     bool *is_io)
 357 {
 358         if (c.opcode == 0)
 359                 return snprintf(buf, len, "nop     ");
 360
 361         switch (c.i.op) {
 362         case OP_SPECIAL:
 363                 return print_op_special(c, buf, len, flags_ptr, nb_flags);
 364         case OP_REGIMM:
 365                 *flags_ptr = opcode_branch_flags;
 366                 *nb_flags = ARRAY_SIZE(opcode_branch_flags);
 367                 return snprintf(buf, len, "%s%s,0x%x",
 368                                 regimm_opcodes[c.i.rt],
 369                                 lightrec_reg_name(c.i.rs),
 370                                 pc + 4 + ((s16)c.i.imm << 2));
 371         case OP_J:
 372         case OP_JAL:
 373                 *flags_ptr = opcode_branch_flags;
 374                 *nb_flags = ARRAY_SIZE(opcode_branch_flags);
 375                 return snprintf(buf, len, "%s0x%x",
 376                                 std_opcodes[c.i.op],
 377                                 (pc & 0xf0000000) | (c.j.imm << 2));
 378         case OP_BEQ:
 379                 if (c.i.rs == c.i.rt) {
 380                         *flags_ptr = opcode_branch_flags;
 381                         *nb_flags = ARRAY_SIZE(opcode_branch_flags);
 382                         return snprintf(buf, len, "b       0x%x",
 383                                         pc + 4 + ((s16)c.i.imm << 2));
 384                 }
 385                 fallthrough;
 386         case OP_BNE:
 387         case OP_BLEZ:
 388         case OP_BGTZ:
 389                 *flags_ptr = opcode_branch_flags;
 390                 *nb_flags = ARRAY_SIZE(opcode_branch_flags);
 391                 return snprintf(buf, len, "%s%s,%s,0x%x",
 392                                 std_opcodes[c.i.op],
 393                                 lightrec_reg_name(c.i.rs),
 394                                 lightrec_reg_name(c.i.rt),
 395                                 pc + 4 + ((s16)c.i.imm << 2));
 396         case OP_ADDI:
 397         case OP_ADDIU:
 398         case OP_SLTI:
 399         case OP_SLTIU:
 400         case OP_ANDI:
 401         case OP_ORI:
 402         case OP_XORI:
 403                 return snprintf(buf, len, "%s%s,%s,0x%04hx",
 404                                 std_opcodes[c.i.op],
 405                                 lightrec_reg_name(c.i.rt),
 406                                 lightrec_reg_name(c.i.rs),
 407                                 (u16)c.i.imm);
 408
 409         case OP_LUI:
 410                 return snprintf(buf, len, "%s%s,0x%04hx",
 411                                 std_opcodes[c.i.op],
 412                                 lightrec_reg_name(c.i.rt),
 413                                 (u16)c.i.imm);
 414         case OP_CP0:
 415                 return print_op_cp(c, buf, len, 0);
 416         case OP_CP2:
 417                 return print_op_cp(c, buf, len, 2);
 418         case OP_LB:
 419         case OP_LH:
 420         case OP_LWL:
 421         case OP_LW:
 422         case OP_LBU:
 423         case OP_LHU:
 424         case OP_LWR:
 425         case OP_SB:
 426         case OP_SH:
 427         case OP_SWL:
 428         case OP_SW:
 429         case OP_SWR:
 430                 *flags_ptr = opcode_io_flags;
 431                 *nb_flags = ARRAY_SIZE(opcode_io_flags);
 432                 *is_io = true;
 433                 return snprintf(buf, len, "%s%s,%hd(%s)",
 434                                 std_opcodes[c.i.op],
 435                                 lightrec_reg_name(c.i.rt),
 436                                 (s16)c.i.imm,
 437                                 lightrec_reg_name(c.i.rs));
 438         case OP_LWC2:
 439         case OP_SWC2:
 440                 *flags_ptr = opcode_io_flags;
 441                 *nb_flags = ARRAY_SIZE(opcode_io_flags);
 442                 return snprintf(buf, len, "%s%s,%hd(%s)",
 443                                 std_opcodes[c.i.op],
 444                                 lightrec_reg_name(c.i.rt),
 445                                 (s16)c.i.imm,
 446                                 lightrec_reg_name(c.i.rs));
 447         case OP_META_MOV:
 448                 return snprintf(buf, len, "move    %s,%s",
 449                                 lightrec_reg_name(c.r.rd),
 450                                 lightrec_reg_name(c.r.rs));
 451         case OP_META_EXTC:
 452                 return snprintf(buf, len, "extc    %s,%s",
 453                                 lightrec_reg_name(c.i.rt),
 454                                 lightrec_reg_name(c.i.rs));
 455         case OP_META_EXTS:
 456                 return snprintf(buf, len, "exts    %s,%s",
 457                                 lightrec_reg_name(c.i.rt),
 458                                 lightrec_reg_name(c.i.rs));
 459         case OP_META_MULT2:
 460         case OP_META_MULTU2:
 461                 *flags_ptr = opcode_multdiv_flags;
 462                 *nb_flags = ARRAY_SIZE(opcode_multdiv_flags);
 463                 return snprintf(buf, len, "%s%s,%s,%s,%u",
 464                                 mult2_opcodes[c.i.op == OP_META_MULTU2],
 465                                 lightrec_reg_name(get_mult_div_hi(c)),
 466                                 lightrec_reg_name(get_mult_div_lo(c)),
 467                                 lightrec_reg_name(c.r.rs), c.r.op);
 468         default:
 469                 return snprintf(buf, len, "unknown (0x%08x)", c.opcode);
 470         }
 471 }
 472
 473 void lightrec_print_disassembly(const struct block *block, const u32 *code_ptr)
 474 {
 475         const struct opcode *op;
 476         const char * const *flags_ptr;
 477         size_t nb_flags, count, count2;
 478         char buf[256], buf2[256], buf3[256];
 479         unsigned int i;
 480         u32 pc, branch_pc, code;
 481         bool is_io;
 482
 483         for (i = 0; i < block->nb_ops; i++) {
 484                 op = &block->opcode_list[i];
 485                 branch_pc = get_branch_pc(block, i, 0);
 486                 pc = block->pc + (i << 2);
 487                 code = LE32TOH(code_ptr[i]);
 488
 489                 count = print_op((union code)code, pc, buf, sizeof(buf),
 490                                  &flags_ptr, &nb_flags, &is_io);
 491
 492                 flags_ptr = NULL;
 493                 nb_flags = 0;
 494                 is_io = false;
 495                 count2 = print_op(op->c, branch_pc, buf2, sizeof(buf2),
 496                                   &flags_ptr, &nb_flags, &is_io);
 497
 498                 if (code == op->c.opcode) {
 499                         *buf2 = '\0';
 500                         count2 = 0;
 501                 }
 502
 503                 print_flags(buf3, sizeof(buf3), op, flags_ptr, nb_flags, is_io);
 504
 505                 printf("0x%08x (0x%x)\t%s%*c%s%*c%s\n", pc, i << 2,
 506                        buf, 30 - (int)count, ' ', buf2, 30 - (int)count2, ' ', buf3);
 507         }
 508 }