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 *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 *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 *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 *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 *cp2_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 *opcode_flags[] = {
  99         "switched branch/DS",
 100         "sync point",
 101 };
 102
 103 static const char *opcode_io_flags[] = {
 104         "self-modifying code",
 105         "no invalidation",
 106         "no mask",
 107 };
 108
 109 static const char *opcode_io_modes[] = {
 110         "Memory access",
 111         "I/O access",
 112         "RAM access",
 113         "BIOS access",
 114         "Scratchpad access",
 115 };
 116
 117 static const char *opcode_branch_flags[] = {
 118         "emulate branch",
 119         "local branch",
 120 };
 121
 122 static const char *opcode_multdiv_flags[] = {
 123         "No LO",
 124         "No HI",
 125         "No div check",
 126 };
 127
 128 static size_t do_snprintf(char *buf, size_t len, bool *first,
 129                           const char *arg1, const char *arg2)
 130 {
 131         size_t bytes;
 132
 133         if (*first)
 134                 bytes = snprintf(buf, len, "(%s%s", arg1, arg2);
 135         else
 136                 bytes = snprintf(buf, len, ", %s%s", arg1, arg2);
 137
 138         *first = false;
 139
 140         return bytes;
 141 }
 142
 143 static const char * const reg_op_token[3] = {
 144         "-", "*", "~",
 145 };
 146
 147 static int print_flags(char *buf, size_t len, const struct opcode *op,
 148                        const char **array, size_t array_size,
 149                        bool is_io)
 150 {
 151         const char *flag_name, *io_mode_name;
 152         unsigned int i, io_mode;
 153         size_t count = 0, bytes;
 154         bool first = true;
 155         u32 flags = op->flags;
 156         unsigned int reg_op;
 157
 158         for (i = 0; i < array_size + ARRAY_SIZE(opcode_flags); i++) {
 159                 if (!(flags & BIT(i)))
 160                         continue;
 161
 162                 if (i < ARRAY_SIZE(opcode_flags))
 163                         flag_name = opcode_flags[i];
 164                 else
 165                         flag_name = array[i - ARRAY_SIZE(opcode_flags)];
 166
 167                 bytes = do_snprintf(buf, len, &first, "", flag_name);
 168                 buf += bytes;
 169                 len -= bytes;
 170                 count += bytes;
 171         }
 172
 173         if (is_io) {
 174                 io_mode = LIGHTREC_FLAGS_GET_IO_MODE(flags);
 175                 if (io_mode > 0) {
 176                         io_mode_name = opcode_io_modes[io_mode - 1];
 177
 178                         bytes = do_snprintf(buf, len, &first, "", io_mode_name);
 179                         buf += bytes;
 180                         len -= bytes;
 181                         count += bytes;
 182                 }
 183         }
 184
 185         if (OPT_EARLY_UNLOAD) {
 186                 reg_op = LIGHTREC_FLAGS_GET_RS(flags);
 187                 if (reg_op) {
 188                         bytes = do_snprintf(buf, len, &first,
 189                                             reg_op_token[reg_op - 1],
 190                                             lightrec_reg_name(op->i.rs));
 191                         buf += bytes;
 192                         len -= bytes;
 193                         count += bytes;
 194                 }
 195
 196                 reg_op = LIGHTREC_FLAGS_GET_RT(flags);
 197                 if (reg_op) {
 198                         bytes = do_snprintf(buf, len, &first,
 199                                             reg_op_token[reg_op - 1],
 200                                             lightrec_reg_name(op->i.rt));
 201                         buf += bytes;
 202                         len -= bytes;
 203                         count += bytes;
 204                 }
 205
 206                 reg_op = LIGHTREC_FLAGS_GET_RD(flags);
 207                 if (reg_op) {
 208                         bytes = do_snprintf(buf, len, &first,
 209                                             reg_op_token[reg_op - 1],
 210                                             lightrec_reg_name(op->r.rd));
 211                         buf += bytes;
 212                         len -= bytes;
 213                         count += bytes;
 214                 }
 215         }
 216
 217         if (!first)
 218                 count += snprintf(buf, len, ")");
 219         else
 220                 *buf = '\0';
 221
 222         return count;
 223 }
 224
 225 static int print_op_special(union code c, char *buf, size_t len,
 226                             const char ***flags_ptr, size_t *nb_flags)
 227 {
 228         switch (c.r.op) {
 229         case OP_SPECIAL_SLL:
 230         case OP_SPECIAL_SRL:
 231         case OP_SPECIAL_SRA:
 232                 return snprintf(buf, len, "%s%s,%s,%u",
 233                                 special_opcodes[c.r.op],
 234                                 lightrec_reg_name(c.r.rd),
 235                                 lightrec_reg_name(c.r.rt),
 236                                 c.r.imm);
 237         case OP_SPECIAL_SLLV:
 238         case OP_SPECIAL_SRLV:
 239         case OP_SPECIAL_SRAV:
 240         case OP_SPECIAL_ADD:
 241         case OP_SPECIAL_ADDU:
 242         case OP_SPECIAL_SUB:
 243         case OP_SPECIAL_SUBU:
 244         case OP_SPECIAL_AND:
 245         case OP_SPECIAL_OR:
 246         case OP_SPECIAL_XOR:
 247         case OP_SPECIAL_NOR:
 248         case OP_SPECIAL_SLT:
 249         case OP_SPECIAL_SLTU:
 250                 return snprintf(buf, len, "%s%s,%s,%s",
 251                                 special_opcodes[c.r.op],
 252                                 lightrec_reg_name(c.r.rd),
 253                                 lightrec_reg_name(c.r.rt),
 254                                 lightrec_reg_name(c.r.rs));
 255         case OP_SPECIAL_JR:
 256                 *flags_ptr = opcode_branch_flags;
 257                 *nb_flags = ARRAY_SIZE(opcode_branch_flags);
 258                 fallthrough;
 259         case OP_SPECIAL_MTHI:
 260         case OP_SPECIAL_MTLO:
 261                 return snprintf(buf, len, "%s%s",
 262                                 special_opcodes[c.r.op],
 263                                 lightrec_reg_name(c.r.rs));
 264         case OP_SPECIAL_JALR:
 265                 return snprintf(buf, len, "%s%s,%s",
 266                                 special_opcodes[c.r.op],
 267                                 lightrec_reg_name(c.r.rd),
 268                                 lightrec_reg_name(c.r.rt));
 269         case OP_SPECIAL_SYSCALL:
 270         case OP_SPECIAL_BREAK:
 271                 return snprintf(buf, len, "%s", special_opcodes[c.r.op]);
 272         case OP_SPECIAL_MFHI:
 273         case OP_SPECIAL_MFLO:
 274                 return snprintf(buf, len, "%s%s",
 275                                 special_opcodes[c.r.op],
 276                                 lightrec_reg_name(c.r.rd));
 277         case OP_SPECIAL_MULT:
 278         case OP_SPECIAL_MULTU:
 279         case OP_SPECIAL_DIV:
 280         case OP_SPECIAL_DIVU:
 281                 *flags_ptr = opcode_multdiv_flags;
 282                 *nb_flags = ARRAY_SIZE(opcode_multdiv_flags);
 283                 return snprintf(buf, len, "%s%s,%s,%s,%s",
 284                                 special_opcodes[c.r.op],
 285                                 lightrec_reg_name(get_mult_div_hi(c)),
 286                                 lightrec_reg_name(get_mult_div_lo(c)),
 287                                 lightrec_reg_name(c.r.rs),
 288                                 lightrec_reg_name(c.r.rt));
 289         default:
 290                 return snprintf(buf, len, "unknown (0x%08x)", c.opcode);
 291         }
 292 }
 293
 294 static int print_op_cp(union code c, char *buf, size_t len, unsigned int cp)
 295 {
 296         if (cp == 2) {
 297                 switch (c.i.rs) {
 298                 case OP_CP0_MFC0:
 299                 case OP_CP0_CFC0:
 300                 case OP_CP0_MTC0:
 301                 case OP_CP0_CTC0:
 302                         return snprintf(buf, len, "%s%s,%u",
 303                                         cp2_opcodes[c.i.rs],
 304                                         lightrec_reg_name(c.i.rt),
 305                                         c.r.rd);
 306                 default:
 307                         return snprintf(buf, len, "cp2     (0x%08x)", c.opcode);
 308                 }
 309         } else {
 310                 switch (c.i.rs) {
 311                 case OP_CP0_MFC0:
 312                 case OP_CP0_CFC0:
 313                 case OP_CP0_MTC0:
 314                 case OP_CP0_CTC0:
 315                         return snprintf(buf, len, "%s%s,%u",
 316                                         cp0_opcodes[c.i.rs],
 317                                         lightrec_reg_name(c.i.rt),
 318                                         c.r.rd);
 319                 case OP_CP0_RFE:
 320                         return snprintf(buf, len, "rfe     ");
 321                 default:
 322                         return snprintf(buf, len, "unknown (0x%08x)", c.opcode);
 323                 }
 324         }
 325 }
 326
 327 static int print_op(union code c, u32 pc, char *buf, size_t len,
 328                     const char ***flags_ptr, size_t *nb_flags,
 329                     bool *is_io)
 330 {
 331         if (c.opcode == 0)
 332                 return snprintf(buf, len, "nop     ");
 333
 334         switch (c.i.op) {
 335         case OP_SPECIAL:
 336                 return print_op_special(c, buf, len, flags_ptr, nb_flags);
 337         case OP_REGIMM:
 338                 *flags_ptr = opcode_branch_flags;
 339                 *nb_flags = ARRAY_SIZE(opcode_branch_flags);
 340                 return snprintf(buf, len, "%s%s,0x%x",
 341                                 regimm_opcodes[c.i.rt],
 342                                 lightrec_reg_name(c.i.rs),
 343                                 pc + 4 + ((s16)c.i.imm << 2));
 344         case OP_J:
 345         case OP_JAL:
 346                 *flags_ptr = opcode_branch_flags;
 347                 *nb_flags = ARRAY_SIZE(opcode_branch_flags);
 348                 return snprintf(buf, len, "%s0x%x",
 349                                 std_opcodes[c.i.op],
 350                                 (pc & 0xf0000000) | (c.j.imm << 2));
 351         case OP_BEQ:
 352                 if (c.i.rs == c.i.rt) {
 353                         *flags_ptr = opcode_branch_flags;
 354                         *nb_flags = ARRAY_SIZE(opcode_branch_flags);
 355                         return snprintf(buf, len, "b       0x%x",
 356                                         pc + 4 + ((s16)c.i.imm << 2));
 357                 }
 358                 fallthrough;
 359         case OP_BNE:
 360         case OP_BLEZ:
 361         case OP_BGTZ:
 362                 *flags_ptr = opcode_branch_flags;
 363                 *nb_flags = ARRAY_SIZE(opcode_branch_flags);
 364                 return snprintf(buf, len, "%s%s,%s,0x%x",
 365                                 std_opcodes[c.i.op],
 366                                 lightrec_reg_name(c.i.rs),
 367                                 lightrec_reg_name(c.i.rt),
 368                                 pc + 4 + ((s16)c.i.imm << 2));
 369         case OP_ADDI:
 370         case OP_ADDIU:
 371         case OP_SLTI:
 372         case OP_SLTIU:
 373         case OP_ANDI:
 374         case OP_ORI:
 375         case OP_XORI:
 376                 return snprintf(buf, len, "%s%s,%s,0x%04hx",
 377                                 std_opcodes[c.i.op],
 378                                 lightrec_reg_name(c.i.rt),
 379                                 lightrec_reg_name(c.i.rs),
 380                                 (u16)c.i.imm);
 381
 382         case OP_LUI:
 383                 return snprintf(buf, len, "%s%s,0x%04hx",
 384                                 std_opcodes[c.i.op],
 385                                 lightrec_reg_name(c.i.rt),
 386                                 (u16)c.i.imm);
 387         case OP_CP0:
 388                 return print_op_cp(c, buf, len, 0);
 389         case OP_CP2:
 390                 return print_op_cp(c, buf, len, 2);
 391         case OP_LB:
 392         case OP_LH:
 393         case OP_LWL:
 394         case OP_LW:
 395         case OP_LBU:
 396         case OP_LHU:
 397         case OP_LWR:
 398         case OP_SB:
 399         case OP_SH:
 400         case OP_SWL:
 401         case OP_SW:
 402         case OP_SWR:
 403                 *flags_ptr = opcode_io_flags;
 404                 *nb_flags = ARRAY_SIZE(opcode_io_flags);
 405                 *is_io = true;
 406                 return snprintf(buf, len, "%s%s,%hd(%s)",
 407                                 std_opcodes[c.i.op],
 408                                 lightrec_reg_name(c.i.rt),
 409                                 (s16)c.i.imm,
 410                                 lightrec_reg_name(c.i.rs));
 411         case OP_LWC2:
 412         case OP_SWC2:
 413                 *flags_ptr = opcode_io_flags;
 414                 *nb_flags = ARRAY_SIZE(opcode_io_flags);
 415                 return snprintf(buf, len, "%s%s,%hd(%s)",
 416                                 std_opcodes[c.i.op],
 417                                 lightrec_reg_name(c.i.rt),
 418                                 (s16)c.i.imm,
 419                                 lightrec_reg_name(c.i.rs));
 420         case OP_META_MOV:
 421                 return snprintf(buf, len, "move    %s,%s",
 422                                 lightrec_reg_name(c.r.rd),
 423                                 lightrec_reg_name(c.r.rs));
 424         case OP_META_EXTC:
 425                 return snprintf(buf, len, "extc    %s,%s",
 426                                 lightrec_reg_name(c.i.rt),
 427                                 lightrec_reg_name(c.i.rs));
 428         case OP_META_EXTS:
 429                 return snprintf(buf, len, "exts    %s,%s",
 430                                 lightrec_reg_name(c.i.rt),
 431                                 lightrec_reg_name(c.i.rs));
 432         default:
 433                 return snprintf(buf, len, "unknown (0x%08x)", c.opcode);
 434         }
 435 }
 436
 437 void lightrec_print_disassembly(const struct block *block, const u32 *code_ptr)
 438 {
 439         const struct opcode *op;
 440         const char **flags_ptr;
 441         size_t nb_flags, count, count2;
 442         char buf[256], buf2[256], buf3[256];
 443         unsigned int i;
 444         u32 pc, branch_pc, code;
 445         bool is_io;
 446
 447         for (i = 0; i < block->nb_ops; i++) {
 448                 op = &block->opcode_list[i];
 449                 branch_pc = get_branch_pc(block, i, 0);
 450                 pc = block->pc + (i << 2);
 451                 code = LE32TOH(code_ptr[i]);
 452
 453                 count = print_op((union code)code, pc, buf, sizeof(buf),
 454                                  &flags_ptr, &nb_flags, &is_io);
 455
 456                 flags_ptr = NULL;
 457                 nb_flags = 0;
 458                 is_io = false;
 459                 count2 = print_op(op->c, branch_pc, buf2, sizeof(buf2),
 460                                   &flags_ptr, &nb_flags, &is_io);
 461
 462                 if (code == op->c.opcode) {
 463                         *buf2 = '\0';
 464                         count2 = 0;
 465                 }
 466
 467                 print_flags(buf3, sizeof(buf3), op, flags_ptr, nb_flags, is_io);
 468
 469                 printf("0x%08x (0x%x)\t%s%*c%s%*c%s\n", pc, i << 2,
 470                        buf, 30 - (int)count, ' ', buf2, 30 - (int)count2, ' ', buf3);
 471         }
 472 }