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