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