sim/microblaze/interp.c

   1 /* Simulator for Xilinx MicroBlaze processor
   2    Copyright 2009-2016 Free Software Foundation, Inc.
   3
   4    This file is part of GDB, the GNU debugger.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include "config.h"
  20 #include <signal.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include "bfd.h"
  25 #include "gdb/callback.h"
  26 #include "libiberty.h"
  27 #include "gdb/remote-sim.h"
  28
  29 #include "sim-main.h"
  30 #include "sim-options.h"
  31
  32 #include "microblaze-dis.h"
  33
  34 #define target_big_endian (CURRENT_TARGET_BYTE_ORDER == BIG_ENDIAN)
  35
  36 static unsigned long
  37 microblaze_extract_unsigned_integer (unsigned char *addr, int len)
  38 {
  39   unsigned long retval;
  40   unsigned char *p;
  41   unsigned char *startaddr = (unsigned char *)addr;
  42   unsigned char *endaddr = startaddr + len;
  43
  44   if (len > (int) sizeof (unsigned long))
  45     printf ("That operation is not available on integers of more than "
  46             "%zu bytes.", sizeof (unsigned long));
  47
  48   /* Start at the most significant end of the integer, and work towards
  49      the least significant.  */
  50   retval = 0;
  51
  52   if (!target_big_endian)
  53     {
  54       for (p = endaddr; p > startaddr;)
  55         retval = (retval << 8) | * -- p;
  56     }
  57   else
  58     {
  59       for (p = startaddr; p < endaddr;)
  60         retval = (retval << 8) | * p ++;
  61     }
  62
  63   return retval;
  64 }
  65
  66 static void
  67 microblaze_store_unsigned_integer (unsigned char *addr, int len,
  68                                    unsigned long val)
  69 {
  70   unsigned char *p;
  71   unsigned char *startaddr = (unsigned char *)addr;
  72   unsigned char *endaddr = startaddr + len;
  73
  74   if (!target_big_endian)
  75     {
  76       for (p = startaddr; p < endaddr;)
  77         {
  78           *p++ = val & 0xff;
  79           val >>= 8;
  80         }
  81     }
  82   else
  83     {
  84       for (p = endaddr; p > startaddr;)
  85         {
  86           *--p = val & 0xff;
  87           val >>= 8;
  88         }
  89     }
  90 }
  91
  92 static void
  93 set_initial_gprs (SIM_CPU *cpu)
  94 {
  95   int i;
  96   long space;
  97
  98   /* Set up machine just out of reset.  */
  99   PC = 0;
 100   MSR = 0;
 101
 102   /* Clean out the GPRs */
 103   for (i = 0; i < 32; i++)
 104     CPU.regs[i] = 0;
 105   CPU.insts = 0;
 106   CPU.cycles = 0;
 107   CPU.imm_enable = 0;
 108 }
 109
 110 static int tracing = 0;
 111
 112 void
 113 sim_engine_run (SIM_DESC sd,
 114                 int next_cpu_nr, /* ignore  */
 115                 int nr_cpus, /* ignore  */
 116                 int siggnal) /* ignore  */
 117 {
 118   SIM_CPU *cpu = STATE_CPU (sd, 0);
 119   int needfetch;
 120   word inst;
 121   enum microblaze_instr op;
 122   int memops;
 123   int bonus_cycles;
 124   int insts;
 125   int w;
 126   int cycs;
 127   word WLhash;
 128   ubyte carry;
 129   int imm_unsigned;
 130   short ra, rb, rd;
 131   long immword;
 132   uword oldpc, newpc;
 133   short delay_slot_enable;
 134   short branch_taken;
 135   short num_delay_slot; /* UNUSED except as reqd parameter */
 136   enum microblaze_instr_type insn_type;
 137
 138   memops = 0;
 139   bonus_cycles = 0;
 140   insts = 0;
 141
 142   while (1)
 143     {
 144       /* Fetch the initial instructions that we'll decode. */
 145       inst = MEM_RD_WORD (PC & 0xFFFFFFFC);
 146
 147       op = get_insn_microblaze (inst, &imm_unsigned, &insn_type,
 148                                 &num_delay_slot);
 149
 150       if (op == invalid_inst)
 151         fprintf (stderr, "Unknown instruction 0x%04x", inst);
 152
 153       if (tracing)
 154         fprintf (stderr, "%.4x: inst = %.4x ", PC, inst);
 155
 156       rd = GET_RD;
 157       rb = GET_RB;
 158       ra = GET_RA;
 159       /*      immword = IMM_W; */
 160
 161       oldpc = PC;
 162       delay_slot_enable = 0;
 163       branch_taken = 0;
 164       if (op == microblaze_brk)
 165         sim_engine_halt (sd, NULL, NULL, NULL_CIA, sim_stopped, SIM_SIGTRAP);
 166       else if (inst == MICROBLAZE_HALT_INST)
 167         {
 168           insts += 1;
 169           bonus_cycles++;
 170           sim_engine_halt (sd, NULL, NULL, NULL_CIA, sim_exited, RETREG);
 171         }
 172       else
 173         {
 174           switch(op)
 175             {
 176 #define INSTRUCTION(NAME, OPCODE, TYPE, ACTION)         \
 177             case NAME:                                  \
 178               ACTION;                                   \
 179               break;
 180 #include "microblaze.isa"
 181 #undef INSTRUCTION
 182
 183             default:
 184               sim_engine_halt (sd, NULL, NULL, NULL_CIA, sim_signalled,
 185                                SIM_SIGILL);
 186               fprintf (stderr, "ERROR: Unknown opcode\n");
 187             }
 188           /* Make R0 consistent */
 189           CPU.regs[0] = 0;
 190
 191           /* Check for imm instr */
 192           if (op == imm)
 193             IMM_ENABLE = 1;
 194           else
 195             IMM_ENABLE = 0;
 196
 197           /* Update cycle counts */
 198           insts ++;
 199           if (insn_type == memory_store_inst || insn_type == memory_load_inst)
 200             memops++;
 201           if (insn_type == mult_inst)
 202             bonus_cycles++;
 203           if (insn_type == barrel_shift_inst)
 204             bonus_cycles++;
 205           if (insn_type == anyware_inst)
 206             bonus_cycles++;
 207           if (insn_type == div_inst)
 208             bonus_cycles += 33;
 209
 210           if ((insn_type == branch_inst || insn_type == return_inst)
 211               && branch_taken)
 212             {
 213               /* Add an extra cycle for taken branches */
 214               bonus_cycles++;
 215               /* For branch instructions handle the instruction in the delay slot */
 216               if (delay_slot_enable)
 217                 {
 218                   newpc = PC;
 219                   PC = oldpc + INST_SIZE;
 220                   inst = MEM_RD_WORD (PC & 0xFFFFFFFC);
 221                   op = get_insn_microblaze (inst, &imm_unsigned, &insn_type,
 222                                             &num_delay_slot);
 223                   if (op == invalid_inst)
 224                     fprintf (stderr, "Unknown instruction 0x%04x", inst);
 225                   if (tracing)
 226                     fprintf (stderr, "%.4x: inst = %.4x ", PC, inst);
 227                   rd = GET_RD;
 228                   rb = GET_RB;
 229                   ra = GET_RA;
 230                   /*          immword = IMM_W; */
 231                   if (op == microblaze_brk)
 232                     {
 233                       if (STATE_VERBOSE_P (sd))
 234                         fprintf (stderr, "Breakpoint set in delay slot "
 235                                  "(at address 0x%x) will not be honored\n", PC);
 236                       /* ignore the breakpoint */
 237                     }
 238                   else if (insn_type == branch_inst || insn_type == return_inst)
 239                     {
 240                       if (STATE_VERBOSE_P (sd))
 241                         fprintf (stderr, "Cannot have branch or return instructions "
 242                                  "in delay slot (at address 0x%x)\n", PC);
 243                       sim_engine_halt (sd, NULL, NULL, NULL_CIA, sim_signalled,
 244                                        SIM_SIGILL);
 245                     }
 246                   else
 247                     {
 248                       switch(op)
 249                         {
 250 #define INSTRUCTION(NAME, OPCODE, TYPE, ACTION)         \
 251                         case NAME:                      \
 252                           ACTION;                       \
 253                           break;
 254 #include "microblaze.isa"
 255 #undef INSTRUCTION
 256
 257                         default:
 258                           sim_engine_halt (sd, NULL, NULL, NULL_CIA,
 259                                            sim_signalled, SIM_SIGILL);
 260                           fprintf (stderr, "ERROR: Unknown opcode at 0x%x\n", PC);
 261                         }
 262                       /* Update cycle counts */
 263                       insts++;
 264                       if (insn_type == memory_store_inst
 265                           || insn_type == memory_load_inst)
 266                         memops++;
 267                       if (insn_type == mult_inst)
 268                         bonus_cycles++;
 269                       if (insn_type == barrel_shift_inst)
 270                         bonus_cycles++;
 271                       if (insn_type == anyware_inst)
 272                         bonus_cycles++;
 273                       if (insn_type == div_inst)
 274                         bonus_cycles += 33;
 275                     }
 276                   /* Restore the PC */
 277                   PC = newpc;
 278                   /* Make R0 consistent */
 279                   CPU.regs[0] = 0;
 280                   /* Check for imm instr */
 281                   if (op == imm)
 282                     IMM_ENABLE = 1;
 283                   else
 284                     IMM_ENABLE = 0;
 285                 }
 286               else
 287                 /* no delay slot: increment cycle count */
 288                 bonus_cycles++;
 289             }
 290         }
 291
 292       if (tracing)
 293         fprintf (stderr, "\n");
 294
 295       if (sim_events_tick (sd))
 296         sim_events_process (sd);
 297     }
 298
 299   /* Hide away the things we've cached while executing.  */
 300   /*  CPU.pc = pc; */
 301   CPU.insts += insts;           /* instructions done ... */
 302   CPU.cycles += insts;          /* and each takes a cycle */
 303   CPU.cycles += bonus_cycles;   /* and extra cycles for branches */
 304   CPU.cycles += memops;         /* and memop cycle delays */
 305 }
 306
 307 static int
 308 microblaze_reg_store (SIM_CPU *cpu, int rn, unsigned char *memory, int length)
 309 {
 310   if (rn < NUM_REGS + NUM_SPECIAL && rn >= 0)
 311     {
 312       if (length == 4)
 313         {
 314           /* misalignment safe */
 315           long ival = microblaze_extract_unsigned_integer (memory, 4);
 316           if (rn < NUM_REGS)
 317             CPU.regs[rn] = ival;
 318           else
 319             CPU.spregs[rn-NUM_REGS] = ival;
 320           return 4;
 321         }
 322       else
 323         return 0;
 324     }
 325   else
 326     return 0;
 327 }
 328
 329 static int
 330 microblaze_reg_fetch (SIM_CPU *cpu, int rn, unsigned char *memory, int length)
 331 {
 332   long ival;
 333
 334   if (rn < NUM_REGS + NUM_SPECIAL && rn >= 0)
 335     {
 336       if (length == 4)
 337         {
 338           if (rn < NUM_REGS)
 339             ival = CPU.regs[rn];
 340           else
 341             ival = CPU.spregs[rn-NUM_REGS];
 342
 343           /* misalignment-safe */
 344           microblaze_store_unsigned_integer (memory, 4, ival);
 345           return 4;
 346         }
 347       else
 348         return 0;
 349     }
 350   else
 351     return 0;
 352 }
 353
 354 void
 355 sim_info (SIM_DESC sd, int verbose)
 356 {
 357   SIM_CPU *cpu = STATE_CPU (sd, 0);
 358   host_callback *callback = STATE_CALLBACK (sd);
 359
 360   callback->printf_filtered (callback, "\n\n# instructions executed  %10d\n",
 361                              CPU.insts);
 362   callback->printf_filtered (callback, "# cycles                 %10d\n",
 363                              (CPU.cycles) ? CPU.cycles+2 : 0);
 364 }
 365
 366 static sim_cia
 367 microblaze_pc_get (sim_cpu *cpu)
 368 {
 369   return cpu->microblaze_cpu.spregs[0];
 370 }
 371
 372 static void
 373 microblaze_pc_set (sim_cpu *cpu, sim_cia pc)
 374 {
 375   cpu->microblaze_cpu.spregs[0] = pc;
 376 }
 377
 378 static void
 379 free_state (SIM_DESC sd)
 380 {
 381   if (STATE_MODULES (sd) != NULL)
 382     sim_module_uninstall (sd);
 383   sim_cpu_free_all (sd);
 384   sim_state_free (sd);
 385 }
 386
 387 SIM_DESC
 388 sim_open (SIM_OPEN_KIND kind, host_callback *cb, struct bfd *abfd, char **argv)
 389 {
 390   int i;
 391   SIM_DESC sd = sim_state_alloc (kind, cb);
 392   SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
 393
 394   /* The cpu data is kept in a separately allocated chunk of memory.  */
 395   if (sim_cpu_alloc_all (sd, 1, /*cgen_cpu_max_extra_bytes ()*/0) != SIM_RC_OK)
 396     {
 397       free_state (sd);
 398       return 0;
 399     }
 400
 401   if (sim_pre_argv_init (sd, argv[0]) != SIM_RC_OK)
 402     {
 403       free_state (sd);
 404       return 0;
 405     }
 406
 407   /* getopt will print the error message so we just have to exit if this fails.
 408      FIXME: Hmmm...  in the case of gdb we need getopt to call
 409      print_filtered.  */
 410   if (sim_parse_args (sd, argv) != SIM_RC_OK)
 411     {
 412       free_state (sd);
 413       return 0;
 414     }
 415
 416   /* Check for/establish the a reference program image.  */
 417   if (sim_analyze_program (sd,
 418                            (STATE_PROG_ARGV (sd) != NULL
 419                             ? *STATE_PROG_ARGV (sd)
 420                             : NULL), abfd) != SIM_RC_OK)
 421     {
 422       free_state (sd);
 423       return 0;
 424     }
 425
 426   /* Configure/verify the target byte order and other runtime
 427      configuration options.  */
 428   if (sim_config (sd) != SIM_RC_OK)
 429     {
 430       sim_module_uninstall (sd);
 431       return 0;
 432     }
 433
 434   if (sim_post_argv_init (sd) != SIM_RC_OK)
 435     {
 436       /* Uninstall the modules to avoid memory leaks,
 437          file descriptor leaks, etc.  */
 438       sim_module_uninstall (sd);
 439       return 0;
 440     }
 441
 442   /* CPU specific initialization.  */
 443   for (i = 0; i < MAX_NR_PROCESSORS; ++i)
 444     {
 445       SIM_CPU *cpu = STATE_CPU (sd, i);
 446
 447       CPU_REG_FETCH (cpu) = microblaze_reg_fetch;
 448       CPU_REG_STORE (cpu) = microblaze_reg_store;
 449       CPU_PC_FETCH (cpu) = microblaze_pc_get;
 450       CPU_PC_STORE (cpu) = microblaze_pc_set;
 451
 452       set_initial_gprs (cpu);
 453     }
 454
 455   /* Default to a 8 Mbyte (== 2^23) memory space.  */
 456   sim_do_commandf (sd, "memory-size 0x800000");
 457
 458   return sd;
 459 }
 460
 461 SIM_RC
 462 sim_create_inferior (SIM_DESC sd, struct bfd *prog_bfd, char **argv, char **env)
 463 {
 464   SIM_CPU *cpu = STATE_CPU (sd, 0);
 465
 466   PC = bfd_get_start_address (prog_bfd);
 467
 468   return SIM_RC_OK;
 469 }