sim/aarch64/interp.c

   1 /* interp.c -- AArch64 sim interface to GDB.
   2
   3    Copyright (C) 2015-2016 Free Software Foundation, Inc.
   4
   5    Contributed by Red Hat.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include <stdio.h>
  24 #include <assert.h>
  25 #include <signal.h>
  26 #include <string.h>
  27 #include <ctype.h>
  28 #include <stdlib.h>
  29
  30 #include "ansidecl.h"
  31 #include "gdb/callback.h"
  32 #include "gdb/remote-sim.h"
  33 #include "gdb/signals.h"
  34 #include "gdb/sim-aarch64.h"
  35
  36 #include "sim-main.h"
  37 #include "sim-options.h"
  38 #include "memory.h"
  39 #include "simulator.h"
  40
  41 #include "dis-asm.h"
  42
  43 static struct disassemble_info  info;
  44 static unsigned long            symcount = 0;
  45 static asymbol **               symtab = NULL;
  46
  47 /* FIXME: 1000 characters should be enough to hold the disassembled
  48    instruction plus any comments that come after it.  But maybe with
  49    C++ programs this might not be enough.  Not sure if it is worth
  50    adding logic to dynamically grow the buffer though.  */
  51 static char opbuf[1000];
  52
  53 static int op_printf (void *, const char *, ...) ATTRIBUTE_FPTR_PRINTF_2;
  54
  55 static int
  56 op_printf (void *stream ATTRIBUTE_UNUSED, const char *fmt, ...)
  57 {
  58   size_t space_remaining;
  59   int ret;
  60   va_list ap;
  61
  62   space_remaining = sizeof (opbuf) - strlen (opbuf);
  63   va_start (ap, fmt);
  64   /* Instead of printing to stream we store the text in opbuf.
  65      This allows us to use the sim_io_eprintf routine to output
  66      the text in aarch64_print_insn.  */
  67   ret = vsnprintf (opbuf + strlen (opbuf), space_remaining, fmt, ap);
  68   va_end (ap);
  69   return ret;
  70 }
  71
  72 void
  73 aarch64_print_insn (SIM_DESC sd, uint64_t addr)
  74 {
  75   int size;
  76
  77   opbuf[0] = 0;
  78   size = print_insn_aarch64 (addr, & info);
  79   sim_io_eprintf (sd, " %*s\n", size, opbuf);
  80 }
  81
  82 static int
  83 sim_dis_read (bfd_vma                     memaddr,
  84               bfd_byte *                  ptr,
  85               unsigned int                length,
  86               struct disassemble_info *   info)
  87 {
  88   aarch64_get_mem_blk (info->application_data, memaddr, (char *) ptr, length);
  89
  90   return 0;
  91 }
  92
  93 /* Filter out (in place) symbols that are useless for disassembly.
  94    COUNT is the number of elements in SYMBOLS.
  95    Return the number of useful symbols. */
  96
  97 static unsigned long
  98 remove_useless_symbols (asymbol **symbols, unsigned long count)
  99 {
 100   asymbol **in_ptr  = symbols;
 101   asymbol **out_ptr = symbols;
 102
 103   while (count-- > 0)
 104     {
 105       asymbol *sym = *in_ptr++;
 106
 107       if (strstr (sym->name, "gcc2_compiled"))
 108         continue;
 109       if (sym->name == NULL || sym->name[0] == '\0')
 110         continue;
 111       if (sym->flags & (BSF_DEBUGGING))
 112         continue;
 113       if (   bfd_is_und_section (sym->section)
 114           || bfd_is_com_section (sym->section))
 115         continue;
 116       if (sym->name[0] == '$')
 117         continue;
 118
 119       *out_ptr++ = sym;
 120     }
 121   return out_ptr - symbols;
 122 }
 123
 124 static signed int
 125 compare_symbols (const void *ap, const void *bp)
 126 {
 127   const asymbol *a = * (const asymbol **) ap;
 128   const asymbol *b = * (const asymbol **) bp;
 129
 130   if (bfd_asymbol_value (a) > bfd_asymbol_value (b))
 131     return 1;
 132   if (bfd_asymbol_value (a) < bfd_asymbol_value (b))
 133     return -1;
 134   return 0;
 135 }
 136
 137 /* Find the name of the function at ADDR.  */
 138 const char *
 139 aarch64_get_func (uint64_t addr)
 140 {
 141   int  min, max;
 142
 143   min = -1;
 144   max = symcount;
 145   while (min < max - 1)
 146     {
 147       int sym;
 148       bfd_vma sa;
 149
 150       sym = (min + max) / 2;
 151       sa = bfd_asymbol_value (symtab[sym]);
 152
 153       if (sa > addr)
 154         max = sym;
 155       else if (sa < addr)
 156         min = sym;
 157       else
 158         {
 159           min = sym;
 160           break;
 161         }
 162     }
 163
 164   if (min != -1)
 165     return bfd_asymbol_name (symtab [min]);
 166
 167   return "";
 168 }
 169
 170 uint64_t
 171 aarch64_get_sym_value (const char *name)
 172 {
 173   unsigned long i;
 174
 175   for (i = 0; i < symcount; i++)
 176     if (strcmp (bfd_asymbol_name (symtab[i]), name) == 0)
 177       return bfd_asymbol_value (symtab[i]);
 178
 179   return 0;
 180 }
 181
 182 SIM_RC
 183 sim_create_inferior (SIM_DESC sd, struct bfd *abfd, char **argv, char **env)
 184 {
 185   sim_cpu *cpu = STATE_CPU (sd, 0);
 186   long storage;
 187   bfd_vma addr = 0;
 188
 189   if (abfd != NULL)
 190     addr = bfd_get_start_address (abfd);
 191
 192   aarch64_set_next_PC (cpu, addr);
 193   aarch64_update_PC (cpu);
 194
 195   /* Standalone mode (i.e. `run`) will take care of the argv for us in
 196      sim_open() -> sim_parse_args().  But in debug mode (i.e. 'target sim'
 197      with `gdb`), we need to handle it because the user can change the
 198      argv on the fly via gdb's 'run'.  */
 199   if (STATE_PROG_ARGV (sd) != argv)
 200     {
 201       freeargv (STATE_PROG_ARGV (sd));
 202       STATE_PROG_ARGV (sd) = dupargv (argv);
 203     }
 204
 205   memset (& info, 0, sizeof (info));
 206   init_disassemble_info (& info, NULL, op_printf);
 207   info.read_memory_func = sim_dis_read;
 208   info.arch = bfd_get_arch (abfd);
 209   info.mach = bfd_get_mach (abfd);
 210   info.application_data = cpu;
 211   if (info.mach == 0)
 212     info.arch = bfd_arch_aarch64;
 213   disassemble_init_for_target (& info);
 214
 215   storage = bfd_get_symtab_upper_bound (abfd);
 216   if (storage > 0)
 217     {
 218       symtab = (asymbol **) xmalloc (storage);
 219       symcount = bfd_canonicalize_symtab (abfd, symtab);
 220       symcount = remove_useless_symbols (symtab, symcount);
 221       qsort (symtab, symcount, sizeof (asymbol *), compare_symbols);
 222     }
 223
 224   aarch64_init (cpu, bfd_get_start_address (abfd));
 225
 226   return SIM_RC_OK;
 227 }
 228
 229 /* Read the LENGTH bytes at BUF as a little-endian value.  */
 230
 231 static bfd_vma
 232 get_le (unsigned char *buf, unsigned int length)
 233 {
 234   bfd_vma acc = 0;
 235
 236   while (length -- > 0)
 237     acc = (acc << 8) + buf[length];
 238
 239   return acc;
 240 }
 241
 242 /* Store VAL as a little-endian value in the LENGTH bytes at BUF.  */
 243
 244 static void
 245 put_le (unsigned char *buf, unsigned int length, bfd_vma val)
 246 {
 247   int i;
 248
 249   for (i = 0; i < length; i++)
 250     {
 251       buf[i] = val & 0xff;
 252       val >>= 8;
 253     }
 254 }
 255
 256 static int
 257 check_regno (int regno)
 258 {
 259   return 0 <= regno && regno < AARCH64_MAX_REGNO;
 260 }
 261
 262 static size_t
 263 reg_size (int regno)
 264 {
 265   if (regno == AARCH64_CPSR_REGNO || regno == AARCH64_FPSR_REGNO)
 266     return 32;
 267   return 64;
 268 }
 269
 270 static int
 271 aarch64_reg_get (SIM_CPU *cpu, int regno, unsigned char *buf, int length)
 272 {
 273   size_t size;
 274   bfd_vma val;
 275
 276   if (!check_regno (regno))
 277     return 0;
 278
 279   size = reg_size (regno);
 280
 281   if (length != size)
 282     return 0;
 283
 284   switch (regno)
 285     {
 286     case AARCH64_MIN_GR ... AARCH64_MAX_GR:
 287       val = aarch64_get_reg_u64 (cpu, regno, 0);
 288       break;
 289
 290     case AARCH64_MIN_FR ... AARCH64_MAX_FR:
 291       val = aarch64_get_FP_double (cpu, regno - 32);
 292       break;
 293
 294     case AARCH64_PC_REGNO:
 295       val = aarch64_get_PC (cpu);
 296       break;
 297
 298     case AARCH64_CPSR_REGNO:
 299       val = aarch64_get_CPSR (cpu);
 300       break;
 301
 302     case AARCH64_FPSR_REGNO:
 303       val = aarch64_get_FPSR (cpu);
 304       break;
 305
 306     default:
 307       sim_io_eprintf (CPU_STATE (cpu),
 308                       "sim: unrecognized register number: %d\n", regno);
 309       return -1;
 310     }
 311
 312   put_le (buf, length, val);
 313
 314   return size;
 315 }
 316
 317 static int
 318 aarch64_reg_set (SIM_CPU *cpu, int regno, unsigned char *buf, int length)
 319 {
 320   size_t size;
 321   bfd_vma val;
 322
 323   if (!check_regno (regno))
 324     return -1;
 325
 326   size = reg_size (regno);
 327
 328   if (length != size)
 329     return -1;
 330
 331   val = get_le (buf, length);
 332
 333   switch (regno)
 334     {
 335     case AARCH64_MIN_GR ... AARCH64_MAX_GR:
 336       aarch64_set_reg_u64 (cpu, regno, 1, val);
 337       break;
 338
 339     case AARCH64_MIN_FR ... AARCH64_MAX_FR:
 340       aarch64_set_FP_double (cpu, regno - 32, (double) val);
 341       break;
 342
 343     case AARCH64_PC_REGNO:
 344       aarch64_set_next_PC (cpu, val);
 345       aarch64_update_PC (cpu);
 346       break;
 347
 348     case AARCH64_CPSR_REGNO:
 349       aarch64_set_CPSR (cpu, val);
 350       break;
 351
 352     case AARCH64_FPSR_REGNO:
 353       aarch64_set_FPSR (cpu, val);
 354       break;
 355
 356     default:
 357       sim_io_eprintf (CPU_STATE (cpu),
 358                       "sim: unrecognized register number: %d\n", regno);
 359       return 0;
 360     }
 361
 362   return size;
 363 }
 364
 365 static sim_cia
 366 aarch64_pc_get (sim_cpu *cpu)
 367 {
 368   return aarch64_get_PC (cpu);
 369 }
 370
 371 static void
 372 aarch64_pc_set (sim_cpu *cpu, sim_cia pc)
 373 {
 374   aarch64_set_next_PC (cpu, pc);
 375   aarch64_update_PC (cpu);
 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 enum
 388 {
 389   OPTION_DISAS = OPTION_START,
 390 };
 391
 392 static SIM_RC
 393 aarch64_option_handler (SIM_DESC  sd ATTRIBUTE_UNUSED,
 394                         sim_cpu * current_cpu ATTRIBUTE_UNUSED,
 395                         int       opt,
 396                         char *    arg ATTRIBUTE_UNUSED,
 397                         int       is_command ATTRIBUTE_UNUSED)
 398 {
 399   switch (opt)
 400     {
 401     case OPTION_DISAS:
 402       disas = TRUE;
 403       return SIM_RC_OK;
 404
 405     default:
 406       sim_io_eprintf (sd, "Unknown AArch64 option %d\n", opt);
 407       return SIM_RC_FAIL;
 408     }
 409 }
 410
 411 static DECLARE_OPTION_HANDLER (aarch64_option_handler);
 412
 413 const OPTION aarch64_options[] =
 414 {
 415   { {"disas", no_argument, NULL, OPTION_DISAS },
 416       '\0', NULL, "Enable instruction disassembly",
 417       aarch64_option_handler, NULL },
 418
 419   { {NULL, no_argument, NULL, 0}, '\0', NULL, NULL, NULL, NULL }
 420 };
 421
 422 SIM_DESC
 423 sim_open (SIM_OPEN_KIND                  kind,
 424           struct host_callback_struct *  callback,
 425           struct bfd *                   abfd,
 426           char **                        argv)
 427 {
 428   int i;
 429   sim_cpu *cpu;
 430   SIM_DESC sd = sim_state_alloc (kind, callback);
 431
 432   if (sd == NULL)
 433     return sd;
 434
 435   SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
 436
 437   sim_add_option_table (sd, NULL, aarch64_options);
 438
 439   /* Perform the initialization steps one by one.  */
 440   if (sim_cpu_alloc_all (sd, 1, 0) != SIM_RC_OK
 441       || sim_pre_argv_init (sd, argv[0]) != SIM_RC_OK
 442       || sim_parse_args (sd, argv) != SIM_RC_OK
 443       || sim_analyze_program (sd,
 444                               (STATE_PROG_ARGV (sd) != NULL
 445                                ? *STATE_PROG_ARGV (sd)
 446                                : NULL), abfd) != SIM_RC_OK
 447       || sim_config (sd) != SIM_RC_OK
 448       || sim_post_argv_init (sd) != SIM_RC_OK)
 449     {
 450       free_state (sd);
 451       return NULL;
 452     }
 453
 454   aarch64_init_LIT_table ();
 455
 456   assert (MAX_NR_PROCESSORS == 1);
 457   cpu = STATE_CPU (sd, 0);
 458   CPU_PC_FETCH (cpu) = aarch64_pc_get;
 459   CPU_PC_STORE (cpu) = aarch64_pc_set;
 460   CPU_REG_FETCH (cpu) = aarch64_reg_get;
 461   CPU_REG_STORE (cpu) = aarch64_reg_set;
 462
 463   /* Set SP, FP and PC to 0 and set LR to -1
 464      so we can detect a top-level return.  */
 465   aarch64_set_reg_u64 (cpu, SP, 1, 0);
 466   aarch64_set_reg_u64 (cpu, FP, 1, 0);
 467   aarch64_set_reg_u64 (cpu, LR, 1, TOP_LEVEL_RETURN_PC);
 468   aarch64_set_next_PC (cpu, 0);
 469   aarch64_update_PC (cpu);
 470
 471   /* Default to a 128 Mbyte (== 2^27) memory space.  */
 472   sim_do_commandf (sd, "memory-size 0x8000000");
 473
 474   return sd;
 475 }
 476
 477 void
 478 sim_engine_run (SIM_DESC sd,
 479                 int next_cpu_nr ATTRIBUTE_UNUSED,
 480                 int nr_cpus ATTRIBUTE_UNUSED,
 481                 int siggnal ATTRIBUTE_UNUSED)
 482 {
 483   aarch64_run (sd);
 484 }