sim/aarch64/interp.c

   1 /* interp.c -- AArch64 sim interface to GDB.
   2
   3    Copyright (C) 2015 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->private_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 (ie aarch64-elf-run) will take care of the argv
 196      for us in sim_open() -> sim_parse_args().  But in debug mode (i.e.
 197      'target sim' with `aarch64-...-gdb`), we need to handle it.  */
 198   if (STATE_OPEN_KIND (sd) == SIM_OPEN_DEBUG)
 199     {
 200       freeargv (STATE_PROG_ARGV (sd));
 201       STATE_PROG_ARGV (sd) = dupargv (argv);
 202     }
 203
 204   memset (& info, 0, sizeof (info));
 205   init_disassemble_info (& info, NULL, op_printf);
 206   info.read_memory_func = sim_dis_read;
 207   info.arch = bfd_get_arch (abfd);
 208   info.mach = bfd_get_mach (abfd);
 209   info.private_data = cpu;
 210   if (info.mach == 0)
 211     info.arch = bfd_arch_aarch64;
 212   disassemble_init_for_target (& info);
 213
 214   storage = bfd_get_symtab_upper_bound (abfd);
 215   if (storage > 0)
 216     {
 217       symtab = (asymbol **) xmalloc (storage);
 218       symcount = bfd_canonicalize_symtab (abfd, symtab);
 219       symcount = remove_useless_symbols (symtab, symcount);
 220       qsort (symtab, symcount, sizeof (asymbol *), compare_symbols);
 221     }
 222
 223   aarch64_init (cpu, bfd_get_start_address (abfd));
 224
 225   return SIM_RC_OK;
 226 }
 227
 228 /* Read the LENGTH bytes at BUF as a little-endian value.  */
 229
 230 static bfd_vma
 231 get_le (unsigned char *buf, unsigned int length)
 232 {
 233   bfd_vma acc = 0;
 234
 235   while (length -- > 0)
 236     acc = (acc << 8) + buf[length];
 237
 238   return acc;
 239 }
 240
 241 /* Store VAL as a little-endian value in the LENGTH bytes at BUF.  */
 242
 243 static void
 244 put_le (unsigned char *buf, unsigned int length, bfd_vma val)
 245 {
 246   int i;
 247
 248   for (i = 0; i < length; i++)
 249     {
 250       buf[i] = val & 0xff;
 251       val >>= 8;
 252     }
 253 }
 254
 255 static int
 256 check_regno (int regno)
 257 {
 258   return 0 <= regno && regno < AARCH64_MAX_REGNO;
 259 }
 260
 261 static size_t
 262 reg_size (int regno)
 263 {
 264   if (regno == AARCH64_CPSR_REGNO || regno == AARCH64_FPSR_REGNO)
 265     return 32;
 266   return 64;
 267 }
 268
 269 static int
 270 aarch64_reg_get (SIM_CPU *cpu, int regno, unsigned char *buf, int length)
 271 {
 272   size_t size;
 273   bfd_vma val;
 274
 275   if (!check_regno (regno))
 276     return 0;
 277
 278   size = reg_size (regno);
 279
 280   if (length != size)
 281     return 0;
 282
 283   switch (regno)
 284     {
 285     case AARCH64_MIN_GR ... AARCH64_MAX_GR:
 286       val = aarch64_get_reg_u64 (cpu, regno, 0);
 287       break;
 288
 289     case AARCH64_MIN_FR ... AARCH64_MAX_FR:
 290       val = aarch64_get_FP_double (cpu, regno - 32);
 291       break;
 292
 293     case AARCH64_PC_REGNO:
 294       val = aarch64_get_PC (cpu);
 295       break;
 296
 297     case AARCH64_CPSR_REGNO:
 298       val = aarch64_get_CPSR (cpu);
 299       break;
 300
 301     case AARCH64_FPSR_REGNO:
 302       val = aarch64_get_FPSR (cpu);
 303       break;
 304
 305     default:
 306       sim_io_eprintf (CPU_STATE (cpu),
 307                       "sim: unrecognized register number: %d\n", regno);
 308       return -1;
 309     }
 310
 311   put_le (buf, length, val);
 312
 313   return size;
 314 }
 315
 316 static int
 317 aarch64_reg_set (SIM_CPU *cpu, int regno, unsigned char *buf, int length)
 318 {
 319   size_t size;
 320   bfd_vma val;
 321
 322   if (!check_regno (regno))
 323     return -1;
 324
 325   size = reg_size (regno);
 326
 327   if (length != size)
 328     return -1;
 329
 330   val = get_le (buf, length);
 331
 332   switch (regno)
 333     {
 334     case AARCH64_MIN_GR ... AARCH64_MAX_GR:
 335       aarch64_set_reg_u64 (cpu, regno, 1, val);
 336       break;
 337
 338     case AARCH64_MIN_FR ... AARCH64_MAX_FR:
 339       aarch64_set_FP_double (cpu, regno - 32, (double) val);
 340       break;
 341
 342     case AARCH64_PC_REGNO:
 343       aarch64_set_next_PC (cpu, val);
 344       aarch64_update_PC (cpu);
 345       break;
 346
 347     case AARCH64_CPSR_REGNO:
 348       aarch64_set_CPSR (cpu, val);
 349       break;
 350
 351     case AARCH64_FPSR_REGNO:
 352       aarch64_set_FPSR (cpu, val);
 353       break;
 354
 355     default:
 356       sim_io_eprintf (CPU_STATE (cpu),
 357                       "sim: unrecognized register number: %d\n", regno);
 358       return 0;
 359     }
 360
 361   return size;
 362 }
 363
 364 static sim_cia
 365 aarch64_pc_get (sim_cpu *cpu)
 366 {
 367   return aarch64_get_PC (cpu);
 368 }
 369
 370 static void
 371 aarch64_pc_set (sim_cpu *cpu, sim_cia pc)
 372 {
 373   aarch64_set_next_PC (cpu, pc);
 374   aarch64_update_PC (cpu);
 375 }
 376
 377 static void
 378 free_state (SIM_DESC sd)
 379 {
 380   if (STATE_MODULES (sd) != NULL)
 381     sim_module_uninstall (sd);
 382   sim_cpu_free_all (sd);
 383   sim_state_free (sd);
 384 }
 385
 386 enum
 387 {
 388   OPTION_DISAS = OPTION_START,
 389 };
 390
 391 static SIM_RC
 392 aarch64_option_handler (SIM_DESC  sd ATTRIBUTE_UNUSED,
 393                         sim_cpu * current_cpu ATTRIBUTE_UNUSED,
 394                         int       opt,
 395                         char *    arg ATTRIBUTE_UNUSED,
 396                         int       is_command ATTRIBUTE_UNUSED)
 397 {
 398   switch (opt)
 399     {
 400     case OPTION_DISAS:
 401       disas = TRUE;
 402       return SIM_RC_OK;
 403
 404     default:
 405       sim_io_eprintf (sd, "Unknown AArch64 option %d\n", opt);
 406       return SIM_RC_FAIL;
 407     }
 408 }
 409
 410 static DECLARE_OPTION_HANDLER (aarch64_option_handler);
 411
 412 const OPTION aarch64_options[] =
 413 {
 414   { {"disas", no_argument, NULL, OPTION_DISAS },
 415       '\0', NULL, "Enable instruction disassembly",
 416       aarch64_option_handler, NULL },
 417
 418   { {NULL, no_argument, NULL, 0}, '\0', NULL, NULL, NULL, NULL }
 419 };
 420
 421 SIM_DESC
 422 sim_open (SIM_OPEN_KIND                  kind,
 423           struct host_callback_struct *  callback,
 424           struct bfd *                   abfd,
 425           char **                        argv)
 426 {
 427   int i;
 428   sim_cpu *cpu;
 429   SIM_DESC sd = sim_state_alloc (kind, callback);
 430
 431   if (sd == NULL)
 432     return sd;
 433
 434   SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
 435
 436   sim_add_option_table (sd, NULL, aarch64_options);
 437
 438   /* Perform the initialization steps one by one.  */
 439   if (sim_cpu_alloc_all (sd, 1, 0) != SIM_RC_OK
 440       || sim_pre_argv_init (sd, argv[0]) != SIM_RC_OK
 441       || sim_parse_args (sd, argv) != SIM_RC_OK
 442       || sim_analyze_program (sd,
 443                               (STATE_PROG_ARGV (sd) != NULL
 444                                ? *STATE_PROG_ARGV (sd)
 445                                : NULL), abfd) != SIM_RC_OK
 446       || sim_config (sd) != SIM_RC_OK
 447       || sim_post_argv_init (sd) != SIM_RC_OK)
 448     {
 449       free_state (sd);
 450       return NULL;
 451     }
 452
 453   aarch64_init_LIT_table ();
 454
 455   assert (MAX_NR_PROCESSORS == 1);
 456   cpu = STATE_CPU (sd, 0);
 457   CPU_PC_FETCH (cpu) = aarch64_pc_get;
 458   CPU_PC_STORE (cpu) = aarch64_pc_set;
 459   CPU_REG_FETCH (cpu) = aarch64_reg_get;
 460   CPU_REG_STORE (cpu) = aarch64_reg_set;
 461
 462   /* Set SP, FP and PC to 0 and set LR to -1
 463      so we can detect a top-level return.  */
 464   aarch64_set_reg_u64 (cpu, SP, 1, 0);
 465   aarch64_set_reg_u64 (cpu, FP, 1, 0);
 466   aarch64_set_reg_u64 (cpu, LR, 1, TOP_LEVEL_RETURN_PC);
 467   aarch64_set_next_PC (cpu, 0);
 468   aarch64_update_PC (cpu);
 469
 470   /* Default to a 128 Mbyte (== 2^27) memory space.  */
 471   sim_do_commandf (sd, "memory-size 0x8000000");
 472
 473   return sd;
 474 }
 475
 476 void
 477 sim_engine_run (SIM_DESC sd,
 478                 int next_cpu_nr ATTRIBUTE_UNUSED,
 479                 int nr_cpus ATTRIBUTE_UNUSED,
 480                 int siggnal ATTRIBUTE_UNUSED)
 481 {
 482   aarch64_run (sd);
 483 }