sim/aarch64/interp.c

   1 /* interp.c -- AArch64 sim interface to GDB.
   2
   3    Copyright (C) 2015-2018 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 "bfd.h"
  32 #include "gdb/callback.h"
  33 #include "gdb/remote-sim.h"
  34 #include "gdb/signals.h"
  35 #include "gdb/sim-aarch64.h"
  36
  37 #include "sim-main.h"
  38 #include "sim-options.h"
  39 #include "memory.h"
  40 #include "simulator.h"
  41
  42 /* Filter out (in place) symbols that are useless for disassembly.
  43    COUNT is the number of elements in SYMBOLS.
  44    Return the number of useful symbols. */
  45
  46 static long
  47 remove_useless_symbols (asymbol **symbols, long count)
  48 {
  49   asymbol **in_ptr  = symbols;
  50   asymbol **out_ptr = symbols;
  51
  52   while (count-- > 0)
  53     {
  54       asymbol *sym = *in_ptr++;
  55
  56       if (strstr (sym->name, "gcc2_compiled"))
  57         continue;
  58       if (sym->name == NULL || sym->name[0] == '\0')
  59         continue;
  60       if (sym->flags & (BSF_DEBUGGING))
  61         continue;
  62       if (   bfd_is_und_section (sym->section)
  63           || bfd_is_com_section (sym->section))
  64         continue;
  65       if (sym->name[0] == '$')
  66         continue;
  67
  68       *out_ptr++ = sym;
  69     }
  70   return out_ptr - symbols;
  71 }
  72
  73 static signed int
  74 compare_symbols (const void *ap, const void *bp)
  75 {
  76   const asymbol *a = * (const asymbol **) ap;
  77   const asymbol *b = * (const asymbol **) bp;
  78
  79   if (bfd_asymbol_value (a) > bfd_asymbol_value (b))
  80     return 1;
  81   if (bfd_asymbol_value (a) < bfd_asymbol_value (b))
  82     return -1;
  83   return 0;
  84 }
  85
  86 /* Find the name of the function at ADDR.  */
  87 const char *
  88 aarch64_get_func (SIM_DESC sd, uint64_t addr)
  89 {
  90   long symcount = STATE_PROG_SYMS_COUNT (sd);
  91   asymbol **symtab = STATE_PROG_SYMS (sd);
  92   int  min, max;
  93
  94   min = -1;
  95   max = symcount;
  96   while (min < max - 1)
  97     {
  98       int sym;
  99       bfd_vma sa;
 100
 101       sym = (min + max) / 2;
 102       sa = bfd_asymbol_value (symtab[sym]);
 103
 104       if (sa > addr)
 105         max = sym;
 106       else if (sa < addr)
 107         min = sym;
 108       else
 109         {
 110           min = sym;
 111           break;
 112         }
 113     }
 114
 115   if (min != -1)
 116     return bfd_asymbol_name (symtab [min]);
 117
 118   return "";
 119 }
 120
 121 SIM_RC
 122 sim_create_inferior (SIM_DESC sd, struct bfd *abfd,
 123                      char * const *argv, char * const *env)
 124 {
 125   sim_cpu *cpu = STATE_CPU (sd, 0);
 126   bfd_vma addr = 0;
 127
 128   if (abfd != NULL)
 129     addr = bfd_get_start_address (abfd);
 130
 131   aarch64_set_next_PC (cpu, addr);
 132   aarch64_update_PC (cpu);
 133
 134   /* Standalone mode (i.e. `run`) will take care of the argv for us in
 135      sim_open() -> sim_parse_args().  But in debug mode (i.e. 'target sim'
 136      with `gdb`), we need to handle it because the user can change the
 137      argv on the fly via gdb's 'run'.  */
 138   if (STATE_PROG_ARGV (sd) != argv)
 139     {
 140       freeargv (STATE_PROG_ARGV (sd));
 141       STATE_PROG_ARGV (sd) = dupargv (argv);
 142     }
 143
 144   if (trace_load_symbols (sd))
 145     {
 146       STATE_PROG_SYMS_COUNT (sd) =
 147         remove_useless_symbols (STATE_PROG_SYMS (sd),
 148                                 STATE_PROG_SYMS_COUNT (sd));
 149       qsort (STATE_PROG_SYMS (sd), STATE_PROG_SYMS_COUNT (sd),
 150              sizeof (asymbol *), compare_symbols);
 151     }
 152
 153   aarch64_init (cpu, addr);
 154
 155   return SIM_RC_OK;
 156 }
 157
 158 /* Read the LENGTH bytes at BUF as a little-endian value.  */
 159
 160 static bfd_vma
 161 get_le (unsigned char *buf, unsigned int length)
 162 {
 163   bfd_vma acc = 0;
 164
 165   while (length -- > 0)
 166     acc = (acc << 8) + buf[length];
 167
 168   return acc;
 169 }
 170
 171 /* Store VAL as a little-endian value in the LENGTH bytes at BUF.  */
 172
 173 static void
 174 put_le (unsigned char *buf, unsigned int length, bfd_vma val)
 175 {
 176   int i;
 177
 178   for (i = 0; i < length; i++)
 179     {
 180       buf[i] = val & 0xff;
 181       val >>= 8;
 182     }
 183 }
 184
 185 static int
 186 check_regno (int regno)
 187 {
 188   return 0 <= regno && regno < AARCH64_MAX_REGNO;
 189 }
 190
 191 static size_t
 192 reg_size (int regno)
 193 {
 194   if (regno == AARCH64_CPSR_REGNO || regno == AARCH64_FPSR_REGNO)
 195     return 32;
 196   return 64;
 197 }
 198
 199 static int
 200 aarch64_reg_get (SIM_CPU *cpu, int regno, unsigned char *buf, int length)
 201 {
 202   size_t size;
 203   bfd_vma val;
 204
 205   if (!check_regno (regno))
 206     return 0;
 207
 208   size = reg_size (regno);
 209
 210   if (length != size)
 211     return 0;
 212
 213   switch (regno)
 214     {
 215     case AARCH64_MIN_GR ... AARCH64_MAX_GR:
 216       val = aarch64_get_reg_u64 (cpu, regno, 0);
 217       break;
 218
 219     case AARCH64_MIN_FR ... AARCH64_MAX_FR:
 220       val = aarch64_get_FP_double (cpu, regno - 32);
 221       break;
 222
 223     case AARCH64_PC_REGNO:
 224       val = aarch64_get_PC (cpu);
 225       break;
 226
 227     case AARCH64_CPSR_REGNO:
 228       val = aarch64_get_CPSR (cpu);
 229       break;
 230
 231     case AARCH64_FPSR_REGNO:
 232       val = aarch64_get_FPSR (cpu);
 233       break;
 234
 235     default:
 236       sim_io_eprintf (CPU_STATE (cpu),
 237                       "sim: unrecognized register number: %d\n", regno);
 238       return -1;
 239     }
 240
 241   put_le (buf, length, val);
 242
 243   return size;
 244 }
 245
 246 static int
 247 aarch64_reg_set (SIM_CPU *cpu, int regno, unsigned char *buf, int length)
 248 {
 249   size_t size;
 250   bfd_vma val;
 251
 252   if (!check_regno (regno))
 253     return -1;
 254
 255   size = reg_size (regno);
 256
 257   if (length != size)
 258     return -1;
 259
 260   val = get_le (buf, length);
 261
 262   switch (regno)
 263     {
 264     case AARCH64_MIN_GR ... AARCH64_MAX_GR:
 265       aarch64_set_reg_u64 (cpu, regno, 1, val);
 266       break;
 267
 268     case AARCH64_MIN_FR ... AARCH64_MAX_FR:
 269       aarch64_set_FP_double (cpu, regno - 32, (double) val);
 270       break;
 271
 272     case AARCH64_PC_REGNO:
 273       aarch64_set_next_PC (cpu, val);
 274       aarch64_update_PC (cpu);
 275       break;
 276
 277     case AARCH64_CPSR_REGNO:
 278       aarch64_set_CPSR (cpu, val);
 279       break;
 280
 281     case AARCH64_FPSR_REGNO:
 282       aarch64_set_FPSR (cpu, val);
 283       break;
 284
 285     default:
 286       sim_io_eprintf (CPU_STATE (cpu),
 287                       "sim: unrecognized register number: %d\n", regno);
 288       return 0;
 289     }
 290
 291   return size;
 292 }
 293
 294 static sim_cia
 295 aarch64_pc_get (sim_cpu *cpu)
 296 {
 297   return aarch64_get_PC (cpu);
 298 }
 299
 300 static void
 301 aarch64_pc_set (sim_cpu *cpu, sim_cia pc)
 302 {
 303   aarch64_set_next_PC (cpu, pc);
 304   aarch64_update_PC (cpu);
 305 }
 306
 307 static void
 308 free_state (SIM_DESC sd)
 309 {
 310   if (STATE_MODULES (sd) != NULL)
 311     sim_module_uninstall (sd);
 312   sim_cpu_free_all (sd);
 313   sim_state_free (sd);
 314 }
 315
 316 SIM_DESC
 317 sim_open (SIM_OPEN_KIND                  kind,
 318           struct host_callback_struct *  callback,
 319           struct bfd *                   abfd,
 320           char * const *                 argv)
 321 {
 322   sim_cpu *cpu;
 323   SIM_DESC sd = sim_state_alloc (kind, callback);
 324
 325   if (sd == NULL)
 326     return sd;
 327
 328   SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
 329
 330   /* Perform the initialization steps one by one.  */
 331   if (sim_cpu_alloc_all (sd, 1, 0) != SIM_RC_OK
 332       || sim_pre_argv_init (sd, argv[0]) != SIM_RC_OK
 333       || sim_parse_args (sd, argv) != SIM_RC_OK
 334       || sim_analyze_program (sd,
 335                               (STATE_PROG_ARGV (sd) != NULL
 336                                ? *STATE_PROG_ARGV (sd)
 337                                : NULL), abfd) != SIM_RC_OK
 338       || sim_config (sd) != SIM_RC_OK
 339       || sim_post_argv_init (sd) != SIM_RC_OK)
 340     {
 341       free_state (sd);
 342       return NULL;
 343     }
 344
 345   aarch64_init_LIT_table ();
 346
 347   assert (MAX_NR_PROCESSORS == 1);
 348   cpu = STATE_CPU (sd, 0);
 349   CPU_PC_FETCH (cpu) = aarch64_pc_get;
 350   CPU_PC_STORE (cpu) = aarch64_pc_set;
 351   CPU_REG_FETCH (cpu) = aarch64_reg_get;
 352   CPU_REG_STORE (cpu) = aarch64_reg_set;
 353
 354   /* Set SP, FP and PC to 0 and set LR to -1
 355      so we can detect a top-level return.  */
 356   aarch64_set_reg_u64 (cpu, SP, 1, 0);
 357   aarch64_set_reg_u64 (cpu, FP, 1, 0);
 358   aarch64_set_reg_u64 (cpu, LR, 1, TOP_LEVEL_RETURN_PC);
 359   aarch64_set_next_PC (cpu, 0);
 360   aarch64_update_PC (cpu);
 361
 362   /* Default to a 128 Mbyte (== 2^27) memory space.  */
 363   sim_do_commandf (sd, "memory-size 0x8000000");
 364
 365   return sd;
 366 }
 367
 368 void
 369 sim_engine_run (SIM_DESC sd,
 370                 int next_cpu_nr ATTRIBUTE_UNUSED,
 371                 int nr_cpus ATTRIBUTE_UNUSED,
 372                 int siggnal ATTRIBUTE_UNUSED)
 373 {
 374   aarch64_run (sd);
 375 }