sim/aarch64/interp.c

   1 /* interp.c -- AArch64 sim interface to GDB.
   2
   3    Copyright (C) 2015-2024 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 /* This must come before any other includes.  */
  23 #include "defs.h"
  24
  25 #include <stdio.h>
  26 #include <assert.h>
  27 #include <signal.h>
  28 #include <string.h>
  29 #include <ctype.h>
  30 #include <stdlib.h>
  31
  32 #include "ansidecl.h"
  33 #include "bfd.h"
  34 #include "sim/callback.h"
  35 #include "sim/sim.h"
  36 #include "gdb/signals.h"
  37 #include "sim/sim-aarch64.h"
  38
  39 #include "sim-main.h"
  40 #include "sim-options.h"
  41 #include "memory.h"
  42 #include "simulator.h"
  43 #include "sim-assert.h"
  44
  45 #include "aarch64-sim.h"
  46
  47 /* Filter out (in place) symbols that are useless for disassembly.
  48    COUNT is the number of elements in SYMBOLS.
  49    Return the number of useful symbols. */
  50
  51 static long
  52 remove_useless_symbols (asymbol **symbols, long count)
  53 {
  54   asymbol **in_ptr  = symbols;
  55   asymbol **out_ptr = symbols;
  56
  57   while (count-- > 0)
  58     {
  59       asymbol *sym = *in_ptr++;
  60
  61       if (strstr (sym->name, "gcc2_compiled"))
  62         continue;
  63       if (sym->name == NULL || sym->name[0] == '\0')
  64         continue;
  65       if (sym->flags & (BSF_DEBUGGING))
  66         continue;
  67       if (   bfd_is_und_section (sym->section)
  68           || bfd_is_com_section (sym->section))
  69         continue;
  70       if (sym->name[0] == '$')
  71         continue;
  72
  73       *out_ptr++ = sym;
  74     }
  75   return out_ptr - symbols;
  76 }
  77
  78 static signed int
  79 compare_symbols (const void *ap, const void *bp)
  80 {
  81   const asymbol *a = * (const asymbol **) ap;
  82   const asymbol *b = * (const asymbol **) bp;
  83
  84   if (bfd_asymbol_value (a) > bfd_asymbol_value (b))
  85     return 1;
  86   if (bfd_asymbol_value (a) < bfd_asymbol_value (b))
  87     return -1;
  88   return 0;
  89 }
  90
  91 /* Find the name of the function at ADDR.  */
  92 const char *
  93 aarch64_get_func (SIM_DESC sd, uint64_t addr)
  94 {
  95   long symcount = STATE_PROG_SYMS_COUNT (sd);
  96   asymbol **symtab = STATE_PROG_SYMS (sd);
  97   int  min, max;
  98
  99   min = -1;
 100   max = symcount;
 101   while (min < max - 1)
 102     {
 103       int sym;
 104       bfd_vma sa;
 105
 106       sym = (min + max) / 2;
 107       sa = bfd_asymbol_value (symtab[sym]);
 108
 109       if (sa > addr)
 110         max = sym;
 111       else if (sa < addr)
 112         min = sym;
 113       else
 114         {
 115           min = sym;
 116           break;
 117         }
 118     }
 119
 120   if (min != -1)
 121     return bfd_asymbol_name (symtab [min]);
 122
 123   return "";
 124 }
 125
 126 SIM_RC
 127 sim_create_inferior (SIM_DESC sd, struct bfd *abfd,
 128                      char * const *argv, char * const *env)
 129 {
 130   sim_cpu *cpu = STATE_CPU (sd, 0);
 131   host_callback *cb = STATE_CALLBACK (sd);
 132   bfd_vma addr = 0;
 133
 134   if (abfd != NULL)
 135     addr = bfd_get_start_address (abfd);
 136
 137   aarch64_set_next_PC (cpu, addr);
 138   aarch64_update_PC (cpu);
 139
 140   /* Standalone mode (i.e. `run`) will take care of the argv for us in
 141      sim_open() -> sim_parse_args().  But in debug mode (i.e. 'target sim'
 142      with `gdb`), we need to handle it because the user can change the
 143      argv on the fly via gdb's 'run'.  */
 144   if (STATE_PROG_ARGV (sd) != argv)
 145     {
 146       freeargv (STATE_PROG_ARGV (sd));
 147       STATE_PROG_ARGV (sd) = dupargv (argv);
 148     }
 149
 150   if (STATE_PROG_ENVP (sd) != env)
 151     {
 152       freeargv (STATE_PROG_ENVP (sd));
 153       STATE_PROG_ENVP (sd) = dupargv (env);
 154     }
 155
 156   cb->argv = STATE_PROG_ARGV (sd);
 157   cb->envp = STATE_PROG_ENVP (sd);
 158
 159   if (trace_load_symbols (sd))
 160     {
 161       STATE_PROG_SYMS_COUNT (sd) =
 162         remove_useless_symbols (STATE_PROG_SYMS (sd),
 163                                 STATE_PROG_SYMS_COUNT (sd));
 164       qsort (STATE_PROG_SYMS (sd), STATE_PROG_SYMS_COUNT (sd),
 165              sizeof (asymbol *), compare_symbols);
 166     }
 167
 168   aarch64_init (cpu, addr);
 169
 170   return SIM_RC_OK;
 171 }
 172
 173 /* Read the LENGTH bytes at BUF as a little-endian value.  */
 174
 175 static bfd_vma
 176 get_le (const unsigned char *buf, unsigned int length)
 177 {
 178   bfd_vma acc = 0;
 179
 180   while (length -- > 0)
 181     acc = (acc << 8) + buf[length];
 182
 183   return acc;
 184 }
 185
 186 /* Store VAL as a little-endian value in the LENGTH bytes at BUF.  */
 187
 188 static void
 189 put_le (unsigned char *buf, unsigned int length, bfd_vma val)
 190 {
 191   int i;
 192
 193   for (i = 0; i < length; i++)
 194     {
 195       buf[i] = val & 0xff;
 196       val >>= 8;
 197     }
 198 }
 199
 200 static int
 201 check_regno (int regno)
 202 {
 203   return 0 <= regno && regno < AARCH64_MAX_REGNO;
 204 }
 205
 206 static size_t
 207 reg_size (int regno)
 208 {
 209   if (regno == AARCH64_CPSR_REGNO || regno == AARCH64_FPSR_REGNO)
 210     return 32;
 211   return 64;
 212 }
 213
 214 static int
 215 aarch64_reg_get (SIM_CPU *cpu, int regno, void *buf, int length)
 216 {
 217   size_t size;
 218   bfd_vma val;
 219
 220   if (!check_regno (regno))
 221     return 0;
 222
 223   size = reg_size (regno);
 224
 225   if (length != size)
 226     return 0;
 227
 228   switch (regno)
 229     {
 230     case AARCH64_MIN_GR ... AARCH64_MAX_GR:
 231       val = aarch64_get_reg_u64 (cpu, regno, 0);
 232       break;
 233
 234     case AARCH64_MIN_FR ... AARCH64_MAX_FR:
 235       val = aarch64_get_FP_double (cpu, regno - 32);
 236       break;
 237
 238     case AARCH64_PC_REGNO:
 239       val = aarch64_get_PC (cpu);
 240       break;
 241
 242     case AARCH64_CPSR_REGNO:
 243       val = aarch64_get_CPSR (cpu);
 244       break;
 245
 246     case AARCH64_FPSR_REGNO:
 247       val = aarch64_get_FPSR (cpu);
 248       break;
 249
 250     default:
 251       sim_io_eprintf (CPU_STATE (cpu),
 252                       "sim: unrecognized register number: %d\n", regno);
 253       return -1;
 254     }
 255
 256   put_le (buf, length, val);
 257
 258   return size;
 259 }
 260
 261 static int
 262 aarch64_reg_set (SIM_CPU *cpu, int regno, const void *buf, int length)
 263 {
 264   size_t size;
 265   bfd_vma val;
 266
 267   if (!check_regno (regno))
 268     return -1;
 269
 270   size = reg_size (regno);
 271
 272   if (length != size)
 273     return -1;
 274
 275   val = get_le (buf, length);
 276
 277   switch (regno)
 278     {
 279     case AARCH64_MIN_GR ... AARCH64_MAX_GR:
 280       aarch64_set_reg_u64 (cpu, regno, 1, val);
 281       break;
 282
 283     case AARCH64_MIN_FR ... AARCH64_MAX_FR:
 284       aarch64_set_FP_double (cpu, regno - 32, (double) val);
 285       break;
 286
 287     case AARCH64_PC_REGNO:
 288       aarch64_set_next_PC (cpu, val);
 289       aarch64_update_PC (cpu);
 290       break;
 291
 292     case AARCH64_CPSR_REGNO:
 293       aarch64_set_CPSR (cpu, val);
 294       break;
 295
 296     case AARCH64_FPSR_REGNO:
 297       aarch64_set_FPSR (cpu, val);
 298       break;
 299
 300     default:
 301       sim_io_eprintf (CPU_STATE (cpu),
 302                       "sim: unrecognized register number: %d\n", regno);
 303       return 0;
 304     }
 305
 306   return size;
 307 }
 308
 309 static sim_cia
 310 aarch64_pc_get (sim_cpu *cpu)
 311 {
 312   return aarch64_get_PC (cpu);
 313 }
 314
 315 static void
 316 aarch64_pc_set (sim_cpu *cpu, sim_cia pc)
 317 {
 318   aarch64_set_next_PC (cpu, pc);
 319   aarch64_update_PC (cpu);
 320 }
 321
 322 static void
 323 free_state (SIM_DESC sd)
 324 {
 325   if (STATE_MODULES (sd) != NULL)
 326     sim_module_uninstall (sd);
 327   sim_cpu_free_all (sd);
 328   sim_state_free (sd);
 329 }
 330
 331 SIM_DESC
 332 sim_open (SIM_OPEN_KIND                  kind,
 333           struct host_callback_struct *  callback,
 334           struct bfd *                   abfd,
 335           char * const *                 argv)
 336 {
 337   sim_cpu *cpu;
 338   SIM_DESC sd = sim_state_alloc (kind, callback);
 339
 340   if (sd == NULL)
 341     return sd;
 342
 343   SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
 344
 345   /* We use NONSTRICT_ALIGNMENT as the default because AArch64 only enforces
 346      4-byte alignment, even for 8-byte reads/writes.  The common core does not
 347      support this, so we opt for non-strict alignment instead.  */
 348   current_alignment = NONSTRICT_ALIGNMENT;
 349
 350   /* Perform the initialization steps one by one.  */
 351   if (sim_cpu_alloc_all_extra (sd, 0, sizeof (struct aarch64_sim_cpu))
 352       != SIM_RC_OK
 353       || sim_pre_argv_init (sd, argv[0]) != SIM_RC_OK
 354       || sim_parse_args (sd, argv) != SIM_RC_OK
 355       || sim_analyze_program (sd, STATE_PROG_FILE (sd), abfd) != SIM_RC_OK
 356       || sim_config (sd) != SIM_RC_OK
 357       || sim_post_argv_init (sd) != SIM_RC_OK)
 358     {
 359       free_state (sd);
 360       return NULL;
 361     }
 362
 363   aarch64_init_LIT_table ();
 364
 365   assert (MAX_NR_PROCESSORS == 1);
 366   cpu = STATE_CPU (sd, 0);
 367   CPU_PC_FETCH (cpu) = aarch64_pc_get;
 368   CPU_PC_STORE (cpu) = aarch64_pc_set;
 369   CPU_REG_FETCH (cpu) = aarch64_reg_get;
 370   CPU_REG_STORE (cpu) = aarch64_reg_set;
 371
 372   /* Set SP, FP and PC to 0 and set LR to -1
 373      so we can detect a top-level return.  */
 374   aarch64_set_reg_u64 (cpu, SP, 1, 0);
 375   aarch64_set_reg_u64 (cpu, FP, 1, 0);
 376   aarch64_set_reg_u64 (cpu, LR, 1, TOP_LEVEL_RETURN_PC);
 377   aarch64_set_next_PC (cpu, 0);
 378   aarch64_update_PC (cpu);
 379
 380   /* Default to a 128 Mbyte (== 2^27) memory space.  */
 381   sim_do_commandf (sd, "memory-size 0x8000000");
 382
 383   return sd;
 384 }
 385
 386 void
 387 sim_engine_run (SIM_DESC sd,
 388                 int next_cpu_nr ATTRIBUTE_UNUSED,
 389                 int nr_cpus ATTRIBUTE_UNUSED,
 390                 int siggnal ATTRIBUTE_UNUSED)
 391 {
 392   aarch64_run (sd);
 393 }