sim/aarch64/interp.c

   1 /* interp.c -- AArch64 sim interface to GDB.
   2
   3    Copyright (C) 2015-2022 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 "gdb/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 /* Filter out (in place) symbols that are useless for disassembly.
  46    COUNT is the number of elements in SYMBOLS.
  47    Return the number of useful symbols. */
  48
  49 static long
  50 remove_useless_symbols (asymbol **symbols, long count)
  51 {
  52   asymbol **in_ptr  = symbols;
  53   asymbol **out_ptr = symbols;
  54
  55   while (count-- > 0)
  56     {
  57       asymbol *sym = *in_ptr++;
  58
  59       if (strstr (sym->name, "gcc2_compiled"))
  60         continue;
  61       if (sym->name == NULL || sym->name[0] == '\0')
  62         continue;
  63       if (sym->flags & (BSF_DEBUGGING))
  64         continue;
  65       if (   bfd_is_und_section (sym->section)
  66           || bfd_is_com_section (sym->section))
  67         continue;
  68       if (sym->name[0] == '$')
  69         continue;
  70
  71       *out_ptr++ = sym;
  72     }
  73   return out_ptr - symbols;
  74 }
  75
  76 static signed int
  77 compare_symbols (const void *ap, const void *bp)
  78 {
  79   const asymbol *a = * (const asymbol **) ap;
  80   const asymbol *b = * (const asymbol **) bp;
  81
  82   if (bfd_asymbol_value (a) > bfd_asymbol_value (b))
  83     return 1;
  84   if (bfd_asymbol_value (a) < bfd_asymbol_value (b))
  85     return -1;
  86   return 0;
  87 }
  88
  89 /* Find the name of the function at ADDR.  */
  90 const char *
  91 aarch64_get_func (SIM_DESC sd, uint64_t addr)
  92 {
  93   long symcount = STATE_PROG_SYMS_COUNT (sd);
  94   asymbol **symtab = STATE_PROG_SYMS (sd);
  95   int  min, max;
  96
  97   min = -1;
  98   max = symcount;
  99   while (min < max - 1)
 100     {
 101       int sym;
 102       bfd_vma sa;
 103
 104       sym = (min + max) / 2;
 105       sa = bfd_asymbol_value (symtab[sym]);
 106
 107       if (sa > addr)
 108         max = sym;
 109       else if (sa < addr)
 110         min = sym;
 111       else
 112         {
 113           min = sym;
 114           break;
 115         }
 116     }
 117
 118   if (min != -1)
 119     return bfd_asymbol_name (symtab [min]);
 120
 121   return "";
 122 }
 123
 124 SIM_RC
 125 sim_create_inferior (SIM_DESC sd, struct bfd *abfd,
 126                      char * const *argv, char * const *env)
 127 {
 128   sim_cpu *cpu = STATE_CPU (sd, 0);
 129   host_callback *cb = STATE_CALLBACK (sd);
 130   bfd_vma addr = 0;
 131
 132   if (abfd != NULL)
 133     addr = bfd_get_start_address (abfd);
 134
 135   aarch64_set_next_PC (cpu, addr);
 136   aarch64_update_PC (cpu);
 137
 138   /* Standalone mode (i.e. `run`) will take care of the argv for us in
 139      sim_open() -> sim_parse_args().  But in debug mode (i.e. 'target sim'
 140      with `gdb`), we need to handle it because the user can change the
 141      argv on the fly via gdb's 'run'.  */
 142   if (STATE_PROG_ARGV (sd) != argv)
 143     {
 144       freeargv (STATE_PROG_ARGV (sd));
 145       STATE_PROG_ARGV (sd) = dupargv (argv);
 146     }
 147
 148   if (STATE_PROG_ENVP (sd) != env)
 149     {
 150       freeargv (STATE_PROG_ENVP (sd));
 151       STATE_PROG_ENVP (sd) = dupargv (env);
 152     }
 153
 154   cb->argv = STATE_PROG_ARGV (sd);
 155   cb->envp = STATE_PROG_ENVP (sd);
 156
 157   if (trace_load_symbols (sd))
 158     {
 159       STATE_PROG_SYMS_COUNT (sd) =
 160         remove_useless_symbols (STATE_PROG_SYMS (sd),
 161                                 STATE_PROG_SYMS_COUNT (sd));
 162       qsort (STATE_PROG_SYMS (sd), STATE_PROG_SYMS_COUNT (sd),
 163              sizeof (asymbol *), compare_symbols);
 164     }
 165
 166   aarch64_init (cpu, addr);
 167
 168   return SIM_RC_OK;
 169 }
 170
 171 /* Read the LENGTH bytes at BUF as a little-endian value.  */
 172
 173 static bfd_vma
 174 get_le (unsigned char *buf, unsigned int length)
 175 {
 176   bfd_vma acc = 0;
 177
 178   while (length -- > 0)
 179     acc = (acc << 8) + buf[length];
 180
 181   return acc;
 182 }
 183
 184 /* Store VAL as a little-endian value in the LENGTH bytes at BUF.  */
 185
 186 static void
 187 put_le (unsigned char *buf, unsigned int length, bfd_vma val)
 188 {
 189   int i;
 190
 191   for (i = 0; i < length; i++)
 192     {
 193       buf[i] = val & 0xff;
 194       val >>= 8;
 195     }
 196 }
 197
 198 static int
 199 check_regno (int regno)
 200 {
 201   return 0 <= regno && regno < AARCH64_MAX_REGNO;
 202 }
 203
 204 static size_t
 205 reg_size (int regno)
 206 {
 207   if (regno == AARCH64_CPSR_REGNO || regno == AARCH64_FPSR_REGNO)
 208     return 32;
 209   return 64;
 210 }
 211
 212 static int
 213 aarch64_reg_get (SIM_CPU *cpu, int regno, unsigned char *buf, int length)
 214 {
 215   size_t size;
 216   bfd_vma val;
 217
 218   if (!check_regno (regno))
 219     return 0;
 220
 221   size = reg_size (regno);
 222
 223   if (length != size)
 224     return 0;
 225
 226   switch (regno)
 227     {
 228     case AARCH64_MIN_GR ... AARCH64_MAX_GR:
 229       val = aarch64_get_reg_u64 (cpu, regno, 0);
 230       break;
 231
 232     case AARCH64_MIN_FR ... AARCH64_MAX_FR:
 233       val = aarch64_get_FP_double (cpu, regno - 32);
 234       break;
 235
 236     case AARCH64_PC_REGNO:
 237       val = aarch64_get_PC (cpu);
 238       break;
 239
 240     case AARCH64_CPSR_REGNO:
 241       val = aarch64_get_CPSR (cpu);
 242       break;
 243
 244     case AARCH64_FPSR_REGNO:
 245       val = aarch64_get_FPSR (cpu);
 246       break;
 247
 248     default:
 249       sim_io_eprintf (CPU_STATE (cpu),
 250                       "sim: unrecognized register number: %d\n", regno);
 251       return -1;
 252     }
 253
 254   put_le (buf, length, val);
 255
 256   return size;
 257 }
 258
 259 static int
 260 aarch64_reg_set (SIM_CPU *cpu, int regno, unsigned char *buf, int length)
 261 {
 262   size_t size;
 263   bfd_vma val;
 264
 265   if (!check_regno (regno))
 266     return -1;
 267
 268   size = reg_size (regno);
 269
 270   if (length != size)
 271     return -1;
 272
 273   val = get_le (buf, length);
 274
 275   switch (regno)
 276     {
 277     case AARCH64_MIN_GR ... AARCH64_MAX_GR:
 278       aarch64_set_reg_u64 (cpu, regno, 1, val);
 279       break;
 280
 281     case AARCH64_MIN_FR ... AARCH64_MAX_FR:
 282       aarch64_set_FP_double (cpu, regno - 32, (double) val);
 283       break;
 284
 285     case AARCH64_PC_REGNO:
 286       aarch64_set_next_PC (cpu, val);
 287       aarch64_update_PC (cpu);
 288       break;
 289
 290     case AARCH64_CPSR_REGNO:
 291       aarch64_set_CPSR (cpu, val);
 292       break;
 293
 294     case AARCH64_FPSR_REGNO:
 295       aarch64_set_FPSR (cpu, val);
 296       break;
 297
 298     default:
 299       sim_io_eprintf (CPU_STATE (cpu),
 300                       "sim: unrecognized register number: %d\n", regno);
 301       return 0;
 302     }
 303
 304   return size;
 305 }
 306
 307 static sim_cia
 308 aarch64_pc_get (sim_cpu *cpu)
 309 {
 310   return aarch64_get_PC (cpu);
 311 }
 312
 313 static void
 314 aarch64_pc_set (sim_cpu *cpu, sim_cia pc)
 315 {
 316   aarch64_set_next_PC (cpu, pc);
 317   aarch64_update_PC (cpu);
 318 }
 319
 320 static void
 321 free_state (SIM_DESC sd)
 322 {
 323   if (STATE_MODULES (sd) != NULL)
 324     sim_module_uninstall (sd);
 325   sim_cpu_free_all (sd);
 326   sim_state_free (sd);
 327 }
 328
 329 SIM_DESC
 330 sim_open (SIM_OPEN_KIND                  kind,
 331           struct host_callback_struct *  callback,
 332           struct bfd *                   abfd,
 333           char * const *                 argv)
 334 {
 335   sim_cpu *cpu;
 336   SIM_DESC sd = sim_state_alloc (kind, callback);
 337
 338   if (sd == NULL)
 339     return sd;
 340
 341   SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
 342
 343   /* We use NONSTRICT_ALIGNMENT as the default because AArch64 only enforces
 344      4-byte alignment, even for 8-byte reads/writes.  The common core does not
 345      support this, so we opt for non-strict alignment instead.  */
 346   current_alignment = NONSTRICT_ALIGNMENT;
 347
 348   /* Perform the initialization steps one by one.  */
 349   if (sim_cpu_alloc_all (sd, 1) != SIM_RC_OK
 350       || sim_pre_argv_init (sd, argv[0]) != SIM_RC_OK
 351       || sim_parse_args (sd, argv) != SIM_RC_OK
 352       || sim_analyze_program (sd, STATE_PROG_FILE (sd), abfd) != SIM_RC_OK
 353       || sim_config (sd) != SIM_RC_OK
 354       || sim_post_argv_init (sd) != SIM_RC_OK)
 355     {
 356       free_state (sd);
 357       return NULL;
 358     }
 359
 360   aarch64_init_LIT_table ();
 361
 362   assert (MAX_NR_PROCESSORS == 1);
 363   cpu = STATE_CPU (sd, 0);
 364   CPU_PC_FETCH (cpu) = aarch64_pc_get;
 365   CPU_PC_STORE (cpu) = aarch64_pc_set;
 366   CPU_REG_FETCH (cpu) = aarch64_reg_get;
 367   CPU_REG_STORE (cpu) = aarch64_reg_set;
 368
 369   /* Set SP, FP and PC to 0 and set LR to -1
 370      so we can detect a top-level return.  */
 371   aarch64_set_reg_u64 (cpu, SP, 1, 0);
 372   aarch64_set_reg_u64 (cpu, FP, 1, 0);
 373   aarch64_set_reg_u64 (cpu, LR, 1, TOP_LEVEL_RETURN_PC);
 374   aarch64_set_next_PC (cpu, 0);
 375   aarch64_update_PC (cpu);
 376
 377   /* Default to a 128 Mbyte (== 2^27) memory space.  */
 378   sim_do_commandf (sd, "memory-size 0x8000000");
 379
 380   return sd;
 381 }
 382
 383 void
 384 sim_engine_run (SIM_DESC sd,
 385                 int next_cpu_nr ATTRIBUTE_UNUSED,
 386                 int nr_cpus ATTRIBUTE_UNUSED,
 387                 int siggnal ATTRIBUTE_UNUSED)
 388 {
 389   aarch64_run (sd);
 390 }