sim/aarch64/interp.c

   1 /* interp.c -- AArch64 sim interface to GDB.
   2
   3    Copyright (C) 2015-2021 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   bfd_vma addr = 0;
 130
 131   if (abfd != NULL)
 132     addr = bfd_get_start_address (abfd);
 133
 134   aarch64_set_next_PC (cpu, addr);
 135   aarch64_update_PC (cpu);
 136
 137   /* Standalone mode (i.e. `run`) will take care of the argv for us in
 138      sim_open() -> sim_parse_args().  But in debug mode (i.e. 'target sim'
 139      with `gdb`), we need to handle it because the user can change the
 140      argv on the fly via gdb's 'run'.  */
 141   if (STATE_PROG_ARGV (sd) != argv)
 142     {
 143       freeargv (STATE_PROG_ARGV (sd));
 144       STATE_PROG_ARGV (sd) = dupargv (argv);
 145     }
 146
 147   if (trace_load_symbols (sd))
 148     {
 149       STATE_PROG_SYMS_COUNT (sd) =
 150         remove_useless_symbols (STATE_PROG_SYMS (sd),
 151                                 STATE_PROG_SYMS_COUNT (sd));
 152       qsort (STATE_PROG_SYMS (sd), STATE_PROG_SYMS_COUNT (sd),
 153              sizeof (asymbol *), compare_symbols);
 154     }
 155
 156   aarch64_init (cpu, addr);
 157
 158   return SIM_RC_OK;
 159 }
 160
 161 /* Read the LENGTH bytes at BUF as a little-endian value.  */
 162
 163 static bfd_vma
 164 get_le (unsigned char *buf, unsigned int length)
 165 {
 166   bfd_vma acc = 0;
 167
 168   while (length -- > 0)
 169     acc = (acc << 8) + buf[length];
 170
 171   return acc;
 172 }
 173
 174 /* Store VAL as a little-endian value in the LENGTH bytes at BUF.  */
 175
 176 static void
 177 put_le (unsigned char *buf, unsigned int length, bfd_vma val)
 178 {
 179   int i;
 180
 181   for (i = 0; i < length; i++)
 182     {
 183       buf[i] = val & 0xff;
 184       val >>= 8;
 185     }
 186 }
 187
 188 static int
 189 check_regno (int regno)
 190 {
 191   return 0 <= regno && regno < AARCH64_MAX_REGNO;
 192 }
 193
 194 static size_t
 195 reg_size (int regno)
 196 {
 197   if (regno == AARCH64_CPSR_REGNO || regno == AARCH64_FPSR_REGNO)
 198     return 32;
 199   return 64;
 200 }
 201
 202 static int
 203 aarch64_reg_get (SIM_CPU *cpu, int regno, unsigned char *buf, int length)
 204 {
 205   size_t size;
 206   bfd_vma val;
 207
 208   if (!check_regno (regno))
 209     return 0;
 210
 211   size = reg_size (regno);
 212
 213   if (length != size)
 214     return 0;
 215
 216   switch (regno)
 217     {
 218     case AARCH64_MIN_GR ... AARCH64_MAX_GR:
 219       val = aarch64_get_reg_u64 (cpu, regno, 0);
 220       break;
 221
 222     case AARCH64_MIN_FR ... AARCH64_MAX_FR:
 223       val = aarch64_get_FP_double (cpu, regno - 32);
 224       break;
 225
 226     case AARCH64_PC_REGNO:
 227       val = aarch64_get_PC (cpu);
 228       break;
 229
 230     case AARCH64_CPSR_REGNO:
 231       val = aarch64_get_CPSR (cpu);
 232       break;
 233
 234     case AARCH64_FPSR_REGNO:
 235       val = aarch64_get_FPSR (cpu);
 236       break;
 237
 238     default:
 239       sim_io_eprintf (CPU_STATE (cpu),
 240                       "sim: unrecognized register number: %d\n", regno);
 241       return -1;
 242     }
 243
 244   put_le (buf, length, val);
 245
 246   return size;
 247 }
 248
 249 static int
 250 aarch64_reg_set (SIM_CPU *cpu, int regno, unsigned char *buf, int length)
 251 {
 252   size_t size;
 253   bfd_vma val;
 254
 255   if (!check_regno (regno))
 256     return -1;
 257
 258   size = reg_size (regno);
 259
 260   if (length != size)
 261     return -1;
 262
 263   val = get_le (buf, length);
 264
 265   switch (regno)
 266     {
 267     case AARCH64_MIN_GR ... AARCH64_MAX_GR:
 268       aarch64_set_reg_u64 (cpu, regno, 1, val);
 269       break;
 270
 271     case AARCH64_MIN_FR ... AARCH64_MAX_FR:
 272       aarch64_set_FP_double (cpu, regno - 32, (double) val);
 273       break;
 274
 275     case AARCH64_PC_REGNO:
 276       aarch64_set_next_PC (cpu, val);
 277       aarch64_update_PC (cpu);
 278       break;
 279
 280     case AARCH64_CPSR_REGNO:
 281       aarch64_set_CPSR (cpu, val);
 282       break;
 283
 284     case AARCH64_FPSR_REGNO:
 285       aarch64_set_FPSR (cpu, val);
 286       break;
 287
 288     default:
 289       sim_io_eprintf (CPU_STATE (cpu),
 290                       "sim: unrecognized register number: %d\n", regno);
 291       return 0;
 292     }
 293
 294   return size;
 295 }
 296
 297 static sim_cia
 298 aarch64_pc_get (sim_cpu *cpu)
 299 {
 300   return aarch64_get_PC (cpu);
 301 }
 302
 303 static void
 304 aarch64_pc_set (sim_cpu *cpu, sim_cia pc)
 305 {
 306   aarch64_set_next_PC (cpu, pc);
 307   aarch64_update_PC (cpu);
 308 }
 309
 310 static void
 311 free_state (SIM_DESC sd)
 312 {
 313   if (STATE_MODULES (sd) != NULL)
 314     sim_module_uninstall (sd);
 315   sim_cpu_free_all (sd);
 316   sim_state_free (sd);
 317 }
 318
 319 SIM_DESC
 320 sim_open (SIM_OPEN_KIND                  kind,
 321           struct host_callback_struct *  callback,
 322           struct bfd *                   abfd,
 323           char * const *                 argv)
 324 {
 325   sim_cpu *cpu;
 326   SIM_DESC sd = sim_state_alloc (kind, callback);
 327
 328   if (sd == NULL)
 329     return sd;
 330
 331   SIM_ASSERT (STATE_MAGIC (sd) == SIM_MAGIC_NUMBER);
 332
 333   /* We use NONSTRICT_ALIGNMENT as the default because AArch64 only enforces
 334      4-byte alignment, even for 8-byte reads/writes.  The common core does not
 335      support this, so we opt for non-strict alignment instead.  */
 336   current_alignment = NONSTRICT_ALIGNMENT;
 337
 338   /* Perform the initialization steps one by one.  */
 339   if (sim_cpu_alloc_all (sd, 1) != SIM_RC_OK
 340       || sim_pre_argv_init (sd, argv[0]) != SIM_RC_OK
 341       || sim_parse_args (sd, argv) != SIM_RC_OK
 342       || sim_analyze_program (sd,
 343                               (STATE_PROG_ARGV (sd) != NULL
 344                                ? *STATE_PROG_ARGV (sd)
 345                                : NULL), abfd) != SIM_RC_OK
 346       || sim_config (sd) != SIM_RC_OK
 347       || sim_post_argv_init (sd) != SIM_RC_OK)
 348     {
 349       free_state (sd);
 350       return NULL;
 351     }
 352
 353   aarch64_init_LIT_table ();
 354
 355   assert (MAX_NR_PROCESSORS == 1);
 356   cpu = STATE_CPU (sd, 0);
 357   CPU_PC_FETCH (cpu) = aarch64_pc_get;
 358   CPU_PC_STORE (cpu) = aarch64_pc_set;
 359   CPU_REG_FETCH (cpu) = aarch64_reg_get;
 360   CPU_REG_STORE (cpu) = aarch64_reg_set;
 361
 362   /* Set SP, FP and PC to 0 and set LR to -1
 363      so we can detect a top-level return.  */
 364   aarch64_set_reg_u64 (cpu, SP, 1, 0);
 365   aarch64_set_reg_u64 (cpu, FP, 1, 0);
 366   aarch64_set_reg_u64 (cpu, LR, 1, TOP_LEVEL_RETURN_PC);
 367   aarch64_set_next_PC (cpu, 0);
 368   aarch64_update_PC (cpu);
 369
 370   /* Default to a 128 Mbyte (== 2^27) memory space.  */
 371   sim_do_commandf (sd, "memory-size 0x8000000");
 372
 373   return sd;
 374 }
 375
 376 void
 377 sim_engine_run (SIM_DESC sd,
 378                 int next_cpu_nr ATTRIBUTE_UNUSED,
 379                 int nr_cpus ATTRIBUTE_UNUSED,
 380                 int siggnal ATTRIBUTE_UNUSED)
 381 {
 382   aarch64_run (sd);
 383 }