gdbserver/linux-tic6x-low.cc

   1 /* Target dependent code for GDB on TI C6x systems.
   2
   3    Copyright (C) 2010-2020 Free Software Foundation, Inc.
   4    Contributed by Andrew Jenner <andrew@codesourcery.com>
   5    Contributed by Yao Qi <yao@codesourcery.com>
   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 "server.h"
  23 #include "linux-low.h"
  24 #include "arch/tic6x.h"
  25 #include "tdesc.h"
  26
  27 #include "nat/gdb_ptrace.h"
  28 #include <endian.h>
  29
  30 #include "gdb_proc_service.h"
  31
  32 #ifndef PTRACE_GET_THREAD_AREA
  33 #define PTRACE_GET_THREAD_AREA 25
  34 #endif
  35
  36 /* There are at most 69 registers accessible in ptrace.  */
  37 #define TIC6X_NUM_REGS 69
  38
  39 #include <asm/ptrace.h>
  40
  41 /* Linux target op definitions for the TI C6x architecture.  */
  42
  43 class tic6x_target : public linux_process_target
  44 {
  45 public:
  46
  47 protected:
  48
  49   void low_arch_setup () override;
  50 };
  51
  52 /* The singleton target ops object.  */
  53
  54 static tic6x_target the_tic6x_target;
  55
  56 /* Defined in auto-generated file tic6x-c64xp-linux.c.  */
  57 void init_registers_tic6x_c64xp_linux (void);
  58 extern const struct target_desc *tdesc_tic6x_c64xp_linux;
  59
  60 /* Defined in auto-generated file tic6x-c64x-linux.c.  */
  61 void init_registers_tic6x_c64x_linux (void);
  62 extern const struct target_desc *tdesc_tic6x_c64x_linux;
  63
  64 /* Defined in auto-generated file tic62x-c6xp-linux.c.  */
  65 void init_registers_tic6x_c62x_linux (void);
  66 extern const struct target_desc *tdesc_tic6x_c62x_linux;
  67
  68 union tic6x_register
  69 {
  70   unsigned char buf[4];
  71
  72   int reg32;
  73 };
  74
  75 /* Return the ptrace ``address'' of register REGNO.  */
  76
  77 #if __BYTE_ORDER == __BIG_ENDIAN
  78 static int tic6x_regmap_c64xp[] = {
  79   /* A0 - A15 */
  80   53, 52, 55, 54, 57, 56, 59, 58,
  81   61, 60, 63, 62, 65, 64, 67, 66,
  82   /* B0 - B15 */
  83   23, 22, 25, 24, 27, 26, 29, 28,
  84   31, 30, 33, 32, 35, 34, 69, 68,
  85   /* CSR PC */
  86   5, 4,
  87   /* A16 - A31 */
  88   37, 36, 39, 38, 41, 40, 43, 42,
  89   45, 44, 47, 46, 49, 48, 51, 50,
  90   /* B16 - B31 */
  91   7,  6,  9,  8,  11, 10, 13, 12,
  92   15, 14, 17, 16, 19, 18, 21, 20,
  93   /* TSR, ILC, RILC */
  94   1,  2, 3
  95 };
  96
  97 static int tic6x_regmap_c64x[] = {
  98   /* A0 - A15 */
  99   51, 50, 53, 52, 55, 54, 57, 56,
 100   59, 58, 61, 60, 63, 62, 65, 64,
 101   /* B0 - B15 */
 102   21, 20, 23, 22, 25, 24, 27, 26,
 103   29, 28, 31, 30, 33, 32, 67, 66,
 104   /* CSR PC */
 105   3,  2,
 106   /* A16 - A31 */
 107   35, 34, 37, 36, 39, 38, 41, 40,
 108   43, 42, 45, 44, 47, 46, 49, 48,
 109   /* B16 - B31 */
 110   5,  4,  7,  6,  9,  8,  11, 10,
 111   13, 12, 15, 14, 17, 16, 19, 18,
 112   -1, -1, -1
 113 };
 114
 115 static int tic6x_regmap_c62x[] = {
 116   /* A0 - A15 */
 117   19, 18, 21, 20, 23, 22, 25, 24,
 118   27, 26, 29, 28, 31, 30, 33, 32,
 119   /* B0 - B15 */
 120    5,  4,  7,  6,  9,  8, 11, 10,
 121   13, 12, 15, 14, 17, 16, 35, 34,
 122   /* CSR, PC */
 123   3, 2,
 124   -1, -1, -1, -1, -1, -1, -1, -1,
 125   -1, -1, -1, -1, -1, -1, -1, -1,
 126   -1, -1, -1, -1, -1, -1, -1, -1,
 127   -1, -1, -1, -1, -1, -1, -1, -1,
 128   -1, -1, -1
 129 };
 130
 131 #else
 132 static int tic6x_regmap_c64xp[] = {
 133   /* A0 - A15 */
 134   52, 53, 54, 55, 56, 57, 58, 59,
 135   60, 61, 62, 63, 64, 65, 66, 67,
 136   /* B0 - B15 */
 137   22, 23, 24, 25, 26, 27, 28, 29,
 138   30, 31, 32, 33, 34, 35, 68, 69,
 139   /* CSR PC */
 140    4,  5,
 141   /* A16 - A31 */
 142   36, 37, 38, 39, 40, 41, 42, 43,
 143   44, 45, 46, 47, 48, 49, 50, 51,
 144   /* B16 -B31 */
 145    6,  7,  8,  9, 10, 11, 12, 13,
 146   14, 15, 16, 17, 18, 19, 20, 31,
 147   /* TSR, ILC, RILC */
 148   0,  3, 2
 149 };
 150
 151 static int tic6x_regmap_c64x[] = {
 152   /* A0 - A15 */
 153   50, 51, 52, 53, 54, 55, 56, 57,
 154   58, 59, 60, 61, 62, 63, 64, 65,
 155   /* B0 - B15 */
 156   20, 21, 22, 23, 24, 25, 26, 27,
 157   28, 29, 30, 31, 32, 33, 66, 67,
 158   /* CSR PC */
 159   2,  3,
 160   /* A16 - A31 */
 161   34, 35, 36, 37, 38, 39, 40, 41,
 162   42, 43, 44, 45, 46, 47, 48, 49,
 163   /* B16 - B31 */
 164   4,  5,  6,  7,  8,  9,  10, 11,
 165   12, 13, 14, 15, 16, 17, 18, 19,
 166   -1, -1, -1
 167 };
 168
 169 static int tic6x_regmap_c62x[] = {
 170   /* A0 - A15 */
 171   18, 19, 20, 21, 22, 23, 24, 25,
 172   26, 27, 28, 29, 30, 31, 32, 33,
 173   /* B0 - B15 */
 174   4,  5,  6,  7,  8,  9, 10, 11,
 175   12, 13, 14, 15, 16, 17, 34, 35,
 176   /* CSR PC */
 177   2,  3,
 178   -1, -1, -1, -1, -1, -1, -1, -1,
 179   -1, -1, -1, -1, -1, -1, -1, -1,
 180   -1, -1, -1, -1, -1, -1, -1, -1,
 181   -1, -1, -1, -1, -1, -1, -1, -1,
 182   -1, -1, -1
 183 };
 184
 185 #endif
 186
 187 extern struct linux_target_ops the_low_target;
 188
 189 static int *tic6x_regmap;
 190 static unsigned int tic6x_breakpoint;
 191 #define tic6x_breakpoint_len 4
 192
 193 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
 194
 195 static const gdb_byte *
 196 tic6x_sw_breakpoint_from_kind (int kind, int *size)
 197 {
 198   *size = tic6x_breakpoint_len;
 199   return (const gdb_byte *) &tic6x_breakpoint;
 200 }
 201
 202 static struct usrregs_info tic6x_usrregs_info =
 203   {
 204     TIC6X_NUM_REGS,
 205     NULL, /* Set in tic6x_read_description.  */
 206   };
 207
 208 static const struct target_desc *
 209 tic6x_read_description (enum c6x_feature feature)
 210 {
 211   static target_desc *tdescs[C6X_LAST] = { };
 212   struct target_desc **tdesc = &tdescs[feature];
 213
 214   if (*tdesc == NULL)
 215     {
 216       *tdesc = tic6x_create_target_description (feature);
 217       static const char *expedite_regs[] = { "A15", "PC", NULL };
 218       init_target_desc (*tdesc, expedite_regs);
 219     }
 220
 221   return *tdesc;
 222 }
 223
 224 static int
 225 tic6x_cannot_fetch_register (int regno)
 226 {
 227   return (tic6x_regmap[regno] == -1);
 228 }
 229
 230 static int
 231 tic6x_cannot_store_register (int regno)
 232 {
 233   return (tic6x_regmap[regno] == -1);
 234 }
 235
 236 static CORE_ADDR
 237 tic6x_get_pc (struct regcache *regcache)
 238 {
 239   union tic6x_register pc;
 240
 241   collect_register_by_name (regcache, "PC", pc.buf);
 242   return pc.reg32;
 243 }
 244
 245 static void
 246 tic6x_set_pc (struct regcache *regcache, CORE_ADDR pc)
 247 {
 248   union tic6x_register newpc;
 249
 250   newpc.reg32 = pc;
 251   supply_register_by_name (regcache, "PC", newpc.buf);
 252 }
 253
 254 static int
 255 tic6x_breakpoint_at (CORE_ADDR where)
 256 {
 257   unsigned int insn;
 258
 259   the_target->read_memory (where, (unsigned char *) &insn, 4);
 260   if (insn == tic6x_breakpoint)
 261     return 1;
 262
 263   /* If necessary, recognize more trap instructions here.  GDB only uses the
 264      one.  */
 265   return 0;
 266 }
 267
 268 /* Fetch the thread-local storage pointer for libthread_db.  */
 269
 270 ps_err_e
 271 ps_get_thread_area (struct ps_prochandle *ph,
 272                     lwpid_t lwpid, int idx, void **base)
 273 {
 274   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
 275     return PS_ERR;
 276
 277   /* IDX is the bias from the thread pointer to the beginning of the
 278      thread descriptor.  It has to be subtracted due to implementation
 279      quirks in libthread_db.  */
 280   *base = (void *) ((char *) *base - idx);
 281
 282   return PS_OK;
 283 }
 284
 285 static void
 286 tic6x_collect_register (struct regcache *regcache, int regno,
 287                         union tic6x_register *reg)
 288 {
 289   union tic6x_register tmp_reg;
 290
 291   collect_register (regcache, regno, &tmp_reg.reg32);
 292   reg->reg32 = tmp_reg.reg32;
 293 }
 294
 295 static void
 296 tic6x_supply_register (struct regcache *regcache, int regno,
 297                        const union tic6x_register *reg)
 298 {
 299   int offset = 0;
 300
 301   supply_register (regcache, regno, reg->buf + offset);
 302 }
 303
 304 static void
 305 tic6x_fill_gregset (struct regcache *regcache, void *buf)
 306 {
 307   auto regset = static_cast<union tic6x_register *> (buf);
 308   int i;
 309
 310   for (i = 0; i < TIC6X_NUM_REGS; i++)
 311     if (tic6x_regmap[i] != -1)
 312       tic6x_collect_register (regcache, i, regset + tic6x_regmap[i]);
 313 }
 314
 315 static void
 316 tic6x_store_gregset (struct regcache *regcache, const void *buf)
 317 {
 318   const auto regset = static_cast<const union tic6x_register *> (buf);
 319   int i;
 320
 321   for (i = 0; i < TIC6X_NUM_REGS; i++)
 322     if (tic6x_regmap[i] != -1)
 323       tic6x_supply_register (regcache, i, regset + tic6x_regmap[i]);
 324 }
 325
 326 static struct regset_info tic6x_regsets[] = {
 327   { PTRACE_GETREGS, PTRACE_SETREGS, 0, TIC6X_NUM_REGS * 4, GENERAL_REGS,
 328     tic6x_fill_gregset, tic6x_store_gregset },
 329   NULL_REGSET
 330 };
 331
 332 void
 333 tic6x_target::low_arch_setup ()
 334 {
 335   register unsigned int csr asm ("B2");
 336   unsigned int cpuid;
 337   enum c6x_feature feature = C6X_CORE;
 338
 339   /* Determine the CPU we're running on to find the register order.  */
 340   __asm__ ("MVC .S2 CSR,%0" : "=r" (csr) :);
 341   cpuid = csr >> 24;
 342   switch (cpuid)
 343     {
 344     case 0x00: /* C62x */
 345     case 0x02: /* C67x */
 346       tic6x_regmap = tic6x_regmap_c62x;
 347       tic6x_breakpoint = 0x0000a122;  /* BNOP .S2 0,5 */
 348       feature = C6X_CORE;
 349       break;
 350     case 0x03: /* C67x+ */
 351       tic6x_regmap = tic6x_regmap_c64x;
 352       tic6x_breakpoint = 0x0000a122;  /* BNOP .S2 0,5 */
 353       feature = C6X_GP;
 354       break;
 355     case 0x0c: /* C64x */
 356       tic6x_regmap = tic6x_regmap_c64x;
 357       tic6x_breakpoint = 0x0000a122;  /* BNOP .S2 0,5 */
 358       feature = C6X_GP;
 359       break;
 360     case 0x10: /* C64x+ */
 361     case 0x14: /* C674x */
 362     case 0x15: /* C66x */
 363       tic6x_regmap = tic6x_regmap_c64xp;
 364       tic6x_breakpoint = 0x56454314;  /* illegal opcode */
 365       feature = C6X_C6XP;
 366       break;
 367     default:
 368       error ("Unknown CPU ID 0x%02x", cpuid);
 369     }
 370   tic6x_usrregs_info.regmap = tic6x_regmap;
 371
 372   current_process ()->tdesc = tic6x_read_description (feature);
 373 }
 374
 375 /* Support for hardware single step.  */
 376
 377 static int
 378 tic6x_supports_hardware_single_step (void)
 379 {
 380   return 1;
 381 }
 382
 383 static struct regsets_info tic6x_regsets_info =
 384   {
 385     tic6x_regsets, /* regsets */
 386     0, /* num_regsets */
 387     NULL, /* disabled_regsets */
 388   };
 389
 390 static struct regs_info regs_info =
 391   {
 392     NULL, /* regset_bitmap */
 393     &tic6x_usrregs_info,
 394     &tic6x_regsets_info
 395   };
 396
 397 static const struct regs_info *
 398 tic6x_regs_info (void)
 399 {
 400   return &regs_info;
 401 }
 402
 403 struct linux_target_ops the_low_target = {
 404   tic6x_regs_info,
 405   tic6x_cannot_fetch_register,
 406   tic6x_cannot_store_register,
 407   NULL, /* fetch_register */
 408   tic6x_get_pc,
 409   tic6x_set_pc,
 410   NULL, /* breakpoint_kind_from_pc */
 411   tic6x_sw_breakpoint_from_kind,
 412   NULL,
 413   0,
 414   tic6x_breakpoint_at,
 415   NULL, /* supports_z_point_type */
 416   NULL, /* insert_point */
 417   NULL, /* remove_point */
 418   NULL, /* stopped_by_watchpoint */
 419   NULL, /* stopped_data_address */
 420   NULL, /* collect_ptrace_register */
 421   NULL, /* supply_ptrace_register */
 422   NULL, /* siginfo_fixup */
 423   NULL, /* new_process */
 424   NULL, /* delete_process */
 425   NULL, /* new_thread */
 426   NULL, /* delete_thread */
 427   NULL, /* new_fork */
 428   NULL, /* prepare_to_resume */
 429   NULL, /* process_qsupported */
 430   NULL, /* supports_tracepoints */
 431   NULL, /* get_thread_area */
 432   NULL, /* install_fast_tracepoint_jump_pad */
 433   NULL, /* emit_ops */
 434   NULL, /* get_min_fast_tracepoint_insn_len */
 435   NULL, /* supports_range_stepping */
 436   NULL, /* breakpoint_kind_from_current_state */
 437   tic6x_supports_hardware_single_step,
 438 };
 439
 440 #if GDB_SELF_TEST
 441 #include "gdbsupport/selftest.h"
 442
 443 namespace selftests {
 444 namespace tdesc {
 445 static void
 446 tic6x_tdesc_test ()
 447 {
 448   SELF_CHECK (*tdesc_tic6x_c62x_linux == *tic6x_read_description (C6X_CORE));
 449   SELF_CHECK (*tdesc_tic6x_c64x_linux == *tic6x_read_description (C6X_GP));
 450   SELF_CHECK (*tdesc_tic6x_c64xp_linux == *tic6x_read_description (C6X_C6XP));
 451 }
 452 }
 453 }
 454 #endif
 455
 456 /* The linux target ops object.  */
 457
 458 linux_process_target *the_linux_target = &the_tic6x_target;
 459
 460 void
 461 initialize_low_arch (void)
 462 {
 463 #if GDB_SELF_TEST
 464   /* Initialize the Linux target descriptions.  */
 465   init_registers_tic6x_c64xp_linux ();
 466   init_registers_tic6x_c64x_linux ();
 467   init_registers_tic6x_c62x_linux ();
 468
 469   selftests::register_test ("tic6x-tdesc", selftests::tdesc::tic6x_tdesc_test);
 470 #endif
 471
 472   initialize_regsets_info (&tic6x_regsets_info);
 473 }