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 };
  48
  49 /* The singleton target ops object.  */
  50
  51 static tic6x_target the_tic6x_target;
  52
  53 /* Defined in auto-generated file tic6x-c64xp-linux.c.  */
  54 void init_registers_tic6x_c64xp_linux (void);
  55 extern const struct target_desc *tdesc_tic6x_c64xp_linux;
  56
  57 /* Defined in auto-generated file tic6x-c64x-linux.c.  */
  58 void init_registers_tic6x_c64x_linux (void);
  59 extern const struct target_desc *tdesc_tic6x_c64x_linux;
  60
  61 /* Defined in auto-generated file tic62x-c6xp-linux.c.  */
  62 void init_registers_tic6x_c62x_linux (void);
  63 extern const struct target_desc *tdesc_tic6x_c62x_linux;
  64
  65 union tic6x_register
  66 {
  67   unsigned char buf[4];
  68
  69   int reg32;
  70 };
  71
  72 /* Return the ptrace ``address'' of register REGNO.  */
  73
  74 #if __BYTE_ORDER == __BIG_ENDIAN
  75 static int tic6x_regmap_c64xp[] = {
  76   /* A0 - A15 */
  77   53, 52, 55, 54, 57, 56, 59, 58,
  78   61, 60, 63, 62, 65, 64, 67, 66,
  79   /* B0 - B15 */
  80   23, 22, 25, 24, 27, 26, 29, 28,
  81   31, 30, 33, 32, 35, 34, 69, 68,
  82   /* CSR PC */
  83   5, 4,
  84   /* A16 - A31 */
  85   37, 36, 39, 38, 41, 40, 43, 42,
  86   45, 44, 47, 46, 49, 48, 51, 50,
  87   /* B16 - B31 */
  88   7,  6,  9,  8,  11, 10, 13, 12,
  89   15, 14, 17, 16, 19, 18, 21, 20,
  90   /* TSR, ILC, RILC */
  91   1,  2, 3
  92 };
  93
  94 static int tic6x_regmap_c64x[] = {
  95   /* A0 - A15 */
  96   51, 50, 53, 52, 55, 54, 57, 56,
  97   59, 58, 61, 60, 63, 62, 65, 64,
  98   /* B0 - B15 */
  99   21, 20, 23, 22, 25, 24, 27, 26,
 100   29, 28, 31, 30, 33, 32, 67, 66,
 101   /* CSR PC */
 102   3,  2,
 103   /* A16 - A31 */
 104   35, 34, 37, 36, 39, 38, 41, 40,
 105   43, 42, 45, 44, 47, 46, 49, 48,
 106   /* B16 - B31 */
 107   5,  4,  7,  6,  9,  8,  11, 10,
 108   13, 12, 15, 14, 17, 16, 19, 18,
 109   -1, -1, -1
 110 };
 111
 112 static int tic6x_regmap_c62x[] = {
 113   /* A0 - A15 */
 114   19, 18, 21, 20, 23, 22, 25, 24,
 115   27, 26, 29, 28, 31, 30, 33, 32,
 116   /* B0 - B15 */
 117    5,  4,  7,  6,  9,  8, 11, 10,
 118   13, 12, 15, 14, 17, 16, 35, 34,
 119   /* CSR, PC */
 120   3, 2,
 121   -1, -1, -1, -1, -1, -1, -1, -1,
 122   -1, -1, -1, -1, -1, -1, -1, -1,
 123   -1, -1, -1, -1, -1, -1, -1, -1,
 124   -1, -1, -1, -1, -1, -1, -1, -1,
 125   -1, -1, -1
 126 };
 127
 128 #else
 129 static int tic6x_regmap_c64xp[] = {
 130   /* A0 - A15 */
 131   52, 53, 54, 55, 56, 57, 58, 59,
 132   60, 61, 62, 63, 64, 65, 66, 67,
 133   /* B0 - B15 */
 134   22, 23, 24, 25, 26, 27, 28, 29,
 135   30, 31, 32, 33, 34, 35, 68, 69,
 136   /* CSR PC */
 137    4,  5,
 138   /* A16 - A31 */
 139   36, 37, 38, 39, 40, 41, 42, 43,
 140   44, 45, 46, 47, 48, 49, 50, 51,
 141   /* B16 -B31 */
 142    6,  7,  8,  9, 10, 11, 12, 13,
 143   14, 15, 16, 17, 18, 19, 20, 31,
 144   /* TSR, ILC, RILC */
 145   0,  3, 2
 146 };
 147
 148 static int tic6x_regmap_c64x[] = {
 149   /* A0 - A15 */
 150   50, 51, 52, 53, 54, 55, 56, 57,
 151   58, 59, 60, 61, 62, 63, 64, 65,
 152   /* B0 - B15 */
 153   20, 21, 22, 23, 24, 25, 26, 27,
 154   28, 29, 30, 31, 32, 33, 66, 67,
 155   /* CSR PC */
 156   2,  3,
 157   /* A16 - A31 */
 158   34, 35, 36, 37, 38, 39, 40, 41,
 159   42, 43, 44, 45, 46, 47, 48, 49,
 160   /* B16 - B31 */
 161   4,  5,  6,  7,  8,  9,  10, 11,
 162   12, 13, 14, 15, 16, 17, 18, 19,
 163   -1, -1, -1
 164 };
 165
 166 static int tic6x_regmap_c62x[] = {
 167   /* A0 - A15 */
 168   18, 19, 20, 21, 22, 23, 24, 25,
 169   26, 27, 28, 29, 30, 31, 32, 33,
 170   /* B0 - B15 */
 171   4,  5,  6,  7,  8,  9, 10, 11,
 172   12, 13, 14, 15, 16, 17, 34, 35,
 173   /* CSR PC */
 174   2,  3,
 175   -1, -1, -1, -1, -1, -1, -1, -1,
 176   -1, -1, -1, -1, -1, -1, -1, -1,
 177   -1, -1, -1, -1, -1, -1, -1, -1,
 178   -1, -1, -1, -1, -1, -1, -1, -1,
 179   -1, -1, -1
 180 };
 181
 182 #endif
 183
 184 extern struct linux_target_ops the_low_target;
 185
 186 static int *tic6x_regmap;
 187 static unsigned int tic6x_breakpoint;
 188 #define tic6x_breakpoint_len 4
 189
 190 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
 191
 192 static const gdb_byte *
 193 tic6x_sw_breakpoint_from_kind (int kind, int *size)
 194 {
 195   *size = tic6x_breakpoint_len;
 196   return (const gdb_byte *) &tic6x_breakpoint;
 197 }
 198
 199 static struct usrregs_info tic6x_usrregs_info =
 200   {
 201     TIC6X_NUM_REGS,
 202     NULL, /* Set in tic6x_read_description.  */
 203   };
 204
 205 static const struct target_desc *
 206 tic6x_read_description (enum c6x_feature feature)
 207 {
 208   static target_desc *tdescs[C6X_LAST] = { };
 209   struct target_desc **tdesc = &tdescs[feature];
 210
 211   if (*tdesc == NULL)
 212     {
 213       *tdesc = tic6x_create_target_description (feature);
 214       static const char *expedite_regs[] = { "A15", "PC", NULL };
 215       init_target_desc (*tdesc, expedite_regs);
 216     }
 217
 218   return *tdesc;
 219 }
 220
 221 static int
 222 tic6x_cannot_fetch_register (int regno)
 223 {
 224   return (tic6x_regmap[regno] == -1);
 225 }
 226
 227 static int
 228 tic6x_cannot_store_register (int regno)
 229 {
 230   return (tic6x_regmap[regno] == -1);
 231 }
 232
 233 static CORE_ADDR
 234 tic6x_get_pc (struct regcache *regcache)
 235 {
 236   union tic6x_register pc;
 237
 238   collect_register_by_name (regcache, "PC", pc.buf);
 239   return pc.reg32;
 240 }
 241
 242 static void
 243 tic6x_set_pc (struct regcache *regcache, CORE_ADDR pc)
 244 {
 245   union tic6x_register newpc;
 246
 247   newpc.reg32 = pc;
 248   supply_register_by_name (regcache, "PC", newpc.buf);
 249 }
 250
 251 static int
 252 tic6x_breakpoint_at (CORE_ADDR where)
 253 {
 254   unsigned int insn;
 255
 256   the_target->read_memory (where, (unsigned char *) &insn, 4);
 257   if (insn == tic6x_breakpoint)
 258     return 1;
 259
 260   /* If necessary, recognize more trap instructions here.  GDB only uses the
 261      one.  */
 262   return 0;
 263 }
 264
 265 /* Fetch the thread-local storage pointer for libthread_db.  */
 266
 267 ps_err_e
 268 ps_get_thread_area (struct ps_prochandle *ph,
 269                     lwpid_t lwpid, int idx, void **base)
 270 {
 271   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
 272     return PS_ERR;
 273
 274   /* IDX is the bias from the thread pointer to the beginning of the
 275      thread descriptor.  It has to be subtracted due to implementation
 276      quirks in libthread_db.  */
 277   *base = (void *) ((char *) *base - idx);
 278
 279   return PS_OK;
 280 }
 281
 282 static void
 283 tic6x_collect_register (struct regcache *regcache, int regno,
 284                         union tic6x_register *reg)
 285 {
 286   union tic6x_register tmp_reg;
 287
 288   collect_register (regcache, regno, &tmp_reg.reg32);
 289   reg->reg32 = tmp_reg.reg32;
 290 }
 291
 292 static void
 293 tic6x_supply_register (struct regcache *regcache, int regno,
 294                        const union tic6x_register *reg)
 295 {
 296   int offset = 0;
 297
 298   supply_register (regcache, regno, reg->buf + offset);
 299 }
 300
 301 static void
 302 tic6x_fill_gregset (struct regcache *regcache, void *buf)
 303 {
 304   auto regset = static_cast<union tic6x_register *> (buf);
 305   int i;
 306
 307   for (i = 0; i < TIC6X_NUM_REGS; i++)
 308     if (tic6x_regmap[i] != -1)
 309       tic6x_collect_register (regcache, i, regset + tic6x_regmap[i]);
 310 }
 311
 312 static void
 313 tic6x_store_gregset (struct regcache *regcache, const void *buf)
 314 {
 315   const auto regset = static_cast<const union tic6x_register *> (buf);
 316   int i;
 317
 318   for (i = 0; i < TIC6X_NUM_REGS; i++)
 319     if (tic6x_regmap[i] != -1)
 320       tic6x_supply_register (regcache, i, regset + tic6x_regmap[i]);
 321 }
 322
 323 static struct regset_info tic6x_regsets[] = {
 324   { PTRACE_GETREGS, PTRACE_SETREGS, 0, TIC6X_NUM_REGS * 4, GENERAL_REGS,
 325     tic6x_fill_gregset, tic6x_store_gregset },
 326   NULL_REGSET
 327 };
 328
 329 static void
 330 tic6x_arch_setup (void)
 331 {
 332   register unsigned int csr asm ("B2");
 333   unsigned int cpuid;
 334   enum c6x_feature feature = C6X_CORE;
 335
 336   /* Determine the CPU we're running on to find the register order.  */
 337   __asm__ ("MVC .S2 CSR,%0" : "=r" (csr) :);
 338   cpuid = csr >> 24;
 339   switch (cpuid)
 340     {
 341     case 0x00: /* C62x */
 342     case 0x02: /* C67x */
 343       tic6x_regmap = tic6x_regmap_c62x;
 344       tic6x_breakpoint = 0x0000a122;  /* BNOP .S2 0,5 */
 345       feature = C6X_CORE;
 346       break;
 347     case 0x03: /* C67x+ */
 348       tic6x_regmap = tic6x_regmap_c64x;
 349       tic6x_breakpoint = 0x0000a122;  /* BNOP .S2 0,5 */
 350       feature = C6X_GP;
 351       break;
 352     case 0x0c: /* C64x */
 353       tic6x_regmap = tic6x_regmap_c64x;
 354       tic6x_breakpoint = 0x0000a122;  /* BNOP .S2 0,5 */
 355       feature = C6X_GP;
 356       break;
 357     case 0x10: /* C64x+ */
 358     case 0x14: /* C674x */
 359     case 0x15: /* C66x */
 360       tic6x_regmap = tic6x_regmap_c64xp;
 361       tic6x_breakpoint = 0x56454314;  /* illegal opcode */
 362       feature = C6X_C6XP;
 363       break;
 364     default:
 365       error ("Unknown CPU ID 0x%02x", cpuid);
 366     }
 367   tic6x_usrregs_info.regmap = tic6x_regmap;
 368
 369   current_process ()->tdesc = tic6x_read_description (feature);
 370 }
 371
 372 /* Support for hardware single step.  */
 373
 374 static int
 375 tic6x_supports_hardware_single_step (void)
 376 {
 377   return 1;
 378 }
 379
 380 static struct regsets_info tic6x_regsets_info =
 381   {
 382     tic6x_regsets, /* regsets */
 383     0, /* num_regsets */
 384     NULL, /* disabled_regsets */
 385   };
 386
 387 static struct regs_info regs_info =
 388   {
 389     NULL, /* regset_bitmap */
 390     &tic6x_usrregs_info,
 391     &tic6x_regsets_info
 392   };
 393
 394 static const struct regs_info *
 395 tic6x_regs_info (void)
 396 {
 397   return &regs_info;
 398 }
 399
 400 struct linux_target_ops the_low_target = {
 401   tic6x_arch_setup,
 402   tic6x_regs_info,
 403   tic6x_cannot_fetch_register,
 404   tic6x_cannot_store_register,
 405   NULL, /* fetch_register */
 406   tic6x_get_pc,
 407   tic6x_set_pc,
 408   NULL, /* breakpoint_kind_from_pc */
 409   tic6x_sw_breakpoint_from_kind,
 410   NULL,
 411   0,
 412   tic6x_breakpoint_at,
 413   NULL, /* supports_z_point_type */
 414   NULL, /* insert_point */
 415   NULL, /* remove_point */
 416   NULL, /* stopped_by_watchpoint */
 417   NULL, /* stopped_data_address */
 418   NULL, /* collect_ptrace_register */
 419   NULL, /* supply_ptrace_register */
 420   NULL, /* siginfo_fixup */
 421   NULL, /* new_process */
 422   NULL, /* delete_process */
 423   NULL, /* new_thread */
 424   NULL, /* delete_thread */
 425   NULL, /* new_fork */
 426   NULL, /* prepare_to_resume */
 427   NULL, /* process_qsupported */
 428   NULL, /* supports_tracepoints */
 429   NULL, /* get_thread_area */
 430   NULL, /* install_fast_tracepoint_jump_pad */
 431   NULL, /* emit_ops */
 432   NULL, /* get_min_fast_tracepoint_insn_len */
 433   NULL, /* supports_range_stepping */
 434   NULL, /* breakpoint_kind_from_current_state */
 435   tic6x_supports_hardware_single_step,
 436 };
 437
 438 #if GDB_SELF_TEST
 439 #include "gdbsupport/selftest.h"
 440
 441 namespace selftests {
 442 namespace tdesc {
 443 static void
 444 tic6x_tdesc_test ()
 445 {
 446   SELF_CHECK (*tdesc_tic6x_c62x_linux == *tic6x_read_description (C6X_CORE));
 447   SELF_CHECK (*tdesc_tic6x_c64x_linux == *tic6x_read_description (C6X_GP));
 448   SELF_CHECK (*tdesc_tic6x_c64xp_linux == *tic6x_read_description (C6X_C6XP));
 449 }
 450 }
 451 }
 452 #endif
 453
 454 /* The linux target ops object.  */
 455
 456 linux_process_target *the_linux_target = &the_tic6x_target;
 457
 458 void
 459 initialize_low_arch (void)
 460 {
 461 #if GDB_SELF_TEST
 462   /* Initialize the Linux target descriptions.  */
 463   init_registers_tic6x_c64xp_linux ();
 464   init_registers_tic6x_c64x_linux ();
 465   init_registers_tic6x_c62x_linux ();
 466
 467   selftests::register_test ("tic6x-tdesc", selftests::tdesc::tic6x_tdesc_test);
 468 #endif
 469
 470   initialize_regsets_info (&tic6x_regsets_info);
 471 }