gdbserver/linux-tic6x-low.cc

   1 /* Target dependent code for GDB on TI C6x systems.
   2
   3    Copyright (C) 2010-2023 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   const regs_info *get_regs_info () override;
  48
  49   const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override;
  50
  51 protected:
  52
  53   void low_arch_setup () override;
  54
  55   bool low_cannot_fetch_register (int regno) override;
  56
  57   bool low_cannot_store_register (int regno) override;
  58
  59   bool low_supports_breakpoints () override;
  60
  61   CORE_ADDR low_get_pc (regcache *regcache) override;
  62
  63   void low_set_pc (regcache *regcache, CORE_ADDR newpc) override;
  64
  65   bool low_breakpoint_at (CORE_ADDR pc) override;
  66 };
  67
  68 /* The singleton target ops object.  */
  69
  70 static tic6x_target the_tic6x_target;
  71
  72 /* Defined in auto-generated file tic6x-c64xp-linux.c.  */
  73 void init_registers_tic6x_c64xp_linux (void);
  74 extern const struct target_desc *tdesc_tic6x_c64xp_linux;
  75
  76 /* Defined in auto-generated file tic6x-c64x-linux.c.  */
  77 void init_registers_tic6x_c64x_linux (void);
  78 extern const struct target_desc *tdesc_tic6x_c64x_linux;
  79
  80 /* Defined in auto-generated file tic62x-c6xp-linux.c.  */
  81 void init_registers_tic6x_c62x_linux (void);
  82 extern const struct target_desc *tdesc_tic6x_c62x_linux;
  83
  84 union tic6x_register
  85 {
  86   unsigned char buf[4];
  87
  88   int reg32;
  89 };
  90
  91 /* Return the ptrace ``address'' of register REGNO.  */
  92
  93 #if __BYTE_ORDER == __BIG_ENDIAN
  94 static int tic6x_regmap_c64xp[] = {
  95   /* A0 - A15 */
  96   53, 52, 55, 54, 57, 56, 59, 58,
  97   61, 60, 63, 62, 65, 64, 67, 66,
  98   /* B0 - B15 */
  99   23, 22, 25, 24, 27, 26, 29, 28,
 100   31, 30, 33, 32, 35, 34, 69, 68,
 101   /* CSR PC */
 102   5, 4,
 103   /* A16 - A31 */
 104   37, 36, 39, 38, 41, 40, 43, 42,
 105   45, 44, 47, 46, 49, 48, 51, 50,
 106   /* B16 - B31 */
 107   7,  6,  9,  8,  11, 10, 13, 12,
 108   15, 14, 17, 16, 19, 18, 21, 20,
 109   /* TSR, ILC, RILC */
 110   1,  2, 3
 111 };
 112
 113 static int tic6x_regmap_c64x[] = {
 114   /* A0 - A15 */
 115   51, 50, 53, 52, 55, 54, 57, 56,
 116   59, 58, 61, 60, 63, 62, 65, 64,
 117   /* B0 - B15 */
 118   21, 20, 23, 22, 25, 24, 27, 26,
 119   29, 28, 31, 30, 33, 32, 67, 66,
 120   /* CSR PC */
 121   3,  2,
 122   /* A16 - A31 */
 123   35, 34, 37, 36, 39, 38, 41, 40,
 124   43, 42, 45, 44, 47, 46, 49, 48,
 125   /* B16 - B31 */
 126   5,  4,  7,  6,  9,  8,  11, 10,
 127   13, 12, 15, 14, 17, 16, 19, 18,
 128   -1, -1, -1
 129 };
 130
 131 static int tic6x_regmap_c62x[] = {
 132   /* A0 - A15 */
 133   19, 18, 21, 20, 23, 22, 25, 24,
 134   27, 26, 29, 28, 31, 30, 33, 32,
 135   /* B0 - B15 */
 136    5,  4,  7,  6,  9,  8, 11, 10,
 137   13, 12, 15, 14, 17, 16, 35, 34,
 138   /* CSR, PC */
 139   3, 2,
 140   -1, -1, -1, -1, -1, -1, -1, -1,
 141   -1, -1, -1, -1, -1, -1, -1, -1,
 142   -1, -1, -1, -1, -1, -1, -1, -1,
 143   -1, -1, -1, -1, -1, -1, -1, -1,
 144   -1, -1, -1
 145 };
 146
 147 #else
 148 static int tic6x_regmap_c64xp[] = {
 149   /* A0 - A15 */
 150   52, 53, 54, 55, 56, 57, 58, 59,
 151   60, 61, 62, 63, 64, 65, 66, 67,
 152   /* B0 - B15 */
 153   22, 23, 24, 25, 26, 27, 28, 29,
 154   30, 31, 32, 33, 34, 35, 68, 69,
 155   /* CSR PC */
 156    4,  5,
 157   /* A16 - A31 */
 158   36, 37, 38, 39, 40, 41, 42, 43,
 159   44, 45, 46, 47, 48, 49, 50, 51,
 160   /* B16 -B31 */
 161    6,  7,  8,  9, 10, 11, 12, 13,
 162   14, 15, 16, 17, 18, 19, 20, 31,
 163   /* TSR, ILC, RILC */
 164   0,  3, 2
 165 };
 166
 167 static int tic6x_regmap_c64x[] = {
 168   /* A0 - A15 */
 169   50, 51, 52, 53, 54, 55, 56, 57,
 170   58, 59, 60, 61, 62, 63, 64, 65,
 171   /* B0 - B15 */
 172   20, 21, 22, 23, 24, 25, 26, 27,
 173   28, 29, 30, 31, 32, 33, 66, 67,
 174   /* CSR PC */
 175   2,  3,
 176   /* A16 - A31 */
 177   34, 35, 36, 37, 38, 39, 40, 41,
 178   42, 43, 44, 45, 46, 47, 48, 49,
 179   /* B16 - B31 */
 180   4,  5,  6,  7,  8,  9,  10, 11,
 181   12, 13, 14, 15, 16, 17, 18, 19,
 182   -1, -1, -1
 183 };
 184
 185 static int tic6x_regmap_c62x[] = {
 186   /* A0 - A15 */
 187   18, 19, 20, 21, 22, 23, 24, 25,
 188   26, 27, 28, 29, 30, 31, 32, 33,
 189   /* B0 - B15 */
 190   4,  5,  6,  7,  8,  9, 10, 11,
 191   12, 13, 14, 15, 16, 17, 34, 35,
 192   /* CSR PC */
 193   2,  3,
 194   -1, -1, -1, -1, -1, -1, -1, -1,
 195   -1, -1, -1, -1, -1, -1, -1, -1,
 196   -1, -1, -1, -1, -1, -1, -1, -1,
 197   -1, -1, -1, -1, -1, -1, -1, -1,
 198   -1, -1, -1
 199 };
 200
 201 #endif
 202
 203 static int *tic6x_regmap;
 204 static unsigned int tic6x_breakpoint;
 205 #define tic6x_breakpoint_len 4
 206
 207 /* Implementation of target ops method "sw_breakpoint_from_kind".  */
 208
 209 const gdb_byte *
 210 tic6x_target::sw_breakpoint_from_kind (int kind, int *size)
 211 {
 212   *size = tic6x_breakpoint_len;
 213   return (const gdb_byte *) &tic6x_breakpoint;
 214 }
 215
 216 static struct usrregs_info tic6x_usrregs_info =
 217   {
 218     TIC6X_NUM_REGS,
 219     NULL, /* Set in tic6x_read_description.  */
 220   };
 221
 222 static const struct target_desc *
 223 tic6x_read_description (enum c6x_feature feature)
 224 {
 225   static target_desc *tdescs[C6X_LAST] = { };
 226   struct target_desc **tdesc = &tdescs[feature];
 227
 228   if (*tdesc == NULL)
 229     {
 230       *tdesc = tic6x_create_target_description (feature);
 231       static const char *expedite_regs[] = { "A15", "PC", NULL };
 232       init_target_desc (*tdesc, expedite_regs);
 233     }
 234
 235   return *tdesc;
 236 }
 237
 238 bool
 239 tic6x_target::low_cannot_fetch_register (int regno)
 240 {
 241   return (tic6x_regmap[regno] == -1);
 242 }
 243
 244 bool
 245 tic6x_target::low_cannot_store_register (int regno)
 246 {
 247   return (tic6x_regmap[regno] == -1);
 248 }
 249
 250 bool
 251 tic6x_target::low_supports_breakpoints ()
 252 {
 253   return true;
 254 }
 255
 256 CORE_ADDR
 257 tic6x_target::low_get_pc (regcache *regcache)
 258 {
 259   union tic6x_register pc;
 260
 261   collect_register_by_name (regcache, "PC", pc.buf);
 262   return pc.reg32;
 263 }
 264
 265 void
 266 tic6x_target::low_set_pc (regcache *regcache, CORE_ADDR pc)
 267 {
 268   union tic6x_register newpc;
 269
 270   newpc.reg32 = pc;
 271   supply_register_by_name (regcache, "PC", newpc.buf);
 272 }
 273
 274 bool
 275 tic6x_target::low_breakpoint_at (CORE_ADDR where)
 276 {
 277   unsigned int insn;
 278
 279   read_memory (where, (unsigned char *) &insn, 4);
 280   if (insn == tic6x_breakpoint)
 281     return true;
 282
 283   /* If necessary, recognize more trap instructions here.  GDB only uses the
 284      one.  */
 285   return false;
 286 }
 287
 288 /* Fetch the thread-local storage pointer for libthread_db.  */
 289
 290 ps_err_e
 291 ps_get_thread_area (struct ps_prochandle *ph,
 292                     lwpid_t lwpid, int idx, void **base)
 293 {
 294   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
 295     return PS_ERR;
 296
 297   /* IDX is the bias from the thread pointer to the beginning of the
 298      thread descriptor.  It has to be subtracted due to implementation
 299      quirks in libthread_db.  */
 300   *base = (void *) ((char *) *base - idx);
 301
 302   return PS_OK;
 303 }
 304
 305 static void
 306 tic6x_collect_register (struct regcache *regcache, int regno,
 307                         union tic6x_register *reg)
 308 {
 309   union tic6x_register tmp_reg;
 310
 311   collect_register (regcache, regno, &tmp_reg.reg32);
 312   reg->reg32 = tmp_reg.reg32;
 313 }
 314
 315 static void
 316 tic6x_supply_register (struct regcache *regcache, int regno,
 317                        const union tic6x_register *reg)
 318 {
 319   int offset = 0;
 320
 321   supply_register (regcache, regno, reg->buf + offset);
 322 }
 323
 324 static void
 325 tic6x_fill_gregset (struct regcache *regcache, void *buf)
 326 {
 327   auto regset = static_cast<union tic6x_register *> (buf);
 328   int i;
 329
 330   for (i = 0; i < TIC6X_NUM_REGS; i++)
 331     if (tic6x_regmap[i] != -1)
 332       tic6x_collect_register (regcache, i, regset + tic6x_regmap[i]);
 333 }
 334
 335 static void
 336 tic6x_store_gregset (struct regcache *regcache, const void *buf)
 337 {
 338   const auto regset = static_cast<const union tic6x_register *> (buf);
 339   int i;
 340
 341   for (i = 0; i < TIC6X_NUM_REGS; i++)
 342     if (tic6x_regmap[i] != -1)
 343       tic6x_supply_register (regcache, i, regset + tic6x_regmap[i]);
 344 }
 345
 346 static struct regset_info tic6x_regsets[] = {
 347   { PTRACE_GETREGS, PTRACE_SETREGS, 0, TIC6X_NUM_REGS * 4, GENERAL_REGS,
 348     tic6x_fill_gregset, tic6x_store_gregset },
 349   NULL_REGSET
 350 };
 351
 352 void
 353 tic6x_target::low_arch_setup ()
 354 {
 355   register unsigned int csr asm ("B2");
 356   unsigned int cpuid;
 357   enum c6x_feature feature = C6X_CORE;
 358
 359   /* Determine the CPU we're running on to find the register order.  */
 360   __asm__ ("MVC .S2 CSR,%0" : "=r" (csr) :);
 361   cpuid = csr >> 24;
 362   switch (cpuid)
 363     {
 364     case 0x00: /* C62x */
 365     case 0x02: /* C67x */
 366       tic6x_regmap = tic6x_regmap_c62x;
 367       tic6x_breakpoint = 0x0000a122;  /* BNOP .S2 0,5 */
 368       feature = C6X_CORE;
 369       break;
 370     case 0x03: /* C67x+ */
 371       tic6x_regmap = tic6x_regmap_c64x;
 372       tic6x_breakpoint = 0x0000a122;  /* BNOP .S2 0,5 */
 373       feature = C6X_GP;
 374       break;
 375     case 0x0c: /* C64x */
 376       tic6x_regmap = tic6x_regmap_c64x;
 377       tic6x_breakpoint = 0x0000a122;  /* BNOP .S2 0,5 */
 378       feature = C6X_GP;
 379       break;
 380     case 0x10: /* C64x+ */
 381     case 0x14: /* C674x */
 382     case 0x15: /* C66x */
 383       tic6x_regmap = tic6x_regmap_c64xp;
 384       tic6x_breakpoint = 0x56454314;  /* illegal opcode */
 385       feature = C6X_C6XP;
 386       break;
 387     default:
 388       error ("Unknown CPU ID 0x%02x", cpuid);
 389     }
 390   tic6x_usrregs_info.regmap = tic6x_regmap;
 391
 392   current_process ()->tdesc = tic6x_read_description (feature);
 393 }
 394
 395 static struct regsets_info tic6x_regsets_info =
 396   {
 397     tic6x_regsets, /* regsets */
 398     0, /* num_regsets */
 399     NULL, /* disabled_regsets */
 400   };
 401
 402 static struct regs_info myregs_info =
 403   {
 404     NULL, /* regset_bitmap */
 405     &tic6x_usrregs_info,
 406     &tic6x_regsets_info
 407   };
 408
 409 const regs_info *
 410 tic6x_target::get_regs_info ()
 411 {
 412   return &myregs_info;
 413 }
 414
 415 #if GDB_SELF_TEST
 416 #include "gdbsupport/selftest.h"
 417
 418 namespace selftests {
 419 namespace tdesc {
 420 static void
 421 tic6x_tdesc_test ()
 422 {
 423   SELF_CHECK (*tdesc_tic6x_c62x_linux == *tic6x_read_description (C6X_CORE));
 424   SELF_CHECK (*tdesc_tic6x_c64x_linux == *tic6x_read_description (C6X_GP));
 425   SELF_CHECK (*tdesc_tic6x_c64xp_linux == *tic6x_read_description (C6X_C6XP));
 426 }
 427 }
 428 }
 429 #endif
 430
 431 /* The linux target ops object.  */
 432
 433 linux_process_target *the_linux_target = &the_tic6x_target;
 434
 435 void
 436 initialize_low_arch (void)
 437 {
 438 #if GDB_SELF_TEST
 439   /* Initialize the Linux target descriptions.  */
 440   init_registers_tic6x_c64xp_linux ();
 441   init_registers_tic6x_c64x_linux ();
 442   init_registers_tic6x_c62x_linux ();
 443
 444   selftests::register_test ("tic6x-tdesc", selftests::tdesc::tic6x_tdesc_test);
 445 #endif
 446
 447   initialize_regsets_info (&tic6x_regsets_info);
 448 }