gdb/gdbserver/linux-tic6x-low.c

   1 /* Target dependent code for GDB on TI C6x systems.
   2
   3    Copyright (C) 2010-2017 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
  25 #include "nat/gdb_ptrace.h"
  26 #include <endian.h>
  27
  28 #include "gdb_proc_service.h"
  29
  30 #ifndef PTRACE_GET_THREAD_AREA
  31 #define PTRACE_GET_THREAD_AREA 25
  32 #endif
  33
  34 /* There are at most 69 registers accessible in ptrace.  */
  35 #define TIC6X_NUM_REGS 69
  36
  37 #include <asm/ptrace.h>
  38
  39 /* Defined in auto-generated file tic6x-c64xp-linux.c.  */
  40 void init_registers_tic6x_c64xp_linux (void);
  41 extern const struct target_desc *tdesc_tic6x_c64xp_linux;
  42
  43 /* Defined in auto-generated file tic6x-c64x-linux.c.  */
  44 void init_registers_tic6x_c64x_linux (void);
  45 extern const struct target_desc *tdesc_tic6x_c64x_linux;
  46
  47 /* Defined in auto-generated file tic62x-c6xp-linux.c.  */
  48 void init_registers_tic6x_c62x_linux (void);
  49 extern const struct target_desc *tdesc_tic6x_c62x_linux;
  50
  51 union tic6x_register
  52 {
  53   unsigned char buf[4];
  54
  55   int reg32;
  56 };
  57
  58 /* Return the ptrace ``address'' of register REGNO.  */
  59
  60 #if __BYTE_ORDER == __BIG_ENDIAN
  61 static int tic6x_regmap_c64xp[] = {
  62   /* A0 - A15 */
  63   53, 52, 55, 54, 57, 56, 59, 58,
  64   61, 60, 63, 62, 65, 64, 67, 66,
  65   /* B0 - B15 */
  66   23, 22, 25, 24, 27, 26, 29, 28,
  67   31, 30, 33, 32, 35, 34, 69, 68,
  68   /* CSR PC */
  69   5, 4,
  70   /* A16 - A31 */
  71   37, 36, 39, 38, 41, 40, 43, 42,
  72   45, 44, 47, 46, 49, 48, 51, 50,
  73   /* B16 - B31 */
  74   7,  6,  9,  8,  11, 10, 13, 12,
  75   15, 14, 17, 16, 19, 18, 21, 20,
  76   /* TSR, ILC, RILC */
  77   1,  2, 3
  78 };
  79
  80 static int tic6x_regmap_c64x[] = {
  81   /* A0 - A15 */
  82   51, 50, 53, 52, 55, 54, 57, 56,
  83   59, 58, 61, 60, 63, 62, 65, 64,
  84   /* B0 - B15 */
  85   21, 20, 23, 22, 25, 24, 27, 26,
  86   29, 28, 31, 30, 33, 32, 67, 66,
  87   /* CSR PC */
  88   3,  2,
  89   /* A16 - A31 */
  90   35, 34, 37, 36, 39, 38, 41, 40,
  91   43, 42, 45, 44, 47, 46, 49, 48,
  92   /* B16 - B31 */
  93   5,  4,  7,  6,  9,  8,  11, 10,
  94   13, 12, 15, 14, 17, 16, 19, 18,
  95   -1, -1, -1
  96 };
  97
  98 static int tic6x_regmap_c62x[] = {
  99   /* A0 - A15 */
 100   19, 18, 21, 20, 23, 22, 25, 24,
 101   27, 26, 29, 28, 31, 30, 33, 32,
 102   /* B0 - B15 */
 103    5,  4,  7,  6,  9,  8, 11, 10,
 104   13, 12, 15, 14, 17, 16, 35, 34,
 105   /* CSR, PC */
 106   3, 2,
 107   -1, -1, -1, -1, -1, -1, -1, -1,
 108   -1, -1, -1, -1, -1, -1, -1, -1,
 109   -1, -1, -1, -1, -1, -1, -1, -1,
 110   -1, -1, -1, -1, -1, -1, -1, -1,
 111   -1, -1, -1
 112 };
 113
 114 #else
 115 static int tic6x_regmap_c64xp[] = {
 116   /* A0 - A15 */
 117   52, 53, 54, 55, 56, 57, 58, 59,
 118   60, 61, 62, 63, 64, 65, 66, 67,
 119   /* B0 - B15 */
 120   22, 23, 24, 25, 26, 27, 28, 29,
 121   30, 31, 32, 33, 34, 35, 68, 69,
 122   /* CSR PC */
 123    4,  5,
 124   /* A16 - A31 */
 125   36, 37, 38, 39, 40, 41, 42, 43,
 126   44, 45, 46, 47, 48, 49, 50, 51,
 127   /* B16 -B31 */
 128    6,  7,  8,  9, 10, 11, 12, 13,
 129   14, 15, 16, 17, 18, 19, 20, 31,
 130   /* TSR, ILC, RILC */
 131   0,  3, 2
 132 };
 133
 134 static int tic6x_regmap_c64x[] = {
 135   /* A0 - A15 */
 136   50, 51, 52, 53, 54, 55, 56, 57,
 137   58, 59, 60, 61, 62, 63, 64, 65,
 138   /* B0 - B15 */
 139   20, 21, 22, 23, 24, 25, 26, 27,
 140   28, 29, 30, 31, 32, 33, 66, 67,
 141   /* CSR PC */
 142   2,  3,
 143   /* A16 - A31 */
 144   34, 35, 36, 37, 38, 39, 40, 41,
 145   42, 43, 44, 45, 46, 47, 48, 49,
 146   /* B16 - B31 */
 147   4,  5,  6,  7,  8,  9,  10, 11,
 148   12, 13, 14, 15, 16, 17, 18, 19,
 149   -1, -1, -1
 150 };
 151
 152 static int tic6x_regmap_c62x[] = {
 153   /* A0 - A15 */
 154   18, 19, 20, 21, 22, 23, 24, 25,
 155   26, 27, 28, 29, 30, 31, 32, 33,
 156   /* B0 - B15 */
 157   4,  5,  6,  7,  8,  9, 10, 11,
 158   12, 13, 14, 15, 16, 17, 34, 35,
 159   /* CSR PC */
 160   2,  3,
 161   -1, -1, -1, -1, -1, -1, -1, -1,
 162   -1, -1, -1, -1, -1, -1, -1, -1,
 163   -1, -1, -1, -1, -1, -1, -1, -1,
 164   -1, -1, -1, -1, -1, -1, -1, -1,
 165   -1, -1, -1
 166 };
 167
 168 #endif
 169
 170 extern struct linux_target_ops the_low_target;
 171
 172 static int *tic6x_regmap;
 173 static unsigned int tic6x_breakpoint;
 174 #define tic6x_breakpoint_len 4
 175
 176 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
 177
 178 static const gdb_byte *
 179 tic6x_sw_breakpoint_from_kind (int kind, int *size)
 180 {
 181   *size = tic6x_breakpoint_len;
 182   return (const gdb_byte *) &tic6x_breakpoint;
 183 }
 184
 185 /* Forward definition.  */
 186 static struct usrregs_info tic6x_usrregs_info;
 187
 188 static const struct target_desc *
 189 tic6x_read_description (void)
 190 {
 191   register unsigned int csr asm ("B2");
 192   unsigned int cpuid;
 193   const struct target_desc *tdesc;
 194
 195   /* Determine the CPU we're running on to find the register order.  */
 196   __asm__ ("MVC .S2 CSR,%0" : "=r" (csr) :);
 197   cpuid = csr >> 24;
 198   switch (cpuid)
 199     {
 200     case 0x00: /* C62x */
 201     case 0x02: /* C67x */
 202       tic6x_regmap = tic6x_regmap_c62x;
 203       tic6x_breakpoint = 0x0000a122;  /* BNOP .S2 0,5 */
 204       tdesc = tdesc_tic6x_c62x_linux;
 205       break;
 206     case 0x03: /* C67x+ */
 207       tic6x_regmap = tic6x_regmap_c64x;
 208       tic6x_breakpoint = 0x0000a122;  /* BNOP .S2 0,5 */
 209       tdesc = tdesc_tic6x_c64x_linux;
 210       break;
 211     case 0x0c: /* C64x */
 212       tic6x_regmap = tic6x_regmap_c64x;
 213       tic6x_breakpoint = 0x0000a122;  /* BNOP .S2 0,5 */
 214       tdesc = tdesc_tic6x_c64x_linux;
 215       break;
 216     case 0x10: /* C64x+ */
 217     case 0x14: /* C674x */
 218     case 0x15: /* C66x */
 219       tic6x_regmap = tic6x_regmap_c64xp;
 220       tic6x_breakpoint = 0x56454314;  /* illegal opcode */
 221       tdesc = tdesc_tic6x_c64xp_linux;
 222       break;
 223     default:
 224       error ("Unknown CPU ID 0x%02x", cpuid);
 225     }
 226   tic6x_usrregs_info.regmap = tic6x_regmap;
 227   return tdesc;
 228 }
 229
 230 static int
 231 tic6x_cannot_fetch_register (int regno)
 232 {
 233   return (tic6x_regmap[regno] == -1);
 234 }
 235
 236 static int
 237 tic6x_cannot_store_register (int regno)
 238 {
 239   return (tic6x_regmap[regno] == -1);
 240 }
 241
 242 static CORE_ADDR
 243 tic6x_get_pc (struct regcache *regcache)
 244 {
 245   union tic6x_register pc;
 246
 247   collect_register_by_name (regcache, "PC", pc.buf);
 248   return pc.reg32;
 249 }
 250
 251 static void
 252 tic6x_set_pc (struct regcache *regcache, CORE_ADDR pc)
 253 {
 254   union tic6x_register newpc;
 255
 256   newpc.reg32 = pc;
 257   supply_register_by_name (regcache, "PC", newpc.buf);
 258 }
 259
 260 static int
 261 tic6x_breakpoint_at (CORE_ADDR where)
 262 {
 263   unsigned int insn;
 264
 265   (*the_target->read_memory) (where, (unsigned char *) &insn, 4);
 266   if (insn == tic6x_breakpoint)
 267     return 1;
 268
 269   /* If necessary, recognize more trap instructions here.  GDB only uses the
 270      one.  */
 271   return 0;
 272 }
 273
 274 /* Fetch the thread-local storage pointer for libthread_db.  */
 275
 276 ps_err_e
 277 ps_get_thread_area (struct ps_prochandle *ph,
 278                     lwpid_t lwpid, int idx, void **base)
 279 {
 280   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
 281     return PS_ERR;
 282
 283   /* IDX is the bias from the thread pointer to the beginning of the
 284      thread descriptor.  It has to be subtracted due to implementation
 285      quirks in libthread_db.  */
 286   *base = (void *) ((char *) *base - idx);
 287
 288   return PS_OK;
 289 }
 290
 291 static void
 292 tic6x_collect_register (struct regcache *regcache, int regno,
 293                         union tic6x_register *reg)
 294 {
 295   union tic6x_register tmp_reg;
 296
 297   collect_register (regcache, regno, &tmp_reg.reg32);
 298   reg->reg32 = tmp_reg.reg32;
 299 }
 300
 301 static void
 302 tic6x_supply_register (struct regcache *regcache, int regno,
 303                        const union tic6x_register *reg)
 304 {
 305   int offset = 0;
 306
 307   supply_register (regcache, regno, reg->buf + offset);
 308 }
 309
 310 static void
 311 tic6x_fill_gregset (struct regcache *regcache, void *buf)
 312 {
 313   union tic6x_register *regset = buf;
 314   int i;
 315
 316   for (i = 0; i < TIC6X_NUM_REGS; i++)
 317     if (tic6x_regmap[i] != -1)
 318       tic6x_collect_register (regcache, i, regset + tic6x_regmap[i]);
 319 }
 320
 321 static void
 322 tic6x_store_gregset (struct regcache *regcache, const void *buf)
 323 {
 324   const union tic6x_register *regset = buf;
 325   int i;
 326
 327   for (i = 0; i < TIC6X_NUM_REGS; i++)
 328     if (tic6x_regmap[i] != -1)
 329       tic6x_supply_register (regcache, i, regset + tic6x_regmap[i]);
 330 }
 331
 332 static struct regset_info tic6x_regsets[] = {
 333   { PTRACE_GETREGS, PTRACE_SETREGS, 0, TIC6X_NUM_REGS * 4, GENERAL_REGS,
 334     tic6x_fill_gregset, tic6x_store_gregset },
 335   NULL_REGSET
 336 };
 337
 338 static void
 339 tic6x_arch_setup (void)
 340 {
 341   current_process ()->tdesc = tic6x_read_description ();
 342 }
 343
 344 /* Support for hardware single step.  */
 345
 346 static int
 347 tic6x_supports_hardware_single_step (void)
 348 {
 349   return 1;
 350 }
 351
 352 static struct regsets_info tic6x_regsets_info =
 353   {
 354     tic6x_regsets, /* regsets */
 355     0, /* num_regsets */
 356     NULL, /* disabled_regsets */
 357   };
 358
 359 static struct usrregs_info tic6x_usrregs_info =
 360   {
 361     TIC6X_NUM_REGS,
 362     NULL, /* Set in tic6x_read_description.  */
 363   };
 364
 365 static struct regs_info regs_info =
 366   {
 367     NULL, /* regset_bitmap */
 368     &tic6x_usrregs_info,
 369     &tic6x_regsets_info
 370   };
 371
 372 static const struct regs_info *
 373 tic6x_regs_info (void)
 374 {
 375   return &regs_info;
 376 }
 377
 378 struct linux_target_ops the_low_target = {
 379   tic6x_arch_setup,
 380   tic6x_regs_info,
 381   tic6x_cannot_fetch_register,
 382   tic6x_cannot_store_register,
 383   NULL, /* fetch_register */
 384   tic6x_get_pc,
 385   tic6x_set_pc,
 386   NULL, /* breakpoint_kind_from_pc */
 387   tic6x_sw_breakpoint_from_kind,
 388   NULL,
 389   0,
 390   tic6x_breakpoint_at,
 391   NULL, /* supports_z_point_type */
 392   NULL, /* insert_point */
 393   NULL, /* remove_point */
 394   NULL, /* stopped_by_watchpoint */
 395   NULL, /* stopped_data_address */
 396   NULL, /* collect_ptrace_register */
 397   NULL, /* supply_ptrace_register */
 398   NULL, /* siginfo_fixup */
 399   NULL, /* new_process */
 400   NULL, /* delete_process */
 401   NULL, /* new_thread */
 402   NULL, /* delete_thread */
 403   NULL, /* new_fork */
 404   NULL, /* prepare_to_resume */
 405   NULL, /* process_qsupported */
 406   NULL, /* supports_tracepoints */
 407   NULL, /* get_thread_area */
 408   NULL, /* install_fast_tracepoint_jump_pad */
 409   NULL, /* emit_ops */
 410   NULL, /* get_min_fast_tracepoint_insn_len */
 411   NULL, /* supports_range_stepping */
 412   NULL, /* breakpoint_kind_from_current_state */
 413   tic6x_supports_hardware_single_step,
 414 };
 415
 416 void
 417 initialize_low_arch (void)
 418 {
 419   /* Initialize the Linux target descriptions.  */
 420   init_registers_tic6x_c64xp_linux ();
 421   init_registers_tic6x_c64x_linux ();
 422   init_registers_tic6x_c62x_linux ();
 423
 424   initialize_regsets_info (&tic6x_regsets_info);
 425 }