gdb/gdbserver/linux-ppc-low.c

   1 /* GNU/Linux/PowerPC specific low level interface, for the remote server for
   2    GDB.
   3    Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2005, 2007, 2008
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "server.h"
  22 #include "linux-low.h"
  23
  24 #include <elf.h>
  25 #include <asm/ptrace.h>
  26
  27 /* These are in <asm/cputable.h> in current kernels.  */
  28 #define PPC_FEATURE_HAS_ALTIVEC         0x10000000
  29 #define PPC_FEATURE_HAS_SPE             0x00800000
  30
  31 static unsigned long ppc_hwcap;
  32
  33
  34 /* Defined in auto-generated file powerpc-32l.c.  */
  35 void init_registers_powerpc_32l (void);
  36 /* Defined in auto-generated file powerpc-altivec32l.c.  */
  37 void init_registers_powerpc_altivec32l (void);
  38 /* Defined in auto-generated file powerpc-e500l.c.  */
  39 void init_registers_powerpc_e500l (void);
  40 /* Defined in auto-generated file powerpc-64l.c.  */
  41 void init_registers_powerpc_64l (void);
  42 /* Defined in auto-generated file powerpc-altivec64l.c.  */
  43 void init_registers_powerpc_altivec64l (void);
  44
  45 #define ppc_num_regs 73
  46
  47 /* This sometimes isn't defined.  */
  48 #ifndef PT_ORIG_R3
  49 #define PT_ORIG_R3 34
  50 #endif
  51 #ifndef PT_TRAP
  52 #define PT_TRAP 40
  53 #endif
  54
  55 #ifdef __powerpc64__
  56 /* We use a constant for FPSCR instead of PT_FPSCR, because
  57    many shipped PPC64 kernels had the wrong value in ptrace.h.  */
  58 static int ppc_regmap[] =
  59  {PT_R0 * 8,     PT_R1 * 8,     PT_R2 * 8,     PT_R3 * 8,
  60   PT_R4 * 8,     PT_R5 * 8,     PT_R6 * 8,     PT_R7 * 8,
  61   PT_R8 * 8,     PT_R9 * 8,     PT_R10 * 8,    PT_R11 * 8,
  62   PT_R12 * 8,    PT_R13 * 8,    PT_R14 * 8,    PT_R15 * 8,
  63   PT_R16 * 8,    PT_R17 * 8,    PT_R18 * 8,    PT_R19 * 8,
  64   PT_R20 * 8,    PT_R21 * 8,    PT_R22 * 8,    PT_R23 * 8,
  65   PT_R24 * 8,    PT_R25 * 8,    PT_R26 * 8,    PT_R27 * 8,
  66   PT_R28 * 8,    PT_R29 * 8,    PT_R30 * 8,    PT_R31 * 8,
  67   PT_FPR0*8,     PT_FPR0*8 + 8, PT_FPR0*8+16,  PT_FPR0*8+24,
  68   PT_FPR0*8+32,  PT_FPR0*8+40,  PT_FPR0*8+48,  PT_FPR0*8+56,
  69   PT_FPR0*8+64,  PT_FPR0*8+72,  PT_FPR0*8+80,  PT_FPR0*8+88,
  70   PT_FPR0*8+96,  PT_FPR0*8+104,  PT_FPR0*8+112,  PT_FPR0*8+120,
  71   PT_FPR0*8+128, PT_FPR0*8+136,  PT_FPR0*8+144,  PT_FPR0*8+152,
  72   PT_FPR0*8+160,  PT_FPR0*8+168,  PT_FPR0*8+176,  PT_FPR0*8+184,
  73   PT_FPR0*8+192,  PT_FPR0*8+200,  PT_FPR0*8+208,  PT_FPR0*8+216,
  74   PT_FPR0*8+224,  PT_FPR0*8+232,  PT_FPR0*8+240,  PT_FPR0*8+248,
  75   PT_NIP * 8,    PT_MSR * 8,    PT_CCR * 8,    PT_LNK * 8,
  76   PT_CTR * 8,    PT_XER * 8,    PT_FPR0*8 + 256,
  77   PT_ORIG_R3 * 8, PT_TRAP * 8 };
  78 #else
  79 /* Currently, don't check/send MQ.  */
  80 static int ppc_regmap[] =
  81  {PT_R0 * 4,     PT_R1 * 4,     PT_R2 * 4,     PT_R3 * 4,
  82   PT_R4 * 4,     PT_R5 * 4,     PT_R6 * 4,     PT_R7 * 4,
  83   PT_R8 * 4,     PT_R9 * 4,     PT_R10 * 4,    PT_R11 * 4,
  84   PT_R12 * 4,    PT_R13 * 4,    PT_R14 * 4,    PT_R15 * 4,
  85   PT_R16 * 4,    PT_R17 * 4,    PT_R18 * 4,    PT_R19 * 4,
  86   PT_R20 * 4,    PT_R21 * 4,    PT_R22 * 4,    PT_R23 * 4,
  87   PT_R24 * 4,    PT_R25 * 4,    PT_R26 * 4,    PT_R27 * 4,
  88   PT_R28 * 4,    PT_R29 * 4,    PT_R30 * 4,    PT_R31 * 4,
  89   PT_FPR0*4,     PT_FPR0*4 + 8, PT_FPR0*4+16,  PT_FPR0*4+24,
  90   PT_FPR0*4+32,  PT_FPR0*4+40,  PT_FPR0*4+48,  PT_FPR0*4+56,
  91   PT_FPR0*4+64,  PT_FPR0*4+72,  PT_FPR0*4+80,  PT_FPR0*4+88,
  92   PT_FPR0*4+96,  PT_FPR0*4+104,  PT_FPR0*4+112,  PT_FPR0*4+120,
  93   PT_FPR0*4+128, PT_FPR0*4+136,  PT_FPR0*4+144,  PT_FPR0*4+152,
  94   PT_FPR0*4+160,  PT_FPR0*4+168,  PT_FPR0*4+176,  PT_FPR0*4+184,
  95   PT_FPR0*4+192,  PT_FPR0*4+200,  PT_FPR0*4+208,  PT_FPR0*4+216,
  96   PT_FPR0*4+224,  PT_FPR0*4+232,  PT_FPR0*4+240,  PT_FPR0*4+248,
  97   PT_NIP * 4,    PT_MSR * 4,    PT_CCR * 4,    PT_LNK * 4,
  98   PT_CTR * 4,    PT_XER * 4,    PT_FPSCR * 4,
  99   PT_ORIG_R3 * 4, PT_TRAP * 4
 100  };
 101
 102 static int ppc_regmap_e500[] =
 103  {PT_R0 * 4,     PT_R1 * 4,     PT_R2 * 4,     PT_R3 * 4,
 104   PT_R4 * 4,     PT_R5 * 4,     PT_R6 * 4,     PT_R7 * 4,
 105   PT_R8 * 4,     PT_R9 * 4,     PT_R10 * 4,    PT_R11 * 4,
 106   PT_R12 * 4,    PT_R13 * 4,    PT_R14 * 4,    PT_R15 * 4,
 107   PT_R16 * 4,    PT_R17 * 4,    PT_R18 * 4,    PT_R19 * 4,
 108   PT_R20 * 4,    PT_R21 * 4,    PT_R22 * 4,    PT_R23 * 4,
 109   PT_R24 * 4,    PT_R25 * 4,    PT_R26 * 4,    PT_R27 * 4,
 110   PT_R28 * 4,    PT_R29 * 4,    PT_R30 * 4,    PT_R31 * 4,
 111   -1,            -1,            -1,            -1,
 112   -1,            -1,            -1,            -1,
 113   -1,            -1,            -1,            -1,
 114   -1,            -1,            -1,            -1,
 115   -1,            -1,            -1,            -1,
 116   -1,            -1,            -1,            -1,
 117   -1,            -1,            -1,            -1,
 118   -1,            -1,            -1,            -1,
 119   PT_NIP * 4,    PT_MSR * 4,    PT_CCR * 4,    PT_LNK * 4,
 120   PT_CTR * 4,    PT_XER * 4,    -1,
 121   PT_ORIG_R3 * 4, PT_TRAP * 4
 122  };
 123 #endif
 124
 125 static int
 126 ppc_cannot_store_register (int regno)
 127 {
 128 #ifndef __powerpc64__
 129   /* Some kernels do not allow us to store fpscr.  */
 130   if (!(ppc_hwcap & PPC_FEATURE_HAS_SPE) && regno == find_regno ("fpscr"))
 131     return 2;
 132 #endif
 133
 134   /* Some kernels do not allow us to store orig_r3 or trap.  */
 135   if (regno == find_regno ("orig_r3")
 136       || regno == find_regno ("trap"))
 137     return 2;
 138
 139   return 0;
 140 }
 141
 142 static int
 143 ppc_cannot_fetch_register (int regno)
 144 {
 145   return 0;
 146 }
 147
 148 static void
 149 ppc_collect_ptrace_register (int regno, char *buf)
 150 {
 151   int size = register_size (regno);
 152
 153   memset (buf, 0, sizeof (long));
 154
 155   if (size < sizeof (long))
 156     collect_register (regno, buf + sizeof (long) - size);
 157   else
 158     collect_register (regno, buf);
 159 }
 160
 161 static void
 162 ppc_supply_ptrace_register (int regno, const char *buf)
 163 {
 164   int size = register_size (regno);
 165   if (size < sizeof (long))
 166     supply_register (regno, buf + sizeof (long) - size);
 167   else
 168     supply_register (regno, buf);
 169 }
 170
 171 static CORE_ADDR
 172 ppc_get_pc (void)
 173 {
 174   if (register_size (0) == 4)
 175     {
 176       unsigned int pc;
 177       collect_register_by_name ("pc", &pc);
 178       return (CORE_ADDR) pc;
 179     }
 180   else
 181     {
 182       unsigned long pc;
 183       collect_register_by_name ("pc", &pc);
 184       return (CORE_ADDR) pc;
 185     }
 186 }
 187
 188 static void
 189 ppc_set_pc (CORE_ADDR pc)
 190 {
 191   if (register_size (0) == 4)
 192     {
 193       unsigned int newpc = pc;
 194       supply_register_by_name ("pc", &newpc);
 195     }
 196   else
 197     {
 198       unsigned long newpc = pc;
 199       supply_register_by_name ("pc", &newpc);
 200     }
 201 }
 202
 203
 204 static int
 205 ppc_get_hwcap (unsigned long *valp)
 206 {
 207   int wordsize = register_size (0);
 208   unsigned char *data = alloca (2 * wordsize);
 209   int offset = 0;
 210
 211   while ((*the_target->read_auxv) (offset, data, 2 * wordsize) == 2 * wordsize)
 212     {
 213       if (wordsize == 4)
 214         {
 215           unsigned int *data_p = (unsigned int *)data;
 216           if (data_p[0] == AT_HWCAP)
 217             {
 218               *valp = data_p[1];
 219               return 1;
 220             }
 221         }
 222       else
 223         {
 224           unsigned long *data_p = (unsigned long *)data;
 225           if (data_p[0] == AT_HWCAP)
 226             {
 227               *valp = data_p[1];
 228               return 1;
 229             }
 230         }
 231
 232       offset += 2 * wordsize;
 233     }
 234
 235   *valp = 0;
 236   return 0;
 237 }
 238
 239 static void
 240 ppc_arch_setup (void)
 241 {
 242 #ifdef __powerpc64__
 243   long msr;
 244
 245   /* On a 64-bit host, assume 64-bit inferior process with no
 246      AltiVec registers.  Reset ppc_hwcap to ensure that the
 247      collect_register call below does not fail.  */
 248   init_registers_powerpc_64l ();
 249   ppc_hwcap = 0;
 250
 251   /* Only if the high bit of the MSR is set, we actually have
 252      a 64-bit inferior.  */
 253   collect_register_by_name ("msr", &msr);
 254   if (msr < 0)
 255     {
 256       ppc_get_hwcap (&ppc_hwcap);
 257       if (ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC)
 258         init_registers_powerpc_altivec64l ();
 259
 260       return;
 261     }
 262 #endif
 263
 264   /* OK, we have a 32-bit inferior.  */
 265   init_registers_powerpc_32l ();
 266
 267   ppc_get_hwcap (&ppc_hwcap);
 268   if (ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC)
 269     init_registers_powerpc_altivec32l ();
 270
 271   /* On 32-bit machines, check for SPE registers.
 272      Set the low target's regmap field as appropriately.  */
 273 #ifndef __powerpc64__
 274   the_low_target.regmap = ppc_regmap;
 275   if (ppc_hwcap & PPC_FEATURE_HAS_SPE)
 276     {
 277       init_registers_powerpc_e500l ();
 278       the_low_target.regmap = ppc_regmap_e500;
 279    }
 280 #endif
 281 }
 282
 283 /* Correct in either endianness.
 284    This instruction is "twge r2, r2", which GDB uses as a software
 285    breakpoint.  */
 286 static const unsigned int ppc_breakpoint = 0x7d821008;
 287 #define ppc_breakpoint_len 4
 288
 289 static int
 290 ppc_breakpoint_at (CORE_ADDR where)
 291 {
 292   unsigned int insn;
 293
 294   (*the_target->read_memory) (where, (unsigned char *) &insn, 4);
 295   if (insn == ppc_breakpoint)
 296     return 1;
 297   /* If necessary, recognize more trap instructions here.  GDB only uses the
 298      one.  */
 299   return 0;
 300 }
 301
 302 /* Provide only a fill function for the general register set.  ps_lgetregs
 303    will use this for NPTL support.  */
 304
 305 static void ppc_fill_gregset (void *buf)
 306 {
 307   int i;
 308
 309   for (i = 0; i < 32; i++)
 310     ppc_collect_ptrace_register (i, (char *) buf + ppc_regmap[i]);
 311
 312   for (i = 64; i < 70; i++)
 313     ppc_collect_ptrace_register (i, (char *) buf + ppc_regmap[i]);
 314
 315   for (i = 71; i < 73; i++)
 316     ppc_collect_ptrace_register (i, (char *) buf + ppc_regmap[i]);
 317 }
 318
 319 #ifndef PTRACE_GETVRREGS
 320 #define PTRACE_GETVRREGS 18
 321 #define PTRACE_SETVRREGS 19
 322 #endif
 323
 324 #define SIZEOF_VRREGS 33*16+4
 325
 326 static void
 327 ppc_fill_vrregset (void *buf)
 328 {
 329   int i, base;
 330   char *regset = buf;
 331
 332   if (!(ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC))
 333     return;
 334
 335   base = find_regno ("vr0");
 336   for (i = 0; i < 32; i++)
 337     collect_register (base + i, &regset[i * 16]);
 338
 339   collect_register_by_name ("vscr", &regset[32 * 16 + 12]);
 340   collect_register_by_name ("vrsave", &regset[33 * 16]);
 341 }
 342
 343 static void
 344 ppc_store_vrregset (const void *buf)
 345 {
 346   int i, base;
 347   const char *regset = buf;
 348
 349   if (!(ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC))
 350     return;
 351
 352   base = find_regno ("vr0");
 353   for (i = 0; i < 32; i++)
 354     supply_register (base + i, &regset[i * 16]);
 355
 356   supply_register_by_name ("vscr", &regset[32 * 16 + 12]);
 357   supply_register_by_name ("vrsave", &regset[33 * 16]);
 358 }
 359
 360 #ifndef PTRACE_GETEVRREGS
 361 #define PTRACE_GETEVRREGS       20
 362 #define PTRACE_SETEVRREGS       21
 363 #endif
 364
 365 struct gdb_evrregset_t
 366 {
 367   unsigned long evr[32];
 368   unsigned long long acc;
 369   unsigned long spefscr;
 370 };
 371
 372 static void
 373 ppc_fill_evrregset (void *buf)
 374 {
 375   int i, ev0;
 376   struct gdb_evrregset_t *regset = buf;
 377
 378   if (!(ppc_hwcap & PPC_FEATURE_HAS_SPE))
 379     return;
 380
 381   ev0 = find_regno ("ev0h");
 382   for (i = 0; i < 32; i++)
 383     collect_register (ev0 + i, &regset->evr[i]);
 384
 385   collect_register_by_name ("acc", &regset->acc);
 386   collect_register_by_name ("spefscr", &regset->spefscr);
 387 }
 388
 389 static void
 390 ppc_store_evrregset (const void *buf)
 391 {
 392   int i, ev0;
 393   const struct gdb_evrregset_t *regset = buf;
 394
 395   if (!(ppc_hwcap & PPC_FEATURE_HAS_SPE))
 396     return;
 397
 398   ev0 = find_regno ("ev0h");
 399   for (i = 0; i < 32; i++)
 400     supply_register (ev0 + i, &regset->evr[i]);
 401
 402   supply_register_by_name ("acc", &regset->acc);
 403   supply_register_by_name ("spefscr", &regset->spefscr);
 404 }
 405
 406 struct regset_info target_regsets[] = {
 407   /* List the extra register sets before GENERAL_REGS.  That way we will
 408      fetch them every time, but still fall back to PTRACE_PEEKUSER for the
 409      general registers.  Some kernels support these, but not the newer
 410      PPC_PTRACE_GETREGS.  */
 411   { PTRACE_GETVRREGS, PTRACE_SETVRREGS, SIZEOF_VRREGS, EXTENDED_REGS,
 412     ppc_fill_vrregset, ppc_store_vrregset },
 413   { PTRACE_GETEVRREGS, PTRACE_SETEVRREGS, 32 * 4 + 8 + 4, EXTENDED_REGS,
 414     ppc_fill_evrregset, ppc_store_evrregset },
 415   { 0, 0, 0, GENERAL_REGS, ppc_fill_gregset, NULL },
 416   { 0, 0, -1, -1, NULL, NULL }
 417 };
 418
 419 struct linux_target_ops the_low_target = {
 420   ppc_arch_setup,
 421   ppc_num_regs,
 422   ppc_regmap,
 423   ppc_cannot_fetch_register,
 424   ppc_cannot_store_register,
 425   ppc_get_pc,
 426   ppc_set_pc,
 427   (const unsigned char *) &ppc_breakpoint,
 428   ppc_breakpoint_len,
 429   NULL,
 430   0,
 431   ppc_breakpoint_at,
 432   NULL,
 433   NULL,
 434   NULL,
 435   NULL,
 436   ppc_collect_ptrace_register,
 437   ppc_supply_ptrace_register,
 438 };