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 reg-ppc.c.  */
  35 void init_registers_ppc (void);
  36 /* Defined in auto-generated file powerpc-32.c.  */
  37 void init_registers_powerpc_32 (void);
  38 /* Defined in auto-generated file powerpc-e500.c.  */
  39 void init_registers_powerpc_e500 (void);
  40 /* Defined in auto-generated file reg-ppc64.c.  */
  41 void init_registers_ppc64 (void);
  42 /* Defined in auto-generated file powerpc-64.c.  */
  43 void init_registers_powerpc_64 (void);
  44
  45 #define ppc_num_regs 71
  46
  47 #ifdef __powerpc64__
  48 /* We use a constant for FPSCR instead of PT_FPSCR, because
  49    many shipped PPC64 kernels had the wrong value in ptrace.h.  */
  50 static int ppc_regmap[] =
  51  {PT_R0 * 8,     PT_R1 * 8,     PT_R2 * 8,     PT_R3 * 8,
  52   PT_R4 * 8,     PT_R5 * 8,     PT_R6 * 8,     PT_R7 * 8,
  53   PT_R8 * 8,     PT_R9 * 8,     PT_R10 * 8,    PT_R11 * 8,
  54   PT_R12 * 8,    PT_R13 * 8,    PT_R14 * 8,    PT_R15 * 8,
  55   PT_R16 * 8,    PT_R17 * 8,    PT_R18 * 8,    PT_R19 * 8,
  56   PT_R20 * 8,    PT_R21 * 8,    PT_R22 * 8,    PT_R23 * 8,
  57   PT_R24 * 8,    PT_R25 * 8,    PT_R26 * 8,    PT_R27 * 8,
  58   PT_R28 * 8,    PT_R29 * 8,    PT_R30 * 8,    PT_R31 * 8,
  59   PT_FPR0*8,     PT_FPR0*8 + 8, PT_FPR0*8+16,  PT_FPR0*8+24,
  60   PT_FPR0*8+32,  PT_FPR0*8+40,  PT_FPR0*8+48,  PT_FPR0*8+56,
  61   PT_FPR0*8+64,  PT_FPR0*8+72,  PT_FPR0*8+80,  PT_FPR0*8+88,
  62   PT_FPR0*8+96,  PT_FPR0*8+104,  PT_FPR0*8+112,  PT_FPR0*8+120,
  63   PT_FPR0*8+128, PT_FPR0*8+136,  PT_FPR0*8+144,  PT_FPR0*8+152,
  64   PT_FPR0*8+160,  PT_FPR0*8+168,  PT_FPR0*8+176,  PT_FPR0*8+184,
  65   PT_FPR0*8+192,  PT_FPR0*8+200,  PT_FPR0*8+208,  PT_FPR0*8+216,
  66   PT_FPR0*8+224,  PT_FPR0*8+232,  PT_FPR0*8+240,  PT_FPR0*8+248,
  67   PT_NIP * 8,    PT_MSR * 8,    PT_CCR * 8,    PT_LNK * 8,
  68   PT_CTR * 8,    PT_XER * 8,    PT_FPR0*8 + 256 };
  69 #else
  70 /* Currently, don't check/send MQ.  */
  71 static int ppc_regmap[] =
  72  {PT_R0 * 4,     PT_R1 * 4,     PT_R2 * 4,     PT_R3 * 4,
  73   PT_R4 * 4,     PT_R5 * 4,     PT_R6 * 4,     PT_R7 * 4,
  74   PT_R8 * 4,     PT_R9 * 4,     PT_R10 * 4,    PT_R11 * 4,
  75   PT_R12 * 4,    PT_R13 * 4,    PT_R14 * 4,    PT_R15 * 4,
  76   PT_R16 * 4,    PT_R17 * 4,    PT_R18 * 4,    PT_R19 * 4,
  77   PT_R20 * 4,    PT_R21 * 4,    PT_R22 * 4,    PT_R23 * 4,
  78   PT_R24 * 4,    PT_R25 * 4,    PT_R26 * 4,    PT_R27 * 4,
  79   PT_R28 * 4,    PT_R29 * 4,    PT_R30 * 4,    PT_R31 * 4,
  80   PT_FPR0*4,     PT_FPR0*4 + 8, PT_FPR0*4+16,  PT_FPR0*4+24,
  81   PT_FPR0*4+32,  PT_FPR0*4+40,  PT_FPR0*4+48,  PT_FPR0*4+56,
  82   PT_FPR0*4+64,  PT_FPR0*4+72,  PT_FPR0*4+80,  PT_FPR0*4+88,
  83   PT_FPR0*4+96,  PT_FPR0*4+104,  PT_FPR0*4+112,  PT_FPR0*4+120,
  84   PT_FPR0*4+128, PT_FPR0*4+136,  PT_FPR0*4+144,  PT_FPR0*4+152,
  85   PT_FPR0*4+160,  PT_FPR0*4+168,  PT_FPR0*4+176,  PT_FPR0*4+184,
  86   PT_FPR0*4+192,  PT_FPR0*4+200,  PT_FPR0*4+208,  PT_FPR0*4+216,
  87   PT_FPR0*4+224,  PT_FPR0*4+232,  PT_FPR0*4+240,  PT_FPR0*4+248,
  88   PT_NIP * 4,    PT_MSR * 4,    PT_CCR * 4,    PT_LNK * 4,
  89   PT_CTR * 4,    PT_XER * 4,    PT_FPSCR * 4
  90  };
  91
  92 static int ppc_regmap_e500[] =
  93  {PT_R0 * 4,     PT_R1 * 4,     PT_R2 * 4,     PT_R3 * 4,
  94   PT_R4 * 4,     PT_R5 * 4,     PT_R6 * 4,     PT_R7 * 4,
  95   PT_R8 * 4,     PT_R9 * 4,     PT_R10 * 4,    PT_R11 * 4,
  96   PT_R12 * 4,    PT_R13 * 4,    PT_R14 * 4,    PT_R15 * 4,
  97   PT_R16 * 4,    PT_R17 * 4,    PT_R18 * 4,    PT_R19 * 4,
  98   PT_R20 * 4,    PT_R21 * 4,    PT_R22 * 4,    PT_R23 * 4,
  99   PT_R24 * 4,    PT_R25 * 4,    PT_R26 * 4,    PT_R27 * 4,
 100   PT_R28 * 4,    PT_R29 * 4,    PT_R30 * 4,    PT_R31 * 4,
 101   -1,            -1,            -1,            -1,
 102   -1,            -1,            -1,            -1,
 103   -1,            -1,            -1,            -1,
 104   -1,            -1,            -1,            -1,
 105   -1,            -1,            -1,            -1,
 106   -1,            -1,            -1,            -1,
 107   -1,            -1,            -1,            -1,
 108   -1,            -1,            -1,            -1,
 109   PT_NIP * 4,    PT_MSR * 4,    PT_CCR * 4,    PT_LNK * 4,
 110   PT_CTR * 4,    PT_XER * 4,    -1
 111  };
 112 #endif
 113
 114 static int
 115 ppc_cannot_store_register (int regno)
 116 {
 117 #ifndef __powerpc64__
 118   /* Some kernels do not allow us to store fpscr.  */
 119   if (!(ppc_hwcap & PPC_FEATURE_HAS_SPE) && regno == find_regno ("fpscr"))
 120     return 2;
 121 #endif
 122
 123   return 0;
 124 }
 125
 126 static int
 127 ppc_cannot_fetch_register (int regno)
 128 {
 129   return 0;
 130 }
 131
 132 static void
 133 ppc_collect_ptrace_register (int regno, char *buf)
 134 {
 135   int size = register_size (regno);
 136   if (size < sizeof (long))
 137     collect_register (regno, buf + sizeof (long) - size);
 138   else
 139     collect_register (regno, buf);
 140 }
 141
 142 static void
 143 ppc_supply_ptrace_register (int regno, const char *buf)
 144 {
 145   int size = register_size (regno);
 146   if (size < sizeof (long))
 147     supply_register (regno, buf + sizeof (long) - size);
 148   else
 149     supply_register (regno, buf);
 150 }
 151
 152 static CORE_ADDR
 153 ppc_get_pc (void)
 154 {
 155   if (register_size (0) == 4)
 156     {
 157       unsigned int pc;
 158       collect_register_by_name ("pc", &pc);
 159       return (CORE_ADDR) pc;
 160     }
 161   else
 162     {
 163       unsigned long pc;
 164       collect_register_by_name ("pc", &pc);
 165       return (CORE_ADDR) pc;
 166     }
 167 }
 168
 169 static void
 170 ppc_set_pc (CORE_ADDR pc)
 171 {
 172   if (register_size (0) == 4)
 173     {
 174       unsigned int newpc = pc;
 175       supply_register_by_name ("pc", &newpc);
 176     }
 177   else
 178     {
 179       unsigned long newpc = pc;
 180       supply_register_by_name ("pc", &newpc);
 181     }
 182 }
 183
 184
 185 static int
 186 ppc_get_hwcap (unsigned long *valp)
 187 {
 188   int wordsize = register_size (0);
 189   unsigned char *data = alloca (2 * wordsize);
 190   int offset = 0;
 191
 192   while ((*the_target->read_auxv) (offset, data, 2 * wordsize) == 2 * wordsize)
 193     {
 194       if (wordsize == 4)
 195         {
 196           unsigned int *data_p = (unsigned int *)data;
 197           if (data_p[0] == AT_HWCAP)
 198             {
 199               *valp = data_p[1];
 200               return 1;
 201             }
 202         }
 203       else
 204         {
 205           unsigned long *data_p = (unsigned long *)data;
 206           if (data_p[0] == AT_HWCAP)
 207             {
 208               *valp = data_p[1];
 209               return 1;
 210             }
 211         }
 212
 213       offset += 2 * wordsize;
 214     }
 215
 216   *valp = 0;
 217   return 0;
 218 }
 219
 220 static void
 221 ppc_arch_setup (void)
 222 {
 223 #ifdef __powerpc64__
 224   long msr;
 225
 226   /* On a 64-bit host, assume 64-bit inferior process with no
 227      AltiVec registers.  Reset ppc_hwcap to ensure that the
 228      collect_register call below does not fail.  */
 229   init_registers_ppc64 ();
 230   ppc_hwcap = 0;
 231
 232   /* Only if the high bit of the MSR is set, we actually have
 233      a 64-bit inferior.  */
 234   collect_register_by_name ("msr", &msr);
 235   if (msr < 0)
 236     {
 237       ppc_get_hwcap (&ppc_hwcap);
 238       if (ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC)
 239         init_registers_powerpc_64 ();
 240
 241       return;
 242     }
 243 #endif
 244
 245   /* OK, we have a 32-bit inferior.  */
 246   init_registers_ppc ();
 247
 248   ppc_get_hwcap (&ppc_hwcap);
 249   if (ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC)
 250     init_registers_powerpc_32 ();
 251
 252   /* On 32-bit machines, check for SPE registers.
 253      Set the low target's regmap field as appropriately.  */
 254 #ifndef __powerpc64__
 255   the_low_target.regmap = ppc_regmap;
 256   if (ppc_hwcap & PPC_FEATURE_HAS_SPE)
 257     {
 258       init_registers_powerpc_e500 ();
 259       the_low_target.regmap = ppc_regmap_e500;
 260    }
 261 #endif
 262 }
 263
 264 /* Correct in either endianness.
 265    This instruction is "twge r2, r2", which GDB uses as a software
 266    breakpoint.  */
 267 static const unsigned int ppc_breakpoint = 0x7d821008;
 268 #define ppc_breakpoint_len 4
 269
 270 static int
 271 ppc_breakpoint_at (CORE_ADDR where)
 272 {
 273   unsigned int insn;
 274
 275   (*the_target->read_memory) (where, (unsigned char *) &insn, 4);
 276   if (insn == ppc_breakpoint)
 277     return 1;
 278   /* If necessary, recognize more trap instructions here.  GDB only uses the
 279      one.  */
 280   return 0;
 281 }
 282
 283 /* Provide only a fill function for the general register set.  ps_lgetregs
 284    will use this for NPTL support.  */
 285
 286 static void ppc_fill_gregset (void *buf)
 287 {
 288   int i;
 289
 290   for (i = 0; i < 32; i++)
 291     ppc_collect_ptrace_register (i, (char *) buf + ppc_regmap[i]);
 292
 293   for (i = 64; i < 70; i++)
 294     ppc_collect_ptrace_register (i, (char *) buf + ppc_regmap[i]);
 295 }
 296
 297 #ifndef PTRACE_GETVRREGS
 298 #define PTRACE_GETVRREGS 18
 299 #define PTRACE_SETVRREGS 19
 300 #endif
 301
 302 #define SIZEOF_VRREGS 33*16+4
 303
 304 static void
 305 ppc_fill_vrregset (void *buf)
 306 {
 307   int i, base;
 308   char *regset = buf;
 309
 310   if (!(ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC))
 311     return;
 312
 313   base = find_regno ("vr0");
 314   for (i = 0; i < 32; i++)
 315     collect_register (base + i, &regset[i * 16]);
 316
 317   collect_register_by_name ("vscr", &regset[32 * 16 + 12]);
 318   collect_register_by_name ("vrsave", &regset[33 * 16]);
 319 }
 320
 321 static void
 322 ppc_store_vrregset (const void *buf)
 323 {
 324   int i, base;
 325   const char *regset = buf;
 326
 327   if (!(ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC))
 328     return;
 329
 330   base = find_regno ("vr0");
 331   for (i = 0; i < 32; i++)
 332     supply_register (base + i, &regset[i * 16]);
 333
 334   supply_register_by_name ("vscr", &regset[32 * 16 + 12]);
 335   supply_register_by_name ("vrsave", &regset[33 * 16]);
 336 }
 337
 338 #ifndef PTRACE_GETEVRREGS
 339 #define PTRACE_GETEVRREGS       20
 340 #define PTRACE_SETEVRREGS       21
 341 #endif
 342
 343 struct gdb_evrregset_t
 344 {
 345   unsigned long evr[32];
 346   unsigned long long acc;
 347   unsigned long spefscr;
 348 };
 349
 350 static void
 351 ppc_fill_evrregset (void *buf)
 352 {
 353   int i, ev0;
 354   struct gdb_evrregset_t *regset = buf;
 355
 356   if (!(ppc_hwcap & PPC_FEATURE_HAS_SPE))
 357     return;
 358
 359   ev0 = find_regno ("ev0h");
 360   for (i = 0; i < 32; i++)
 361     collect_register (ev0 + i, &regset->evr[i]);
 362
 363   collect_register_by_name ("acc", &regset->acc);
 364   collect_register_by_name ("spefscr", &regset->spefscr);
 365 }
 366
 367 static void
 368 ppc_store_evrregset (const void *buf)
 369 {
 370   int i, ev0;
 371   const struct gdb_evrregset_t *regset = buf;
 372
 373   if (!(ppc_hwcap & PPC_FEATURE_HAS_SPE))
 374     return;
 375
 376   ev0 = find_regno ("ev0h");
 377   for (i = 0; i < 32; i++)
 378     supply_register (ev0 + i, &regset->evr[i]);
 379
 380   supply_register_by_name ("acc", &regset->acc);
 381   supply_register_by_name ("spefscr", &regset->spefscr);
 382 }
 383
 384 struct regset_info target_regsets[] = {
 385   /* List the extra register sets before GENERAL_REGS.  That way we will
 386      fetch them every time, but still fall back to PTRACE_PEEKUSER for the
 387      general registers.  Some kernels support these, but not the newer
 388      PPC_PTRACE_GETREGS.  */
 389   { PTRACE_GETVRREGS, PTRACE_SETVRREGS, SIZEOF_VRREGS, EXTENDED_REGS,
 390     ppc_fill_vrregset, ppc_store_vrregset },
 391   { PTRACE_GETEVRREGS, PTRACE_SETEVRREGS, 32 * 4 + 8 + 4, EXTENDED_REGS,
 392     ppc_fill_evrregset, ppc_store_evrregset },
 393   { 0, 0, 0, GENERAL_REGS, ppc_fill_gregset, NULL },
 394   { 0, 0, -1, -1, NULL, NULL }
 395 };
 396
 397 struct linux_target_ops the_low_target = {
 398   ppc_arch_setup,
 399   ppc_num_regs,
 400   ppc_regmap,
 401   ppc_cannot_fetch_register,
 402   ppc_cannot_store_register,
 403   ppc_get_pc,
 404   ppc_set_pc,
 405   (const unsigned char *) &ppc_breakpoint,
 406   ppc_breakpoint_len,
 407   NULL,
 408   0,
 409   ppc_breakpoint_at,
 410   NULL,
 411   NULL,
 412   NULL,
 413   NULL,
 414   ppc_collect_ptrace_register,
 415   ppc_supply_ptrace_register,
 416 };