gdb/sparcnbsd-tdep.c

   1 /* Target-dependent code for NetBSD/sparc.
   2
   3    Copyright (C) 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011
   4    Free Software Foundation, Inc.
   5    Contributed by Wasabi Systems, Inc.
   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 "defs.h"
  23 #include "frame.h"
  24 #include "frame-unwind.h"
  25 #include "gdbcore.h"
  26 #include "gdbtypes.h"
  27 #include "osabi.h"
  28 #include "regcache.h"
  29 #include "regset.h"
  30 #include "solib-svr4.h"
  31 #include "symtab.h"
  32 #include "trad-frame.h"
  33
  34 #include "gdb_assert.h"
  35 #include "gdb_string.h"
  36
  37 #include "sparc-tdep.h"
  38 #include "nbsd-tdep.h"
  39
  40 /* Macros to extract fields from SPARC instructions.  */
  41 #define X_RS1(i) (((i) >> 14) & 0x1f)
  42 #define X_RS2(i) ((i) & 0x1f)
  43 #define X_I(i) (((i) >> 13) & 1)
  44
  45 const struct sparc_gregset sparc32nbsd_gregset =
  46 {
  47   0 * 4,                        /* %psr */
  48   1 * 4,                        /* %pc */
  49   2 * 4,                        /* %npc */
  50   3 * 4,                        /* %y */
  51   -1,                           /* %wim */
  52   -1,                           /* %tbr */
  53   5 * 4,                        /* %g1 */
  54   -1                            /* %l0 */
  55 };
  56
  57 static void
  58 sparc32nbsd_supply_gregset (const struct regset *regset,
  59                             struct regcache *regcache,
  60                             int regnum, const void *gregs, size_t len)
  61 {
  62   sparc32_supply_gregset (&sparc32nbsd_gregset, regcache, regnum, gregs);
  63
  64   /* Traditional NetBSD core files don't use multiple register sets.
  65      Instead, the general-purpose and floating-point registers are
  66      lumped together in a single section.  */
  67   if (len >= 212)
  68     sparc32_supply_fpregset (regcache, regnum, (const char *) gregs + 80);
  69 }
  70
  71 static void
  72 sparc32nbsd_supply_fpregset (const struct regset *regset,
  73                              struct regcache *regcache,
  74                              int regnum, const void *fpregs, size_t len)
  75 {
  76   sparc32_supply_fpregset (regcache, regnum, fpregs);
  77 }
  78
  79 \f
  80 /* Signal trampolines.  */
  81
  82 /* The following variables describe the location of an on-stack signal
  83    trampoline.  The current values correspond to the memory layout for
  84    NetBSD 1.3 and up.  These shouldn't be necessary for NetBSD 2.0 and
  85    up, since NetBSD uses signal trampolines provided by libc now.  */
  86
  87 static const CORE_ADDR sparc32nbsd_sigtramp_start = 0xeffffef0;
  88 static const CORE_ADDR sparc32nbsd_sigtramp_end = 0xeffffff0;
  89
  90 static int
  91 sparc32nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
  92 {
  93   if (pc >= sparc32nbsd_sigtramp_start && pc < sparc32nbsd_sigtramp_end)
  94     return 1;
  95
  96   return nbsd_pc_in_sigtramp (pc, name);
  97 }
  98
  99 struct trad_frame_saved_reg *
 100 sparc32nbsd_sigcontext_saved_regs (struct frame_info *this_frame)
 101 {
 102   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 103   struct trad_frame_saved_reg *saved_regs;
 104   CORE_ADDR addr, sigcontext_addr;
 105   int regnum, delta;
 106   ULONGEST psr;
 107
 108   saved_regs = trad_frame_alloc_saved_regs (this_frame);
 109
 110   /* We find the appropriate instance of `struct sigcontext' at a
 111      fixed offset in the signal frame.  */
 112   addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);
 113   sigcontext_addr = addr + 64 + 16;
 114
 115   /* The registers are saved in bits and pieces scattered all over the
 116      place.  The code below records their location on the assumption
 117      that the part of the signal trampoline that saves the state has
 118      been executed.  */
 119
 120   saved_regs[SPARC_SP_REGNUM].addr = sigcontext_addr + 8;
 121   saved_regs[SPARC32_PC_REGNUM].addr = sigcontext_addr + 12;
 122   saved_regs[SPARC32_NPC_REGNUM].addr = sigcontext_addr + 16;
 123   saved_regs[SPARC32_PSR_REGNUM].addr = sigcontext_addr + 20;
 124   saved_regs[SPARC_G1_REGNUM].addr = sigcontext_addr + 24;
 125   saved_regs[SPARC_O0_REGNUM].addr = sigcontext_addr + 28;
 126
 127   /* The remaining `global' registers and %y are saved in the `local'
 128      registers.  */
 129   delta = SPARC_L0_REGNUM - SPARC_G0_REGNUM;
 130   for (regnum = SPARC_G2_REGNUM; regnum <= SPARC_G7_REGNUM; regnum++)
 131     saved_regs[regnum].realreg = regnum + delta;
 132   saved_regs[SPARC32_Y_REGNUM].realreg = SPARC_L1_REGNUM;
 133
 134   /* The remaining `out' registers can be found in the current frame's
 135      `in' registers.  */
 136   delta = SPARC_I0_REGNUM - SPARC_O0_REGNUM;
 137   for (regnum = SPARC_O1_REGNUM; regnum <= SPARC_O5_REGNUM; regnum++)
 138     saved_regs[regnum].realreg = regnum + delta;
 139   saved_regs[SPARC_O7_REGNUM].realreg = SPARC_I7_REGNUM;
 140
 141   /* The `local' and `in' registers have been saved in the register
 142      save area.  */
 143   addr = saved_regs[SPARC_SP_REGNUM].addr;
 144   addr = get_frame_memory_unsigned (this_frame, addr, 4);
 145   for (regnum = SPARC_L0_REGNUM;
 146        regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)
 147     saved_regs[regnum].addr = addr;
 148
 149   /* Handle StackGhost.  */
 150   {
 151     ULONGEST wcookie = sparc_fetch_wcookie (gdbarch);
 152
 153     if (wcookie != 0)
 154       {
 155         ULONGEST i7;
 156
 157         addr = saved_regs[SPARC_I7_REGNUM].addr;
 158         i7 = get_frame_memory_unsigned (this_frame, addr, 4);
 159         trad_frame_set_value (saved_regs, SPARC_I7_REGNUM, i7 ^ wcookie);
 160       }
 161   }
 162
 163   /* The floating-point registers are only saved if the EF bit in %prs
 164      has been set.  */
 165
 166 #define PSR_EF  0x00001000
 167
 168   addr = saved_regs[SPARC32_PSR_REGNUM].addr;
 169   psr = get_frame_memory_unsigned (this_frame, addr, 4);
 170   if (psr & PSR_EF)
 171     {
 172       CORE_ADDR sp;
 173
 174       sp = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
 175       saved_regs[SPARC32_FSR_REGNUM].addr = sp + 96;
 176       for (regnum = SPARC_F0_REGNUM, addr = sp + 96 + 8;
 177            regnum <= SPARC_F31_REGNUM; regnum++, addr += 4)
 178         saved_regs[regnum].addr = addr;
 179     }
 180
 181   return saved_regs;
 182 }
 183
 184 static struct sparc_frame_cache *
 185 sparc32nbsd_sigcontext_frame_cache (struct frame_info *this_frame,
 186                                     void **this_cache)
 187 {
 188   struct sparc_frame_cache *cache;
 189   CORE_ADDR addr;
 190
 191   if (*this_cache)
 192     return *this_cache;
 193
 194   cache = sparc_frame_cache (this_frame, this_cache);
 195   gdb_assert (cache == *this_cache);
 196
 197   /* If we couldn't find the frame's function, we're probably dealing
 198      with an on-stack signal trampoline.  */
 199   if (cache->pc == 0)
 200     {
 201       cache->pc = sparc32nbsd_sigtramp_start;
 202
 203       /* Since we couldn't find the frame's function, the cache was
 204          initialized under the assumption that we're frameless.  */
 205       cache->frameless_p = 0;
 206       addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);
 207       cache->base = addr;
 208     }
 209
 210   cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (this_frame);
 211
 212   return cache;
 213 }
 214
 215 static void
 216 sparc32nbsd_sigcontext_frame_this_id (struct frame_info *this_frame,
 217                                       void **this_cache,
 218                                       struct frame_id *this_id)
 219 {
 220   struct sparc_frame_cache *cache =
 221     sparc32nbsd_sigcontext_frame_cache (this_frame, this_cache);
 222
 223   (*this_id) = frame_id_build (cache->base, cache->pc);
 224 }
 225
 226 static struct value *
 227 sparc32nbsd_sigcontext_frame_prev_register (struct frame_info *this_frame,
 228                                             void **this_cache, int regnum)
 229 {
 230   struct sparc_frame_cache *cache =
 231     sparc32nbsd_sigcontext_frame_cache (this_frame, this_cache);
 232
 233   return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);
 234 }
 235
 236 static int
 237 sparc32nbsd_sigcontext_frame_sniffer (const struct frame_unwind *self,
 238                                       struct frame_info *this_frame,
 239                                       void **this_cache)
 240 {
 241   CORE_ADDR pc = get_frame_pc (this_frame);
 242   char *name;
 243
 244   find_pc_partial_function (pc, &name, NULL, NULL);
 245   if (sparc32nbsd_pc_in_sigtramp (pc, name))
 246     {
 247       if (name == NULL || strncmp (name, "__sigtramp_sigcontext", 21))
 248         return 1;
 249     }
 250
 251   return 0;
 252 }
 253
 254 static const struct frame_unwind sparc32nbsd_sigcontext_frame_unwind =
 255 {
 256   SIGTRAMP_FRAME,
 257   sparc32nbsd_sigcontext_frame_this_id,
 258   sparc32nbsd_sigcontext_frame_prev_register,
 259   NULL,
 260   sparc32nbsd_sigcontext_frame_sniffer
 261 };
 262 \f
 263 /* Return the address of a system call's alternative return
 264    address.  */
 265
 266 CORE_ADDR
 267 sparcnbsd_step_trap (struct frame_info *frame, unsigned long insn)
 268 {
 269   if ((X_I (insn) == 0 && X_RS1 (insn) == 0 && X_RS2 (insn) == 0)
 270       || (X_I (insn) == 1 && X_RS1 (insn) == 0 && (insn & 0x7f) == 0))
 271     {
 272       /* "New" system call.  */
 273       ULONGEST number = get_frame_register_unsigned (frame, SPARC_G1_REGNUM);
 274
 275       if (number & 0x400)
 276         return get_frame_register_unsigned (frame, SPARC_G2_REGNUM);
 277       if (number & 0x800)
 278         return get_frame_register_unsigned (frame, SPARC_G7_REGNUM);
 279     }
 280
 281   return 0;
 282 }
 283 \f
 284
 285 static void
 286 sparc32nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 287 {
 288   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 289
 290   /* NetBSD doesn't support the 128-bit `long double' from the psABI.  */
 291   set_gdbarch_long_double_bit (gdbarch, 64);
 292   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
 293
 294   tdep->gregset = regset_alloc (gdbarch, sparc32nbsd_supply_gregset, NULL);
 295   tdep->sizeof_gregset = 20 * 4;
 296
 297   tdep->fpregset = regset_alloc (gdbarch, sparc32nbsd_supply_fpregset, NULL);
 298   tdep->sizeof_fpregset = 33 * 4;
 299
 300   /* Make sure we can single-step "new" syscalls.  */
 301   tdep->step_trap = sparcnbsd_step_trap;
 302
 303   frame_unwind_append_unwinder (gdbarch, &sparc32nbsd_sigcontext_frame_unwind);
 304 }
 305
 306 static void
 307 sparc32nbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 308 {
 309   sparc32nbsd_init_abi (info, gdbarch);
 310 }
 311
 312 void
 313 sparc32nbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 314 {
 315   sparc32nbsd_init_abi (info, gdbarch);
 316
 317   set_solib_svr4_fetch_link_map_offsets
 318     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 319 }
 320
 321 static enum gdb_osabi
 322 sparcnbsd_aout_osabi_sniffer (bfd *abfd)
 323 {
 324   if (strcmp (bfd_get_target (abfd), "a.out-sparc-netbsd") == 0)
 325     return GDB_OSABI_NETBSD_AOUT;
 326
 327   return GDB_OSABI_UNKNOWN;
 328 }
 329
 330 /* OpenBSD uses the traditional NetBSD core file format, even for
 331    ports that use ELF.  Therefore, if the default OS ABI is OpenBSD
 332    ELF, we return that instead of NetBSD a.out.  This is mainly for
 333    the benfit of OpenBSD/sparc64, which inherits the sniffer below
 334    since we include this file for an OpenBSD/sparc64 target.  For
 335    OpenBSD/sparc, the NetBSD a.out OS ABI is probably similar enough
 336    to both the OpenBSD a.out and the OpenBSD ELF OS ABI.  */
 337 #if defined (GDB_OSABI_DEFAULT) && (GDB_OSABI_DEFAULT == GDB_OSABI_OPENBSD_ELF)
 338 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF
 339 #else
 340 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_NETBSD_AOUT
 341 #endif
 342
 343 static enum gdb_osabi
 344 sparcnbsd_core_osabi_sniffer (bfd *abfd)
 345 {
 346   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
 347     return GDB_OSABI_NETBSD_CORE;
 348
 349   return GDB_OSABI_UNKNOWN;
 350 }
 351
 352 \f
 353 /* Provide a prototype to silence -Wmissing-prototypes.  */
 354 void _initialize_sparcnbsd_tdep (void);
 355
 356 void
 357 _initialize_sparcnbsd_tdep (void)
 358 {
 359   gdbarch_register_osabi_sniffer (bfd_arch_sparc, bfd_target_aout_flavour,
 360                                   sparcnbsd_aout_osabi_sniffer);
 361
 362   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
 363   gdbarch_register_osabi_sniffer (bfd_arch_sparc, bfd_target_unknown_flavour,
 364                                   sparcnbsd_core_osabi_sniffer);
 365
 366   gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_NETBSD_AOUT,
 367                           sparc32nbsd_aout_init_abi);
 368   gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_NETBSD_ELF,
 369                           sparc32nbsd_elf_init_abi);
 370 }