gdb/sparcnbsd-tdep.c

   1 /* Target-dependent code for NetBSD/sparc.
   2
   3    Copyright (C) 2002, 2003, 2004, 2006, 2007, 2008
   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 trad_frame_saved_reg *saved_regs;
 103   CORE_ADDR addr, sigcontext_addr;
 104   int regnum, delta;
 105   ULONGEST psr;
 106
 107   saved_regs = trad_frame_alloc_saved_regs (this_frame);
 108
 109   /* We find the appropriate instance of `struct sigcontext' at a
 110      fixed offset in the signal frame.  */
 111   addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);
 112   sigcontext_addr = addr + 64 + 16;
 113
 114   /* The registers are saved in bits and pieces scattered all over the
 115      place.  The code below records their location on the assumption
 116      that the part of the signal trampoline that saves the state has
 117      been executed.  */
 118
 119   saved_regs[SPARC_SP_REGNUM].addr = sigcontext_addr + 8;
 120   saved_regs[SPARC32_PC_REGNUM].addr = sigcontext_addr + 12;
 121   saved_regs[SPARC32_NPC_REGNUM].addr = sigcontext_addr + 16;
 122   saved_regs[SPARC32_PSR_REGNUM].addr = sigcontext_addr + 20;
 123   saved_regs[SPARC_G1_REGNUM].addr = sigcontext_addr + 24;
 124   saved_regs[SPARC_O0_REGNUM].addr = sigcontext_addr + 28;
 125
 126   /* The remaining `global' registers and %y are saved in the `local'
 127      registers.  */
 128   delta = SPARC_L0_REGNUM - SPARC_G0_REGNUM;
 129   for (regnum = SPARC_G2_REGNUM; regnum <= SPARC_G7_REGNUM; regnum++)
 130     saved_regs[regnum].realreg = regnum + delta;
 131   saved_regs[SPARC32_Y_REGNUM].realreg = SPARC_L1_REGNUM;
 132
 133   /* The remaining `out' registers can be found in the current frame's
 134      `in' registers.  */
 135   delta = SPARC_I0_REGNUM - SPARC_O0_REGNUM;
 136   for (regnum = SPARC_O1_REGNUM; regnum <= SPARC_O5_REGNUM; regnum++)
 137     saved_regs[regnum].realreg = regnum + delta;
 138   saved_regs[SPARC_O7_REGNUM].realreg = SPARC_I7_REGNUM;
 139
 140   /* The `local' and `in' registers have been saved in the register
 141      save area.  */
 142   addr = saved_regs[SPARC_SP_REGNUM].addr;
 143   addr = get_frame_memory_unsigned (this_frame, addr, 4);
 144   for (regnum = SPARC_L0_REGNUM;
 145        regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)
 146     saved_regs[regnum].addr = addr;
 147
 148   /* Handle StackGhost.  */
 149   {
 150     ULONGEST wcookie = sparc_fetch_wcookie ();
 151
 152     if (wcookie != 0)
 153       {
 154         ULONGEST i7;
 155
 156         addr = saved_regs[SPARC_I7_REGNUM].addr;
 157         i7 = get_frame_memory_unsigned (this_frame, addr, 4);
 158         trad_frame_set_value (saved_regs, SPARC_I7_REGNUM, i7 ^ wcookie);
 159       }
 160   }
 161
 162   /* The floating-point registers are only saved if the EF bit in %prs
 163      has been set.  */
 164
 165 #define PSR_EF  0x00001000
 166
 167   addr = saved_regs[SPARC32_PSR_REGNUM].addr;
 168   psr = get_frame_memory_unsigned (this_frame, addr, 4);
 169   if (psr & PSR_EF)
 170     {
 171       CORE_ADDR sp;
 172
 173       sp = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
 174       saved_regs[SPARC32_FSR_REGNUM].addr = sp + 96;
 175       for (regnum = SPARC_F0_REGNUM, addr = sp + 96 + 8;
 176            regnum <= SPARC_F31_REGNUM; regnum++, addr += 4)
 177         saved_regs[regnum].addr = addr;
 178     }
 179
 180   return saved_regs;
 181 }
 182
 183 static struct sparc_frame_cache *
 184 sparc32nbsd_sigcontext_frame_cache (struct frame_info *this_frame,
 185                                     void **this_cache)
 186 {
 187   struct sparc_frame_cache *cache;
 188   CORE_ADDR addr;
 189
 190   if (*this_cache)
 191     return *this_cache;
 192
 193   cache = sparc_frame_cache (this_frame, this_cache);
 194   gdb_assert (cache == *this_cache);
 195
 196   /* If we couldn't find the frame's function, we're probably dealing
 197      with an on-stack signal trampoline.  */
 198   if (cache->pc == 0)
 199     {
 200       cache->pc = sparc32nbsd_sigtramp_start;
 201
 202       /* Since we couldn't find the frame's function, the cache was
 203          initialized under the assumption that we're frameless.  */
 204       cache->frameless_p = 0;
 205       addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);
 206       cache->base = addr;
 207     }
 208
 209   cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (this_frame);
 210
 211   return cache;
 212 }
 213
 214 static void
 215 sparc32nbsd_sigcontext_frame_this_id (struct frame_info *this_frame,
 216                                       void **this_cache,
 217                                       struct frame_id *this_id)
 218 {
 219   struct sparc_frame_cache *cache =
 220     sparc32nbsd_sigcontext_frame_cache (this_frame, this_cache);
 221
 222   (*this_id) = frame_id_build (cache->base, cache->pc);
 223 }
 224
 225 static struct value *
 226 sparc32nbsd_sigcontext_frame_prev_register (struct frame_info *this_frame,
 227                                             void **this_cache, int regnum)
 228 {
 229   struct sparc_frame_cache *cache =
 230     sparc32nbsd_sigcontext_frame_cache (this_frame, this_cache);
 231
 232   return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);
 233 }
 234
 235 static int
 236 sparc32nbsd_sigcontext_frame_sniffer (const struct frame_unwind *self,
 237                                       struct frame_info *this_frame,
 238                                       void **this_cache)
 239 {
 240   CORE_ADDR pc = get_frame_pc (this_frame);
 241   char *name;
 242
 243   find_pc_partial_function (pc, &name, NULL, NULL);
 244   if (sparc32nbsd_pc_in_sigtramp (pc, name))
 245     {
 246       if (name == NULL || strncmp (name, "__sigtramp_sigcontext", 21))
 247         return 1;
 248     }
 249
 250   return 0;
 251 }
 252
 253 static const struct frame_unwind sparc32nbsd_sigcontext_frame_unwind =
 254 {
 255   SIGTRAMP_FRAME,
 256   sparc32nbsd_sigcontext_frame_this_id,
 257   sparc32nbsd_sigcontext_frame_prev_register,
 258   NULL,
 259   sparc32nbsd_sigcontext_frame_sniffer
 260 };
 261 \f
 262 /* Return the address of a system call's alternative return
 263    address.  */
 264
 265 CORE_ADDR
 266 sparcnbsd_step_trap (struct frame_info *frame, unsigned long insn)
 267 {
 268   if ((X_I (insn) == 0 && X_RS1 (insn) == 0 && X_RS2 (insn) == 0)
 269       || (X_I (insn) == 1 && X_RS1 (insn) == 0 && (insn & 0x7f) == 0))
 270     {
 271       /* "New" system call.  */
 272       ULONGEST number = get_frame_register_unsigned (frame, SPARC_G1_REGNUM);
 273
 274       if (number & 0x400)
 275         return get_frame_register_unsigned (frame, SPARC_G2_REGNUM);
 276       if (number & 0x800)
 277         return get_frame_register_unsigned (frame, SPARC_G7_REGNUM);
 278     }
 279
 280   return 0;
 281 }
 282 \f
 283
 284 static void
 285 sparc32nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 286 {
 287   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 288
 289   /* NetBSD doesn't support the 128-bit `long double' from the psABI.  */
 290   set_gdbarch_long_double_bit (gdbarch, 64);
 291   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
 292
 293   tdep->gregset = regset_alloc (gdbarch, sparc32nbsd_supply_gregset, NULL);
 294   tdep->sizeof_gregset = 20 * 4;
 295
 296   tdep->fpregset = regset_alloc (gdbarch, sparc32nbsd_supply_fpregset, NULL);
 297   tdep->sizeof_fpregset = 33 * 4;
 298
 299   /* Make sure we can single-step "new" syscalls.  */
 300   tdep->step_trap = sparcnbsd_step_trap;
 301
 302   frame_unwind_append_unwinder (gdbarch, &sparc32nbsd_sigcontext_frame_unwind);
 303 }
 304
 305 static void
 306 sparc32nbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 307 {
 308   sparc32nbsd_init_abi (info, gdbarch);
 309 }
 310
 311 void
 312 sparc32nbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 313 {
 314   sparc32nbsd_init_abi (info, gdbarch);
 315
 316   set_solib_svr4_fetch_link_map_offsets
 317     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 318 }
 319
 320 static enum gdb_osabi
 321 sparcnbsd_aout_osabi_sniffer (bfd *abfd)
 322 {
 323   if (strcmp (bfd_get_target (abfd), "a.out-sparc-netbsd") == 0)
 324     return GDB_OSABI_NETBSD_AOUT;
 325
 326   return GDB_OSABI_UNKNOWN;
 327 }
 328
 329 /* OpenBSD uses the traditional NetBSD core file format, even for
 330    ports that use ELF.  Therefore, if the default OS ABI is OpenBSD
 331    ELF, we return that instead of NetBSD a.out.  This is mainly for
 332    the benfit of OpenBSD/sparc64, which inherits the sniffer below
 333    since we include this file for an OpenBSD/sparc64 target.  For
 334    OpenBSD/sparc, the NetBSD a.out OS ABI is probably similar enough
 335    to both the OpenBSD a.out and the OpenBSD ELF OS ABI.  */
 336 #if defined (GDB_OSABI_DEFAULT) && (GDB_OSABI_DEFAULT == GDB_OSABI_OPENBSD_ELF)
 337 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF
 338 #else
 339 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_NETBSD_AOUT
 340 #endif
 341
 342 static enum gdb_osabi
 343 sparcnbsd_core_osabi_sniffer (bfd *abfd)
 344 {
 345   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
 346     return GDB_OSABI_NETBSD_CORE;
 347
 348   return GDB_OSABI_UNKNOWN;
 349 }
 350
 351 \f
 352 /* Provide a prototype to silence -Wmissing-prototypes.  */
 353 void _initialize_sparcnbsd_tdep (void);
 354
 355 void
 356 _initialize_sparnbsd_tdep (void)
 357 {
 358   gdbarch_register_osabi_sniffer (bfd_arch_sparc, bfd_target_aout_flavour,
 359                                   sparcnbsd_aout_osabi_sniffer);
 360
 361   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
 362   gdbarch_register_osabi_sniffer (bfd_arch_sparc, bfd_target_unknown_flavour,
 363                                   sparcnbsd_core_osabi_sniffer);
 364
 365   gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_NETBSD_AOUT,
 366                           sparc32nbsd_aout_init_abi);
 367   gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_NETBSD_ELF,
 368                           sparc32nbsd_elf_init_abi);
 369 }