gdb/sparcnbsd-tdep.c

   1 /* Target-dependent code for NetBSD/sparc.
   2
   3    Copyright (C) 2002, 2003, 2004, 2006, 2007 Free Software Foundation, Inc.
   4    Contributed by Wasabi Systems, 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 "defs.h"
  22 #include "frame.h"
  23 #include "frame-unwind.h"
  24 #include "gdbcore.h"
  25 #include "gdbtypes.h"
  26 #include "osabi.h"
  27 #include "regcache.h"
  28 #include "regset.h"
  29 #include "solib-svr4.h"
  30 #include "symtab.h"
  31 #include "trad-frame.h"
  32
  33 #include "gdb_assert.h"
  34 #include "gdb_string.h"
  35
  36 #include "sparc-tdep.h"
  37 #include "nbsd-tdep.h"
  38
  39 /* Macros to extract fields from SPARC instructions.  */
  40 #define X_RS1(i) (((i) >> 14) & 0x1f)
  41 #define X_RS2(i) ((i) & 0x1f)
  42 #define X_I(i) (((i) >> 13) & 1)
  43
  44 const struct sparc_gregset sparc32nbsd_gregset =
  45 {
  46   0 * 4,                        /* %psr */
  47   1 * 4,                        /* %pc */
  48   2 * 4,                        /* %npc */
  49   3 * 4,                        /* %y */
  50   -1,                           /* %wim */
  51   -1,                           /* %tbr */
  52   5 * 4,                        /* %g1 */
  53   -1                            /* %l0 */
  54 };
  55
  56 static void
  57 sparc32nbsd_supply_gregset (const struct regset *regset,
  58                             struct regcache *regcache,
  59                             int regnum, const void *gregs, size_t len)
  60 {
  61   sparc32_supply_gregset (&sparc32nbsd_gregset, regcache, regnum, gregs);
  62
  63   /* Traditional NetBSD core files don't use multiple register sets.
  64      Instead, the general-purpose and floating-point registers are
  65      lumped together in a single section.  */
  66   if (len >= 212)
  67     sparc32_supply_fpregset (regcache, regnum, (const char *) gregs + 80);
  68 }
  69
  70 static void
  71 sparc32nbsd_supply_fpregset (const struct regset *regset,
  72                              struct regcache *regcache,
  73                              int regnum, const void *fpregs, size_t len)
  74 {
  75   sparc32_supply_fpregset (regcache, regnum, fpregs);
  76 }
  77
  78 \f
  79 /* Signal trampolines.  */
  80
  81 /* The following variables describe the location of an on-stack signal
  82    trampoline.  The current values correspond to the memory layout for
  83    NetBSD 1.3 and up.  These shouldn't be necessary for NetBSD 2.0 and
  84    up, since NetBSD uses signal trampolines provided by libc now.  */
  85
  86 static const CORE_ADDR sparc32nbsd_sigtramp_start = 0xeffffef0;
  87 static const CORE_ADDR sparc32nbsd_sigtramp_end = 0xeffffff0;
  88
  89 static int
  90 sparc32nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
  91 {
  92   if (pc >= sparc32nbsd_sigtramp_start && pc < sparc32nbsd_sigtramp_end)
  93     return 1;
  94
  95   return nbsd_pc_in_sigtramp (pc, name);
  96 }
  97
  98 struct trad_frame_saved_reg *
  99 sparc32nbsd_sigcontext_saved_regs (struct frame_info *next_frame)
 100 {
 101   struct trad_frame_saved_reg *saved_regs;
 102   CORE_ADDR addr, sigcontext_addr;
 103   int regnum, delta;
 104   ULONGEST psr;
 105
 106   saved_regs = trad_frame_alloc_saved_regs (next_frame);
 107
 108   /* We find the appropriate instance of `struct sigcontext' at a
 109      fixed offset in the signal frame.  */
 110   addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM);
 111   sigcontext_addr = addr + 64 + 16;
 112
 113   /* The registers are saved in bits and pieces scattered all over the
 114      place.  The code below records their location on the assumption
 115      that the part of the signal trampoline that saves the state has
 116      been executed.  */
 117
 118   saved_regs[SPARC_SP_REGNUM].addr = sigcontext_addr + 8;
 119   saved_regs[SPARC32_PC_REGNUM].addr = sigcontext_addr + 12;
 120   saved_regs[SPARC32_NPC_REGNUM].addr = sigcontext_addr + 16;
 121   saved_regs[SPARC32_PSR_REGNUM].addr = sigcontext_addr + 20;
 122   saved_regs[SPARC_G1_REGNUM].addr = sigcontext_addr + 24;
 123   saved_regs[SPARC_O0_REGNUM].addr = sigcontext_addr + 28;
 124
 125   /* The remaining `global' registers and %y are saved in the `local'
 126      registers.  */
 127   delta = SPARC_L0_REGNUM - SPARC_G0_REGNUM;
 128   for (regnum = SPARC_G2_REGNUM; regnum <= SPARC_G7_REGNUM; regnum++)
 129     saved_regs[regnum].realreg = regnum + delta;
 130   saved_regs[SPARC32_Y_REGNUM].realreg = SPARC_L1_REGNUM;
 131
 132   /* The remaining `out' registers can be found in the current frame's
 133      `in' registers.  */
 134   delta = SPARC_I0_REGNUM - SPARC_O0_REGNUM;
 135   for (regnum = SPARC_O1_REGNUM; regnum <= SPARC_O5_REGNUM; regnum++)
 136     saved_regs[regnum].realreg = regnum + delta;
 137   saved_regs[SPARC_O7_REGNUM].realreg = SPARC_I7_REGNUM;
 138
 139   /* The `local' and `in' registers have been saved in the register
 140      save area.  */
 141   addr = saved_regs[SPARC_SP_REGNUM].addr;
 142   addr = get_frame_memory_unsigned (next_frame, addr, 4);
 143   for (regnum = SPARC_L0_REGNUM;
 144        regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)
 145     saved_regs[regnum].addr = addr;
 146
 147   /* Handle StackGhost.  */
 148   {
 149     ULONGEST wcookie = sparc_fetch_wcookie ();
 150
 151     if (wcookie != 0)
 152       {
 153         ULONGEST i7;
 154
 155         addr = saved_regs[SPARC_I7_REGNUM].addr;
 156         i7 = get_frame_memory_unsigned (next_frame, addr, 4);
 157         trad_frame_set_value (saved_regs, SPARC_I7_REGNUM, i7 ^ wcookie);
 158       }
 159   }
 160
 161   /* The floating-point registers are only saved if the EF bit in %prs
 162      has been set.  */
 163
 164 #define PSR_EF  0x00001000
 165
 166   addr = saved_regs[SPARC32_PSR_REGNUM].addr;
 167   psr = get_frame_memory_unsigned (next_frame, addr, 4);
 168   if (psr & PSR_EF)
 169     {
 170       CORE_ADDR sp;
 171
 172       sp = frame_unwind_register_unsigned (next_frame, SPARC_SP_REGNUM);
 173       saved_regs[SPARC32_FSR_REGNUM].addr = sp + 96;
 174       for (regnum = SPARC_F0_REGNUM, addr = sp + 96 + 8;
 175            regnum <= SPARC_F31_REGNUM; regnum++, addr += 4)
 176         saved_regs[regnum].addr = addr;
 177     }
 178
 179   return saved_regs;
 180 }
 181
 182 static struct sparc_frame_cache *
 183 sparc32nbsd_sigcontext_frame_cache (struct frame_info *next_frame,
 184                                     void **this_cache)
 185 {
 186   struct sparc_frame_cache *cache;
 187   CORE_ADDR addr;
 188
 189   if (*this_cache)
 190     return *this_cache;
 191
 192   cache = sparc_frame_cache (next_frame, this_cache);
 193   gdb_assert (cache == *this_cache);
 194
 195   /* If we couldn't find the frame's function, we're probably dealing
 196      with an on-stack signal trampoline.  */
 197   if (cache->pc == 0)
 198     {
 199       cache->pc = sparc32nbsd_sigtramp_start;
 200
 201       /* Since we couldn't find the frame's function, the cache was
 202          initialized under the assumption that we're frameless.  */
 203       cache->frameless_p = 0;
 204       addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM);
 205       cache->base = addr;
 206     }
 207
 208   cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (next_frame);
 209
 210   return cache;
 211 }
 212
 213 static void
 214 sparc32nbsd_sigcontext_frame_this_id (struct frame_info *next_frame,
 215                                       void **this_cache,
 216                                       struct frame_id *this_id)
 217 {
 218   struct sparc_frame_cache *cache =
 219     sparc32nbsd_sigcontext_frame_cache (next_frame, this_cache);
 220
 221   (*this_id) = frame_id_build (cache->base, cache->pc);
 222 }
 223
 224 static void
 225 sparc32nbsd_sigcontext_frame_prev_register (struct frame_info *next_frame,
 226                                             void **this_cache,
 227                                             int regnum, int *optimizedp,
 228                                             enum lval_type *lvalp,
 229                                             CORE_ADDR *addrp,
 230                                             int *realnump, gdb_byte *valuep)
 231 {
 232   struct sparc_frame_cache *cache =
 233     sparc32nbsd_sigcontext_frame_cache (next_frame, this_cache);
 234
 235   trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum,
 236                                 optimizedp, lvalp, addrp, realnump, valuep);
 237 }
 238
 239 static const struct frame_unwind sparc32nbsd_sigcontext_frame_unwind =
 240 {
 241   SIGTRAMP_FRAME,
 242   sparc32nbsd_sigcontext_frame_this_id,
 243   sparc32nbsd_sigcontext_frame_prev_register
 244 };
 245
 246 static const struct frame_unwind *
 247 sparc32nbsd_sigtramp_frame_sniffer (struct frame_info *next_frame)
 248 {
 249   CORE_ADDR pc = frame_pc_unwind (next_frame);
 250   char *name;
 251
 252   find_pc_partial_function (pc, &name, NULL, NULL);
 253   if (sparc32nbsd_pc_in_sigtramp (pc, name))
 254     {
 255       if (name == NULL || strncmp (name, "__sigtramp_sigcontext", 21))
 256         return &sparc32nbsd_sigcontext_frame_unwind;
 257     }
 258
 259   return NULL;
 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_sniffer (gdbarch, sparc32nbsd_sigtramp_frame_sniffer);
 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 }