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/* Target-dependent code for NetBSD/sparc.

   Copyright (C) 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010

   Free Software Foundation, Inc.

   Contributed by Wasabi Systems, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"

#include "frame.h"

#include "frame-unwind.h"

#include "gdbcore.h"

#include "gdbtypes.h"

#include "osabi.h"

#include "regcache.h"

#include "regset.h"

#include "solib-svr4.h"

#include "symtab.h"

#include "trad-frame.h"

#include "gdb_assert.h"

#include "gdb_string.h"

#include "sparc-tdep.h"

#include "nbsd-tdep.h"

/* Macros to extract fields from SPARC instructions.  */

#define X_RS1(i) (((i) >> 14) & 0x1f)

#define X_RS2(i) ((i) & 0x1f)

#define X_I(i) (((i) >> 13) & 1)

const struct sparc_gregset sparc32nbsd_gregset =

{

  1 * 4,                        /* %pc */

  2 * 4,                        /* %npc */

  3 * 4,                        /* %y */

  -1,                           /* %wim */

  -1,                           /* %tbr */

  5 * 4,                        /* %g1 */

  -1                            /* %l0 */

};

static void

sparc32nbsd_supply_gregset (const struct regset *regset,

                            struct regcache *regcache,

                            int regnum, const void *gregs, size_t len)

{

  sparc32_supply_gregset (&sparc32nbsd_gregset, regcache, regnum, gregs);

  /* Traditional NetBSD core files don't use multiple register sets.

     Instead, the general-purpose and floating-point registers are

     lumped together in a single section.  */

  if (len >= 212)

    sparc32_supply_fpregset (regcache, regnum, (const char *) gregs + 80);

}

static void

sparc32nbsd_supply_fpregset (const struct regset *regset,

                             struct regcache *regcache,

                             int regnum, const void *fpregs, size_t len)

{

  sparc32_supply_fpregset (regcache, regnum, fpregs);

}

/* Signal trampolines.  */

/* The following variables describe the location of an on-stack signal

   trampoline.  The current values correspond to the memory layout for

   NetBSD 1.3 and up.  These shouldn't be necessary for NetBSD 2.0 and

   up, since NetBSD uses signal trampolines provided by libc now.  */

static const CORE_ADDR sparc32nbsd_sigtramp_start = 0xeffffef0;

static const CORE_ADDR sparc32nbsd_sigtramp_end = 0xeffffff0;

static int

sparc32nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name)

{

  if (pc >= sparc32nbsd_sigtramp_start && pc < sparc32nbsd_sigtramp_end)

    return 1;

  return nbsd_pc_in_sigtramp (pc, name);

}

struct trad_frame_saved_reg *

sparc32nbsd_sigcontext_saved_regs (struct frame_info *this_frame)

{

  struct gdbarch *gdbarch = get_frame_arch (this_frame);

  struct trad_frame_saved_reg *saved_regs;

  CORE_ADDR addr, sigcontext_addr;

  int regnum, delta;

  ULONGEST psr;

  saved_regs = trad_frame_alloc_saved_regs (this_frame);

  /* We find the appropriate instance of `struct sigcontext' at a

     fixed offset in the signal frame.  */

  addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);

  sigcontext_addr = addr + 64 + 16;

  /* The registers are saved in bits and pieces scattered all over the

     place.  The code below records their location on the assumption

     that the part of the signal trampoline that saves the state has

     been executed.  */

  saved_regs[SPARC_SP_REGNUM].addr = sigcontext_addr + 8;

  saved_regs[SPARC32_PC_REGNUM].addr = sigcontext_addr + 12;

  saved_regs[SPARC32_NPC_REGNUM].addr = sigcontext_addr + 16;

  saved_regs[SPARC32_PSR_REGNUM].addr = sigcontext_addr + 20;

  saved_regs[SPARC_G1_REGNUM].addr = sigcontext_addr + 24;

  saved_regs[SPARC_O0_REGNUM].addr = sigcontext_addr + 28;

  /* The remaining `global' registers and %y are saved in the `local'

     registers.  */

  delta = SPARC_L0_REGNUM - SPARC_G0_REGNUM;

  for (regnum = SPARC_G2_REGNUM; regnum <= SPARC_G7_REGNUM; regnum++)

    saved_regs[regnum].realreg = regnum + delta;

  saved_regs[SPARC32_Y_REGNUM].realreg = SPARC_L1_REGNUM;

  /* The remaining `out' registers can be found in the current frame's

     `in' registers.  */

  delta = SPARC_I0_REGNUM - SPARC_O0_REGNUM;

  for (regnum = SPARC_O1_REGNUM; regnum <= SPARC_O5_REGNUM; regnum++)

    saved_regs[regnum].realreg = regnum + delta;

  saved_regs[SPARC_O7_REGNUM].realreg = SPARC_I7_REGNUM;

  /* The `local' and `in' registers have been saved in the register

     save area.  */

  addr = saved_regs[SPARC_SP_REGNUM].addr;

  addr = get_frame_memory_unsigned (this_frame, addr, 4);

  for (regnum = SPARC_L0_REGNUM;

       regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)

    saved_regs[regnum].addr = addr;

  /* Handle StackGhost.  */

  {

    ULONGEST wcookie = sparc_fetch_wcookie (gdbarch);

    if (wcookie != 0)

      {

        ULONGEST i7;

        addr = saved_regs[SPARC_I7_REGNUM].addr;

        i7 = get_frame_memory_unsigned (this_frame, addr, 4);

        trad_frame_set_value (saved_regs, SPARC_I7_REGNUM, i7 ^ wcookie);

      }

  }

  /* The floating-point registers are only saved if the EF bit in %prs

     has been set.  */

#define PSR_EF  0x00001000

  addr = saved_regs[SPARC32_PSR_REGNUM].addr;

  psr = get_frame_memory_unsigned (this_frame, addr, 4);

  if (psr & PSR_EF)

    {

      CORE_ADDR sp;

      sp = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);

      saved_regs[SPARC32_FSR_REGNUM].addr = sp + 96;

      for (regnum = SPARC_F0_REGNUM, addr = sp + 96 + 8;

           regnum <= SPARC_F31_REGNUM; regnum++, addr += 4)

        saved_regs[regnum].addr = addr;

    }

  return saved_regs;

}

static struct sparc_frame_cache *

sparc32nbsd_sigcontext_frame_cache (struct frame_info *this_frame,

                                    void **this_cache)

{

  struct sparc_frame_cache *cache;

  CORE_ADDR addr;

  if (*this_cache)

    return *this_cache;

  cache = sparc_frame_cache (this_frame, this_cache);

  gdb_assert (cache == *this_cache);

  /* If we couldn't find the frame's function, we're probably dealing

     with an on-stack signal trampoline.  */

  if (cache->pc == 0)

    {

      cache->pc = sparc32nbsd_sigtramp_start;

      /* Since we couldn't find the frame's function, the cache was

         initialized under the assumption that we're frameless.  */

      cache->frameless_p = 0;

      addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);

      cache->base = addr;

    }

  cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (this_frame);

  return cache;

}

static void

sparc32nbsd_sigcontext_frame_this_id (struct frame_info *this_frame,

                                      void **this_cache,

                                      struct frame_id *this_id)

{

  struct sparc_frame_cache *cache =

    sparc32nbsd_sigcontext_frame_cache (this_frame, this_cache);

  (*this_id) = frame_id_build (cache->base, cache->pc);

}

static struct value *

sparc32nbsd_sigcontext_frame_prev_register (struct frame_info *this_frame,

                                            void **this_cache, int regnum)

{

  struct sparc_frame_cache *cache =

    sparc32nbsd_sigcontext_frame_cache (this_frame, this_cache);

  return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);

}

static int

sparc32nbsd_sigcontext_frame_sniffer (const struct frame_unwind *self,

                                      struct frame_info *this_frame,

                                      void **this_cache)

{

  CORE_ADDR pc = get_frame_pc (this_frame);

  char *name;

  find_pc_partial_function (pc, &name, NULL, NULL);

  if (sparc32nbsd_pc_in_sigtramp (pc, name))

    {

      if (name == NULL || strncmp (name, "__sigtramp_sigcontext", 21))

        return 1;

    }

  return 0;

}

static const struct frame_unwind sparc32nbsd_sigcontext_frame_unwind =

{

  SIGTRAMP_FRAME,

  sparc32nbsd_sigcontext_frame_this_id,

  sparc32nbsd_sigcontext_frame_prev_register,

  NULL,

  sparc32nbsd_sigcontext_frame_sniffer

};

/* Return the address of a system call's alternative return

   address.  */

CORE_ADDR

sparcnbsd_step_trap (struct frame_info *frame, unsigned long insn)

{

  if ((X_I (insn) == 0 && X_RS1 (insn) == 0 && X_RS2 (insn) == 0)

      || (X_I (insn) == 1 && X_RS1 (insn) == 0 && (insn & 0x7f) == 0))

    {

      /* "New" system call.  */

      ULONGEST number = get_frame_register_unsigned (frame, SPARC_G1_REGNUM);

      if (number & 0x400)

        return get_frame_register_unsigned (frame, SPARC_G2_REGNUM);

      if (number & 0x800)

        return get_frame_register_unsigned (frame, SPARC_G7_REGNUM);

    }

  return 0;

}

static void

sparc32nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)

{

  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  /* NetBSD doesn't support the 128-bit `long double' from the psABI.  */

  set_gdbarch_long_double_bit (gdbarch, 64);

  set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);

  tdep->gregset = regset_alloc (gdbarch, sparc32nbsd_supply_gregset, NULL);

  tdep->sizeof_gregset = 20 * 4;

  tdep->fpregset = regset_alloc (gdbarch, sparc32nbsd_supply_fpregset, NULL);

  tdep->sizeof_fpregset = 33 * 4;

  /* Make sure we can single-step "new" syscalls.  */

  tdep->step_trap = sparcnbsd_step_trap;

  frame_unwind_append_unwinder (gdbarch, &sparc32nbsd_sigcontext_frame_unwind);

}

static void

sparc32nbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)

{

  sparc32nbsd_init_abi (info, gdbarch);

}

void

sparc32nbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)

{

  sparc32nbsd_init_abi (info, gdbarch);

  set_solib_svr4_fetch_link_map_offsets

    (gdbarch, svr4_ilp32_fetch_link_map_offsets);

}

static enum gdb_osabi

sparcnbsd_aout_osabi_sniffer (bfd *abfd)

{

  if (strcmp (bfd_get_target (abfd), "a.out-sparc-netbsd") == 0)

    return GDB_OSABI_NETBSD_AOUT;

  return GDB_OSABI_UNKNOWN;

}

/* OpenBSD uses the traditional NetBSD core file format, even for

   ports that use ELF.  Therefore, if the default OS ABI is OpenBSD

   ELF, we return that instead of NetBSD a.out.  This is mainly for

   the benfit of OpenBSD/sparc64, which inherits the sniffer below

   since we include this file for an OpenBSD/sparc64 target.  For

   OpenBSD/sparc, the NetBSD a.out OS ABI is probably similar enough

   to both the OpenBSD a.out and the OpenBSD ELF OS ABI.  */

#if defined (GDB_OSABI_DEFAULT) && (GDB_OSABI_DEFAULT == GDB_OSABI_OPENBSD_ELF)

#define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF

#else

#define GDB_OSABI_NETBSD_CORE GDB_OSABI_NETBSD_AOUT

#endif

static enum gdb_osabi

sparcnbsd_core_osabi_sniffer (bfd *abfd)

{

  if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)

    return GDB_OSABI_NETBSD_CORE;

  return GDB_OSABI_UNKNOWN;

}

/* Provide a prototype to silence -Wmissing-prototypes.  */

void _initialize_sparcnbsd_tdep (void);

void

_initialize_sparcnbsd_tdep (void)

{

  gdbarch_register_osabi_sniffer (bfd_arch_sparc, bfd_target_aout_flavour,

                                  sparcnbsd_aout_osabi_sniffer);

  /* BFD doesn't set a flavour for NetBSD style a.out core files.  */

  gdbarch_register_osabi_sniffer (bfd_arch_sparc, bfd_target_unknown_flavour,

                                  sparcnbsd_core_osabi_sniffer);

  gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_NETBSD_AOUT,

                          sparc32nbsd_aout_init_abi);

  gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_NETBSD_ELF,

                          sparc32nbsd_elf_init_abi);

}