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/* Target-dependent code for Motorola 68000 BSD's.

   Copyright (C) 2004, 2005, 2007, 2008, 2009, 2010

   Free Software Foundation, 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 "arch-utils.h"

#include "frame.h"

#include "osabi.h"

#include "regcache.h"

#include "regset.h"

#include "trad-frame.h"

#include "tramp-frame.h"

#include "gdbtypes.h"

#include "gdb_assert.h"

#include "gdb_string.h"

#include "m68k-tdep.h"

#include "solib-svr4.h"

/* Core file support.  */

/* Sizeof `struct reg' in <machine/reg.h>.  */

#define M68KBSD_SIZEOF_GREGS    (18 * 4)

/* Sizeof `struct fpreg' in <machine/reg.h.  */

#define M68KBSD_SIZEOF_FPREGS   (((8 * 3) + 3) * 4)

int

m68kbsd_fpreg_offset (struct gdbarch *gdbarch, int regnum)

{

  int fp_len = TYPE_LENGTH (gdbarch_register_type (gdbarch, regnum));

  if (regnum >= M68K_FPC_REGNUM)

    return 8 * fp_len + (regnum - M68K_FPC_REGNUM) * 4;

  return (regnum - M68K_FP0_REGNUM) * fp_len;

}

/* Supply register REGNUM from the buffer specified by FPREGS and LEN

   in the floating-point register set REGSET to register cache

   REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */

static void

m68kbsd_supply_fpregset (const struct regset *regset,

                         struct regcache *regcache,

                         int regnum, const void *fpregs, size_t len)

{

  struct gdbarch *gdbarch = get_regcache_arch (regcache);

  const gdb_byte *regs = fpregs;

  int i;

  gdb_assert (len >= M68KBSD_SIZEOF_FPREGS);

  for (i = M68K_FP0_REGNUM; i <= M68K_PC_REGNUM; i++)

    {

      if (regnum == i || regnum == -1)

        regcache_raw_supply (regcache, i,

                             regs + m68kbsd_fpreg_offset (gdbarch, i));

    }

}

/* Supply register REGNUM from the buffer specified by GREGS and LEN

   in the general-purpose register set REGSET to register cache

   REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */

static void

m68kbsd_supply_gregset (const struct regset *regset,

                        struct regcache *regcache,

                        int regnum, const void *gregs, size_t len)

{

  const gdb_byte *regs = gregs;

  int i;

  gdb_assert (len >= M68KBSD_SIZEOF_GREGS);

  for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++)

    {

      if (regnum == i || regnum == -1)

        regcache_raw_supply (regcache, i, regs + i * 4);

    }

  if (len >= M68KBSD_SIZEOF_GREGS + M68KBSD_SIZEOF_FPREGS)

    {

      regs += M68KBSD_SIZEOF_GREGS;

      len -= M68KBSD_SIZEOF_GREGS;

      m68kbsd_supply_fpregset (regset, regcache, regnum, regs, len);

    }

}

/* Motorola 68000 register sets.  */

static struct regset m68kbsd_gregset =

{

  NULL,

  m68kbsd_supply_gregset

};

static struct regset m68kbsd_fpregset =

{

  NULL,

  m68kbsd_supply_fpregset

};

/* Return the appropriate register set for the core section identified

   by SECT_NAME and SECT_SIZE.  */

static const struct regset *

m68kbsd_regset_from_core_section (struct gdbarch *gdbarch,

                                  const char *sect_name, size_t sect_size)

{

  if (strcmp (sect_name, ".reg") == 0 && sect_size >= M68KBSD_SIZEOF_GREGS)

    return &m68kbsd_gregset;

  if (strcmp (sect_name, ".reg2") == 0 && sect_size >= M68KBSD_SIZEOF_FPREGS)

    return &m68kbsd_fpregset;

  return NULL;

}

/* Signal trampolines.  */

static void

m68kobsd_sigtramp_cache_init (const struct tramp_frame *self,

                              struct frame_info *this_frame,

                              struct trad_frame_cache *this_cache,

                              CORE_ADDR func)

{

  CORE_ADDR addr, base, pc;

  int regnum;

  base = get_frame_register_unsigned (this_frame, M68K_SP_REGNUM);

  /* The 'addql #4,%sp' instruction at offset 8 adjusts the stack

     pointer.  Adjust the frame base accordingly.  */

  pc = get_frame_register_unsigned (this_frame, M68K_PC_REGNUM);

  if ((pc - func) > 8)

    base -= 4;

  /* Get frame pointer, stack pointer, program counter and processor

     state from `struct sigcontext'.  */

  addr = get_frame_memory_unsigned (this_frame, base + 8, 4);

  trad_frame_set_reg_addr (this_cache, M68K_FP_REGNUM, addr + 8);

  trad_frame_set_reg_addr (this_cache, M68K_SP_REGNUM, addr + 12);

  trad_frame_set_reg_addr (this_cache, M68K_PC_REGNUM, addr + 20);

  trad_frame_set_reg_addr (this_cache, M68K_PS_REGNUM, addr + 24);

  /* The sc_ap member of `struct sigcontext' points to additional

     hardware state.  Here we find the missing registers.  */

  addr = get_frame_memory_unsigned (this_frame, addr + 16, 4) + 4;

  for (regnum = M68K_D0_REGNUM; regnum < M68K_FP_REGNUM; regnum++, addr += 4)

    trad_frame_set_reg_addr (this_cache, regnum, addr);

  /* Construct the frame ID using the function start.  */

  trad_frame_set_id (this_cache, frame_id_build (base, func));

}

static const struct tramp_frame m68kobsd_sigtramp = {

  SIGTRAMP_FRAME,

  2,

  {

    { 0x206f, -1 }, { 0x000c, -1},      /* moveal %sp@(12),%a0 */

    { 0x4e90, -1 },                     /* jsr %a0@ */

    { 0x588f, -1 },                     /* addql #4,%sp */

    { 0x4e41, -1 },                     /* trap #1 */

    { 0x2f40, -1 }, { 0x0004, -1 },     /* moveal %d0,%sp@(4) */

    { 0x7001, -1 },                     /* moveq #SYS_exit,%d0 */

    { 0x4e40, -1 },                     /* trap #0 */

    { TRAMP_SENTINEL_INSN, -1 }

  },

  m68kobsd_sigtramp_cache_init

};

static void

m68kbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)

{

  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  tdep->jb_pc = 5;

  tdep->jb_elt_size = 4;

  set_gdbarch_decr_pc_after_break (gdbarch, 2);

  set_gdbarch_regset_from_core_section

    (gdbarch, m68kbsd_regset_from_core_section);

}

/* OpenBSD and NetBSD a.out.  */

static void

m68kbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)

{

  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  m68kbsd_init_abi (info, gdbarch);

  tdep->struct_return = reg_struct_return;

  tramp_frame_prepend_unwinder (gdbarch, &m68kobsd_sigtramp);

}

/* NetBSD ELF.  */

static void

m68kbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)

{

  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  m68kbsd_init_abi (info, gdbarch);

  /* NetBSD ELF uses the SVR4 ABI.  */

  m68k_svr4_init_abi (info, gdbarch);

  tdep->struct_return = pcc_struct_return;

  /* NetBSD ELF uses SVR4-style shared libraries.  */

  set_solib_svr4_fetch_link_map_offsets

    (gdbarch, svr4_ilp32_fetch_link_map_offsets);

}

static enum gdb_osabi

m68kbsd_aout_osabi_sniffer (bfd *abfd)

{

  if (strcmp (bfd_get_target (abfd), "a.out-m68k-netbsd") == 0

      || strcmp (bfd_get_target (abfd), "a.out-m68k4k-netbsd") == 0)

    return GDB_OSABI_NETBSD_AOUT;

  return GDB_OSABI_UNKNOWN;

}

static enum gdb_osabi

m68kbsd_core_osabi_sniffer (bfd *abfd)

{

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

    return GDB_OSABI_NETBSD_AOUT;

  return GDB_OSABI_UNKNOWN;

}

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

void _initialize_m68kbsd_tdep (void);

void

_initialize_m68kbsd_tdep (void)

{

  gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_aout_flavour,

                                  m68kbsd_aout_osabi_sniffer);

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

  gdbarch_register_osabi_sniffer (bfd_arch_m68k, bfd_target_unknown_flavour,

                                  m68kbsd_core_osabi_sniffer);

  gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_AOUT,

                          m68kbsd_aout_init_abi);

  gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_NETBSD_ELF,

                          m68kbsd_elf_init_abi);

}