/* GNU/Linux/m68k specific low level interface, for the remote server for GDB.
   Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 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 "server.h"
#include "linux-low.h"

/* Defined in auto-generated file reg-m68k.c.  */
void init_registers_m68k (void);

#ifdef HAVE_SYS_REG_H
#include <sys/reg.h>
#endif

#define m68k_num_regs 29
#define m68k_num_gregs 18

/* This table must line up with REGISTER_NAMES in tm-m68k.h */
static int m68k_regmap[] =
{
#ifdef PT_D0
  PT_D0 * 4, PT_D1 * 4, PT_D2 * 4, PT_D3 * 4,
  PT_D4 * 4, PT_D5 * 4, PT_D6 * 4, PT_D7 * 4,
  PT_A0 * 4, PT_A1 * 4, PT_A2 * 4, PT_A3 * 4,
  PT_A4 * 4, PT_A5 * 4, PT_A6 * 4, PT_USP * 4,
  PT_SR * 4, PT_PC * 4,
#else
  14 * 4, 0 * 4, 1 * 4, 2 * 4, 3 * 4, 4 * 4, 5 * 4, 6 * 4,
  7 * 4, 8 * 4, 9 * 4, 10 * 4, 11 * 4, 12 * 4, 13 * 4, 15 * 4,
  17 * 4, 18 * 4,
#endif
#ifdef PT_FP0
  PT_FP0 * 4, PT_FP1 * 4, PT_FP2 * 4, PT_FP3 * 4,
  PT_FP4 * 4, PT_FP5 * 4, PT_FP6 * 4, PT_FP7 * 4,
  PT_FPCR * 4, PT_FPSR * 4, PT_FPIAR * 4
#else
  21 * 4, 24 * 4, 27 * 4, 30 * 4, 33 * 4, 36 * 4,
  39 * 4, 42 * 4, 45 * 4, 46 * 4, 47 * 4
#endif
};

static int
m68k_cannot_store_register (int regno)
{
  return (regno >= m68k_num_regs);
}

static int
m68k_cannot_fetch_register (int regno)
{
  return (regno >= m68k_num_regs);
}

#ifdef HAVE_PTRACE_GETREGS
#include <sys/procfs.h>
#include <sys/ptrace.h>

static void
m68k_fill_gregset (struct regcache *regcache, void *buf)
{
  int i;

  for (i = 0; i < m68k_num_gregs; i++)
    collect_register (regcache, i, (char *) buf + m68k_regmap[i]);
}

static void
m68k_store_gregset (struct regcache *regcache, const void *buf)
{
  int i;

  for (i = 0; i < m68k_num_gregs; i++)
    supply_register (regcache, i, (const char *) buf + m68k_regmap[i]);
}

static void
m68k_fill_fpregset (struct regcache *regcache, void *buf)
{
  int i;

  for (i = m68k_num_gregs; i < m68k_num_regs; i++)
    collect_register (regcache, i, ((char *) buf
			 + (m68k_regmap[i] - m68k_regmap[m68k_num_gregs])));
}

static void
m68k_store_fpregset (struct regcache *regcache, const void *buf)
{
  int i;

  for (i = m68k_num_gregs; i < m68k_num_regs; i++)
    supply_register (regcache, i, ((const char *) buf
			 + (m68k_regmap[i] - m68k_regmap[m68k_num_gregs])));
}

#endif /* HAVE_PTRACE_GETREGS */

struct regset_info target_regsets[] = {
#ifdef HAVE_PTRACE_GETREGS
  { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
    GENERAL_REGS,
    m68k_fill_gregset, m68k_store_gregset },
  { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, sizeof (elf_fpregset_t),
    FP_REGS,
    m68k_fill_fpregset, m68k_store_fpregset },
#endif /* HAVE_PTRACE_GETREGS */
  { 0, 0, 0, -1, -1, NULL, NULL }
};

static const unsigned char m68k_breakpoint[] = { 0x4E, 0x4F };
#define m68k_breakpoint_len 2

static CORE_ADDR
m68k_get_pc (struct regcache *regcache)
{
  unsigned long pc;

  collect_register_by_name (regcache, "pc", &pc);
  return pc;
}

static void
m68k_set_pc (struct regcache *regcache, CORE_ADDR value)
{
  unsigned long newpc = value;

  supply_register_by_name (regcache, "pc", &newpc);
}

static int
m68k_breakpoint_at (CORE_ADDR pc)
{
  unsigned char c[2];

  read_inferior_memory (pc, c, 2);
  if (c[0] == 0x4E && c[1] == 0x4F)
    return 1;

  return 0;
}

#include <asm/ptrace.h>

#ifdef PTRACE_GET_THREAD_AREA
/* Fetch the thread-local storage pointer for libthread_db.  */

ps_err_e
ps_get_thread_area (const struct ps_prochandle *ph,
		    lwpid_t lwpid, int idx, void **base)
{
  if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
    return PS_ERR;

  /* IDX is the bias from the thread pointer to the beginning of the
     thread descriptor.  It has to be subtracted due to implementation
     quirks in libthread_db.  */
  *base = (void *) ((char *)*base - idx);

  return PS_OK;
}
#endif /* PTRACE_GET_THREAD_AREA */

struct linux_target_ops the_low_target = {
  init_registers_m68k,
  m68k_num_regs,
  m68k_regmap,
  m68k_cannot_fetch_register,
  m68k_cannot_store_register,
  m68k_get_pc,
  m68k_set_pc,
  m68k_breakpoint,
  m68k_breakpoint_len,
  NULL,
  2,
  m68k_breakpoint_at,
};