/* Target-dependent code for GNU/Linux UltraSPARC.

   Copyright 2003, 2004 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 2 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, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "frame.h"
#include "frame-unwind.h"
#include "tramp-frame.h"
#include "gdbarch.h"
#include "osabi.h"
#include "solib-svr4.h"
#include "symtab.h"
#include "trad-frame.h"

#include "sparc64-tdep.h"

/* The instruction sequence for RT signals is
       mov __NR_rt_sigreturn, %g1	! hex: 0x82102065
       ta  0x6d				! hex: 0x91d0206d

   The effect is to call the system call rt_sigreturn.
   Note that 64-bit binaries only use this RT signal return method.  */

#define LINUX64_RT_SIGTRAMP_INSN0	0x82102065
#define LINUX64_RT_SIGTRAMP_INSN1	0x91d0206d


static void sparc64_linux_sigframe_init (const struct tramp_frame *self,
					 struct frame_info *next_frame,
					 struct trad_frame_cache *this_cache,
					 CORE_ADDR func);

static const struct tramp_frame sparc64_linux_rt_sigframe = {
  SIGTRAMP_FRAME,
  4,
  {
    { LINUX64_RT_SIGTRAMP_INSN0, -1 },
    { LINUX64_RT_SIGTRAMP_INSN1, -1 },
    { TRAMP_SENTINEL_INSN, -1 }
  },
  sparc64_linux_sigframe_init
};

static void
sparc64_linux_sigframe_init (const struct tramp_frame *self,
			     struct frame_info *next_frame,
			     struct trad_frame_cache *this_cache,
			     CORE_ADDR func)
{
  CORE_ADDR base, addr;
  int regnum;

  base = frame_unwind_register_unsigned (next_frame, SPARC_O1_REGNUM);
  base += 128;

  /* Offsets from <bits/sigcontext.h> */

  /* Since %g0 is always zero, keep the identity encoding.  */
  addr = base + 0x08;
  for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++)
    {
      trad_frame_set_reg_addr (this_cache, regnum, addr);
      addr += 8;
    }

  trad_frame_set_reg_addr (this_cache, SPARC64_STATE_REGNUM, addr + 0x00);
  trad_frame_set_reg_addr (this_cache, SPARC64_PC_REGNUM,    addr + 0x08);
  trad_frame_set_reg_addr (this_cache, SPARC64_NPC_REGNUM,   addr + 0x10);
  trad_frame_set_reg_addr (this_cache, SPARC64_Y_REGNUM,     addr + 0x18);
  trad_frame_set_reg_addr (this_cache, SPARC64_FPRS_REGNUM,  addr + 0x1c);

  addr = frame_unwind_register_unsigned (next_frame, SPARC_SP_REGNUM);
  if (addr & 1)
    addr += BIAS;

  base = addr;
  for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
    {
      trad_frame_set_reg_addr (this_cache, regnum, addr);
      addr += 8;
    }
  trad_frame_set_id (this_cache, frame_id_build (base, func));
}

static void
sparc64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  tramp_frame_prepend_unwinder (gdbarch, &sparc64_linux_rt_sigframe);

  /* GNU/Linux is very similar to Solaris ...  */
  sparc64_sol2_init_abi (info, gdbarch);

  /* ... but doesn't have kernel-assisted single-stepping support.  */
  set_gdbarch_software_single_step (gdbarch, sparc_software_single_step);

  /* Enable TLS support.  */
  set_gdbarch_fetch_tls_load_module_address (gdbarch,
                                             svr4_fetch_objfile_link_map);
}

/* Provide a prototype to silence -Wmissing-prototypes.  */
extern void _initialize_sparc64_linux_tdep (void);

void
_initialize_sparc64_linux_tdep (void)
{
  gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9,
			  GDB_OSABI_LINUX, sparc64_linux_init_abi);
}