/* Low level Alpha interface, for GDB when running native.
   Copyright 1993, 1995, 1996, 1998, 1999, 2000, 2001
   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 "inferior.h"
#include "gdbcore.h"
#include "target.h"
#include "regcache.h"
#include <sys/ptrace.h>
#ifdef __linux__
#include <asm/reg.h>
#include <alpha/ptrace.h>
#else
#include <machine/reg.h>
#endif
#include <sys/user.h>

/* Prototypes for local functions. */

static void fetch_osf_core_registers (char *, unsigned, int, CORE_ADDR);
static void fetch_elf_core_registers (char *, unsigned, int, CORE_ADDR);

/* Size of elements in jmpbuf */

#define JB_ELEMENT_SIZE 8

/* The definition for JB_PC in machine/reg.h is wrong.
   And we can't get at the correct definition in setjmp.h as it is
   not always available (eg. if _POSIX_SOURCE is defined which is the
   default). As the defintion is unlikely to change (see comment
   in <setjmp.h>, define the correct value here.  */

#undef JB_PC
#define JB_PC 2

/* Figure out where the longjmp will land.
   We expect the first arg to be a pointer to the jmp_buf structure from which
   we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
   This routine returns true on success. */

int
get_longjmp_target (CORE_ADDR *pc)
{
  CORE_ADDR jb_addr;
  char raw_buffer[MAX_REGISTER_RAW_SIZE];

  jb_addr = read_register (A0_REGNUM);

  if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, raw_buffer,
			  sizeof (CORE_ADDR)))
    return 0;

  *pc = extract_address (raw_buffer, sizeof (CORE_ADDR));
  return 1;
}

/* Extract the register values out of the core file and store
   them where `read_register' will find them.

   CORE_REG_SECT points to the register values themselves, read into memory.
   CORE_REG_SIZE is the size of that area.
   WHICH says which set of registers we are handling (0 = int, 2 = float
   on machines where they are discontiguous).
   REG_ADDR is the offset from u.u_ar0 to the register values relative to
   core_reg_sect.  This is used with old-fashioned core files to
   locate the registers in a large upage-plus-stack ".reg" section.
   Original upage address X is at location core_reg_sect+x+reg_addr.
 */

static void
fetch_osf_core_registers (char *core_reg_sect, unsigned core_reg_size,
			  int which, CORE_ADDR reg_addr)
{
  register int regno;
  register int addr;
  int bad_reg = -1;

  /* Table to map a gdb regnum to an index in the core register section.
     The floating point register values are garbage in OSF/1.2 core files.  */
  static int core_reg_mapping[NUM_REGS] =
  {
#define EFL (EF_SIZE / 8)
    EF_V0, EF_T0, EF_T1, EF_T2, EF_T3, EF_T4, EF_T5, EF_T6,
    EF_T7, EF_S0, EF_S1, EF_S2, EF_S3, EF_S4, EF_S5, EF_S6,
    EF_A0, EF_A1, EF_A2, EF_A3, EF_A4, EF_A5, EF_T8, EF_T9,
    EF_T10, EF_T11, EF_RA, EF_T12, EF_AT, EF_GP, EF_SP, -1,
    EFL + 0, EFL + 1, EFL + 2, EFL + 3, EFL + 4, EFL + 5, EFL + 6, EFL + 7,
    EFL + 8, EFL + 9, EFL + 10, EFL + 11, EFL + 12, EFL + 13, EFL + 14, EFL + 15,
    EFL + 16, EFL + 17, EFL + 18, EFL + 19, EFL + 20, EFL + 21, EFL + 22, EFL + 23,
    EFL + 24, EFL + 25, EFL + 26, EFL + 27, EFL + 28, EFL + 29, EFL + 30, EFL + 31,
    EF_PC, -1
  };
  static char zerobuf[MAX_REGISTER_RAW_SIZE] =
  {0};

  for (regno = 0; regno < NUM_REGS; regno++)
    {
      if (CANNOT_FETCH_REGISTER (regno))
	{
	  supply_register (regno, zerobuf);
	  continue;
	}
      addr = 8 * core_reg_mapping[regno];
      if (addr < 0 || addr >= core_reg_size)
	{
	  if (bad_reg < 0)
	    bad_reg = regno;
	}
      else
	{
	  supply_register (regno, core_reg_sect + addr);
	}
    }
  if (bad_reg >= 0)
    {
      error ("Register %s not found in core file.", REGISTER_NAME (bad_reg));
    }
}

static void
fetch_elf_core_registers (char *core_reg_sect, unsigned core_reg_size,
			  int which, CORE_ADDR reg_addr)
{
  if (core_reg_size < 32 * 8)
    {
      error ("Core file register section too small (%u bytes).", core_reg_size);
      return;
    }

  if (which == 2)
    {
      /* The FPU Registers.  */
      memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], core_reg_sect, 31 * 8);
      memset (&registers[REGISTER_BYTE (FP0_REGNUM + 31)], 0, 8);
      memset (&register_valid[FP0_REGNUM], 1, 32);
    }
  else
    {
      /* The General Registers.  */
      memcpy (&registers[REGISTER_BYTE (V0_REGNUM)], core_reg_sect, 31 * 8);
      memcpy (&registers[REGISTER_BYTE (PC_REGNUM)], core_reg_sect + 31 * 8, 8);
      memset (&registers[REGISTER_BYTE (ZERO_REGNUM)], 0, 8);
      memset (&register_valid[V0_REGNUM], 1, 32);
      register_valid[PC_REGNUM] = 1;
    }
}


/* Map gdb internal register number to a ptrace ``address''.
   These ``addresses'' are defined in <sys/ptrace.h> */

#define REGISTER_PTRACE_ADDR(regno) \
   (regno < FP0_REGNUM ? 	GPR_BASE + (regno) \
  : regno == PC_REGNUM ?	PC	\
  : regno >= FP0_REGNUM ?	FPR_BASE + ((regno) - FP0_REGNUM) \
  : 0)

/* Return the ptrace ``address'' of register REGNO. */

CORE_ADDR
register_addr (int regno, CORE_ADDR blockend)
{
  return REGISTER_PTRACE_ADDR (regno);
}

int
kernel_u_size (void)
{
  return (sizeof (struct user));
}

#if defined(USE_PROC_FS) || defined(HAVE_GREGSET_T)
#include <sys/procfs.h>

/* Prototypes for supply_gregset etc. */
#include "gregset.h"

/*
 * See the comment in m68k-tdep.c regarding the utility of these functions.
 */

void
supply_gregset (gdb_gregset_t *gregsetp)
{
  register int regi;
  register long *regp = ALPHA_REGSET_BASE (gregsetp);
  static char zerobuf[MAX_REGISTER_RAW_SIZE] =
  {0};

  for (regi = 0; regi < 31; regi++)
    supply_register (regi, (char *) (regp + regi));

  supply_register (PC_REGNUM, (char *) (regp + 31));

  /* Fill inaccessible registers with zero.  */
  supply_register (ZERO_REGNUM, zerobuf);
  supply_register (FP_REGNUM, zerobuf);
}

void
fill_gregset (gdb_gregset_t *gregsetp, int regno)
{
  int regi;
  register long *regp = ALPHA_REGSET_BASE (gregsetp);

  for (regi = 0; regi < 31; regi++)
    if ((regno == -1) || (regno == regi))
      *(regp + regi) = *(long *) &registers[REGISTER_BYTE (regi)];

  if ((regno == -1) || (regno == PC_REGNUM))
    *(regp + 31) = *(long *) &registers[REGISTER_BYTE (PC_REGNUM)];
}

/*
 * Now we do the same thing for floating-point registers.
 * Again, see the comments in m68k-tdep.c.
 */

void
supply_fpregset (gdb_fpregset_t *fpregsetp)
{
  register int regi;
  register long *regp = ALPHA_REGSET_BASE (fpregsetp);

  for (regi = 0; regi < 32; regi++)
    supply_register (regi + FP0_REGNUM, (char *) (regp + regi));
}

void
fill_fpregset (gdb_fpregset_t *fpregsetp, int regno)
{
  int regi;
  register long *regp = ALPHA_REGSET_BASE (fpregsetp);

  for (regi = FP0_REGNUM; regi < FP0_REGNUM + 32; regi++)
    {
      if ((regno == -1) || (regno == regi))
	{
	  *(regp + regi - FP0_REGNUM) =
	    *(long *) &registers[REGISTER_BYTE (regi)];
	}
    }
}
#endif


/* Register that we are able to handle alpha core file formats. */

static struct core_fns alpha_osf_core_fns =
{
  /* This really is bfd_target_unknown_flavour.  */

  bfd_target_unknown_flavour,		/* core_flavour */
  default_check_format,			/* check_format */
  default_core_sniffer,			/* core_sniffer */
  fetch_osf_core_registers,		/* core_read_registers */
  NULL					/* next */
};

static struct core_fns alpha_elf_core_fns =
{
  bfd_target_elf_flavour,		/* core_flavour */
  default_check_format,			/* check_format */
  default_core_sniffer,			/* core_sniffer */
  fetch_elf_core_registers,		/* core_read_registers */
  NULL					/* next */
};

void
_initialize_core_alpha (void)
{
  add_core_fns (&alpha_osf_core_fns);
  add_core_fns (&alpha_elf_core_fns);
}
