/* Low level DECstation interface to ptrace, for GDB when running native.
   Copyright 1988, 1989, 1991, 1992 Free Software Foundation, Inc.
   Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
   and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.

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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "defs.h"
#include "inferior.h"
#include "gdbcore.h"
#include <sys/ptrace.h>
#include <setjmp.h>		/* For JB_XXX.  */

/* Size of elements in jmpbuf */

#define JB_ELEMENT_SIZE 4

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

#define REGISTER_PTRACE_ADDR(regno) \
   (regno < 32 ? 		GPR_BASE + regno \
  : regno == PC_REGNUM ?	PC	\
  : regno == CAUSE_REGNUM ?	CAUSE	\
  : regno == HI_REGNUM ?	MMHI	\
  : regno == LO_REGNUM ?	MMLO	\
  : regno == FCRCS_REGNUM ?	FPC_CSR	\
  : regno == FCRIR_REGNUM ?	FPC_EIR	\
  : regno >= FP0_REGNUM ?	FPR_BASE + (regno - FP0_REGNUM) \
  : 0)

static const char zerobuf[MAX_REGISTER_RAW_SIZE];

/* Get all registers from the inferior */

void
fetch_inferior_registers (regno)
     int regno;
{
  register unsigned int regaddr;
  char buf[MAX_REGISTER_RAW_SIZE];
  register int i;

  registers_fetched ();

  for (regno = 1; regno < NUM_REGS; regno++)
    {
      regaddr = REGISTER_PTRACE_ADDR (regno);
      for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
 	{
 	  *(int *) &buf[i] = ptrace (PT_READ_U, inferior_pid,
				     (PTRACE_ARG3_TYPE) regaddr, 0);
 	  regaddr += sizeof (int);
 	}
      supply_register (regno, buf);
    }

  supply_register (ZERO_REGNUM, zerobuf);
  /* Frame ptr reg must appear to be 0; it is faked by stack handling code. */
  supply_register (FP_REGNUM, zerobuf);
}

/* Store our register values back into the inferior.
   If REGNO is -1, do this for all registers.
   Otherwise, REGNO specifies which register (so we can save time).  */

void
store_inferior_registers (regno)
     int regno;
{
  register unsigned int regaddr;
  char buf[80];

  if (regno == 0)
    return;

  if (regno > 0)
    {
      regaddr = REGISTER_PTRACE_ADDR (regno);
      errno = 0;
      ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
	      read_register (regno));
      if (errno != 0)
	{
	  sprintf (buf, "writing register number %d", regno);
	  perror_with_name (buf);
	}
    }
  else
    {
      for (regno = 0; regno < NUM_REGS; regno++)
	{
	  if (regno == ZERO_REGNUM || regno == PS_REGNUM
	      || regno == BADVADDR_REGNUM || regno == CAUSE_REGNUM
	      || regno == FCRIR_REGNUM || regno == FP_REGNUM
	      || (regno >= FIRST_EMBED_REGNUM && regno <= LAST_EMBED_REGNUM))
	    continue;
	  regaddr = register_addr (regno, 1);
	  errno = 0;
	  ptrace (6, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
		  read_register (regno));
	  if (errno != 0)
	    {
	      sprintf (buf, "writing all regs, number %d", regno);
	      perror_with_name (buf);
	    }
	}
    }
}


/* 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(pc)
     CORE_ADDR *pc;
{
  CORE_ADDR jb_addr;

  jb_addr = read_register(A0_REGNUM);

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

  SWAP_TARGET_AND_HOST(pc, sizeof(CORE_ADDR));

  return 1;
}