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/* memory support for Z8KSIM

   Copyright (C) 1987, 1992 Free Software Foundation, Inc.

This file is part of Z8KSIM

Z8KSIM 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, or (at your option)

any later version.

Z8KSIM 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 Z8KZIM; if not, write to the Free Software

Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#include "config.h"

#include <ansidecl.h>

#ifdef HAVE_STDLIB_H

#include <stdlib.h>

#endif

#include "tm.h"

#include "mem.h"

#include "sim.h"

#define INLINE

static

long

sitoptr (si)

long si;

{

  return ((si & 0xff000000) >> 8) | (si & 0xffff);

}

static

unsigned short *

get_page_and_offset (context, where, offset_ptr)

     sim_state_type *context;

     sim_phys_addr_type where;

     int *offset_ptr;

{

  /* Is the page allocated ? */

  if (context->memory == 0)

    {

      /* Must allocate 16MB in order to run Z8001 programs.  */

      context->memory  = (unsigned short *)calloc(64*1024*64,4);

    }

  *offset_ptr = sitoptr(where);

  return context->memory;

}

void

sim_write_byte (context, where, what)

     sim_state_type *context;

     sim_phys_addr_type where;

     int what;

{

  unsigned int offset;

  char *ptr = (char *)get_page_and_offset (context, where, &offset);

  ptr[offset] = what;

}

void

sim_write_short (context, where, what)

     sim_state_type *context;

     sim_phys_addr_type where;

     int what;

{

  int offset;

  char *ptr = (char *)get_page_and_offset (context, where, &offset);

  ptr[offset] = what >> 8;

  ptr[offset + 1] = what;

}

void

sim_write_long (context, where, what)

     sim_state_type *context;

     sim_phys_addr_type where;

     int what;

{

  int offset;

  char *ptr = (char *)get_page_and_offset (context, where, &offset);

  ptr[offset] = what >> 24;

  ptr[offset + 1] = what >> 16;

  ptr[offset + 3] = what >> 8;

  ptr[offset + 4] = what;

}

int

sim_read_byte (context, where)

     sim_state_type *context;

     sim_phys_addr_type where;

{

  int offset;

  char *ptr = (char *)get_page_and_offset (context, where, &offset);

 return ptr[offset];

}

unsigned

sim_read_short (context, where)

     sim_state_type *context;

     sim_phys_addr_type where;

{

  int what;

  int offset;

  char *ptr = (char *)get_page_and_offset (context, where, &offset);

  what = (ptr[offset] << 8) | ptr[offset + 1];

  return what;

}