sim/z8k/mem.c

   1 /* memory support for Z8KSIM
   2    Copyright (C) 1987, 1992 Free Software Foundation, Inc.
   3
   4 This file is part of Z8KSIM
   5
   6 Z8KSIM is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 Z8KSIM is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with Z8KZIM; if not, write to the Free Software
  18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 #include "config.h"
  21
  22 #include <ansidecl.h>
  23
  24 #ifdef HAVE_STDLIB_H
  25 #include <stdlib.h>
  26 #endif
  27
  28 #include "tm.h"
  29 #include "mem.h"
  30 #include "sim.h"
  31
  32 #define INLINE
  33 static
  34 long
  35 sitoptr (si)
  36 long si;
  37 {
  38   return ((si & 0xff000000) >> 8) | (si & 0xffff);
  39 }
  40
  41 static
  42 unsigned short *
  43 get_page_and_offset (context, where, offset_ptr)
  44      sim_state_type *context;
  45      sim_phys_addr_type where;
  46      int *offset_ptr;
  47 {
  48   /* Is the page allocated ? */
  49
  50   if (context->memory == 0)
  51     {
  52       /* Must allocate 16MB in order to run Z8001 programs.  */
  53       context->memory  = (unsigned short *)calloc(64*1024*64,4);
  54     }
  55
  56   *offset_ptr = sitoptr(where);
  57   return context->memory;
  58 }
  59
  60 void
  61 sim_write_byte (context, where, what)
  62      sim_state_type *context;
  63      sim_phys_addr_type where;
  64      int what;
  65 {
  66   unsigned int offset;
  67   char *ptr = (char *)get_page_and_offset (context, where, &offset);
  68
  69   ptr[offset] = what;
  70 }
  71
  72 void
  73 sim_write_short (context, where, what)
  74      sim_state_type *context;
  75      sim_phys_addr_type where;
  76      int what;
  77 {
  78   int offset;
  79   char *ptr = (char *)get_page_and_offset (context, where, &offset);
  80
  81   ptr[offset] = what >> 8;
  82   ptr[offset + 1] = what;
  83 }
  84
  85 void
  86 sim_write_long (context, where, what)
  87      sim_state_type *context;
  88      sim_phys_addr_type where;
  89      int what;
  90 {
  91   int offset;
  92   char *ptr = (char *)get_page_and_offset (context, where, &offset);
  93
  94   ptr[offset] = what >> 24;
  95   ptr[offset + 1] = what >> 16;
  96   ptr[offset + 3] = what >> 8;
  97   ptr[offset + 4] = what;
  98 }
  99
 100 int
 101 sim_read_byte (context, where)
 102      sim_state_type *context;
 103      sim_phys_addr_type where;
 104 {
 105   int offset;
 106   char *ptr = (char *)get_page_and_offset (context, where, &offset);
 107
 108  return ptr[offset];
 109 }
 110
 111 unsigned
 112 sim_read_short (context, where)
 113      sim_state_type *context;
 114      sim_phys_addr_type where;
 115 {
 116   int what;
 117   int offset;
 118
 119   char *ptr = (char *)get_page_and_offset (context, where, &offset);
 120
 121   what = (ptr[offset] << 8) | ptr[offset + 1];
 122   return what;
 123 }
 124
 125
 126