[thirdparty/binutils-gdb.git] / sim / rl78 / mem.c

/* mem.c --- memory for RL78 simulator.

   Copyright (C) 2011-2013 Free Software Foundation, Inc.
   Contributed by Red Hat, Inc.

   This file is part of the GNU simulators.

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "opcode/rl78.h"
#include "mem.h"
#include "cpu.h"

#define ILLEGAL_OPCODE 0xff

int rom_limit = 0x100000;
int ram_base = 0xf8000;
unsigned char memory[MEM_SIZE];
#define MASK 0xfffff

unsigned char initted[MEM_SIZE];
int skip_init = 0;

#define tprintf if (trace) printf

void
init_mem (void)
{
  memset (memory, ILLEGAL_OPCODE, sizeof (memory));
  memset (memory + 0xf0000, 0x33, 0x10000);

  memset (initted, 0, sizeof (initted));
  memset (initted + 0xffee0, 1, 0x00120);
  memset (initted + 0xf0000, 1, 0x01000);
}

void
mem_ram_size (int ram_bytes)
{
  ram_base = 0x100000 - ram_bytes;
}

void
mem_rom_size (int rom_bytes)
{
  rom_limit = rom_bytes;
}

/* ---------------------------------------------------------------------- */
/* Note: the RL78 memory map has a few surprises.  For starters, part
   of the first 64k is mapped to the last 64k, depending on an SFR bit
   and how much RAM the chip has.  This is simulated here, as are a
   few peripherals.  */

/* This is stdout.  We only care about the data byte, not the upper byte.  */
#define SDR00	0xfff10
#define SSR00	0xf0100
#define TS0	0xf01b2

/* RL78/G13 multiply/divide peripheral.  */
#define MDUC	0xf00e8
#define MDAL	0xffff0
#define MDAH	0xffff2
#define MDBL	0xffff4
#define MDBH	0xffff6
#define MDCL	0xf00e0
#define MDCH	0xf00e2
static long long mduc_clock = 0;
static int mda_set = 0;
#define MDA_SET  15

static int last_addr_was_mirror;

static int
address_mapping (int address)
{
  address &= MASK;
  if (address >= 0xf1000 && address < ram_base)
    {
      address &= 0xffff;
      tprintf ("&");
      if (memory[RL78_SFR_PMC] & 1)
	{
	  tprintf ("|");
	  address |= 0x10000;
	}
      last_addr_was_mirror = 1;
    }
  else
      last_addr_was_mirror = 0;
    
  return address;
}

static void
mem_put_byte (int address, unsigned char value)
{
  address = address_mapping (address);
  memory [address] = value;
  initted [address] = 1;
  if (address == SDR00)
    {
      putchar (value);
      fflush (stdout);
    }
  if (address == TS0)
    {
      if (timer_enabled == 2)
	{
	  total_clocks = 0;
	  pending_clocks = 0;
	  memset (counts_per_insn, 0, sizeof (counts_per_insn));
	  memory[0xf0180] = 0xff;
	  memory[0xf0181] = 0xff;
	}
      if (value & 1)
	timer_enabled = 1;
      else
	timer_enabled = 0;
    }
  if (address == RL78_SFR_SP && value & 1)
    {
      printf ("Warning: SP value 0x%04x truncated at pc=0x%05x\n", value, pc);
      value &= ~1;
    }
  if (address == MDUC)
    {
      if ((value & 0x81) == 0x81)
	{
	  /* division */
	  mduc_clock = total_clocks;
	}
    }
  if ((address & ~3) == MDAL)
    {
      mda_set |= (1 << (address & 3));
      if (mda_set == MDA_SET)
	{
	  long als, ahs;
	  unsigned long alu, ahu;
	  long rvs;
	  long mdc;
	  unsigned long rvu;
	  mda_set = 0;
	  switch (memory [MDUC] & 0xc8)
	    {
	    case 0x00:
	      alu = mem_get_hi (MDAL);
	      ahu = mem_get_hi (MDAH);
	      rvu = alu * ahu;
	      tprintf  ("MDUC: %lu * %lu = %lu\n", alu, ahu, rvu);
	      mem_put_si (MDBL, rvu);
	      break;
	    case 0x08:
	      als = sign_ext (mem_get_hi (MDAL), 16);
	      ahs = sign_ext (mem_get_hi (MDAH), 16);
	      rvs = als * ahs;
	      tprintf  ("MDUC: %ld * %ld = %ld\n", als, ahs, rvs);
	      mem_put_si (MDBL, rvs);
	      break;
	    case 0x40:
	      alu = mem_get_hi (MDAL);
	      ahu = mem_get_hi (MDAH);
	      rvu = alu * ahu;
	      mem_put_si (MDBL, rvu);
	      mdc = mem_get_si (MDCL);
	      tprintf  ("MDUC: %lu * %lu + %lu = ", alu, ahu, mdc);
	      mdc += (long) rvu;
	      tprintf ("%lu\n", mdc);
	      mem_put_si (MDCL, mdc);
	      break;
	    case 0x48:
	      als = sign_ext (mem_get_hi (MDAL), 16);
	      ahs = sign_ext (mem_get_hi (MDAH), 16);
	      rvs = als * ahs;
	      mem_put_si (MDBL, rvs);
	      mdc = mem_get_si (MDCL);
	      tprintf  ("MDUC: %ld * %ld + %ld = ", als, ahs, mdc);
	      tprintf ("%ld\n", mdc);
	      mdc += rvs;
	      mem_put_si (MDCL, mdc);
	      break;
	    }
	}
    }
}

extern long long total_clocks;

static unsigned char
mem_get_byte (int address)
{
  address = address_mapping (address);
  switch (address)
    {
    case SSR00:
    case SSR00 + 1:
      return 0x00;
    case 0xf00f0:
      return 0;
    case 0xf0180:
    case 0xf0181:
      return memory[address];

    case MDUC:
      {
	unsigned char mduc = memory [MDUC];
	if ((mduc & 0x81) == 0x81
	    && total_clocks > mduc_clock + 16)
	  {
	    unsigned long a, b, q, r;
	    memory [MDUC] &= 0xfe;
	    a = mem_get_si (MDAL);
	    b = mem_get_si (MDAL);
	    if (b == 0)
	      {
		q = ~0;
		r = ~0;
	      }
	    else
	      {
		q = a / b;
		r = a % b;
	      }
	    tprintf  ("MDUC: %lu / %lu = q %lu, r %lu\n", a, b, q, r);
	    mem_put_si (MDAL, q);
	    mem_put_si (MDCL, r);
	  }
	return memory[address];
      }
    case MDCL:
    case MDCL + 1:
    case MDCH:
    case MDCH + 1:
      return memory[address];
    }
  if (address < 0xf1000 && address >= 0xf0000)
    {
#if 1
      /* Note: comment out this return to trap the invalid access
	 instead of returning an "undefined" value.  */
      return 0x11;
#else
      fprintf (stderr, "SFR access error: addr 0x%05x pc 0x%05x\n", address, pc);
      exit (1);
#endif
    }
#if 0
  /* Uncomment this block if you want to trap on reads from unwritten memory.  */
  if (!skip_init && !initted [address])
    {
      static int uninit_count = 0;
      fprintf (stderr, "\033[31mwarning :read from uninit addr %05x pc %05x\033[0m\n", address, pc);
      uninit_count ++;
      if (uninit_count > 5)
	exit (1);
    }
#endif
  return memory [address];
}

extern jmp_buf decode_jmp_buf;
#define DO_RETURN(x) longjmp (decode_jmp_buf, x)

#define CHECK_ALIGNMENT(a,v,m) \
  if (a & m) { printf ("Misalignment addr 0x%05x val 0x%04x pc %05x\n", (int)a, (int)v, (int)pc); \
    DO_RETURN (RL78_MAKE_HIT_BREAK ()); }

/* ---------------------------------------------------------------------- */
#define SPECIAL_ADDR(a) (0xffff0 <= a || (0xffee0 <= a && a < 0xfff00))

void
mem_put_qi (int address, unsigned char value)
{
  if (!SPECIAL_ADDR (address))
    tprintf ("\033[34m([%05X]<-%02X)\033[0m", address, value);
  mem_put_byte (address, value);
}

void
mem_put_hi (int address, unsigned short value)
{
  if (!SPECIAL_ADDR (address))
    tprintf ("\033[34m([%05X]<-%04X)\033[0m", address, value);
  CHECK_ALIGNMENT (address, value, 1);
  if (address > 0xffff8 && address != RL78_SFR_SP)
    {
      tprintf ("Word access to 0x%05x!!\n", address);
      DO_RETURN (RL78_MAKE_HIT_BREAK ());
    }
  mem_put_byte (address, value);
  mem_put_byte (address + 1, value >> 8);
}

void
mem_put_psi (int address, unsigned long value)
{
  tprintf ("\033[34m([%05X]<-%06lX)\033[0m", address, value);
  mem_put_byte (address, value);
  mem_put_byte (address + 1, value >> 8);
  mem_put_byte (address + 2, value >> 16);
}

void
mem_put_si (int address, unsigned long value)
{
  tprintf ("\033[34m([%05X]<-%08lX)\033[0m", address, value);
  CHECK_ALIGNMENT (address, value, 3);
  mem_put_byte (address, value);
  mem_put_byte (address + 1, value >> 8);
  mem_put_byte (address + 2, value >> 16);
  mem_put_byte (address + 3, value >> 24);
}

void
mem_put_blk (int address, const void *bufptr, int nbytes)
{
  const unsigned char *bp = (unsigned char *)bufptr;
  while (nbytes --)
    mem_put_byte (address ++, *bp ++);
}

unsigned char
mem_get_pc (int address)
{
  /* Catch obvious problems.  */
  if (address >= rom_limit && address < 0xf0000)
    return 0xff;
  /* This does NOT go through the flash mirror area; you cannot
     execute out of the mirror.  */
  return memory [address & MASK];
}

unsigned char
mem_get_qi (int address)
{
  int v;
  v = mem_get_byte (address);
  if (!SPECIAL_ADDR (address))
    tprintf ("\033[35m([%05X]->%04X)\033[0m", address, v);
  if (last_addr_was_mirror)
    {
      pending_clocks += 3;
      tprintf ("ROM read\n");
    }
  return v;
}

unsigned short
mem_get_hi (int address)
{
  int v;
  v = mem_get_byte (address)
    | mem_get_byte (address + 1) * 256;
  CHECK_ALIGNMENT (address, v, 1);
  if (!SPECIAL_ADDR (address))
    tprintf ("\033[35m([%05X]->%04X)\033[0m", address, v);
  if (last_addr_was_mirror)
    {
      pending_clocks += 3;
      tprintf ("ROM read\n");
    }
  return v;
}

unsigned long
mem_get_psi (int address)
{
  int v;
  v = mem_get_byte (address)
    | mem_get_byte (address + 1) * 256
    | mem_get_byte (address + 2) * 65536;
  tprintf ("\033[35m([%05X]->%04X)\033[0m", address, v);
  return v;
}

unsigned long
mem_get_si (int address)
{
  int v;
  v = mem_get_byte (address)
    | mem_get_byte (address + 1) * 256
    | mem_get_byte (address + 2) * 65536
    | mem_get_byte (address + 2) * 16777216;
  CHECK_ALIGNMENT (address, v, 3);
  tprintf ("(\033[35m[%05X]->%04X)\033[0m", address, v);
  return v;
}

void
mem_get_blk (int address, void *bufptr, int nbytes)
{
  unsigned char *bp = (unsigned char *)bufptr;
  while (nbytes --)
    *bp ++ = mem_get_byte (address ++);
}

int
sign_ext (int v, int bits)
{
  if (bits < 8 * sizeof (int))
    {
      v &= (1 << bits) - 1;
      if (v & (1 << (bits - 1)))
	v -= (1 << bits);
    }
  return v;
}
Commit	Line	Data
87326c78 DD	1	/* mem.c --- memory for RL78 simulator.
87326c78 DD	2
8acc9f48	3	Copyright (C) 2011-2013 Free Software Foundation, Inc.
87326c78 DD	4	Contributed by Red Hat, Inc.
	5
	6	This file is part of the GNU simulators.
	7
	8	This program is free software; you can redistribute it and/or modify
	9	it under the terms of the GNU General Public License as published by
	10	the Free Software Foundation; either version 3 of the License, or
	11	(at your option) any later version.
	12
	13	This program is distributed in the hope that it will be useful,
	14	but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	GNU General Public License for more details.
	17
	18	You should have received a copy of the GNU General Public License
	19	along with this program. If not, see <http://www.gnu.org/licenses/>.
	20	*/
	21
	22	#include "config.h"
	23	#include <stdio.h>
	24	#include <stdlib.h>
	25	#include <string.h>
	26
	27	#include "opcode/rl78.h"
	28	#include "mem.h"
	29	#include "cpu.h"
	30
	31	#define ILLEGAL_OPCODE 0xff
	32
	33	int rom_limit = 0x100000;
	34	int ram_base = 0xf8000;
	35	unsigned char memory[MEM_SIZE];
	36	#define MASK 0xfffff
	37
	38	unsigned char initted[MEM_SIZE];
	39	int skip_init = 0;
	40
	41	#define tprintf if (trace) printf
	42
	43	void
	44	init_mem (void)
	45	{
	46	memset (memory, ILLEGAL_OPCODE, sizeof (memory));
	47	memset (memory + 0xf0000, 0x33, 0x10000);
	48
	49	memset (initted, 0, sizeof (initted));
	50	memset (initted + 0xffee0, 1, 0x00120);
	51	memset (initted + 0xf0000, 1, 0x01000);
	52	}
	53
	54	void
	55	mem_ram_size (int ram_bytes)
	56	{
	57	ram_base = 0x100000 - ram_bytes;
	58	}
	59
	60	void
	61	mem_rom_size (int rom_bytes)
	62	{
	63	rom_limit = rom_bytes;
	64	}
	65
	66	/* ---------------------------------------------------------------------- */
	67	/* Note: the RL78 memory map has a few surprises. For starters, part
68	of the first 64k is mapped to the last 64k, depending on an SFR bit
69	and how much RAM the chip has. This is simulated here, as are a
70	few peripherals. */
71
72	/* This is stdout. We only care about the data byte, not the upper byte. */
73	#define SDR00 0xfff10
74	#define SSR00 0xf0100
75	#define TS0 0xf01b2
76
77	/* RL78/G13 multiply/divide peripheral. */
78	#define MDUC 0xf00e8
79	#define MDAL 0xffff0
80	#define MDAH 0xffff2
81	#define MDBL 0xffff4
82	#define MDBH 0xffff6
83	#define MDCL 0xf00e0
84	#define MDCH 0xf00e2
85	static long long mduc_clock = 0;
86	static int mda_set = 0;
87	#define MDA_SET 15
88
89	static int last_addr_was_mirror;
90
91	static int
92	address_mapping (int address)
93	{
94	address &= MASK;
95	if (address >= 0xf1000 && address < ram_base)
96	{
97	address &= 0xffff;
98	tprintf ("&");
99	if (memory[RL78_SFR_PMC] & 1)
100	{
101	tprintf ("\|");
102	address \|= 0x10000;
103	}
104	last_addr_was_mirror = 1;
105	}
106	else
107	last_addr_was_mirror = 0;
108
109	return address;
110	}
111
112	static void
113	mem_put_byte (int address, unsigned char value)
114	{
115	address = address_mapping (address);
116	memory [address] = value;
117	initted [address] = 1;
118	if (address == SDR00)
119	{
120	putchar (value);
121	fflush (stdout);
122	}
123	if (address == TS0)
124	{
125	if (timer_enabled == 2)
126	{
127	total_clocks = 0;
128	pending_clocks = 0;
129	memset (counts_per_insn, 0, sizeof (counts_per_insn));
130	memory[0xf0180] = 0xff;
131	memory[0xf0181] = 0xff;
132	}
133	if (value & 1)
134	timer_enabled = 1;
135	else
136	timer_enabled = 0;
137	}
138	if (address == RL78_SFR_SP && value & 1)
139	{
140	printf ("Warning: SP value 0x%04x truncated at pc=0x%05x\n", value, pc);
141	value &= ~1;
142	}
143	if (address == MDUC)
144	{
145	if ((value & 0x81) == 0x81)
146	{
147	/* division */
148	mduc_clock = total_clocks;
149	}
150	}
151	if ((address & ~3) == MDAL)
152	{
153	mda_set \|= (1 << (address & 3));
154	if (mda_set == MDA_SET)
155	{
156	long als, ahs;
157	unsigned long alu, ahu;
158	long rvs;
159	long mdc;
160	unsigned long rvu;
161	mda_set = 0;
162	switch (memory [MDUC] & 0xc8)
163	{
164	case 0x00:
165	alu = mem_get_hi (MDAL);
166	ahu = mem_get_hi (MDAH);
167	rvu = alu * ahu;
168	tprintf ("MDUC: %lu * %lu = %lu\n", alu, ahu, rvu);
169	mem_put_si (MDBL, rvu);
170	break;
171	case 0x08:
172	als = sign_ext (mem_get_hi (MDAL), 16);
173	ahs = sign_ext (mem_get_hi (MDAH), 16);
174	rvs = als * ahs;
175	tprintf ("MDUC: %ld * %ld = %ld\n", als, ahs, rvs);
176	mem_put_si (MDBL, rvs);
177	break;
178	case 0x40:
179	alu = mem_get_hi (MDAL);
180	ahu = mem_get_hi (MDAH);
181	rvu = alu * ahu;
182	mem_put_si (MDBL, rvu);
183	mdc = mem_get_si (MDCL);
184	tprintf ("MDUC: %lu * %lu + %lu = ", alu, ahu, mdc);
185	mdc += (long) rvu;
186	tprintf ("%lu\n", mdc);
187	mem_put_si (MDCL, mdc);
188	break;
189	case 0x48:
190	als = sign_ext (mem_get_hi (MDAL), 16);
191	ahs = sign_ext (mem_get_hi (MDAH), 16);
192	rvs = als * ahs;
193	mem_put_si (MDBL, rvs);
194	mdc = mem_get_si (MDCL);
195	tprintf ("MDUC: %ld * %ld + %ld = ", als, ahs, mdc);
196	tprintf ("%ld\n", mdc);
197	mdc += rvs;
198	mem_put_si (MDCL, mdc);
199	break;
200	}
201	}
202	}
203	}
204
205	extern long long total_clocks;
206
207	static unsigned char
208	mem_get_byte (int address)
209	{
210	address = address_mapping (address);
211	switch (address)
212	{
213	case SSR00:
214	case SSR00 + 1:
215	return 0x00;
216	case 0xf00f0:
217	return 0;
218	case 0xf0180:
219	case 0xf0181:
220	return memory[address];
221
222	case MDUC:
223	{
224	unsigned char mduc = memory [MDUC];
225	if ((mduc & 0x81) == 0x81
226	&& total_clocks > mduc_clock + 16)
227	{
228	unsigned long a, b, q, r;
229	memory [MDUC] &= 0xfe;
230	a = mem_get_si (MDAL);
231	b = mem_get_si (MDAL);
232	if (b == 0)
233	{
234	q = ~0;
235	r = ~0;
236	}
237	else
238	{
239	q = a / b;
240	r = a % b;
241	}
242	tprintf ("MDUC: %lu / %lu = q %lu, r %lu\n", a, b, q, r);
243	mem_put_si (MDAL, q);
244	mem_put_si (MDCL, r);
245	}
246	return memory[address];
247	}
248	case MDCL:
249	case MDCL + 1:
250	case MDCH:
251	case MDCH + 1:
252	return memory[address];
253	}
254	if (address < 0xf1000 && address >= 0xf0000)
255	{
256	#if 1
257	/* Note: comment out this return to trap the invalid access
258	instead of returning an "undefined" value. */
259	return 0x11;
260	#else
261	fprintf (stderr, "SFR access error: addr 0x%05x pc 0x%05x\n", address, pc);
262	exit (1);
263	#endif
264	}
265	#if 0
266	/* Uncomment this block if you want to trap on reads from unwritten memory. */
267	if (!skip_init && !initted [address])
268	{
269	static int uninit_count = 0;
270	fprintf (stderr, "\033[31mwarning :read from uninit addr %05x pc %05x\033[0m\n", address, pc);
271	uninit_count ++;
272	if (uninit_count > 5)
273	exit (1);
274	}
275	#endif
276	return memory [address];
277	}
278
279	extern jmp_buf decode_jmp_buf;
280	#define DO_RETURN(x) longjmp (decode_jmp_buf, x)
281
282	#define CHECK_ALIGNMENT(a,v,m) \
283	if (a & m) { printf ("Misalignment addr 0x%05x val 0x%04x pc %05x\n", (int)a, (int)v, (int)pc); \
284	DO_RETURN (RL78_MAKE_HIT_BREAK ()); }
285
286	/* ---------------------------------------------------------------------- */
287	#define SPECIAL_ADDR(a) (0xffff0 <= a \|\| (0xffee0 <= a && a < 0xfff00))
288
289	void
290	mem_put_qi (int address, unsigned char value)
291	{
292	if (!SPECIAL_ADDR (address))
293	tprintf ("\033[34m([%05X]<-%02X)\033[0m", address, value);
294	mem_put_byte (address, value);
295	}
296
297	void
298	mem_put_hi (int address, unsigned short value)
299	{
300	if (!SPECIAL_ADDR (address))
301	tprintf ("\033[34m([%05X]<-%04X)\033[0m", address, value);
302	CHECK_ALIGNMENT (address, value, 1);
303	if (address > 0xffff8 && address != RL78_SFR_SP)
304	{
305	tprintf ("Word access to 0x%05x!!\n", address);
306	DO_RETURN (RL78_MAKE_HIT_BREAK ());
307	}
308	mem_put_byte (address, value);
309	mem_put_byte (address + 1, value >> 8);
310	}
311
312	void
313	mem_put_psi (int address, unsigned long value)
314	{
315	tprintf ("\033[34m([%05X]<-%06lX)\033[0m", address, value);
316	mem_put_byte (address, value);
317	mem_put_byte (address + 1, value >> 8);
318	mem_put_byte (address + 2, value >> 16);
319	}
320
321	void
322	mem_put_si (int address, unsigned long value)
323	{
324	tprintf ("\033[34m([%05X]<-%08lX)\033[0m", address, value);
325	CHECK_ALIGNMENT (address, value, 3);
326	mem_put_byte (address, value);
327	mem_put_byte (address + 1, value >> 8);
328	mem_put_byte (address + 2, value >> 16);
329	mem_put_byte (address + 3, value >> 24);
330	}
331
332	void
333	mem_put_blk (int address, const void *bufptr, int nbytes)
334	{
335	const unsigned char bp = (unsigned char )bufptr;
336	while (nbytes --)
337	mem_put_byte (address ++, *bp ++);
338	}
339
340	unsigned char
341	mem_get_pc (int address)
342	{
343	/* Catch obvious problems. */
344	if (address >= rom_limit && address < 0xf0000)
345	return 0xff;
346	/* This does NOT go through the flash mirror area; you cannot
347	execute out of the mirror. */
348	return memory [address & MASK];
349	}
350
351	unsigned char
352	mem_get_qi (int address)
353	{
354	int v;
355	v = mem_get_byte (address);
356	if (!SPECIAL_ADDR (address))
357	tprintf ("\033[35m([%05X]->%04X)\033[0m", address, v);
358	if (last_addr_was_mirror)
359	{
360	pending_clocks += 3;
361	tprintf ("ROM read\n");
362	}
363	return v;
364	}
365
366	unsigned short
367	mem_get_hi (int address)
368	{
369	int v;
370	v = mem_get_byte (address)
371	\| mem_get_byte (address + 1) * 256;
372	CHECK_ALIGNMENT (address, v, 1);
373	if (!SPECIAL_ADDR (address))
374	tprintf ("\033[35m([%05X]->%04X)\033[0m", address, v);
375	if (last_addr_was_mirror)
376	{
377	pending_clocks += 3;
378	tprintf ("ROM read\n");
379	}
380	return v;
381	}
382
383	unsigned long
384	mem_get_psi (int address)
385	{
386	int v;
387	v = mem_get_byte (address)
388	\| mem_get_byte (address + 1) * 256
389	\| mem_get_byte (address + 2) * 65536;
390	tprintf ("\033[35m([%05X]->%04X)\033[0m", address, v);
391	return v;
392	}
393
394	unsigned long
395	mem_get_si (int address)
396	{
397	int v;
398	v = mem_get_byte (address)
399	\| mem_get_byte (address + 1) * 256
400	\| mem_get_byte (address + 2) * 65536
401	\| mem_get_byte (address + 2) * 16777216;
402	CHECK_ALIGNMENT (address, v, 3);
403	tprintf ("(\033[35m[%05X]->%04X)\033[0m", address, v);
404	return v;
405	}
406
407	void
408	mem_get_blk (int address, void *bufptr, int nbytes)
409	{
410	unsigned char bp = (unsigned char )bufptr;
411	while (nbytes --)
412	*bp ++ = mem_get_byte (address ++);
413	}
414
415	int
416	sign_ext (int v, int bits)
417	{
418	if (bits < 8 * sizeof (int))
419	{
420	v &= (1 << bits) - 1;
421	if (v & (1 << (bits - 1)))
422	v -= (1 << bits);
423	}
424	return v;
425	}