* msp430: New Directory.

	* configure.tgt: Add it.
	* configure: Regenerate.

	* gennltvals.sh: Add msp430 support.
	* nltvals.def: Regenerate.

	* Makefile.in: New.
	* aclocal.m4: Generate.
	* config.in: Generate.
	* configure.ac: New.
	* configure: Generate.
	* msp430-sim.c: New.
	* msp430-sim.h: New.
	* sim-main.h: New.
	* trace.c: New.
	* trace.h: New.

1 files changed, 1425 insertions, 0 deletions

diff --git a/sim/msp430/msp430-sim.c b/sim/msp430/msp430-sim.c
new file mode 100644
index 0000000..ed785aa
--- /dev/null
+++ b/sim/msp430/msp430-sim.c
@@ -0,0 +1,1425 @@
+/* Simulator for TI MSP430 and MSP430X
+
+   Copyright (C) 2013 Free Software Foundation, Inc.
+   Contributed by Red Hat.
+   Based on sim/bfin/bfin-sim.c which was contributed by Analog Devices, Inc.
+
+   This file is part of 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 <inttypes.h>
+#include <assert.h>
+#include "bfd.h"
+#include "opcode/msp430-decode.h"
+#include "sim-main.h"
+#include "dis-asm.h"
+#include "targ-vals.h"
+
+static int
+loader_write_mem (SIM_DESC sd,
+		  SIM_ADDR taddr,
+		  const unsigned char *buf,
+		  int bytes)
+{
+  SIM_CPU *cpu = MSP430_CPU (sd);
+  return sim_core_write_buffer (sd, cpu, write_map, buf, taddr, bytes);
+}
+
+static sim_cia
+msp430_pc_fetch (SIM_CPU *cpu)
+{
+  return cpu->state.regs[0];
+}
+
+static void
+msp430_pc_store (SIM_CPU *cpu, sim_cia newpc)
+{
+  cpu->state.regs[0] = newpc;
+}
+
+static long
+lookup_symbol (SIM_DESC sd, const char *name)
+{
+  struct bfd *abfd = STATE_PROG_BFD (sd);
+  asymbol **symbol_table = STATE_SYMBOL_TABLE (sd);
+  long number_of_symbols = STATE_NUM_SYMBOLS (sd);
+  long i;
+
+  if (symbol_table == NULL)
+    {
+      long storage_needed;
+
+      storage_needed = bfd_get_symtab_upper_bound (abfd);
+      if (storage_needed <= 0)
+	return -1;
+
+      STATE_SYMBOL_TABLE (sd) = symbol_table = xmalloc (storage_needed);
+      STATE_NUM_SYMBOLS (sd) = number_of_symbols =
+	bfd_canonicalize_symtab (abfd, symbol_table);
+    }
+
+  for (i = 0; i < number_of_symbols; i++)
+    if (strcmp (symbol_table[i]->name, name) == 0)
+      {
+	long val = symbol_table[i]->section->vma + symbol_table[i]->value;
+	return val;
+      }
+  return -1;
+}
+
+static int
+msp430_reg_fetch (SIM_CPU *cpu, int regno, unsigned char *buf, int len)
+{
+  if (0 <= regno && regno < 16)
+    {
+      if (len == 2)
+	{
+	  int val = cpu->state.regs[regno];
+	  buf[0] = val & 0xff;
+	  buf[1] = (val >> 8) & 0xff;
+	  return 0;
+	}
+      else if (len == 4)
+	{
+	  int val = cpu->state.regs[regno];
+	  buf[0] = val & 0xff;
+	  buf[1] = (val >> 8) & 0xff;
+	  buf[2] = (val >> 16) & 0x0f; /* Registers are only 20 bits wide.  */
+	  buf[3] = 0;
+	  return 0;
+	}
+      else
+	return -1;
+    }
+  else
+    return -1;
+}
+
+static int
+msp430_reg_store (SIM_CPU *cpu, int regno, unsigned char *buf, int len)
+{
+  if (0 <= regno && regno < 16)
+    {
+      if (len == 2)
+	{
+	  cpu->state.regs[regno] = (buf[1] << 8) | buf[0];
+	  return len;
+	}
+
+      if (len == 4)
+	{
+	  cpu->state.regs[regno] = ((buf[2] << 16) & 0xf0000)
+				   | (buf[1] << 8) | buf[0];
+	  return len;
+	}
+    }
+
+  return -1;
+}
+
+static inline void
+msp430_initialize_cpu (SIM_DESC sd, SIM_CPU *cpu)
+{
+  memset (&cpu->state, 0, sizeof (cpu->state));
+}
+
+SIM_DESC
+sim_open (SIM_OPEN_KIND kind,
+	  struct host_callback_struct *callback,
+	  struct bfd *abfd,
+	  char **argv)
+{
+  SIM_DESC sd = sim_state_alloc (kind, callback);
+  char c;
+  struct bfd *prog_bfd;
+
+  /* Initialise the simulator.  */
+
+  if (sim_cpu_alloc_all (sd, 1, /*cgen_cpu_max_extra_bytes ()*/0) != SIM_RC_OK)
+    {
+      sim_state_free (sd);
+      return 0;
+    }
+
+  if (sim_pre_argv_init (sd, argv[0]) != SIM_RC_OK)
+    {
+      sim_state_free (sd);
+      return 0;
+    }
+
+  if (sim_parse_args (sd, argv) != SIM_RC_OK)
+    {
+      sim_state_free (sd);
+      return 0;
+    }
+
+  CPU_PC_FETCH (MSP430_CPU (sd)) = msp430_pc_fetch;
+  CPU_PC_STORE (MSP430_CPU (sd)) = msp430_pc_store;
+  CPU_REG_FETCH (MSP430_CPU (sd)) = msp430_reg_fetch;
+  CPU_REG_STORE (MSP430_CPU (sd)) = msp430_reg_store;
+
+  /* Allocate memory if none specified by user.  */
+  if (sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, &c, 0x200, 1) == 0)
+    sim_do_commandf (sd, "memory-region 0,0x10000");
+  if (sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, &c, 0xfffe, 1) == 0)
+    sim_do_commandf (sd, "memory-region 0xfffe,2");
+  if (sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, &c, 0x10000, 1) == 0)
+    sim_do_commandf (sd, "memory-region 0x10000,0x100000");
+
+  /* Check for/establish the a reference program image.  */
+  if (sim_analyze_program (sd,
+			   (STATE_PROG_ARGV (sd) != NULL
+			    ? *STATE_PROG_ARGV (sd)
+			    : NULL), abfd) != SIM_RC_OK)
+    {
+      sim_state_free (sd);
+      return 0;
+    }
+
+  prog_bfd = sim_load_file (sd, argv[0], callback,
+			    "the program",
+			    STATE_PROG_BFD (sd),
+			    0 /* verbose */,
+			    1 /* use LMA instead of VMA */,
+			    loader_write_mem);
+  if (prog_bfd == NULL)
+    {
+      sim_state_free (sd);
+      return 0;
+    }
+
+  /* Establish any remaining configuration options.  */
+  if (sim_config (sd) != SIM_RC_OK)
+    {
+      sim_state_free (sd);
+      return 0;
+    }
+
+  if (sim_post_argv_init (sd) != SIM_RC_OK)
+    {
+      sim_state_free (sd);
+      return 0;
+    }
+
+  /* CPU specific initialization.  */
+  assert (MAX_NR_PROCESSORS == 1);
+  msp430_initialize_cpu (sd, MSP430_CPU (sd));
+
+  msp430_trace_init (STATE_PROG_BFD (sd));
+
+  MSP430_CPU (sd)->state.cio_breakpoint = lookup_symbol (sd, "C$$IO$$");
+  MSP430_CPU (sd)->state.cio_buffer = lookup_symbol (sd, "__CIOBUF__");
+  if (MSP430_CPU (sd)->state.cio_buffer == -1)
+    MSP430_CPU (sd)->state.cio_buffer = lookup_symbol (sd, "_CIOBUF_");
+
+  return sd;
+}
+
+void
+sim_close (SIM_DESC sd,
+	   int quitting)
+{
+  free (STATE_SYMBOL_TABLE (sd));
+  sim_state_free (sd);
+}
+
+SIM_RC
+sim_create_inferior (SIM_DESC sd,
+		     struct bfd *abfd,
+		     char **argv,
+		     char **env)
+{
+  unsigned char resetv[2];
+  int c;
+  int new_pc;
+
+  c = sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, resetv, 0xfffe, 2);
+
+  new_pc = resetv[0] + 256 * resetv[1];
+  sim_pc_set (MSP430_CPU (sd), new_pc);
+  msp430_pc_store (MSP430_CPU (sd), new_pc);
+
+  return SIM_RC_OK;
+}
+
+typedef struct
+{
+  SIM_DESC sd;
+  int gb_addr;
+} Get_Byte_Local_Data;
+
+static int
+msp430_getbyte (void *vld)
+{
+  Get_Byte_Local_Data *ld = (Get_Byte_Local_Data *)vld;
+  char buf[1];
+  SIM_DESC sd = ld->sd;
+
+  sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, buf, ld->gb_addr, 1);
+  ld->gb_addr ++;
+  return buf[0];
+}
+
+#define REG(N) MSP430_CPU (sd)->state.regs[(N)]
+#define PC REG(MSR_PC)
+#define SP REG(MSR_SP)
+#define SR REG(MSR_SR)
+
+static const char *
+register_names[] =
+{
+  "PC", "SP", "SR", "CG", "R4", "R5", "R6", "R7", "R8",
+  "R9", "R10", "R11", "R12", "R13", "R14", "R15"
+};
+
+static void
+trace_reg_put (SIM_DESC sd, int n, unsigned int v)
+{
+  if (TRACE_VPU_P (MSP430_CPU (sd)))
+    trace_generic (sd, MSP430_CPU (sd), TRACE_VPU_IDX,
+		   "PUT: %#x -> %s", v, register_names [n]);
+  REG (n) = v;
+}
+
+static unsigned int
+trace_reg_get (SIM_DESC sd, int n)
+{
+  if (TRACE_VPU_P (MSP430_CPU (sd)))
+    trace_generic (sd, MSP430_CPU (sd), TRACE_VPU_IDX,
+		   "GET: %s -> %#x", register_names [n], REG (n));
+  return REG (n);
+}
+
+#define REG_PUT(N,V) trace_reg_put (sd, N, V)
+#define REG_GET(N)   trace_reg_get (sd, N)
+
+static int
+get_op (SIM_DESC sd, MSP430_Opcode_Decoded *opc, int n)
+{
+  MSP430_Opcode_Operand *op = opc->op + n;
+  int rv;
+  int addr;
+  unsigned char buf[4];
+  int incval = 0;
+
+  switch (op->type)
+    {
+    case MSP430_Operand_Immediate:
+      rv =  op->addend;
+      break;
+    case MSP430_Operand_Register:
+      rv = REG_GET (op->reg);
+      break;
+    case MSP430_Operand_Indirect:
+    case MSP430_Operand_Indirect_Postinc:
+      addr = op->addend;
+      if (op->reg != MSR_None)
+	{
+	  int reg;
+	  /* Index values are signed, but the sum is limited to 16
+	     bits if the register < 64k, for MSP430 compatibility in
+	     MSP430X chips.  */
+	  if (addr & 0x8000)
+	    addr |= -1 << 16;
+	  reg = REG_GET (op->reg);
+	  addr += reg;
+	  if (reg < 0x10000 && ! opc->ofs_430x)
+	    addr &= 0xffff;
+	}
+      addr &= 0xfffff;
+      switch (opc->size)
+	{
+	case 8:
+	  sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, buf, addr, 1);
+	  rv = buf[0];
+	  break;
+	case 16:
+	  sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, buf, addr, 2);
+	  rv = buf[0] | (buf[1] << 8);
+	  break;
+	case 20:
+	case 32:
+	  sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, buf, addr, 4);
+	  rv = buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
+	  break;
+	default:
+	  assert (! opc->size);
+	  break;
+	}
+#if 0
+      /* Hack - MSP430X5438 serial port status register.  */
+      if (addr == 0x5dd)
+	rv = 2;
+#endif
+      if (TRACE_MEMORY_P (MSP430_CPU (sd)))
+	trace_generic (sd, MSP430_CPU (sd), TRACE_MEMORY_IDX,
+		       "GET: [%#x].%d -> %#x", addr, opc->size, rv);
+      break;
+    default:
+      fprintf (stderr, "invalid operand %d type %d\n", n, op->type);
+      abort ();
+    }
+
+  switch (opc->size)
+    {
+    case 8:
+      rv &= 0xff;
+      incval = 1;
+      break;
+    case 16:
+      rv &= 0xffff;
+      incval = 2;
+      break;
+    case 20:
+      rv &= 0xfffff;
+      incval = 4;
+      break;
+    case 32:
+      rv &= 0xffffffff;
+      incval = 4;
+      break;
+    }
+
+  if (op->type == MSP430_Operand_Indirect_Postinc)
+    REG_PUT (op->reg, REG_GET (op->reg) + incval);
+
+  return rv;
+}
+
+static int
+put_op (SIM_DESC sd, MSP430_Opcode_Decoded *opc, int n, int val)
+{
+  MSP430_Opcode_Operand *op = opc->op + n;
+  int rv;
+  int addr;
+  unsigned char buf[4];
+  int incval = 0;
+
+  switch (opc->size)
+    {
+    case 8:
+      val &= 0xff;
+      break;
+    case 16:
+      val &= 0xffff;
+      break;
+    case 20:
+      val &= 0xfffff;
+      break;
+    case 32:
+      val &= 0xffffffff;
+      break;
+    }
+
+  switch (op->type)
+    {
+    case MSP430_Operand_Register:
+      REG (op->reg) = val;
+      REG_PUT (op->reg, val);
+      break;
+    case MSP430_Operand_Indirect:
+    case MSP430_Operand_Indirect_Postinc:
+      addr = op->addend;
+      if (op->reg != MSR_None)
+	{
+	  int reg;
+	  /* Index values are signed, but the sum is limited to 16
+	     bits if the register < 64k, for MSP430 compatibility in
+	     MSP430X chips.  */
+	  if (addr & 0x8000)
+	    addr |= -1 << 16;
+	  reg = REG_GET (op->reg);
+	  addr += reg;
+	  if (reg < 0x10000)
+	    addr &= 0xffff;
+	}
+      addr &= 0xfffff;
+
+      if (TRACE_MEMORY_P (MSP430_CPU (sd)))
+	trace_generic (sd, MSP430_CPU (sd), TRACE_MEMORY_IDX,
+		       "PUT: [%#x].%d <- %#x", addr, opc->size, val);
+#if 0
+      /* Hack - MSP430X5438 serial port transmit register.  */
+      if (addr == 0x5ce)
+	putchar (val);
+#endif
+      switch (opc->size)
+	{
+	case 8:
+	  buf[0] = val;
+	  sim_core_write_buffer (sd, MSP430_CPU (sd), write_map, buf, addr, 1);
+	  break;
+	case 16:
+	  buf[0] = val;
+	  buf[1] = val >> 8;
+	  sim_core_write_buffer (sd, MSP430_CPU (sd), write_map, buf, addr, 2);
+	  break;
+	case 20:
+	case 32:
+	  buf[0] = val;
+	  buf[1] = val >> 8;
+	  buf[2] = val >> 16;
+	  buf[3] = val >> 24;
+	  sim_core_write_buffer (sd, MSP430_CPU (sd), write_map, buf, addr, 4);
+	  break;
+	default:
+	  assert (! opc->size);
+	  break;
+	}
+      break;
+    default:
+      fprintf (stderr, "invalid operand %d type %d\n", n, op->type);
+      abort ();
+    }
+
+  switch (opc->size)
+    {
+    case 8:
+      rv &= 0xff;
+      incval = 1;
+      break;
+    case 16:
+      rv &= 0xffff;
+      incval = 2;
+      break;
+    case 20:
+      rv &= 0xfffff;
+      incval = 4;
+      break;
+    case 32:
+      rv &= 0xffffffff;
+      incval = 4;
+      break;
+    }
+
+  if (op->type == MSP430_Operand_Indirect_Postinc)
+    {
+      int new_val = REG_GET (op->reg) + incval;
+      /* SP is always word-aligned.  */
+      if (op->reg == MSR_SP && (new_val & 1))
+	new_val ++;
+      REG_PUT (op->reg, new_val);
+    }
+
+  return rv;
+}
+
+static void
+mem_put_val (SIM_DESC sd, int addr, int val, int bits)
+{
+  MSP430_Opcode_Decoded opc;
+
+  opc.size = bits;
+  opc.op[0].type = MSP430_Operand_Indirect;
+  opc.op[0].addend = addr;
+  opc.op[0].reg = MSR_None;
+  put_op (sd, &opc, 0, val);
+}
+
+static int
+mem_get_val (SIM_DESC sd, int addr, int bits)
+{
+  MSP430_Opcode_Decoded opc;
+
+  opc.size = bits;
+  opc.op[0].type = MSP430_Operand_Indirect;
+  opc.op[0].addend = addr;
+  opc.op[0].reg = MSR_None;
+  return get_op (sd, &opc, 0);
+}
+
+#define CIO_OPEN    (0xF0)
+#define CIO_CLOSE   (0xF1)
+#define CIO_READ    (0xF2)
+#define CIO_WRITE   (0xF3)
+#define CIO_LSEEK   (0xF4)
+#define CIO_UNLINK  (0xF5)
+#define CIO_GETENV  (0xF6)
+#define CIO_RENAME  (0xF7)
+#define CIO_GETTIME (0xF8)
+#define CIO_GETCLK  (0xF9)
+#define CIO_SYNC    (0xFF)
+
+#define CIO_I(n) (parms[(n)] + parms[(n)+1] * 256)
+#define CIO_L(n) (parms[(n)] + parms[(n)+1] * 256 \
+		  + parms[(n)+2] * 65536 + parms[(n)+3] * 16777216)
+
+static void
+msp430_cio (SIM_DESC sd)
+{
+  /* A block of data at __CIOBUF__ describes the I/O operation to
+     perform.  */
+
+  unsigned char raw_parms[13];
+  unsigned char parms[8];
+  long length;
+  int command;
+  unsigned char buffer[512];
+  long ret_buflen = 0;
+  long fd, addr, len, rv;
+
+  sim_core_read_buffer (sd, MSP430_CPU (sd), 0, parms,
+			MSP430_CPU (sd)->state.cio_buffer, 5);
+  length = CIO_I (0);
+  command = parms[2];
+
+  sim_core_read_buffer (sd, MSP430_CPU (sd), 0, parms,
+			MSP430_CPU (sd)->state.cio_buffer + 3, 8);
+
+  sim_core_read_buffer (sd, MSP430_CPU (sd), 0, buffer,
+			MSP430_CPU (sd)->state.cio_buffer + 11, length);
+
+  switch (command)
+    {
+    case CIO_WRITE:
+      fd = CIO_I (0);
+      len = CIO_I (2);
+
+      rv = write (fd, buffer, len);
+      parms[0] = rv & 0xff;
+      parms[1] = rv >> 8;
+
+      break;
+    }
+
+  sim_core_write_buffer (sd, MSP430_CPU (sd), 0, parms,
+			 MSP430_CPU (sd)->state.cio_buffer + 4, 8);
+  if (ret_buflen)
+    sim_core_write_buffer (sd, MSP430_CPU (sd), 0, buffer,
+			   MSP430_CPU (sd)->state.cio_buffer + 12, ret_buflen);
+}
+
+#define SRC     get_op (sd, opcode, 1)
+#define DSRC    get_op (sd, opcode, 0)
+#define DEST(V) put_op (sd, opcode, 0, (V))
+
+static int
+msp430_dis_read (bfd_vma memaddr,
+		 bfd_byte *myaddr,
+		 unsigned int length,
+		 struct disassemble_info *dinfo)
+{
+  SIM_DESC sd = dinfo->private_data;
+  sim_core_read_buffer (sd, MSP430_CPU (sd), 0, myaddr, memaddr, length);
+  return 0;
+}
+
+#define DO_ALU(OP,SOP,MORE)						\
+  {									\
+    int s1 = DSRC;							\
+    int s2 = SRC;							\
+    int result = s1 OP s2 MORE;						\
+    if (TRACE_ALU_P (MSP430_CPU (sd)))					\
+      trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,		\
+		     "ALU: %#x %s %#x %s = %#x", s1, SOP, s2, #MORE, result); \
+    DEST (result);							\
+  }
+
+#define SIGN   (1 << (opcode->size - 1))
+#define POS(x) (((x) & SIGN) ? 0 : 1)
+#define NEG(x) (((x) & SIGN) ? 1 : 0)
+
+static int
+zero_ext (int v, int bits)
+{
+  v &= ((1 << bits) - 1);
+  return v;
+}
+
+static int
+sign_ext (int v, int bits)
+{
+  int sb = 1 << (bits-1);	/* Sign bit.  */
+  int mb = (1 << (bits-1)) - 1; /* Mantissa bits.  */
+
+  if (v & sb)
+    v = v | ~mb;
+  else
+    v = v & mb;
+  return v;
+}
+
+#define SX(v) sign_ext (v, opcode->size)
+#define ZX(v) zero_ext (v, opcode->size)
+
+static char *
+flags2string (int f)
+{
+  static char buf[2][6];
+  static int bi = 0;
+  char *bp = buf[bi];
+
+  bi = (bi + 1) % 2;
+
+  bp[0] = f & MSP430_FLAG_V ? 'V' : '-';
+  bp[1] = f & MSP430_FLAG_N ? 'N' : '-';
+  bp[2] = f & MSP430_FLAG_Z ? 'Z' : '-';
+  bp[3] = f & MSP430_FLAG_C ? 'C' : '-';
+  bp[4] = 0;
+  return bp;
+}
+
+/* Random number that won't show up in our usual logic.  */
+#define MAGIC_OVERFLOW 0x55000F
+
+static void
+do_flags (SIM_DESC sd,
+	  MSP430_Opcode_Decoded *opcode,
+	  int vnz_val, /* Signed result.  */
+	  int carry,
+	  int overflow)
+{
+  int f = SR;
+  int new_f = 0;
+  int signbit = 1 << (opcode->size - 1);
+
+  f &= ~opcode->flags_0;
+  f &= ~opcode->flags_set;
+  f |= opcode->flags_1;
+
+  if (vnz_val & signbit)
+    new_f |= MSP430_FLAG_N;
+  if (! (vnz_val & ((signbit << 1) - 1)))
+    new_f |= MSP430_FLAG_Z;
+  if (overflow == MAGIC_OVERFLOW)
+    {
+      if (vnz_val != SX (vnz_val))
+	new_f |= MSP430_FLAG_V;
+    }
+  else
+    if (overflow)
+      new_f |= MSP430_FLAG_V;
+  if (carry)
+    new_f |= MSP430_FLAG_C;
+
+  new_f = f | (new_f & opcode->flags_set);
+  if (TRACE_ALU_P (MSP430_CPU (sd)))
+    {
+      if (SR != new_f)
+	trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+		       "FLAGS: %s -> %s", flags2string (SR),
+		       flags2string (new_f));
+      else
+	trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+		       "FLAGS: %s", flags2string (new_f));
+    }
+  SR = new_f;
+}
+
+#define FLAGS(vnz,c)    do_flags (sd, opcode, vnz, c, MAGIC_OVERFLOW)
+#define FLAGSV(vnz,c,v) do_flags (sd, opcode, vnz, c, v)
+
+/* These two assume unsigned 16-bit (four digit) words.
+   Mask off unwanted bits for byte operations.  */
+
+static int
+bcd_to_binary (int v)
+{
+  int r = (  ((v >>  0) & 0xf) * 1
+	   + ((v >>  4) & 0xf) * 10
+	   + ((v >>  8) & 0xf) * 100
+	   + ((v >> 12) & 0xf) * 1000);
+  return r;
+}
+
+static int
+binary_to_bcd (int v)
+{
+  int r = ( ((v /    1) % 10) <<  0
+	  | ((v /   10) % 10) <<  4
+	  | ((v /  100) % 10) <<  8
+	  | ((v / 1000) % 10) << 12);
+  return r;
+}
+
+static int
+syscall_read_mem (host_callback *cb, struct cb_syscall *sc,
+		  unsigned long taddr, char *buf, int bytes)
+{
+  SIM_DESC sd = (SIM_DESC) sc->p1;
+  SIM_CPU *cpu = (SIM_CPU *) sc->p2;
+
+  return sim_core_read_buffer (sd, cpu, read_map, buf, taddr, bytes);
+}
+
+static int
+syscall_write_mem (host_callback *cb, struct cb_syscall *sc,
+		  unsigned long taddr, const char *buf, int bytes)
+{
+  SIM_DESC sd = (SIM_DESC) sc->p1;
+  SIM_CPU *cpu = (SIM_CPU *) sc->p2;
+
+  return sim_core_write_buffer (sd, cpu, write_map, buf, taddr, bytes);
+}
+
+static const char *
+cond_string (int cond)
+{
+  switch (cond)
+    {
+    case MSC_nz:
+      return "NZ";
+    case MSC_z:
+      return "Z";
+    case MSC_nc:
+      return "NC";
+    case MSC_c:
+      return "C";
+    case MSC_n:
+      return "N";
+    case MSC_ge:
+      return "GE";
+    case MSC_l:
+      return "L";
+    case MSC_true:
+      return "MP";
+    default:
+      return "??";
+    }
+}
+
+/* Checks a CALL to address CALL_ADDR.  If this is a special
+   syscall address then the call is simulated and non-zero is
+   returned.  Otherwise 0 is returned.  */
+
+static int
+maybe_perform_syscall (SIM_DESC sd, int call_addr)
+{
+  if (call_addr == 0x00160)
+    {
+      int i;
+
+      for (i = 0; i < 16; i++)
+	{
+	  if (i % 4 == 0)
+	    fprintf (stderr, "\t");
+	  fprintf (stderr, "R%-2d %05x   ", i, MSP430_CPU (sd)->state.regs[i]);
+	  if (i % 4 == 3)
+	    {
+	      int sp = SP + (3 - (i / 4)) * 2;
+	      unsigned char buf[2];
+
+	      sim_core_read_buffer (sd, MSP430_CPU (sd), read_map, buf, sp, 2);
+
+	      fprintf (stderr, "\tSP%+d: %04x", sp - SP,
+		       buf[0] + buf[1] * 256);
+
+	      if (i / 4 == 0)
+		{
+		  int flags = SR;
+
+		  fprintf (stderr, flags & 0x100 ? "   V" : "   -");
+		  fprintf (stderr, flags & 0x004 ? "N" : "-");
+		  fprintf (stderr, flags & 0x002 ? "Z" : "-");
+		  fprintf (stderr, flags & 0x001 ? "C" : "-");
+		}
+
+	      fprintf (stderr, "\n");
+	    }
+	}
+      return 1;
+    }
+
+  if ((call_addr & ~0x3f) == 0x00180)
+    {
+      /* Syscall!  */
+      int syscall_num = call_addr & 0x3f;
+      host_callback *cb = STATE_CALLBACK (sd);
+      CB_SYSCALL sc;
+
+      CB_SYSCALL_INIT (&sc);
+
+      sc.func = syscall_num;
+      sc.arg1 = MSP430_CPU (sd)->state.regs[12];
+      sc.arg2 = MSP430_CPU (sd)->state.regs[13];
+      sc.arg3 = MSP430_CPU (sd)->state.regs[14];
+      sc.arg4 = MSP430_CPU (sd)->state.regs[15];
+
+      if (TRACE_SYSCALL_P (MSP430_CPU (sd)))
+	{
+	  const char *syscall_name = "*unknown*";
+
+	  switch (syscall_num)
+	    {
+	    case TARGET_SYS_exit:
+	      syscall_name = "exit(%d)";
+	      break;
+	    case TARGET_SYS_open:
+	      syscall_name = "open(%#x,%#x)";
+	      break;
+	    case TARGET_SYS_close:
+	      syscall_name = "close(%d)";
+	      break;
+	    case TARGET_SYS_read:
+	      syscall_name = "read(%d,%#x,%d)";
+	      break;
+	    case TARGET_SYS_write:
+	      syscall_name = "write(%d,%#x,%d)";
+	      break;
+	    }
+	  trace_generic (sd, MSP430_CPU (sd), TRACE_SYSCALL_IDX,
+			 syscall_name, sc.arg1, sc.arg2, sc.arg3, sc.arg4);
+	}
+
+      /* Handle SYS_exit here.  */
+      if (syscall_num == 1)
+	{
+	  sim_engine_halt (sd, MSP430_CPU (sd), NULL,
+			   MSP430_CPU (sd)->state.regs[0],
+			   sim_exited, sc.arg1);
+	  return 1;
+	}
+
+      sc.p1 = sd;
+      sc.p2 = MSP430_CPU (sd);
+      sc.read_mem = syscall_read_mem;
+      sc.write_mem = syscall_write_mem;
+
+      cb_syscall (cb, &sc);
+
+      if (TRACE_SYSCALL_P (MSP430_CPU (sd)))
+	trace_generic (sd, MSP430_CPU (sd), TRACE_SYSCALL_IDX,
+		       "returns %d", sc.result);
+
+      MSP430_CPU (sd)->state.regs[12] = sc.result;
+      return 1;
+    }
+
+  return 0;
+}
+
+static void
+msp430_step_once (SIM_DESC sd)
+{
+  Get_Byte_Local_Data ld;
+  unsigned char buf[100];
+  int i;
+  int opsize;
+  unsigned int opcode_pc;
+  MSP430_Opcode_Decoded opcode_buf;
+  MSP430_Opcode_Decoded *opcode = &opcode_buf;
+  int s1, s2, result;
+  int u1, u2, uresult;
+  int c, reg;
+  int sp;
+  int carry_to_use;
+  int n_repeats;
+  int rept;
+  int op_bytes, op_bits;
+
+  PC &= 0xfffff;
+  opcode_pc = PC;
+
+  if (opcode_pc < 0x10)
+    {
+      fprintf (stderr, "Fault: PC(%#x) is less than 0x10\n", opcode_pc);
+      sim_engine_halt (sd, MSP430_CPU (sd), NULL,
+		       MSP430_CPU (sd)->state.regs[0],
+		       sim_exited, -1);
+      return;
+    }
+
+  if (PC == MSP430_CPU (sd)->state.cio_breakpoint
+      && STATE_OPEN_KIND (sd) != SIM_OPEN_DEBUG)
+    msp430_cio (sd);
+
+  ld.sd = sd;
+  ld.gb_addr = PC;
+  opsize = msp430_decode_opcode (MSP430_CPU (sd)->state.regs[0],
+				 opcode, msp430_getbyte, &ld);
+  PC += opsize;
+  if (opsize <= 0)
+    {
+      fprintf (stderr, "Fault: undecodable opcode at %#x\n", opcode_pc);
+      sim_engine_halt (sd, MSP430_CPU (sd), NULL,
+		       MSP430_CPU (sd)->state.regs[0],
+		       sim_exited, -1);
+      return;
+    }
+
+  if (opcode->repeat_reg)
+    n_repeats = (MSP430_CPU (sd)->state.regs[opcode->repeats] & 0x000f) + 1;
+  else
+    n_repeats = opcode->repeats + 1;
+
+  op_bits = opcode->size;
+  switch (op_bits)
+    {
+    case 8:
+      op_bytes = 1;
+      break;
+    case 16:
+      op_bytes = 2;
+      break;
+    case 20:
+    case 32:
+      op_bytes = 4;
+      break;
+    }
+
+  if (TRACE_INSN_P (MSP430_CPU (sd)))
+    {
+      disassemble_info info;
+      unsigned char b[10];
+
+      msp430_trace_one (opcode_pc);
+
+      sim_core_read_buffer (sd, MSP430_CPU (sd), 0, b, opcode_pc, opsize);
+
+      init_disassemble_info (&info, stderr, fprintf);
+      info.private_data = sd;
+      info.read_memory_func = msp430_dis_read;
+      fprintf (stderr, "%#8x  ", opcode_pc);
+      for (i = 0; i < opsize; i += 2)
+	fprintf (stderr, " %02x%02x", b[i+1], b[i]);
+      for (; i < 6; i += 2)
+	fprintf (stderr, "     ");
+      fprintf (stderr, "  ");
+      print_insn_msp430 (opcode_pc, &info);
+      fprintf (stderr, "\n");
+      fflush (stdout);
+    }
+
+  if (TRACE_ANY_P (MSP430_CPU (sd)))
+    trace_prefix (sd, MSP430_CPU (sd), NULL_CIA, opcode_pc,
+    TRACE_LINENUM_P (MSP430_CPU (sd)), NULL, 0, "");
+
+  carry_to_use = 0;
+  switch (opcode->id)
+    {
+    case MSO_unknown:
+      break;
+
+      /* Double-operand instructions.  */
+    case MSO_mov:
+      if (opcode->n_bytes == 2
+	  && opcode->op[0].type == MSP430_Operand_Register
+	  && opcode->op[0].reg == MSR_CG
+	  && opcode->op[1].type == MSP430_Operand_Immediate
+	  && opcode->op[1].addend == 0
+	  /* A 16-bit write of #0 is a NOP; an 8-bit write is a BRK.  */
+	  && opcode->size == 8)
+	{
+	  /* This is the designated software breakpoint instruction.  */
+	  PC -= opsize;
+	  sim_engine_halt (sd, MSP430_CPU (sd), NULL,
+			   MSP430_CPU (sd)->state.regs[0],
+			   sim_stopped, SIM_SIGTRAP);
+
+	}
+      else
+	{
+	  /* Otherwise, do the move.  */
+	  for (rept = 0; rept < n_repeats; rept ++)
+	    {
+	      DEST (SRC);
+	    }
+	}
+      break;
+
+    case MSO_addc:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  carry_to_use = (SR & MSP430_FLAG_C) ? 1 : 0;
+	  u1 = DSRC;
+	  u2 = SRC;
+	  s1 = SX (u1);
+	  s2 = SX (u2);
+	  uresult = u1 + u2 + carry_to_use;
+	  result = s1 + s2 + carry_to_use;
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "ADDC: %#x + %#x + %d = %#x",
+			   u1, u2, carry_to_use, uresult);
+	  DEST (result);
+	  FLAGS (result, uresult != ZX (uresult));
+	}
+      break;
+
+    case MSO_add:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  u1 = DSRC;
+	  u2 = SRC;
+	  s1 = SX (u1);
+	  s2 = SX (u2);
+	  uresult = u1 + u2;
+	  result = s1 + s2;
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "ADD: %#x + %#x = %#x",
+			   u1, u2, uresult);
+	  DEST (result);
+	  FLAGS (result, uresult != ZX (uresult));
+	}
+      break;
+
+    case MSO_subc:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  carry_to_use = (SR & MSP430_FLAG_C) ? 1 : 0;
+	  u1 = DSRC;
+	  u2 = SRC;
+	  s1 = SX (u1);
+	  s2 = SX (u2);
+	  uresult = ZX (~u2) + u1 + carry_to_use;
+	  result = s1 - s2 + (carry_to_use - 1);
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "SUBC: %#x - %#x + %d = %#x",
+			   u1, u2, carry_to_use, uresult);
+	  DEST (result);
+	  FLAGS (result, uresult != ZX (uresult));
+	}
+      break;
+
+    case MSO_sub:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  u1 = DSRC;
+	  u2 = SRC;
+	  s1 = SX (u1);
+	  s2 = SX (u2);
+	  uresult = ZX (~u2) + u1 + 1;
+	  result = SX (uresult);
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "SUB: %#x - %#x = %#x",
+			   u1, u2, uresult);
+	  DEST (result);
+	  FLAGS (result, uresult != ZX (uresult));
+	}
+      break;
+
+    case MSO_cmp:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  u1 = DSRC;
+	  u2 = SRC;
+	  s1 = SX (u1);
+	  s2 = SX (u2);
+	  uresult = ZX (~u2) + u1 + 1;
+	  result = s1 - s2;
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "CMP: %#x - %#x = %x",
+			   u1, u2, uresult);
+	  FLAGS (result, uresult != ZX (uresult));
+	}
+      break;
+
+    case MSO_dadd:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  carry_to_use = (SR & MSP430_FLAG_C) ? 1 : 0;
+	  u1 = DSRC;
+	  u2 = SRC;
+	  uresult = bcd_to_binary (u1) + bcd_to_binary (u2) + carry_to_use;
+	  result = binary_to_bcd (uresult);
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "DADD: %#x + %#x + %d = %#x",
+			   u1, u2, carry_to_use, result);
+	  DEST (result);
+	  FLAGS (result, uresult > ((opcode->size == 8) ? 99 : 9999));
+	}
+      break;
+
+    case MSO_and:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  u1 = DSRC;
+	  u2 = SRC;
+	  uresult = u1 & u2;
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "AND: %#x & %#x = %#x",
+			   u1, u2, uresult);
+	  DEST (uresult);
+	  FLAGS (uresult, uresult != 0);
+	}
+      break;
+
+    case MSO_bit:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  u1 = DSRC;
+	  u2 = SRC;
+	  uresult = u1 & u2;
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "BIT: %#x & %#x -> %#x",
+			   u1, u2, uresult);
+	  FLAGS (uresult, uresult != 0);
+	}
+      break;
+
+    case MSO_bic:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  u1 = DSRC;
+	  u2 = SRC;
+	  uresult = u1 & ~ u2;
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "BIC: %#x & ~ %#x = %#x",
+			   u1, u2, uresult);
+	  DEST (uresult);
+	}
+      break;
+
+    case MSO_bis:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  u1 = DSRC;
+	  u2 = SRC;
+	  uresult = u1 | u2;
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "BIS: %#x | %#x = %#x",
+			   u1, u2, uresult);
+	  DEST (uresult);
+	}
+      break;
+
+    case MSO_xor:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  s1 = 1 << (opcode->size - 1);
+	  u1 = DSRC;
+	  u2 = SRC;
+	  uresult = u1 ^ u2;
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "XOR: %#x & %#x = %#x",
+			   u1, u2, uresult);
+	  DEST (uresult);
+	  FLAGSV (uresult, uresult != 0, (u1 & s1) && (u2 & s1));
+	}
+      break;
+
+    /* Single-operand instructions.  Note: the decoder puts the same
+       operand in SRC as in DEST, for our convenience.  */
+
+    case MSO_rrc:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  u1 = SRC;
+	  carry_to_use = u1 & 1;
+	  uresult = u1 >> 1;
+	  if (SR & MSP430_FLAG_C)
+	  uresult |= (1 << (opcode->size - 1));
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "RRC: %#x >>= %#x",
+			   u1, uresult);
+	  DEST (uresult);
+	  FLAGS (uresult, carry_to_use);
+	}
+      break;
+
+    case MSO_swpb:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  u1 = SRC;
+	  uresult = ((u1 >> 8) & 0x00ff) | ((u1 << 8) & 0xff00);
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "SWPB: %#x -> %#x",
+			   u1, uresult);
+	  DEST (uresult);
+	}
+      break;
+
+    case MSO_rra:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  u1 = SRC;
+	  c = u1 & 1;
+	  s1 = 1 << (opcode->size - 1);
+	  uresult = (u1 >> 1) | (u1 & s1);
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "RRA: %#x >>= %#x",
+			   u1, uresult);
+	  DEST (uresult);
+	  FLAGS (uresult, c);
+	}
+      break;
+
+    case MSO_rru:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  u1 = SRC;
+	  c = u1 & 1;
+	  uresult = (u1 >> 1);
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "RRU: %#x >>= %#x",
+			   u1, uresult);
+	  DEST (uresult);
+	  FLAGS (uresult, c);
+	}
+      break;
+
+    case MSO_sxt:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  u1 = SRC;
+	  if (u1 & 0x80)
+	    uresult = u1 | 0xfff00;
+	  else
+	    uresult = u1 & 0x000ff;
+	  if (TRACE_ALU_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+			   "SXT: %#x -> %#x",
+			   u1, uresult);
+	  DEST (uresult);
+	  FLAGS (uresult, c);
+	}
+      break;
+
+    case MSO_push:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  int new_sp;
+
+	  new_sp = REG_GET (MSR_SP) - op_bytes;
+	  /* SP is always word-aligned.  */
+	  if (new_sp & 1)
+	    new_sp --;
+	  REG_PUT (MSR_SP, new_sp);
+	  u1 = SRC;
+	  mem_put_val (sd, SP, u1, op_bits);
+	  if (opcode->op[1].type == MSP430_Operand_Register)
+	    opcode->op[1].reg --;
+	}
+      break;
+
+    case MSO_pop:
+      for (rept = 0; rept < n_repeats; rept ++)
+	{
+	  int new_sp;
+
+	  u1 = mem_get_val (sd, SP, op_bits);
+	  DEST (u1);
+	  if (opcode->op[0].type == MSP430_Operand_Register)
+	    opcode->op[0].reg ++;
+	  new_sp = REG_GET (MSR_SP) + op_bytes;
+	  /* SP is always word-aligned.  */
+	  if (new_sp & 1)
+	    new_sp ++;
+	  REG_PUT (MSR_SP, new_sp);
+	}
+      break;
+
+    case MSO_call:
+      u1 = SRC;
+
+      if (maybe_perform_syscall (sd, u1))
+	break;
+
+      REG_PUT (MSR_SP, REG_GET (MSR_SP) - op_bytes);
+      mem_put_val (sd, SP, PC, op_bits);
+      if (TRACE_ALU_P (MSP430_CPU (sd)))
+	trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+		       "CALL: func %#x ret %#x, sp %#x",
+		       u1, PC, SP);
+      REG_PUT (MSR_PC, u1);
+      break;
+
+    case MSO_reti:
+      SR = mem_get_val (sd, SP, op_bits);
+      SP += 2;
+      PC = mem_get_val (sd, SP, op_bits);
+      SP += 2;
+      if (TRACE_ALU_P (MSP430_CPU (sd)))
+	trace_generic (sd, MSP430_CPU (sd), TRACE_ALU_IDX,
+		       "RETI: pc %#x sr %#x",
+		       PC, SR);
+      break;
+
+      /* Jumps.  */
+
+    case MSO_jmp:
+      i = SRC;
+      switch (opcode->cond)
+	{
+	case MSC_nz:
+	  u1 = (SR & MSP430_FLAG_Z) ? 0 : 1;
+	  break;
+	case MSC_z:
+	  u1 = (SR & MSP430_FLAG_Z) ? 1 : 0;
+	  break;
+	case MSC_nc:
+	  u1 = (SR & MSP430_FLAG_C) ? 0 : 1;
+	  break;
+	case MSC_c:
+	  u1 = (SR & MSP430_FLAG_C) ? 1 : 0;
+	  break;
+	case MSC_n:
+	  u1 = (SR & MSP430_FLAG_N) ? 1 : 0;
+	  break;
+	case MSC_ge:
+	  u1 = (!!(SR & MSP430_FLAG_N) == !!(SR & MSP430_FLAG_V)) ? 1 : 0;
+	  break;
+	case MSC_l:
+	  u1 = (!!(SR & MSP430_FLAG_N) == !!(SR & MSP430_FLAG_V)) ? 0 : 1;
+	  break;
+	case MSC_true:
+	  u1 = 1;
+	  break;
+	}
+
+      if (u1)
+	{
+	  if (TRACE_BRANCH_P (MSP430_CPU (sd)))
+	    trace_generic (sd, MSP430_CPU (sd), TRACE_BRANCH_IDX,
+			   "J%s: pc %#x -> %#x sr %#x, taken",
+			   cond_string (opcode->cond), PC, i, SR);
+	  PC = i;
+	  if (PC == opcode_pc)
+	    exit (0);
+	}
+      else
+	if (TRACE_BRANCH_P (MSP430_CPU (sd)))
+	  trace_generic (sd, MSP430_CPU (sd), TRACE_BRANCH_IDX,
+			 "J%s: pc %#x to %#x sr %#x, not taken",
+			 cond_string (opcode->cond), PC, i, SR);
+      break;
+
+    default:
+      fprintf (stderr, "error: unexpected opcode id %d\n", opcode->id);
+      exit (1);
+    }
+}
+
+void
+sim_engine_run (SIM_DESC sd,
+		int next_cpu_nr,
+		int nr_cpus,
+		int siggnal)
+{
+  while (1)
+    {
+      msp430_step_once (sd);
+      if (sim_events_tick (sd))
+	sim_events_process (sd);
+    }
+}