/* IQ2000 simulator support code
   Copyright (C) 2000, 2004, 2007, 2008, 2009, 2010
   Free Software Foundation, Inc.
   Contributed by Cygnus Support.

   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/>.  */

#define WANT_CPU
#define WANT_CPU_IQ2000BF

#include "sim-main.h"
#include "cgen-mem.h"
#include "cgen-ops.h"

enum
{
  GPR0_REGNUM = 0,
  NR_GPR = 32,
  PC_REGNUM = 32
};

enum libgloss_syscall
{
  SYS_exit = 1,
  SYS_open = 2, 
  SYS_close = 3, 
  SYS_read = 4,
  SYS_write = 5, 
  SYS_lseek = 6, 
  SYS_unlink = 7,
  SYS_getpid = 8,
  SYS_kill = 9,
  SYS_fstat = 10, 
  SYS_argvlen = 12, 
  SYS_argv = 13,
  SYS_chdir = 14, 
  SYS_stat = 15, 
  SYS_chmod = 16, 
  SYS_utime = 17,
  SYS_time = 18,
  SYS_gettimeofday = 19,
  SYS_times = 20
};

/* Read a null terminated string from memory, return in a buffer */
static char *
fetch_str (current_cpu, pc, addr)
     SIM_CPU *current_cpu;
     PCADDR pc;
     DI addr;
{
  char *buf;
  int nr = 0;
  while (sim_core_read_1 (current_cpu,
                          pc, read_map, CPU2DATA(addr + nr)) != 0)
    nr++;
  buf = NZALLOC (char, nr + 1);
  sim_read (CPU_STATE (current_cpu), CPU2DATA(addr), buf, nr);
  return buf;
}

void
do_syscall (SIM_CPU *current_cpu, PCADDR pc)
{
#if 0
  int syscall = H2T_4 (iq2000bf_h_gr_get (current_cpu, 11));
#endif
  int syscall_function = iq2000bf_h_gr_get (current_cpu, 4);
  int i;
  char *buf;
  int PARM1 = iq2000bf_h_gr_get (current_cpu, 5);
  int PARM2 = iq2000bf_h_gr_get (current_cpu, 6);
  int PARM3 = iq2000bf_h_gr_get (current_cpu, 7);
  const int ret_reg = 2;
	
  switch (syscall_function)
    {
    case 0:
      switch (H2T_4 (iq2000bf_h_gr_get (current_cpu, 11)))
	{
	case 0:
	  /* Pass.  */
	  puts ("pass");
	  exit (0);
	case 1:
	  /* Fail.  */
	  puts ("fail");
	  exit (1);
	}

    case SYS_write:
      buf = zalloc (PARM3);
      sim_read (CPU_STATE (current_cpu), CPU2DATA(PARM2), buf, PARM3);
      SET_H_GR (ret_reg,
		sim_io_write (CPU_STATE (current_cpu),
			      PARM1, buf, PARM3));
      zfree (buf);
      break;

    case SYS_lseek:
      SET_H_GR (ret_reg,
		sim_io_lseek (CPU_STATE (current_cpu),
			      PARM1, PARM2, PARM3));
      break;
	    
    case SYS_exit:
      sim_engine_halt (CPU_STATE (current_cpu), current_cpu,
		       NULL, pc, sim_exited, PARM1);
      break;

    case SYS_read:
      buf = zalloc (PARM3);
      SET_H_GR (ret_reg,
		sim_io_read (CPU_STATE (current_cpu),
			     PARM1, buf, PARM3));
      sim_write (CPU_STATE (current_cpu), CPU2DATA(PARM2), buf, PARM3);
      zfree (buf);
      break;
	    
    case SYS_open:
      buf = fetch_str (current_cpu, pc, PARM1);
      SET_H_GR (ret_reg,
		sim_io_open (CPU_STATE (current_cpu),
			     buf, PARM2));
      zfree (buf);
      break;

    case SYS_close:
      SET_H_GR (ret_reg,
		sim_io_close (CPU_STATE (current_cpu), PARM1));
      break;

    case SYS_time:
      SET_H_GR (ret_reg, time (0));
      break;

    default:
      SET_H_GR (ret_reg, -1);
    }
}

void 
do_break (SIM_CPU *current_cpu, PCADDR pc)
{
  SIM_DESC sd = CPU_STATE (current_cpu);
  sim_engine_halt (sd, current_cpu, NULL, pc, sim_stopped, SIM_SIGTRAP);
}

/* The semantic code invokes this for invalid (unrecognized) instructions.  */

SEM_PC
sim_engine_invalid_insn (SIM_CPU *current_cpu, IADDR cia, SEM_PC vpc)
{
  SIM_DESC sd = CPU_STATE (current_cpu);
  sim_engine_halt (sd, current_cpu, NULL, cia, sim_stopped, SIM_SIGILL);

  return vpc;
}


/* Process an address exception.  */

void
iq2000_core_signal (SIM_DESC sd, SIM_CPU *current_cpu, sim_cia cia,
                  unsigned int map, int nr_bytes, address_word addr,
                  transfer_type transfer, sim_core_signals sig)
{
  sim_core_signal (sd, current_cpu, cia, map, nr_bytes, addr,
		   transfer, sig);
}


/* Initialize cycle counting for an insn.
   FIRST_P is non-zero if this is the first insn in a set of parallel
   insns.  */

void
iq2000bf_model_insn_before (SIM_CPU *cpu, int first_p)
{
  /* Do nothing.  */
}


/* Record the cycles computed for an insn.
   LAST_P is non-zero if this is the last insn in a set of parallel insns,
   and we update the total cycle count.
   CYCLES is the cycle count of the insn.  */

void
iq2000bf_model_insn_after(SIM_CPU *cpu, int last_p, int cycles)
{
  /* Do nothing.  */
}


int
iq2000bf_model_iq2000_u_exec (SIM_CPU *cpu, const IDESC *idesc,
			    int unit_num, int referenced)
{
  return idesc->timing->units[unit_num].done;
}

PCADDR
get_h_pc (SIM_CPU *cpu)
{
  return CPU_CGEN_HW(cpu)->h_pc;
}

void
set_h_pc (SIM_CPU *cpu, PCADDR addr)
{
  CPU_CGEN_HW(cpu)->h_pc = addr | IQ2000_INSN_MASK;
}

int
iq2000bf_fetch_register (SIM_CPU *cpu, int nr, unsigned char *buf, int len)
{
  if (nr >= GPR0_REGNUM
      && nr < (GPR0_REGNUM + NR_GPR)
      && len == 4)
    {
      *((unsigned32*)buf) =
	H2T_4 (iq2000bf_h_gr_get (cpu, nr - GPR0_REGNUM));
      return 4;
    }
  else if (nr == PC_REGNUM
	   && len == 4)
    {
      *((unsigned32*)buf) = H2T_4 (get_h_pc (cpu));
      return 4;
    }
  else
    return 0;
}

int
iq2000bf_store_register (SIM_CPU *cpu, int nr, unsigned char *buf, int len)
{
  if (nr >= GPR0_REGNUM
      && nr < (GPR0_REGNUM + NR_GPR)
      && len == 4)
    {
      iq2000bf_h_gr_set (cpu, nr - GPR0_REGNUM, T2H_4 (*((unsigned32*)buf)));
      return 4;
    }
  else if (nr == PC_REGNUM
	   && len == 4)
    {
      set_h_pc (cpu, T2H_4 (*((unsigned32*)buf)));
      return 4;
    }
  else
    return 0;
}