path: root/leon3.c

/*
 * This file is part of SIS.
 *
 * SIS, SPARC instruction simulator V2.5 Copyright (C) 1995 Jiri Gaisler,
 * European Space Agency
 *
 * 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/>.
 *
 * Leon3 emulation, loosely based on erc32.c.
 */

#ifdef WORDS_BIGENDIAN
#define EBT 0
#else
#define EBT 3
#endif

#define ROM_START 	0x00000000
#define RAM_START 	0x40000000

#include "config.h"
#include <errno.h>
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#ifdef HAVE_TERMIOS_H
#include <termios.h>
#endif
#include <sys/file.h>
#include <unistd.h>
#include "sis.h"
#include "grlib.h"

/* APB registers */
#define APBSTART	0x80000000
#define APBEND		0x80100000

/* Memory exception waitstates.  */
#define MEM_EX_WS 	1

#define MOK		0

/* LEON3 APB register addresses.  */

#define IRQMP_IPR	0x204
#define IRQMP_IFR 	0x208
#define IRQMP_ICR 	0x20C
#define IRQMP_ISR 	0x210
#define IRQMP_IBR 	0x214
#define IRQMP_IMR 	0x240
#define IRQMP_IMR1	0x244
#define IRQMP_IMR2	0x248
#define IRQMP_IMR3	0x24C
#define IRQMP_IFR0 	0x280
#define IRQMP_IFR1 	0x284
#define IRQMP_IFR2 	0x288
#define IRQMP_IFR3 	0x28C
#define GPTIMER_SCALER  0x300
#define GPTIMER_SCLOAD  0x304
#define GPTIMER_CONFIG  0x308
#define GPTIMER_TIMER1 	0x310
#define GPTIMER_RELOAD1	0x314
#define GPTIMER_CTRL1 	0x318
#define GPTIMER_TIMER2 	0x320
#define GPTIMER_RELOAD2	0x324
#define GPTIMER_CTRL2 	0x328

#define APBUART_RXTX	0x100
#define APBUART_STATUS  0x104
#define APBUART_CTRL    0x108

/* Size of UART buffers (bytes).  */
#define UARTBUF	1024

/* Number of simulator ticks between flushing the UARTS.  */
/* For good performance, keep above 1000.  */
#define UART_FLUSH_TIME	  3000

/* New uart defines.  */
#define UART_TX_TIME	1000
#define UART_RX_TIME	1000
#define UARTA_DR	0x1
#define UARTA_SRE	0x2
#define UARTA_HRE	0x4
#define UARTA_OR	0x10

/* IRQMP registers.  */

static uint32 irqmp_ipr;
static uint32 irqmp_ibr;
static uint32 irqmp_imr[NCPU];
static uint32 irqmp_ifr[NCPU];

/* GPTIMER registers.  */

#define NGPTIMERS  2
#define GPTIMER_IRQ 8

static uint32 gpt_scaler;
static uint64 gpt_scaler_start;
static uint32 gpt_counter[NGPTIMERS];
static uint32 gpt_reload[NGPTIMERS];
static uint64 gpt_counter_start[NGPTIMERS];
static uint32 gpt_ctrl[NGPTIMERS];

/* UART support variables.  */

/* File descriptor for input file.  */
static int32 fd1, fd2;

/* UART status register */
static int32 Ucontrol;

static unsigned char aq[UARTBUF], bq[UARTBUF];
static int32 anum, aind = 0;
static int32 bnum, bind = 0;
static char wbufa[UARTBUF], wbufb[UARTBUF];
static unsigned wnuma;
static unsigned wnumb;
static FILE *f1in, *f1out;
#ifdef HAVE_TERMIOS_H
static struct termios ioc1, ioc2, iocold1, iocold2;
#endif
#ifndef O_NONBLOCK
#define O_NONBLOCK 0
#endif

static int f1open = 0;

static char uarta_sreg, uarta_hreg;
static uint32 uart_stat_reg;
static uint32 uarta_data;

/* Forward declarations. */

static void mem_init (void);
static void close_port (void);
static void leon3_reset (void);
static void irqmp_intack (int level, int cpu);
static void chk_irq (void);
static void set_irq (int32 level);
static int32 apb_read (uint32 addr, uint32 * data);
static int apb_write (uint32 addr, uint32 data);
static void port_init (void);
static uint32 grlib_read_uart (uint32 addr);
static void grlib_write_uart (uint32 addr, uint32 data);
static void flush_uart (void);
static void uarta_tx (void);
static void uart_rx (int32 arg);
static void uart_intr (int32 arg);
static void uart_irq_start (void);
static void gpt_intr (int32 arg);
static void gpt_init (void);
static void gpt_reset (void);
static void gpt_scaler_set (uint32 val);
static void timer_ctrl (uint32 val, int i);
static char *get_mem_ptr (uint32 addr, uint32 size);
static void store_bytes (char *mem, uint32 waddr,
			 uint32 * data, int sz, int32 * ws);
static void gpt_add_intr (int i);

/* One-time init. */

static void
init_sim (void)
{
  grlib_init ();
  mem_init ();
  port_init ();
  gpt_init ();
  ebase.ramstart = RAM_START;
}

/* Power-on reset init. */

static void
reset (void)
{
  leon3_reset ();
  uart_irq_start ();
  gpt_reset ();
}

/* IU error mode manager. */

static void
error_mode (uint32 pc)
{

}

/* Memory init. */

static void
mem_init (void)
{

/* Add AMBA P&P record for SRCTRL memory controller */

  grlib_ahbspp_add (GRLIB_PP_ID (VENDOR_GAISLER, GAISLER_SRCTRL, 0, 0),
		    GRLIB_PP_AHBADDR (0x00000000, 0xE00, 1, 1, 2),
		    GRLIB_PP_AHBADDR (0x40000000, 0xC00, 1, 1, 2),
		    GRLIB_PP_AHBADDR (0x20000000, 0xE00, 0, 0, 2), 0);
  if (sis_verbose)
    printf ("RAM start: 0x%x, RAM size: %d K, ROM size: %d K\n",
	    RAM_START, (RAM_MASK + 1) / 1024, (ROM_MASK + 1) / 1024);
}

/* Flush ports when simulator stops. */

static void
sim_halt (void)
{
#ifdef FAST_UART
  flush_uart ();
#endif
}

static void
close_port (void)
{
  if (f1open && f1in != stdin)
    fclose (f1in);
}

static void
exit_sim (void)
{
  close_port ();
}

static void
leon3_reset (void)
{
  int i;

  irqmp_ipr = 0;
  for (i = 0; i < NCPU; i++)
    {
      irqmp_imr[i] = 0;
      irqmp_ifr[i] = 0;
      sregs[i].intack = irqmp_intack;
    }
  wnuma = wnumb = 0;
  anum = aind = bnum = bind = 0;

  uart_stat_reg = UARTA_SRE | UARTA_HRE;

  gpt_counter[0] = 0xffffffff;
  gpt_reload[0] = 0xffffffff;
  gpt_scaler = 0xffff;
  gpt_ctrl[0] = 0;
  gpt_ctrl[1] = 0;

}

static void
irqmp_intack (int level, int cpu)
{
  int irq_test;

  if ((sis_verbose > 2) && (level != 10))
    printf ("%8" PRIu64 " cpu %d interrupt %d acknowledged\n",
	    ebase.simtime, cpu, level);
  if (irqmp_ifr[cpu] & (1 << level))
    irqmp_ifr[cpu] &= ~(1 << level);
  else
    irqmp_ipr &= ~(1 << level);
  chk_irq ();
}

static void
chk_irq ()
{
  int32 i, cpu;
  uint32 itmp;
  int old_irl;

  for (cpu = 0; cpu < ncpu; cpu++)
    {
      old_irl = ext_irl[cpu];
      itmp = ((irqmp_ipr | irqmp_ifr[cpu]) & irqmp_imr[cpu]) & 0x0fffe;
      ext_irl[cpu] = 0;
      if (itmp != 0)
	{
	  for (i = 15; i > 0; i--)
	    {
	      if (((itmp >> i) & 1) != 0)
		{
		  if ((sis_verbose > 2) && (i != old_irl))
		    printf ("%8" PRIu64 " cpu %d irl: %d\n",
			    ebase.simtime, cpu, i);
		  ext_irl[cpu] = i;
		  break;
		}
	    }
	}
    }
}

static void
set_irq (int32 level)
{
  int i;

  if ((irqmp_ibr >> level) & 1)
    for (i = 0; i < ncpu; i++)
      irqmp_ifr[i] |= (1 << level);
  else
    irqmp_ipr |= (1 << level);
  chk_irq ();
}

static uint32
gpt_counter_read (int i)
{
  if (gpt_ctrl[i] & 1)
    return gpt_counter[i] -
      ((now () - gpt_counter_start[i]) / (gpt_scaler + 1));
  else
    return gpt_counter[i];
}

static uint32
gpt_scaler_read ()
{
  return gpt_scaler - ((now () - gpt_scaler_start) % (gpt_scaler + 1));
}

static int32
apb_read (uint32 addr, uint32 * data)
{
  int i;

  switch (addr & 0xfff)
    {

    case APBUART_RXTX:		/* 0x100 */
    case APBUART_STATUS:	/* 0x104 */
      *data = grlib_read_uart (addr);
      break;
    case APBUART_CTRL:		/* 0x108 */
      *data = 3;
      break;

    case IRQMP_IPR:		/* 0x204 */
      *data = irqmp_ipr;
      break;

    case IRQMP_IFR:		/* 0x208 */
      *data = irqmp_ifr[0];
      break;

    case IRQMP_ISR:		/* 0x210 */
      *data = ((ncpu - 1) << 28);
      for (i = 0; i < ncpu; i++)
	*data |= (sregs[i].pwd_mode << i);
      break;

    case IRQMP_IBR:		/* 0x214 */
      *data = irqmp_ibr;
      break;

    case IRQMP_IMR:		/* 0x240 */
      *data = irqmp_imr[0];
      break;

    case IRQMP_IMR1:		/* 0x244 */
      *data = irqmp_imr[1];
      break;

    case IRQMP_IMR2:		/* 0x248 */
      *data = irqmp_imr[2];
      break;

    case IRQMP_IMR3:		/* 0x24C */
      *data = irqmp_imr[3];
      break;

    case IRQMP_IFR0:		/* 0x280 */
      *data = irqmp_ifr[0];
      break;

    case IRQMP_IFR1:		/* 0x284 */
      *data = irqmp_ifr[1];
      break;

    case IRQMP_IFR2:		/* 0x288 */
      *data = irqmp_ifr[2];
      break;

    case IRQMP_IFR3:		/* 0x28C */
      *data = irqmp_ifr[3];
      break;

    case GPTIMER_SCALER:	/* 0x300 */
      *data = gpt_scaler_read ();
      break;

    case GPTIMER_SCLOAD:	/* 0x304 */
      *data = gpt_scaler;
      break;

    case GPTIMER_CONFIG:	/* 0x308 */
      *data = 0x100 | (GPTIMER_IRQ << 3) | NGPTIMERS;
      break;

    case GPTIMER_TIMER1:	/* 0x310 */
      *data = gpt_counter_read (0);
      break;

    case GPTIMER_RELOAD1:	/* 0x314 */
      *data = gpt_reload[0];
      break;

    case GPTIMER_CTRL1:	/* 0x318 */
      *data = gpt_ctrl[0];
      break;

    case GPTIMER_TIMER2:	/* 0x320 */
      *data = gpt_counter_read (1);
      break;

    case GPTIMER_RELOAD2:	/* 0x324 */
      *data = gpt_reload[1];
      break;

    case GPTIMER_CTRL2:	/* 0x328 */
      *data = gpt_ctrl[1];
      break;

    default:
      *data = 0;
      if (sis_verbose > 1)
	printf ("%8" PRIu64
		" cpu %d APB read  a: %08x, d: %08x  unimplemented!\n",
		ebase.simtime, cpu, addr, *data);
      break;
    }

  if (sis_verbose > 1)
    if ((addr & 0xF00) != 0x100)
      printf ("%8" PRIu64 " cpu %d APB read  a: %08x, d: %08x\n",
	      ebase.simtime, cpu, addr, *data);

  return MOK;
}

static int
apb_write (uint32 addr, uint32 data)
{
  int i;

  if (sis_verbose > 1)
    if ((addr & 0xF00) != 0x100)
      printf ("%8" PRIu64 " cpu %d APB write a: %08x, d: %08x\n",
	      ebase.simtime, cpu, addr, data);
  switch (addr & 0xfff)
    {

    case APBUART_RXTX:		/* 0x100 */
    case APBUART_STATUS:	/* 0x104 */
      grlib_write_uart (addr, data);
      break;
    case APBUART_CTRL:		/* 0x108 */
      break;

    case IRQMP_IFR:		/* 0x208 */
      irqmp_ifr[0] = data & 0xfffe;
      chk_irq ();
      break;

    case IRQMP_ICR:		/* 0x20C */
      irqmp_ipr &= ~data & 0x0fffe;
      chk_irq ();
      break;

    case IRQMP_ISR:		/* 0x210 */
      for (i = 0; i < ncpu; i++)
	{
	  if ((data >> i) & 1)
	    {
	      if (sregs[i].pwd_mode)
		{
		  sregs[i].simtime = ebase.simtime;
		  if (sis_verbose > 1)
		    printf ("%8" PRIu64 " cpu %d starting\n", ebase.simtime,
			    i);
		  sregs[i].pwdtime += ebase.simtime - sregs[i].pwdstart;
		}
	      sregs[i].pwd_mode = 0;
	    }
	}
      break;

    case IRQMP_IBR:		/* 0x214 */
      irqmp_ibr = data & 0xfffe;
      break;

    case IRQMP_IMR:		/* 0x240 */
      irqmp_imr[0] = data & 0x7ffe;
      chk_irq ();
      break;

    case IRQMP_IMR1:		/* 0x244 */
      irqmp_imr[1] = data & 0x7ffe;
      chk_irq ();
      break;

    case IRQMP_IMR2:		/* 0x248 */
      irqmp_imr[2] = data & 0x7ffe;
      chk_irq ();
      break;

    case IRQMP_IMR3:		/* 0x24C */
      irqmp_imr[3] = data & 0x7ffe;
      chk_irq ();
      break;

    case IRQMP_IFR0:		/* 0x280 */
      irqmp_ifr[0] = data & 0xfffe;
      chk_irq ();
      break;

    case IRQMP_IFR1:		/* 0x284 */
      irqmp_ifr[1] = data & 0xfffe;
      chk_irq ();
      break;

    case IRQMP_IFR2:		/* 0x288 */
      irqmp_ifr[2] = data & 0xfffe;
      chk_irq ();
      break;

    case IRQMP_IFR3:		/* 0x28C */
      irqmp_ifr[3] = data & 0xfffe;
      chk_irq ();
      break;

    case GPTIMER_SCLOAD:	/* 0x304 */
      gpt_scaler_set (data);
      break;

    case GPTIMER_TIMER1:	/* 0x310 */
      gpt_counter[0] = data;
      remove_event (gpt_intr, 0);
      gpt_add_intr (0);
      break;

    case GPTIMER_RELOAD1:	/* 0x314 */
      gpt_reload[0] = data;
      break;

    case GPTIMER_CTRL1:	/* 0x318 */
      timer_ctrl (data, 0);
      break;

    case GPTIMER_TIMER2:	/* 0x320 */
      gpt_counter[1] = data;
      remove_event (gpt_intr, 1);
      gpt_add_intr (1);
      break;

    case GPTIMER_RELOAD2:	/* 0x324 */
      gpt_reload[1] = data;
      break;

    case GPTIMER_CTRL2:	/* 0x328 */
      timer_ctrl (data, 1);
      break;

    default:
      if (sis_verbose)
	printf ("%8" PRIu64
		" cpu %d APB write a: %08x, d: %08x  unimplemented!\n",
		ebase.simtime, cpu, addr, data);
      break;
    }
  return MOK;
}


/* APBUART.  */

static int ifd1 = -1, ofd1 = -1;

static void
init_stdio (void)
{
  if (dumbio)
    return;
#ifdef HAVE_TERMIOS_H
  if (ifd1 == 0 && f1open)
    {
      tcsetattr (0, TCSANOW, &ioc1);
      tcflush (ifd1, TCIFLUSH);
    }
#endif
}

static void
restore_stdio (void)
{
  if (dumbio)
    return;
#ifdef HAVE_TERMIOS_H
  if (ifd1 == 0 && f1open && tty_setup)
    tcsetattr (0, TCSANOW, &iocold1);
#endif
}

#define DO_STDIO_READ( _fd_, _buf_, _len_ )          \
		( dumbio || nouartrx ? (0) : read( _fd_, _buf_, _len_ ) )

static void
port_init (void)
{
  f1in = stdin;
  f1out = stdout;
  if (uart_dev1[0] != 0)
    {
      if ((fd1 = open (uart_dev1, O_RDWR | O_NONBLOCK)) < 0)
	{
	  printf ("Warning, couldn't open output device %s\n", uart_dev1);
	}
      else
	{
	  if (sis_verbose)
	    printf ("serial port A on %s\n", uart_dev1);
	  f1in = f1out = fdopen (fd1, "r+");
	  setbuf (f1out, NULL);
	  f1open = 1;
	}
    }
  if (f1in)
    ifd1 = fileno (f1in);
  if (ifd1 == 0)
    {
      if (sis_verbose)
	printf ("serial port A on stdin/stdout\n");
      if (!dumbio)
	{
#ifdef HAVE_TERMIOS_H
	  tcgetattr (ifd1, &ioc1);
	  if (tty_setup)
	    {
	      iocold1 = ioc1;
	      ioc1.c_lflag &= ~(ICANON | ECHO);
	      ioc1.c_cc[VMIN] = 0;
	      ioc1.c_cc[VTIME] = 0;
	    }
#endif
	}
      f1open = 1;
    }

  if (f1out)
    {
      ofd1 = fileno (f1out);
      if (!dumbio && tty_setup && ofd1 == 1)
	setbuf (f1out, NULL);
    }

  wnuma = 0;

  grlib_apbpp_add (GRLIB_PP_ID (VENDOR_GAISLER, GAISLER_APBUART, 1, 3),
		   GRLIB_PP_APBADDR (0x80000100, 0xFFF));
}

static uint32
grlib_read_uart (uint32 addr)
{
  unsigned tmp = 0;

  switch (addr & 0xff)
    {

    case 0x00:			/* UART 1 RX/TX */
#ifndef _WIN32
#ifdef FAST_UART

      if (aind < anum)
	{
	  if ((aind + 1) < anum)
	    set_irq (3);
	  return (uint32) aq[aind++];
	}
      else
	{
	  if (f1open)
	    anum = DO_STDIO_READ (ifd1, aq, UARTBUF);
	  else
	    anum = 0;
	  if (anum > 0)
	    {
	      aind = 0;
	      if ((aind + 1) < anum)
		set_irq (3);
	      return (uint32) aq[aind++];
	    }
	  else
	    return (uint32) aq[aind];
	}
#else
      tmp = uarta_data;
      uarta_data &= ~UART_DR;
      uart_stat_reg &= ~UARTA_DR;
      return tmp;
#endif
#else
      return 0;
#endif
      break;

    case 0x04:			/* UART status register  */
#ifndef _WIN32
#ifdef FAST_UART

      Ucontrol = 0;
      if (aind < anum)
	{
	  Ucontrol |= 0x00000001;
	}
      else
	{
	  if (f1open)
	    anum = DO_STDIO_READ (ifd1, aq, UARTBUF);
	  else
	    anum = 0;
	  if (anum > 0)
	    {
	      Ucontrol |= 0x00000001;
	      aind = 0;
	      set_irq (3);
	    }
	}
      Ucontrol |= 0x00000006;
      return Ucontrol;
#else
      return uart_stat_reg;
#endif
#else
      return 0x00060006;
#endif
      break;
    default:
      if (sis_verbose)
	printf ("Read from unimplemented UART register (%x)\n", addr);
    }

  return 0;
}

static void
grlib_write_uart (uint32 addr, uint32 data)
{
  unsigned char c;

  c = (unsigned char) data;
  switch (addr & 0xff)
    {

    case 0x00:			/* UART A */
#ifdef FAST_UART
      if (f1open)
	{
	  if (wnuma < UARTBUF)
	    wbufa[wnuma++] = c;
	  else
	    {
	      while (wnuma)
		{
		  wnuma -= fwrite (wbufa, 1, wnuma, f1out);
		}
	      wbufa[wnuma++] = c;
	    }
	}
      set_irq (3);
#else
      if (uart_stat_reg & UARTA_SRE)
	{
	  uarta_sreg = c;
	  uart_stat_reg &= ~UARTA_SRE;
	  event (uarta_tx, 0, UART_TX_TIME);
	}
      else
	{
	  uarta_hreg = c;
	  uart_stat_reg &= ~UARTA_HRE;
	}
#endif
      break;

    case 0x04:			/* UART status register */
#ifndef FAST_UART
      uart_stat_reg &= 1;
#endif
      break;
    default:
      if (sis_verbose)
	printf ("Write to unimplemented UART register (%x)\n", addr);
    }
}

static void
flush_uart (void)
{
  while (wnuma && f1open)
    {
      wnuma -= fwrite (wbufa, 1, wnuma, f1out);
    }
}

static void
uarta_tx (void)
{
  while (f1open)
    {
      while (fwrite (&uarta_sreg, 1, 1, f1out) != 1)
	continue;
    }
  if (uart_stat_reg & UARTA_HRE)
    {
      uart_stat_reg |= UARTA_SRE;
    }
  else
    {
      uarta_sreg = uarta_hreg;
      uart_stat_reg |= UARTA_HRE;
      event (uarta_tx, 0, UART_TX_TIME);
    }
  set_irq (3);
}

static void
uart_rx (int32 arg)
{
  char rxd;
  int32 rsize = 0;


  if (f1open)
    rsize = DO_STDIO_READ (ifd1, &rxd, 1);
  else
    rsize = 0;
  if (rsize > 0)
    {
      uarta_data = rxd;
      if (uart_stat_reg & UARTA_DR)
	{
	  uart_stat_reg |= UARTA_OR;
	}
      uart_stat_reg |= UARTA_DR;
      set_irq (3);
    }
  event (uart_rx, 0, UART_RX_TIME);
}

static void
uart_intr (int32 arg)
{
  /* Check for UART interrupts every 1000 clk.  */
  grlib_read_uart (APBUART_STATUS);
  flush_uart ();
  event (uart_intr, 0, UART_FLUSH_TIME);
}


static void
uart_irq_start (void)
{
#ifdef FAST_UART
  event (uart_intr, 0, UART_FLUSH_TIME);
#else
#ifndef _WIN32
  event (uart_rx, 0, UART_RX_TIME);
#endif
#endif
}

/* GPTIMER.  */

static void
gpt_add_intr (int i)
{
  if (gpt_ctrl[i] & 1)
    {
      event (gpt_intr, i,
	     (uint64) (gpt_scaler + 1) * (uint64) ((uint64) gpt_counter[i] +
						   (uint64) 1));
      gpt_counter_start[i] = now ();
    }
}

static void
gpt_intr (int32 i)
{
  gpt_counter[i] = -1;
  if (gpt_ctrl[i] & 1)
    {
      if (gpt_ctrl[i] & 2)
	{
	  gpt_counter[i] = gpt_reload[i];
	}
      if (gpt_ctrl[i] & 8)
	{
	  set_irq (GPTIMER_IRQ + i);
	}
      gpt_add_intr (i);
    }
}

static void
gpt_init (void)
{
  if (sis_verbose)
    printf ("GPT started (period %d)\n\r", gpt_scaler + 1);

  grlib_apbpp_add (GRLIB_PP_ID (VENDOR_GAISLER, GAISLER_GPTIMER, 0, 8),
		   GRLIB_PP_APBADDR (0x80000300, 0xFFF));
}

static void
gpt_reset (void)
{
//  event (gpt_intr, 0, gpt_scaler + 1);
  remove_event (gpt_intr, -1);
  gpt_scaler_start = now ();
}

static void
gpt_add_intr_all ()
{
  int i;

  for (i = 0; i < NGPTIMERS; i++)
    {
      gpt_add_intr (i);
    }
}

static void
gpt_scaler_set (uint32 val)
{
  /* Mask for 16-bit scaler. */
  if (gpt_scaler != (val & 0x0ffff))
    {
      gpt_scaler = val & 0x0ffff;
      remove_event (gpt_intr, -1);
      gpt_scaler_start = now ();
      gpt_add_intr_all ();
    }
}

static void
timer_ctrl (uint32 val, int i)
{
  if (val & 4)
    {
      /* Reload.  */
      gpt_counter[i] = gpt_reload[i];
    }
  if (val & 1)
    {
      gpt_ctrl[i] = val & 0xb;
      remove_event (gpt_intr, i);
      gpt_add_intr (i);
    }
  gpt_ctrl[i] = val & 0xb;
}

/* Store data in host byte order.  MEM points to the beginning of the
   emulated memory; WADDR contains the index the emulated memory,
   DATA points to words in host byte order to be stored.  SZ contains log(2)
   of the number of bytes to retrieve, and can be 0 (1 byte), 1 (one half-word),
   2 (one word), or 3 (two words); WS should return the number of wait-states. */

static void
store_bytes (char *mem, uint32 waddr, uint32 * data, int32 sz, int32 * ws)
{
  if (sz == 2)
    memcpy (&mem[waddr], data, 4);
  else
    switch (sz)
      {
      case 0:
	waddr ^= arch->endian;
	mem[waddr] = *data & 0x0ff;
	break;
      case 1:
	waddr ^= arch->endian & 2;
	memcpy (&mem[waddr], data, 2);
	break;
      case 3:
	memcpy (&mem[waddr], data, 8);
	break;
      }
  *ws = 0;
}


/* Memory emulation.  */

static int
memory_iread (uint32 addr, uint32 * data, int32 * ws)
{
  if ((addr >= RAM_START) && (addr < RAM_END))
    {
      memcpy (data, &ramb[addr & RAM_MASK], 4);
      *ws = 0;
      return 0;
    }
  else if (addr < ROM_END)
    {
      memcpy (data, &romb[addr], 4);
      *ws = 0;
      return 0;
    }

  if (sis_verbose)
    printf ("Memory exception at %x (illegal address)\n", addr);
  *ws = MEM_EX_WS;
  return 1;
}

static int
memory_read (uint32 addr, uint32 * data, int32 * ws)
{
  int32 mexc;

  if ((addr >= RAM_START) && (addr < RAM_END))
    {
      memcpy (data, &ramb[addr & RAM_MASK], 4);
      *ws = 0;
      return 0;
    }
  else if ((addr >= APBPP_START) && (addr <= APBPP_END))
    {
      *data = grlib_apbpnp_read (addr);
      if (sis_verbose > 1)
	printf ("APB PP read a: %08x, d: %08x\n", addr, *data);
      *ws = 4;
      return 0;
    }
  else if ((addr >= APBSTART) && (addr < APBEND))
    {
      mexc = apb_read (addr, data);
      if (mexc)
	*ws = MEM_EX_WS;
      else
	*ws = 0;
      return mexc;
    }
  else if ((addr >= AHBPP_START) && (addr <= AHBPP_END))
    {
      *data = grlib_ahbpnp_read (addr);
      if (sis_verbose > 1)
	printf ("AHB PP read a: %08x, d: %08x\n", addr, *data);
      *ws = 4;
      return 0;
    }
  else if (addr < ROM_END)
    {
      memcpy (data, &romb[addr], 4);
      *ws = 0;
      return 0;
    }

  if (sis_verbose)
    printf ("Memory exception at %x (illegal address)\n", addr);
  *ws = MEM_EX_WS;
  return 1;
}

static int
memory_write (uint32 addr, uint32 * data, int32 sz, int32 * ws)
{
  uint32 byte_addr;
  uint32 byte_mask;
  uint32 waddr;
  uint32 *ram;
  int32 mexc;
  int i;
  int wphit[2];

  if ((addr >= RAM_START) && (addr < RAM_END))
    {
      waddr = addr & RAM_MASK;
      store_bytes (ramb, waddr, data, sz, ws);
      return 0;
    }
  else if ((addr >= APBSTART) && (addr < APBEND))
    {
      if (sz != 2)
	{
	  *ws = MEM_EX_WS;
	  return 1;
	}
      apb_write (addr, *data);
      *ws = 0;
      return 0;

    }
  else if (addr < ROM_END)
    {
      *ws = 0;
      store_bytes (romb, addr, data, sz, ws);
      return 0;
    }

  *ws = MEM_EX_WS;
  return 1;
}

static char *
get_mem_ptr (uint32 addr, uint32 size)
{
  if ((addr + size) < ROM_END)
    {
      return &romb[addr];
    }
  else if ((addr >= RAM_START) && ((addr + size) < RAM_END))
    {
      return &ramb[addr & RAM_MASK];
    }

  return (char *) -1;
}

static int
sis_memory_write (uint32 addr, const char *data, uint32 length)
{
  char *mem;
  int32 ws;

  if ((mem = get_mem_ptr (addr, length)) != ((char *) -1))
    {
      memcpy (mem, data, length);
      return length;
    }
  else if (length == 4)
    memory_write (addr, (uint32 *) data, 2, &ws);
  return 0;
}

static int
sis_memory_read (uint32 addr, char *data, uint32 length)
{
  char *mem;
  int ws;

  if (length == 4)
    {
      memory_read (addr, (uint32 *) data, &ws);
      return 4;
    }

  if ((mem = get_mem_ptr (addr, length)) == ((char *) -1))
    return 0;

  memcpy (data, mem, length);
  return length;
}

static void
boot_init (void)
{

  int i;

  /* Generate 1 MHz RTC tick.  */
//  apb_write (GPTIMER_SCALER, ebase.freq - 1);
  apb_write (GPTIMER_SCLOAD, ebase.freq - 1);
  apb_write (GPTIMER_TIMER1, -1);
  apb_write (GPTIMER_RELOAD1, -1);
  apb_write (GPTIMER_CTRL1, 0x7);

  for (i = 0; i < NCPU; i++)
    {
      sregs[i].wim = 2;
      sregs[i].psr = 0xF30010e0;
      sregs[i].r[30] = RAM_END - (i * 0x20000);
      sregs[i].r[14] = sregs[i].r[30] - 96 * 4;
      sregs[i].cache_ctrl = 0x81000f;
      sregs[i].r[2] = sregs[i].r[30];	/* sp on RISCV-V */
    }
}

const struct memsys leon3 = {
  init_sim,
  reset,
  error_mode,
  sim_halt,
  exit_sim,
  init_stdio,
  restore_stdio,
  memory_iread,
  memory_read,
  memory_write,
  sis_memory_write,
  sis_memory_read,
  boot_init
};