boards/z80/ez80/makerlisp/src/ez80_boot.c

/****************************************************************************
 * boards/z80/ez80/makerlisp/src/ez80_boot.c
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <stdbool.h>

#include <nuttx/arch.h>
#include <arch/chip/io.h>

#include "chip.h"
#include "z80_internal.h"
#include "makerlisp.h"

/****************************************************************************
 * Public Data
 ****************************************************************************/

bool g_ebpresent = false;  /* True:  I/O Expansion board is present */

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#define VGA_MAX_DELAY 2000000

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: ez80_vga_initialize
 *
 * Description:
 *   If CONFIG_MAKERLISP_VGA is defined and the I/O controller is attached,
 *   then initialize the VGA interface.
 *
 ****************************************************************************/

#ifdef CONFIG_MAKERLISP_VGA
static void ez80_vga_initialize(void)
{
  /* I/O Expansion board attached? */

  if (g_ebpresent)
    {
      bool vgapresent = false;
      int delay;

      /* Wait for VGA ready */

      for (delay = 0; delay < VGA_MAX_DELAY; delay++)
        {
          if ((inp(EZ80_PB_DR) & EZ80_GPIOD1) != 0)
            {
              vgapresent = true;
              break;
            }
        }

      /* Is VGA ready (and, hence, present)? */

      if (vgapresent)
        {
          /* Yes.. set newline mode, graphic attributes:
           *
           * \e = ESCAPE character
           * Assumption:  VGA is on the console UART.
           */

          up_puts("\e[20h\e[0m");

          /* Clear, home cursor, beep */

          up_puts("\e[2J\e[H\a");

          /* The VGA display controller and keyboard controller come up by
           * default emulating a terminal with "newline mode" on.  The
           * following turns off that mode.
           */

          up_puts("\e[20l");
        }
    }
}
#endif

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: ez80_board_initialize
 *
 * Description:
 *   All eZ80 architectures must provide the following entry point.  This
 *   entry point is called early in the initialization -- after basic CPU
 *   configuration is complete but before any devices have been initialized.
 *
 ****************************************************************************/

void ez80_board_initialize(void)
{
  register uint8_t regval;

  /* Port B pin 5 is set if the I/O expansion board is present */

  regval = inp(EZ80_PB_DR);
  g_ebpresent = (regval & EZ80_GPIOD5 != 0);

  /* Set Port B pin 5 as output, assert /sysreset, SD card power off */

  regval &= ~EZ80_GPIOD5;
  outp(EZ80_PB_DR, regval);

  regval  = inp(EZ80_PB_ALT1);
  regval &= ~EZ80_GPIOD5;
  outp(EZ80_PB_ALT1, regval);

  regval  = inp(EZ80_PB_ALT2);
  regval &= ~EZ80_GPIOD5;
  outp(EZ80_PB_ALT2, regval);

  regval  = inp(EZ80_PB_DDR);
  regval &= ~EZ80_GPIOD5;
  outp(EZ80_PB_DDR, regval);

#ifdef CONFIG_EZ80_SPI
  /* Initialize SPI chip selects */

  ez80_spidev_initialize();
#endif

  /* Leave /sysreset asserted for awhile longer */

  up_udelay(150);

  /* Take the system out of reset and and turn on SD card power */

  regval  = inp(EZ80_PB_DR);
  regval |= EZ80_GPIOD5;
  outp(EZ80_PB_DR, regval);

  /* Wait for the SD card to power up */

  up_udelay(750);

#ifdef CONFIG_MAKERLISP_VGA
  /* Initialize the VGA interface.  We want to do this as early as possible
   * in the boot-up sequence.  Debug output prior initializing VGA will be
   * lost.
   */

  ez80_vga_initialize();
#endif
}

/****************************************************************************
 * Name: board_late_initialize
 *
 * Description:
 *   If CONFIG_BOARD_LATE_INITIALIZE is selected, then an additional
 *   initialization call will be performed in the boot-up sequence to a
 *   function called board_late_initialize(). board_late_initialize() will be
 *   called immediately after up_initialize() is called and just before the
 *   initial application is started.  This additional initialization phase
 *   may be used, for example, to initialize board-specific device drivers.
 *
 ****************************************************************************/

#ifdef CONFIG_BOARD_LATE_INITIALIZE
void board_late_initialize(void)
{
  /* Perform board-specific initialization */

  ez80_bringup();
}
#endif