/* hercules.c - hercules console interface */

/*

 *  GRUB  --  GRand Unified Bootloader

 *  Copyright (C) 2001,2002  Free Software Foundation, Inc.

 *

 *  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 2 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, write to the Free Software

 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 */

#ifdef SUPPORT_HERCULES

#include <shared.h>

#include <hercules.h>

#include <term.h>

/* The position of the cursor.  */

static int herc_x;

static int herc_y;

static int herc_standard_color = A_NORMAL;

static int herc_normal_color = A_NORMAL;

static int herc_highlight_color = A_REVERSE;

static int herc_current_color = A_NORMAL;

static color_state herc_color_state = COLOR_STATE_STANDARD;

static int herc_cursor_state = 1;

/* Write a byte to a port.  */

static inline void

outb (unsigned short port, unsigned char value)

{

  asm volatile ("outb	%b0, %w1" : : "a" (value), "Nd" (port));

}

static void

herc_set_cursor (void)

{

  unsigned offset = herc_y * HERCULES_WIDTH + herc_x;

  outb (HERCULES_INDEX_REG, 0x0f);

  outb (0x80, 0);

  outb (HERCULES_DATA_REG, offset & 0xFF);

  outb (0x80, 0);

  outb (HERCULES_INDEX_REG, 0x0e);

  outb (0x80, 0);

  outb (HERCULES_DATA_REG, offset >> 8);

  outb (0x80, 0);

}

void

hercules_putchar (int c)

{

  switch (c)

    {

    case '\b':

      if (herc_x > 0)

	herc_x--;

      break;

    case '\n':

      herc_y++;

      break;

    case '\r':

      herc_x = 0;

      break;

    case '\a':

      break;

    default:

      {

	volatile unsigned short *video

	  = (unsigned short *) HERCULES_VIDEO_ADDR;

	video[herc_y * HERCULES_WIDTH + herc_x]

	  = (herc_current_color << 8) | c;

	herc_x++;

	if (herc_x >= HERCULES_WIDTH)

	  {

	    herc_x = 0;

	    herc_y++;

	  }

      }

      break;

    }

  if (herc_y >= HERCULES_HEIGHT)

    {

      volatile unsigned long *video = (unsigned long *) HERCULES_VIDEO_ADDR;

      int i;

      herc_y = HERCULES_HEIGHT - 1;

      grub_memmove ((char *) HERCULES_VIDEO_ADDR,

		    (char *) HERCULES_VIDEO_ADDR + HERCULES_WIDTH * 2,

		    HERCULES_WIDTH * (HERCULES_HEIGHT - 1) * 2);

      for (i = HERCULES_WIDTH * (HERCULES_HEIGHT - 1) / 2;

	   i < HERCULES_WIDTH * HERCULES_HEIGHT / 2;

	   i++)

	video[i] = 0x07200720;

    }

}

void

hercules_cls (void)

{

  int i;

  volatile unsigned long *video = (unsigned long *) HERCULES_VIDEO_ADDR;

  for (i = 0; i < HERCULES_WIDTH * HERCULES_HEIGHT / 2; i++)

    video[i] = 0x07200720;

  herc_x = herc_y = 0;

  herc_set_cursor ();

}

int

hercules_getxy (void)

{

  return (herc_x << 8) | herc_y;

}

void

hercules_gotoxy (int x, int y)

{

  herc_x = x;

  herc_y = y;

  herc_set_cursor ();

}

void

hercules_setcolorstate (color_state state)

{

  switch (state) {

    case COLOR_STATE_STANDARD:

      herc_current_color = herc_standard_color;

      break;

    case COLOR_STATE_NORMAL:

      herc_current_color = herc_normal_color;

      break;

    case COLOR_STATE_HIGHLIGHT:

      herc_current_color = herc_highlight_color;

      break;

    default:

      herc_current_color = herc_standard_color;

      break;

  }

  herc_color_state = state;

}

void

hercules_setcolor (int normal_color, int highlight_color)

{

  herc_normal_color = normal_color;

  herc_highlight_color = highlight_color;

  hercules_setcolorstate (herc_color_state);

}

int

hercules_setcursor (int on)

{

  int old_state = herc_cursor_state;

  outb (HERCULES_INDEX_REG, 0x0a);

  outb (0x80, 0);

  outb (HERCULES_DATA_REG, on ? 0 : (1 << 5));

  outb (0x80, 0);

  herc_cursor_state = on;

  return old_state;

}

#endif /* SUPPORT_HERCULES */