cons_svga.cxx

C++ 编写的EROS RTOS

/*
 * Copyright (C) 2001, Jonathan S. Shapiro.
 *
 * This file is part of the EROS Operating System.
 *
 * 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,
 * 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/* Implementation of the kernel frame buffer console logic. We make
 * the simplifying assumption here that the console is a VGA
 * (640x480x256) display. If the machine-specific initialization code
 * has somehow placed the display buffer in some other state (e.g. we
 * have a large VESA display or some such), then it is the
 * responsibility of the machine-specific code to suitably place a
 * 640x480 bitmap somewhere on the tube.  Remember that this console
 * isn't going to get used for very long -- only until the user-mode
 * console driver takes over the world.
 */

#include <kerninc/kernel.hxx>
#include <kerninc/Console.hxx>
#include <kerninc/MsgLog.hxx>

static uint8_t *screen = (uint8_t *) PTOV(0xA0000u);

/* The implementation of the console frame buffer is inherently
 * video card specific... */
struct ConsSVGA: public Console {
  void Clear();

  void Put(uint8_t c);
  void SetFrameBuffer(kva_t);
};

ConsSVGA TheConsSVGA;

bool
Console::InitSVGA()
{
#if 0
  TheConsSVGA.offset = 0;

  /* Do something here to set the video mode?... */

  TheConsSVGA.Clear();
  
  MsgLog::RegisterSink(&TheConsSVGA);

  return true;
#else
  return false;
#endif
}

/* FIX: This is NOT RIGHT!! */
void
ConsSVGA::Put(uint8_t c)
{
  unsigned i;
  unsigned long line = offset / 80;
  unsigned long col = offset % 80;

  uint8_t *where = screen + (line * 16) + col;

  for (i = 0; i < 16; i++) {
    /* FIX: set the color to write! */
    *where = console_font[c * 16 + i];
    where += 80;
  }
}

void
ConsSVGA::Clear()
{
  unsigned i;

  /* This is screamingly inefficient... */
  unsigned long old_offset = offset;

  offset = 0;

  for (i = 0; i < (30 * 80); i++) {
    Put(' ');
    offset ++;
  }

  offset = old_offset;
}