source: rtems/c/src/lib/libbsp/i386/pc386/console/outch.c @ 2efdd08

/*
 * outch.c  - This file contains code for displaying characters
 *            on the console uisng information that should be
 *            maintained by the BIOS in its data Area.
 *
 * Copyright (C) 1998  valette@crf.canon.fr 
 *
 * Canon Centre Recherche France.
 *
 * This code is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This code 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this file; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * $Header$
 */


#include <bsp.h>

#include <stdlib.h>
#include <string.h>

#include <crt.h>

extern void wr_cursor(int, unsigned short);

#define TAB_SPACE 4
static unsigned short *bitMapBaseAddr;
static unsigned short ioCrtBaseAddr;
static unsigned short maxCol;
static unsigned short maxRow;
static unsigned char  row;
static unsigned char  column;
static unsigned short attribute;
static unsigned int   nLines;

    static void 
scroll()
{
    int i, j;                               /* Counters */
    unsigned short *pt_scroll, *pt_bitmap;  /* Pointers on the bit-map  */
      
    pt_bitmap = bitMapBaseAddr;
    j = 0;
    pt_bitmap = pt_bitmap + j;
    pt_scroll = pt_bitmap + maxCol;
    for (i = j; i < (maxRow - 1) * maxCol; i++) {
        *pt_bitmap++ = *pt_scroll++;
    }
    
    /*
     * Blank characters are displayed on the last line.
     */ 
    for (i = 0; i < maxCol; i++) {      
        *pt_bitmap++ = (short) (' ' | attribute);
    }
}

    static void
endColumn()
{
    if (++row == maxRow) { 
        scroll();       /* Scroll the screen now */
        row = maxRow - 1; 
    }
    column = 0;
    nLines++;
    /* Move cursor on the next location  */
    wr_cursor(row * maxCol + column, ioCrtBaseAddr);
}



    static void 
videoPutChar(char car)
{
    unsigned short *pt_bitmap = bitMapBaseAddr + row * maxCol;
  
    switch (car) {
        case '\b': {
            if (column) column--;
            /* Move cursor on the previous location  */
            wr_cursor(row * maxCol + column, ioCrtBaseAddr);
            return;
        }
        case '\t': {
            int i;

            i = TAB_SPACE - (column & (TAB_SPACE - 1));
            pt_bitmap += column;
            column += i;
            if (column >= maxCol) {
                endColumn();
                return;
            }
            while (i--) *pt_bitmap++ = ' ' | attribute;         
            wr_cursor(row * maxCol + column, ioCrtBaseAddr);
            return;
        }
        case '\n': {
            endColumn();
            return;
        }
        case 7: {       /* Bell code must be inserted here */
            return;
        }
        case '\r' : {   /* Already handled via \n */
            return;
        }
        default: {
            pt_bitmap += column;
            *pt_bitmap = car | attribute;
            if (++column == maxCol) endColumn();
            else wr_cursor(row * maxCol + column, 
                          ioCrtBaseAddr);
            return;
        }
    }
}       

    void
clear_screen()
{
    int i,j;

    for (j = 0; j <= maxRow; j++) {
      for (i = 0; i <= maxCol; i++) {
        videoPutChar(' ');
      }
    }
    column  = 0;
    row     = 0;
}

/*-------------------------------------------------------------------------+
|         Function: _IBMPC_outch
|      Description: Higher level (console) interface to consPutc.
| Global Variables: None.
|        Arguments: c - character to write to console.
|          Returns: Nothing. 
+--------------------------------------------------------------------------*/
void
_IBMPC_outch(char c)
{
  videoPutChar(c);
} /* _IBMPC_outch */


/*-------------------------------------------------------------------------+
|         Function: _IBMPC_initVideo
|      Description: Video system initialization. Hook for any early setup.
| Global Variables: bitMapBaseAddr, ioCrtBaseAddr, maxCol, maxRow, row
|                   column, attribute, nLines;
|        Arguments: None.
|          Returns: Nothing. 
+--------------------------------------------------------------------------*/
void
_IBMPC_initVideo(void)
{
    unsigned char* pt = (unsigned char*) (VIDEO_MODE_ADDR);

    if (*pt == VGAMODE7) {
      bitMapBaseAddr = (unsigned short*) V_MONO;
    }
    else {
      bitMapBaseAddr = (unsigned short*) V_COLOR;
    }
    ioCrtBaseAddr = *(unsigned short*) DISPLAY_CRT_BASE_IO_ADDR;
    maxCol  = * (unsigned short*) NB_MAX_COL_ADDR;
    maxRow  = * (unsigned char*)  NB_MAX_ROW_ADDR;
    column  = 0;
    row     = 0;
    attribute = ((BLACK << 4) | WHITE)<<8;
    nLines = 0;
    clear_screen();
#ifdef DEBUG_EARLY_STAGE    
    printk("bitMapBaseAddr = %X, display controller base IO = %X\n",
           (unsigned) bitMapBaseAddr,
           (unsigned) ioCrtBaseAddr);
    videoPrintf("maxCol = %d, maxRow = %d\n", (unsigned) maxCol, (unsigned) maxRow);
#endif
} /* _IBMPC_initVideo */