/*-------------------------------------------------------------------------+
| outch.c v1.1 - PC386 BSP - 1997/08/07
+--------------------------------------------------------------------------+
| (C) Copyright 1997 -
| - NavIST Group - Real-Time Distributed Systems and Industrial Automation
|
| http://pandora.ist.utl.pt
|
| Instituto Superior Tecnico * Lisboa * PORTUGAL
+--------------------------------------------------------------------------+
| Disclaimer:
|
| This file is provided "AS IS" without warranty of any kind, either
| expressed or implied.
+--------------------------------------------------------------------------+
| This code is based on:
| outch.c,v 1.4 1995/12/19 20:07:27 joel Exp - go32 BSP
| With the following copyright notice:
| **************************************************************************
| * COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994. *
| * On-Line Applications Research Corporation (OAR). *
| * All rights assigned to U.S. Government, 1994. *
| * *
| * This material may be reproduced by or for the U.S. Government pursuant *
| * to the copyright license under the clause at DFARS 252.227-7013. This *
| * notice must appear in all copies of this file and its derivatives. *
| **************************************************************************
+--------------------------------------------------------------------------*/
#include <bsp.h>
#include <stdlib.h>
#include <string.h>
/*-------------------------------------------------------------------------+
| Constants
+--------------------------------------------------------------------------*/
#define DISPLAY_CELL_COUNT (MAX_ROW * MAX_COL)
/* Number of display cells. */
#define TABSIZE 4 /* Number of spaces for TAB (\t) char. */
#define WHITE 0x0700 /* White on Black background colour. */
#define BLANK (WHITE | ' ') /* Blank character. */
/*-------------------------------------------------------------------------+
| Global Variables
+--------------------------------------------------------------------------*/
static rtems_unsigned16 *videoRam = TVRAM;
/* Physical address of start of video text memory. */
static rtems_unsigned16 *videoRamPtr = TVRAM;
/* Pointer for current output position in display. */
static rtems_unsigned8 videoRows = MAX_ROW; /* Number of rows in display. */
static rtems_unsigned8 videoCols = MAX_COL; /* Number of columns in display. */
static rtems_unsigned8 cursRow = 0; /* Current cursor row. */
static rtems_unsigned8 cursCol = 0; /* Current cursor column. */
/*-------------------------------------------------------------------------+
| Function: setHardwareCursorPos
| Description: Set hardware video cursor at given offset into video RAM.
| Global Variables: None.
| Arguments: videoCursor - Offset into video memory.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
static inline void
setHardwareCursorPos(rtems_unsigned16 videoCursor)
{
outport_byte(GDC_REG_PORT, 0xe);
outport_byte(GDC_VAL_PORT, (videoCursor >> 8) & 0xff);
outport_byte(GDC_REG_PORT, 0xf);
outport_byte(GDC_VAL_PORT, videoCursor & 0xff);
} /* setHardwareCursorPos */
/*-------------------------------------------------------------------------+
| Function: updateVideoRamPtr
| Description: Updates value of global variable "videoRamPtr" based on
| current window's cursor position.
| Global Variables: videoRamPtr, cursRow, cursCol.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
static inline void
updateVideoRamPtr(void)
{
videoRamPtr = videoRam + cursRow * videoCols + cursCol;
} /* updateVideoRamPtr */
/*-------------------------------------------------------------------------+
| Function: scrollUp
| Description: Scrolls display up n lines.
| Global Variables: None.
| Arguments: lines - number of lines to scroll.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
static void
scrollUp(rtems_unsigned8 lines)
{
rtems_unsigned16 blankCount;
/* Number of blank display cells on bottom of window. */
rtems_unsigned16 *ptrDst, *ptrSrc;
/* Source and destination pointers for memory copy operations. */
if (lines < videoRows) /* Move window's contents up. */
{
rtems_unsigned16 nonBlankCount;
/* Number of non-blank cells on upper part of display (total - blank). */
blankCount = lines * videoCols;
nonBlankCount = DISPLAY_CELL_COUNT - blankCount;
ptrSrc = videoRam + blankCount;
ptrDst = videoRam;
while(nonBlankCount--)
*ptrDst++ = *ptrSrc++;
}
else /* Clear the whole display. */
{
blankCount = DISPLAY_CELL_COUNT;
ptrDst = videoRam;
}
/* Fill bottom with blanks. */
while (blankCount-- > 0)
*ptrDst++ = BLANK;
} /* scrollUp */
/*-------------------------------------------------------------------------+
| Function: printCHAR
| Description: Print printable character to display.
| Global Variables: videoRamPtr, cursRow, cursCol.
| Arguments: c - character to write to display.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
static void
printCHAR(char c)
{
*videoRamPtr++ = c | WHITE;
cursCol++;
if (cursCol == videoCols)
{
cursCol = 0;
cursRow++;
if (cursRow == videoRows)
{
cursRow--;
scrollUp(1);
videoRamPtr -= videoCols;
}
}
} /* printCHAR */
/*-------------------------------------------------------------------------+
| Function: printBS
| Description: Print BS (BackSpace - '\b') character to display.
| Global Variables: videoRamPtr, cursRow, cursCol.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
static inline void
printBS(void)
{
/* Move cursor back one cell. */
if (cursCol > 0)
cursCol--;
else if (cursRow > 0)
{
cursRow--;
cursCol = videoCols - 1;
}
else
return;
/* Write a whitespace. */
*(--videoRamPtr) = BLANK;
} /* printBS */
/*-------------------------------------------------------------------------+
| Function: printHT
| Description: Print HT (Horizontal Tab - '\t') character to display.
| Global Variables: cursCol.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
static inline void
printHT(void)
{
do
printCHAR(' ');
while (cursCol % TABSIZE);
} /* printHT */
/*-------------------------------------------------------------------------+
| Function: printLF
| Description: Print LF (Line Feed - '\n') character to display.
| Global Variables: cursRow.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
static inline void
printLF(void)
{
cursRow++;
if (cursRow == videoRows)
{
cursRow--;
scrollUp(1);
}
updateVideoRamPtr();
} /* printLF */
/*-------------------------------------------------------------------------+
| Function: printCR
| Description: Print CR (Carriage Return - '\r') to display.
| Global Variables: cursCol.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
static inline void
printCR(void)
{
cursCol = 0;
updateVideoRamPtr();
} /* printCR */
/*-------------------------------------------------------------------------+
| Function: consPutc
| Description: Print a character to display at current position.
| Global Variables: videoRamPtr, videoRam.
| Arguments: c - character to write to display.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
static void
consPutc(char c)
{
switch (c)
{
case '\b': printBS(); break;
case '\t': printHT(); break;
case '\n': printLF(); break;
case '\r': printCR(); break;
default: printCHAR(c); break;
} /* switch */
setHardwareCursorPos(videoRamPtr - videoRam);
/* At current offset into videoRam */
} /* consPutc */
/*-------------------------------------------------------------------------+
| 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)
{
consPutc(c);
} /* _IBMPC_outch */
/*-------------------------------------------------------------------------+
| Function: _IBMPC_initVideo
| Description: Video system initialization. Hook for any early setup.
| Global Variables: videoRows.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
void
_IBMPC_initVideo(void)
{
scrollUp(videoRows); /* Clear entire screen */
setHardwareCursorPos(0); /* Cursor at upper left corner */
} /* _IBMPC_initVideo */
