/*
* This file contains the TTY driver for VGA
*
* COPYRIGHT (c) 1998 by Radstone Technology
*
*
* THIS FILE IS PROVIDED TO YOU, THE USER, "AS IS", WITHOUT WARRANTY OF ANY
* KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK
* AS TO THE QUALITY AND PERFORMANCE OF ALL CODE IN THIS FILE IS WITH YOU.
*
* You are hereby granted permission to use, copy, modify, and distribute
* this file, provided that this notice, plus the above copyright notice
* and disclaimer, appears in all copies. Radstone Technology will provide
* no support for this code.
*
* This driver uses the termios pseudo driver.
*/
/*-------------------------------------------------------------------------+
| (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>
#include "vga_p.h"
/*-------------------------------------------------------------------------+
| Constants
+--------------------------------------------------------------------------*/
#define DISPLAY_CELL_COUNT (VGA_NUM_ROWS * VGA_NUM_COLS)
/* Number of display cells. */
#define TABSIZE 4 /* Number of spaces for TAB (\t) char. */
#define WHITE 0x0007 /* White on Black background colour. */
#define BLANK (WHITE | (' '<<8)) /* Blank character. */
/*
* This is imported from i8042.c to provide flow control
*/
extern volatile boolean bScrollLock;
/*-------------------------------------------------------------------------+
| Global Variables
+--------------------------------------------------------------------------*/
/* Physical address of start of video text memory. */
static unsigned16 *videoRam = (unsigned16 *)VGA_FB;
/* Pointer for current output position in display. */
static unsigned16 *videoRamPtr = (unsigned16 *)VGA_FB;
static unsigned8 videoRows = VGA_NUM_ROWS; /* Number of rows in display. */
static unsigned8 videoCols = VGA_NUM_COLS; /* Number of columns in display. */
static unsigned8 cursRow = 0; /* Current cursor row. */
static 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(unsigned16 videoCursor)
{
VGA_WRITE_CRTC(0x0e, (videoCursor >> 8) & 0xff);
VGA_WRITE_CRTC(0x0f, 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(unsigned8 lines)
{
/* Number of blank display cells on bottom of window. */
unsigned16 blankCount;
/* Source and destination pointers for memory copy operations. */
unsigned16 *ptrDst, *ptrSrc;
if(lines<videoRows) /* Move window's contents up. */
{
/*
* Number of non-blank cells on upper part
* of display (total - blank).
*/
unsigned16 nonBlankCount;
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<<8) | 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 */
/*
* Console Device Driver Entry Points
*/
void
vga_write(
int minor,
char cChar)
{
switch (cChar)
{
case '\b':
printBS();
break;
case '\t':
printHT();
break;
case '\n':
printLF();
break;
case '\r':
printCR();
break;
default:
printCHAR(cChar);
break;
}
setHardwareCursorPos(videoRamPtr - videoRam);
} /* vga_write */
/*
* vga_write_support
*
* Console Termios output entry point.
*
*/
int vga_write_support(
int minor,
const char *buf,
int len
)
{
int nwrite = 0;
while(bScrollLock)
{
/*
* The Scroll lock on the keyboard is active
*/
/*
* Yield while we wait
*/
rtems_task_wake_after(RTEMS_YIELD_PROCESSOR);
}
/*
* Write each byte in the string to the display
*/
while (nwrite<len)
{
/*
* transmit character
*/
vga_write(minor, *buf++);
nwrite++;
}
/*
* return the number of bytes written.
*/
return nwrite;
}
boolean vga_probe(int minor)
{
unsigned8 ucMiscIn;
/*
* Check for presence of VGA adaptor
*/
inport_byte(0x3cc, ucMiscIn);
if(ucMiscIn!=0xff)
{
/*
* VGA device is present
*/
return(TRUE);
}
return(FALSE);
}
void vga_init(int minor)
{
scrollUp(videoRows); /* Clear entire screen */
setHardwareCursorPos(0); /* Cursor at upper left corner */
/*
* Enable the cursor
*/
VGA_WRITE_CRTC(0x0a, 0x0e); /* Crt cursor start */
}
