/* Copyright (C) 2004 David Decotigny
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., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
USA.
*/
#include <sos/klibc.h>
#include <hwcore/ioports.h>
#include "x86_videomem.h"
/* The text video memory starts at address 0xB8000. Odd bytes are the
ASCII value of the character, even bytes are attribute for the
preceding character. */
#define VIDEO 0xb8000
/* Console screen size */
#define LINES 25
#define COLUMNS 80
/** The structure of a character element in the video memory. @see
http://webster.cs.ucr.edu/AoA DOS edition chapter 23 */
typedef struct {
unsigned char character;
unsigned char attribute;
} __attribute__ ((packed)) x86_video_mem[LINES*COLUMNS];
/** The base pointer for the video memory */
static volatile x86_video_mem *video = (volatile x86_video_mem*)VIDEO;
sos_ret_t sos_x86_videomem_setup(void)
{
/*
* Hide cursor. @see Ralf Brown's interrupt (and port) list
* http://www-2.cs.cmu.edu/~ralf/files.html
*/
#define CRT_REG_INDEX 0x3d4
#define CRT_REG_DATA 0x3d5
/* CRT index port => ask for access to register 0xa ("cursor
start") */
outb(0x0a, CRT_REG_INDEX);
/* (RBIL Tables 708 & 654) CRT Register 0xa => bit 5 = cursor OFF */
outb(1 << 5, CRT_REG_DATA);
return SOS_OK;
}
sos_ret_t sos_x86_videomem_cls(unsigned char attribute)
{
/* Clears the screen */
int i;
for(i = 0 ; i < LINES*COLUMNS ; i++)
{
(*video)[i].character = 0;
(*video)[i].attribute = attribute;
}
return SOS_OK;
}
sos_ret_t sos_x86_videomem_putstring(unsigned char row, unsigned char col,
unsigned char attribute,
const char *str)
{
unsigned video_offs = row*COLUMNS + col;
if (video_offs >= LINES*COLUMNS)
return -SOS_EINVAL;
for ( ; str && *str && (video_offs < LINES*COLUMNS) ; str++, video_offs++)
{
(*video)[video_offs].character = (unsigned char)*str;
(*video)[video_offs].attribute = attribute;
}
return SOS_OK;
}
sos_ret_t sos_x86_videomem_putchar(unsigned char row, unsigned char col,
unsigned char attribute,
unsigned char c)
{
unsigned video_offs = row*COLUMNS + col;
if (video_offs >= LINES*COLUMNS)
return -SOS_EINVAL;
(*video)[video_offs].character = c;
(*video)[video_offs].attribute = attribute;
return SOS_OK;
}
sos_ret_t sos_x86_videomem_printf(unsigned char row, unsigned char col,
unsigned char attribute,
const char *format, /* args */...)
{
char buff[256];
va_list ap;
va_start(ap, format);
vsnprintf(buff, sizeof(buff), format, ap);
va_end(ap);
return sos_x86_videomem_putstring(row, col, attribute, buff);
}
