/*
* Copyright (C) 2001-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <arch/ega.h>
#include <putchar.h>
#include <mm/page.h>
#include <synch/spinlock.h>
#include <arch/types.h>
#include <arch/asm.h>
/*
* The EGA driver.
* Simple and short. Function for displaying characters and "scrolling".
*/
static spinlock_t egalock;
static __u32 ega_cursor;
void ega_move_cursor(void);
void ega_init(void)
{
__u8 hi, lo;
map_page_to_frame(VIDEORAM, VIDEORAM, PAGE_NOT_CACHEABLE, 0);
outb(0x3d4,0xe);
hi = inb(0x3d5);
outb(0x3d4,0xf);
lo = inb(0x3d5);
ega_cursor = (hi<<8)|lo;
ega_putchar('\n');
}
void ega_display_char(char ch)
{
__u8 *vram = (__u8 *) VIDEORAM;
vram[ega_cursor*2] = ch;
}
/*
* This function takes care of scrolling.
*/
void ega_check_cursor(void)
{
if (ega_cursor < SCREEN)
return;
memcopy(VIDEORAM + ROW*2, VIDEORAM, (SCREEN - ROW)*2);
memsetw(VIDEORAM + (SCREEN - ROW)*2, ROW, 0x0720);
ega_cursor = ega_cursor - ROW;
}
void ega_putchar(const char ch)
{
pri_t pri;
pri = cpu_priority_high();
spinlock_lock(&egalock);
switch (ch) {
case '\n':
ega_cursor = (ega_cursor + ROW) - ega_cursor % ROW;
break;
case '\t':
ega_cursor = (ega_cursor + 8) - ega_cursor % 8;
break;
default:
ega_display_char(ch);
ega_cursor++;
break;
}
ega_check_cursor();
ega_move_cursor();
spinlock_unlock(&egalock);
cpu_priority_restore(pri);
}
void ega_move_cursor(void)
{
outb(0x3d4,0xe);
outb(0x3d5,(ega_cursor>>8)&0xff);
outb(0x3d4,0xf);
outb(0x3d5,ega_cursor&0xff);
}
{
ega_putchar(ch);
}