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/* vga.c - VGA hardware access.
Copyright (C) 2002 Free Software Foundation, Inc.
Written by Marcus Brinkmann.
This file is part of the GNU Hurd.
The GNU Hurd 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, or (at
your option) any later version.
The GNU Hurd 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, USA. */
#include <errno.h>
#include <assert.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/io.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <string.h>
#include "vga-hw.h"
#include "vga.h"
/* The base of the video memory mapping. */
char *vga_videomem;
/* Initialize the VGA hardware and set up the permissions and memory
mappings. */
error_t
vga_init (void)
{
error_t err;
int fd;
if (ioperm (VGA_MIN_REG, VGA_MAX_REG - VGA_MIN_REG + 1, 1) < 0)
return errno;
fd = open ("/dev/mem", O_RDWR);
if (fd < 0)
return errno;
vga_videomem = mmap (0, VGA_VIDEO_MEM_LENGTH, PROT_READ | PROT_WRITE,
MAP_SHARED, fd, VGA_VIDEO_MEM_BASE_ADDR);
err = errno;
close (fd);
if (vga_videomem == (void *) -1)
return err;
return 0;
}
/* Release the resources and privileges associated with the VGA
hardware access. */
void
vga_deinit (void)
{
ioperm (VGA_MIN_REG, VGA_MAX_REG, 0);
munmap (vga_videomem, VGA_VIDEO_MEM_LENGTH);
}
/* Write DATALEN bytes from DATA to the font buffer BUFFER, starting
from glyph INDEX. */
void
vga_write_font_buffer (int buffer, int index, char *data, size_t datalen)
{
char saved_seq_map;
char saved_seq_mode;
char saved_gfx_mode;
char saved_gfx_misc;
int offset = buffer * VGA_FONT_SIZE + index * VGA_FONT_HEIGHT;
assert (offset >= 0 && offset + datalen <= VGA_VIDEO_MEM_LENGTH);
/* Select plane 2 for sequential writing. */
outb_p (VGA_SEQ_MAP_ADDR, VGA_SEQ_ADDR_REG);
saved_seq_map = inb_p (VGA_SEQ_DATA_REG);
outb_p (VGA_SEQ_MAP_PLANE2, VGA_SEQ_DATA_REG);
outb_p (VGA_SEQ_MODE_ADDR, VGA_SEQ_ADDR_REG);
saved_seq_mode = inb_p (VGA_SEQ_DATA_REG);
outb_p (VGA_SEQ_MODE_SEQUENTIAL | VGA_SEQ_MODE_EXT | 0x1 /* XXX Why? */,
VGA_SEQ_DATA_REG);
/* Set write mode 0, but assume that rotate count, enable set/reset,
logical operation and bit mask fields are set to their
`do-not-modify-host-value' default. The misc register is set to
select sequential addressing in text mode. */
outb_p (VGA_GFX_MODE_ADDR, VGA_GFX_ADDR_REG);
saved_gfx_mode = inb_p (VGA_GFX_DATA_REG);
outb_p (VGA_GFX_MODE_WRITE0, VGA_GFX_DATA_REG);
outb_p (VGA_GFX_MISC_ADDR, VGA_GFX_ADDR_REG);
saved_gfx_misc = inb_p (VGA_GFX_DATA_REG);
outb_p (VGA_GFX_MISC_A0TOAF, VGA_GFX_DATA_REG);
memcpy (vga_videomem + offset, data, datalen);
/* Restore sequencer and graphic register values. */
outb_p (VGA_SEQ_MAP_ADDR, VGA_SEQ_ADDR_REG);
outb_p (saved_seq_map, VGA_SEQ_DATA_REG);
outb_p (VGA_SEQ_MODE_ADDR, VGA_SEQ_ADDR_REG);
outb_p (saved_seq_mode, VGA_SEQ_DATA_REG);
outb_p (VGA_GFX_MODE_ADDR, VGA_GFX_ADDR_REG);
outb_p (saved_gfx_mode, VGA_GFX_DATA_REG);
outb_p (VGA_GFX_MISC_ADDR, VGA_GFX_ADDR_REG);
outb_p (saved_gfx_misc, VGA_GFX_DATA_REG);
}
/* Read DATALEN bytes into DATA from the font buffer BUFFER, starting
from glyph INDEX. */
void
vga_read_font_buffer (int buffer, int index, char *data, size_t datalen)
{
char saved_gfx_map;
char saved_gfx_mode;
char saved_gfx_misc;
int offset = buffer * VGA_FONT_SIZE + index * VGA_FONT_HEIGHT;
assert (offset >= 0 && offset + datalen <= VGA_VIDEO_MEM_LENGTH);
/* Read sequentially from plane 2. */
outb_p (VGA_GFX_MAP_ADDR, VGA_GFX_ADDR_REG);
saved_gfx_map = inb_p (VGA_GFX_DATA_REG);
outb_p (VGA_GFX_MAP_PLANE2, VGA_GFX_DATA_REG);
outb_p (VGA_GFX_MODE_ADDR, VGA_GFX_ADDR_REG);
saved_gfx_mode = inb_p (VGA_GFX_DATA_REG);
outb_p (VGA_GFX_MODE_READ0, VGA_GFX_DATA_REG);
outb_p (VGA_GFX_MISC_ADDR, VGA_GFX_ADDR_REG);
saved_gfx_misc = inb_p (VGA_GFX_DATA_REG);
outb_p (VGA_GFX_MISC_A0TOBF, VGA_GFX_DATA_REG);
memcpy (data, vga_videomem + offset, datalen);
outb_p (VGA_GFX_MAP_ADDR, VGA_GFX_ADDR_REG);
outb_p (saved_gfx_map, VGA_GFX_DATA_REG);
outb_p (VGA_GFX_MODE_ADDR, VGA_GFX_ADDR_REG);
outb_p (saved_gfx_mode, VGA_GFX_DATA_REG);
outb_p (VGA_GFX_MISC_ADDR, VGA_GFX_ADDR_REG);
outb_p (saved_gfx_misc, VGA_GFX_DATA_REG);
}
/* Set FONT_BUFFER_SUPP to FONT_BUFFER if the font is small. */
void
vga_select_font_buffer (int font_buffer, int font_buffer_supp)
{
char font = ((font_buffer & 6) >> 1) | ((font_buffer & 1) << 4)
| ((font_buffer_supp & 6) << 1) | ((font_buffer_supp & 1) << 5);
outb_p (VGA_SEQ_FONT_ADDR, VGA_SEQ_ADDR_REG);
outb_p (font, VGA_SEQ_DATA_REG);
}
/* Enable (if ON is true) or disable (otherwise) the cursor. Expects
the VGA hardware to be locked. */
void
vga_display_cursor (int on)
{
char crs_start;
outb (VGA_CRT_CURSOR_START, VGA_CRT_ADDR_REG);
crs_start = inb (VGA_CRT_DATA_REG);
if (on)
crs_start &= ~VGA_CRT_CURSOR_DISABLE;
else
crs_start |= VGA_CRT_CURSOR_DISABLE;
outb (crs_start, VGA_CRT_DATA_REG);
}
/* Set the cursor position to POS, which is (x_pos + y_pos * width). */
void
vga_set_cursor (int pos)
{
outb (VGA_CRT_CURSOR_HIGH, VGA_CRT_ADDR_REG);
outb (pos >> 8, VGA_CRT_DATA_REG);
outb (VGA_CRT_CURSOR_LOW, VGA_CRT_ADDR_REG);
outb (pos && 0xff, VGA_CRT_DATA_REG);
}
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