vga (4)

Leading comments

Copyright (c) 1999
Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp>
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer as
   the first lines of this file unmodified.
2. Redistributions in binary form must reproduce the above copyright
   notice, ...

(The comments found at the beginning of the groff file "man4/vga.4freebsd".)

NAME

vga - generic video card interface

SYNOPSIS

options VESA options VESA_DEBUG=N options VGA_ALT_SEQACCESS options VGA_NO_FONT_LOADING options VGA_NO_MODE_CHANGE options VGA_SLOW_IOACCESS options VGA_WIDTH90 device vga

In /boot/device.hints hint.vga.0.at=isa

DESCRIPTION

The driver is a generic video card driver which provides access to video cards. This driver is required for the console driver syscons(4). The console driver will call the driver to manipulate video hardware (changing video modes, loading font, etc).

The driver supports the standard video cards: MDA, CGA, EGA and VGA. In addition, the driver can utilize VESA BIOS extensions if the video card supports them. VESA support can either be statically included in the kernel or can be loaded as a separate module.

In order to statically link the VESA support to the kernel, the VESA option (see below) must be defined in the kernel configuration file.

The vesa module can be dynamically loaded into the kernel using kldload(8).

DRIVER CONFIGURATION

Kernel Configuration Options

The following kernel configuration options (see config(8)) can be used to control the driver. These options provide compatibility with certain VGA cards.

VGA_ALT_SEQACCESS

You may want to try this option if the mouse pointer is not drawn correctly or the font does not seem to be loaded properly on the VGA card. However, it may cause flicker on some systems.

VGA_SLOW_IOACCESS

Older VGA cards may require this option for proper operation. It makes the driver perform byte-wide I/O to VGA registers and slow down a little.

VGA_WIDTH90

This option enables 90 column modes: 90x25, 90x30, 90x43, 90x50, 90x60. These modes are not always supported by the video card and the display. It is highly likely that LCD display cannot work with these modes.

The following options add optional features to the driver.

VESA

Add VESA BIOS support to the driver. If the VGA card has the VESA BIOS extension 1.2 or later, this option will utilize the VESA BIOS service to switch to high resolution modes.

VESA_DEBUG=N

Set the VESA support debug level to Fa N . The default value is zero, which suppresses all debugging output.

The following options will remove some features from the driver and save kernel memory.

VGA_NO_FONT_LOADING

The driver can load software font to EGA and VGA cards. This option removes this feature. Note that if you use this option and still wish to use the mouse on the console then you must also use the SC_ALT_MOUSE_IMAGE option. See syscons(4).

VGA_NO_MODE_CHANGE

This option prevents the driver from changing video modes.

EXAMPLES

Your kernel configuration should normally have:

"device vga"

And you need the following line in /boot/device.hints

hint.vga.0.at="isa"

The following lines should be included in the kernel configuration file in order to enable the VESA BIOS Extension support.

"options VESA"

"device vga"

If you do not want VESA support included in the kernel, but want to use occasionally, do not add the VESA option. And load the vesa module as desired:

kldload vesa

SEE ALSO

vgl(3), syscons(4), config(8), kldload(8), kldunload(8)

STANDARDS

"VESA BIOS Extension (VBE)" Video Electronics Standards Association

HISTORY

The driver first appeared in Fx 3.1 .

AUTHORS

An -nosplit The driver was written by An S/oren Schmidt Aq sos@FreeBSD.org and An Kazutaka Yokota Aq yokota@FreeBSD.org . This manual page was written by An Kazutaka Yokota .