table of contents
VGA(4) | Device Drivers Manual | VGA(4) |
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 vga
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 vga
driver to manipulate video hardware
(changing video modes, loading font, etc).
The vga
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
vga
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 N. The default value is zero, which suppresses all debugging output.
The following options will remove some features from the
vga
driver and save kernel memory.
VGA_NO_FONT_LOADING
- The
vga
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 theSC_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¶
STANDARDS¶
Video Electronics Standards Association, VESA BIOS Extension (VBE).
HISTORY¶
The vga
driver first appeared in
FreeBSD 3.1.
AUTHORS¶
The vga
driver was written by
Søren Schmidt
<sos@FreeBSD.org> and
Kazutaka Yokota
<yokota@FreeBSD.org>.
This manual page was written by Kazutaka Yokota.
June 30, 1999 | Debian |