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FreeBSD Kernel Internals Video Posted
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VGA(4) BSD Kernel Interfaces 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 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
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 Soren Schmidt <sos@FreeBSD.org> and Kazutaka Yokota <yokota@FreeBSD.org>. This manual page was written by Kazutaka Yokota. BSD
June 30, 1999 BSD
