|VGA(4)||FreeBSD Kernel Interfaces Manual||VGA(4)|
NAMEvga — generic video card interface
DESCRIPTIONThe 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).
Kernel Configuration OptionsThe following kernel configuration options (see config(8)) can be used to control the vga driver. These options provide compatibility with certain VGA cards.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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).
- This option prevents the driver from changing video modes.
EXAMPLESYour kernel configuration should normally have:
And you need the following line in /boot/device.hints.
The following lines should be included in the kernel configuration file in order to enable the VESA BIOS Extension support.
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:
STANDARDSVideo Electronics Standards Association, VESA BIOS Extension (VBE).
HISTORYThe vga driver first appeared in FreeBSD 3.1.
AUTHORSThe vga driver was written by <sos@FreeBSD.org> and <yokota@FreeBSD.org>. This manual page was written by .
|June 30, 1999||FreeBSD|