VGA(4) OpenBSD Programmer's Manual VGA(4)NAMEvga - VGA graphics driver for wscons
SYNOPSIS
vga0 at isa?
vga* at pci?
wsdisplay* at vga?
agp* at vga?
DESCRIPTION
This driver handles VGA graphics hardware within the wscons(4) console
framework. It doesn't provide direct device driver entry points but
makes its functions available via the internal wsdisplay(4) interface.
The vga driver supports multiple virtual screens on one physical display.
The screens allocated on one display can be of different ``types'', where
a type refers to various display properties. The type is determined at
the time the virtual screen is created and can't be changed later.
Screens are either created at kernel startup (then the default type is
used) or later with help of the wsconscfg(8) utility.
Currently, the following screen types are supported:
80x25 This is the standard VGA text mode with 80 columns and 25 rows.
16 different colors can be displayed at the same time.
Characters are 8 x 16 pixels large, and a font consists of 256
characters. A built-in font of this size is always present on a
VGA card. It's also possible to use a downloaded font instead.
80x25bf A modified version of the previous. It only allows 8 colors to
be displayed. In exchange, it can access two fonts at the same
time, so that 512 different characters can be displayed.
80x40 A text mode with 80 columns and 40 rows. Similar to the standard
mode, 16 colors and 256 characters are available. Characters are
8 x 10 pixels large. For this mode to be useful, a font of that
character size must be downloaded.
80x40bf A modified version of the previous. It only allows 8 colors to
be displayed. In exchange, it can access two fonts at the same
time, so that 512 different characters can be displayed.
80x50 A text mode with 80 columns and 50 rows. Similar to the standard
mode, 16 colors and 256 characters are available. Characters are
8 x 8 pixels large. For this mode to be useful, a font of that
character size must be downloaded.
80x50bf A modified version of the previous. It only allows 8 colors to
be displayed. In exchange, it can access two fonts at the same
time, so that 512 different characters can be displayed.
80x24 A variant of the ``80x25'' screen type which displays 24 lines
only. It uses the standard 8x16 VGA font. This mode might be
useful for applications which depend on closer DEC VT100
compatibility.
80x24bf A modified version of the previous. It only allows 8 colors to
be displayed. In exchange, it can access two fonts at the same
time, so that 512 different characters can be displayed.
The vga driver can display fonts of the original IBM type and ISO-8859-1
encoded fonts. As an experimental feature, the ``higher half'' fonts of
the former OpenBSD/i386 pcvt driver distribution can be used too if
option WSCONS_SUPPORT_PCVTFONTS was set at kernel compile time. This is
only useful with the ``*bf'' screen types; a font containing the ASCII
range of characters must be available too on this screen.
SEE ALSOagp(4), intro(4), isa(4), pcdisplay(4), pci(4), wscons(4), wsdisplay(4),
wsconscfg(8), wsfontload(8)BUGS
Only a subset of the possible text modes is supported.
VGA cards are supposed to emulate an MDA if a monochrome display is
connected. In this case, the device will naturally not support colors at
all, but offer the capability to display underlined characters instead.
The ``80x25bf'', ``80x40bf'', ``80x50bf'', and ``80x24bf'' screen types
will not be available. This mode of operation is not tested.
OpenBSD 4.9 March 16, 2008 OpenBSD 4.9