xref: /freebsd/share/man/man4/vga.4 (revision b6cd2dbdc521272be1813fd12be3e48024f5e3d9)
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2.\" Copyright (c) 1999
3.\" Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp>
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27.\" $FreeBSD$
28.\"
29.Dd June 30, 1999
30.Dt VGA 4
31.Os FreeBSD
32.Sh NAME
33.Nm vga
34.Nd
35generic video card interface
36.Sh SYNOPSIS
37.Cd "options VESA"
38.Cd "options VESA_DEBUG=N"
39.Cd "options VGA_ALT_SEQACCESS"
40.Cd "options VGA_NO_FONT_LOADING"
41.Cd "options VGA_NO_MODE_CHANGE"
42.Cd "options VGA_SLOW_IOACCESS"
43.Cd "options VGA_WIDTH90"
44.Cd "device vga0 at isa? port ? conflicts"
45.Sh DESCRIPTION
46The
47.Nm
48driver is a generic video card driver which provides access to
49video cards.  This driver is required for the console driver
50.Xr syscons 4 .
51The console driver will call the
52.Nm
53driver to manipulate video hardware (changing video modes, loading font, etc).
54.Pp
55The keyword
56.Dv conflicts
57is required, as the video card may use I/O ports in the same range
58as other drivers.
59.Pp
60The
61.Nm
62driver supports the standard video cards: MDA, CGA, EGA and VGA.
63In
64addition, the driver can utilize VESA BIOS extensions if the video card
65supports them.
66VESA support can either be statically included in the kernel
67or can be loaded as a separate module.
68.Pp
69In order to statically link the VESA support to the kernel, the
70.Dv VESA
71option (see below) must be defined in the kernel configuration file.
72.Pp
73The
74.Nm vesa
75module can be dynamically loaded into the kernel using
76.Xr kldload 8 .
77.Sh DRIVER CONFIGURATION
78.Ss Kernel Configuration Options
79The following kernel configuration options
80.Pq see Xr config 8
81can be used to control the
82.Nm
83driver.
84These options provide compatibility with certain VGA cards.
85.Bl -tag -width MOUSE
86.It Dv VGA_ALT_SEQACCESS
87You may want to try this option if the mouse pointer is not drawn correctly
88or the font does not seem to be loaded properly on the VGA card.
89However, it may cause flicker on some systems.
90.It Dv VGA_SLOW_IOACCESS
91Older VGA cards may require this option for proper operation.
92It makes the driver perform byte-wide I/O to VGA registers and
93slow down a little.
94.It Dv VGA_WIDTH90
95This option enables 90 column modes: 90x25, 90x30, 90x43, 90x50, 90x60.
96These modes are not always supported by the video card and the display.
97It is highly likely that LCD display cannot work with these modes.
98.El
99.Pp
100The following options add optional features to the driver.
101.Bl -tag -width MOUSE
102.It Dv VESA
103Add VESA BIOS support to the driver.
104If the VGA card has the VESA BIOS extension 1.2 or later,
105this option will utilize the VESA BIOS service to switch to high
106resolution modes.
107.It Dv VESA_DEBUG=N
108Set the VESA support debug level to
109.Fa N .
110The default value is zero, which suppresses all debugging output.
111.El
112.Pp
113The following options will remove some features from the
114.Nm
115driver and save kernel memory.
116.Bl -tag -width MOUSE
117.It Dv VGA_NO_FONT_LOADING
118The
119.Nm
120driver can load software font to EGA and VGA cards.
121This option removes this feature.
122Note that if you use this option and
123still wish to use the mouse on the console then you must also use the
124.Dv SC_ALT_MOUSE_IMAGE
125option.  See
126.Xr syscons 4 .
127.It Dv VGA_NO_MODE_CHANGE
128This option prevents the driver from changing video modes.
129.El
130.\".Sh FILES
131.Sh EXAMPLE
132Your kernel configuration should normally have:
133.Pp
134.Dl "device vga0 at isa? port ? conflicts"
135.Pp
136The following lines should be included in the kernel configuration file
137in order to enable the VESA BIOS Extension support.
138.Pp
139.Dl "options VESA"
140.Dl "device vga0 at isa? port ? conflicts"
141.Pp
142If you do not want VESA support included in the kernel, but
143want to use occasionally, do not add the
144.Dv VESA
145option.  And load the
146.Nm vesa
147module as desired:
148.Pp
149.Dl kldload vesa
150.Pp
151.\".Sh DIAGNOSTICS
152.\".Sh CAVEATS
153.\".Sh BUGS
154.Sh SEE ALSO
155.Xr vgl 3 ,
156.Xr syscons 4 ,
157.Xr config 8 ,
158.Xr kldload 8 ,
159.Xr kldunload 8 .
160.Sh STANDARD
161.Rs
162.%T "VESA BIOS Extension (VBE)"
163.%A Video Electronics Standards Association
164.Re
165.Sh HISTORY
166The
167.Nm
168driver first appeared in
169.Fx 3.1 .
170.Sh AUTHORS
171The
172.Nm
173driver was written by
174.An S�ren Schmidt Aq sos@FreeBSD.org
175and
176.An Kazutaka Yokota Aq yokota@FreeBSD.org .
177This manual page was written by
178.An Kazutaka Yokota .
179