xref: /freebsd/share/man/man4/vga.4 (revision 3d45e180f437865262fc7c39fc3239641f305737)
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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
32.Sh NAME
33.Nm vga
34.Nd generic video card interface
35.Sh SYNOPSIS
36.Cd "options VESA"
37.Cd "options VESA_DEBUG=N"
38.Cd "options VGA_ALT_SEQACCESS"
39.Cd "options VGA_NO_FONT_LOADING"
40.Cd "options VGA_NO_MODE_CHANGE"
41.Cd "options VGA_SLOW_IOACCESS"
42.Cd "options VGA_WIDTH90"
43.Cd "device vga0 at isa? port ? conflicts"
44.Sh DESCRIPTION
45The
46.Nm
47driver is a generic video card driver which provides access to
48video cards.  This driver is required for the console driver
49.Xr syscons 4 .
50The console driver will call the
51.Nm
52driver to manipulate video hardware (changing video modes, loading font, etc).
53.Pp
54The keyword
55.Dv conflicts
56is required, as the video card may use I/O ports in the same range
57as other drivers.
58.Pp
59The
60.Nm
61driver supports the standard video cards: MDA, CGA, EGA and VGA.
62In
63addition, the driver can utilize VESA BIOS extensions if the video card
64supports them.
65VESA support can either be statically included in the kernel
66or can be loaded as a separate module.
67.Pp
68In order to statically link the VESA support to the kernel, the
69.Dv VESA
70option (see below) must be defined in the kernel configuration file.
71.Pp
72The
73.Nm vesa
74module can be dynamically loaded into the kernel using
75.Xr kldload 8 .
76.Sh DRIVER CONFIGURATION
77.Ss Kernel Configuration Options
78The following kernel configuration options
79.Pq see Xr config 8
80can be used to control the
81.Nm
82driver.
83These options provide compatibility with certain VGA cards.
84.Bl -tag -width MOUSE
85.It Dv VGA_ALT_SEQACCESS
86You may want to try this option if the mouse pointer is not drawn correctly
87or the font does not seem to be loaded properly on the VGA card.
88However, it may cause flicker on some systems.
89.It Dv VGA_SLOW_IOACCESS
90Older VGA cards may require this option for proper operation.
91It makes the driver perform byte-wide I/O to VGA registers and
92slow down a little.
93.It Dv VGA_WIDTH90
94This option enables 90 column modes: 90x25, 90x30, 90x43, 90x50, 90x60.
95These modes are not always supported by the video card and the display.
96It is highly likely that LCD display cannot work with these modes.
97.El
98.Pp
99The following options add optional features to the driver.
100.Bl -tag -width MOUSE
101.It Dv VESA
102Add VESA BIOS support to the driver.
103If the VGA card has the VESA BIOS extension 1.2 or later,
104this option will utilize the VESA BIOS service to switch to high
105resolution modes.
106.It Dv VESA_DEBUG=N
107Set the VESA support debug level to
108.Fa N .
109The default value is zero, which suppresses all debugging output.
110.El
111.Pp
112The following options will remove some features from the
113.Nm
114driver and save kernel memory.
115.Bl -tag -width MOUSE
116.It Dv VGA_NO_FONT_LOADING
117The
118.Nm
119driver can load software font to EGA and VGA cards.
120This option removes this feature.
121Note that if you use this option and
122still wish to use the mouse on the console then you must also use the
123.Dv SC_ALT_MOUSE_IMAGE
124option.  See
125.Xr syscons 4 .
126.It Dv VGA_NO_MODE_CHANGE
127This option prevents the driver from changing video modes.
128.El
129.\".Sh FILES
130.Sh EXAMPLES
131Your kernel configuration should normally have:
132.Pp
133.Dl "device vga0 at isa? port ? conflicts"
134.Pp
135The following lines should be included in the kernel configuration file
136in order to enable the VESA BIOS Extension support.
137.Pp
138.Dl "options VESA"
139.Dl "device vga0 at isa? port ? conflicts"
140.Pp
141If you do not want VESA support included in the kernel, but
142want to use occasionally, do not add the
143.Dv VESA
144option.  And load the
145.Nm vesa
146module as desired:
147.Pp
148.Dl kldload vesa
149.Pp
150.\".Sh DIAGNOSTICS
151.\".Sh CAVEATS
152.\".Sh BUGS
153.Sh SEE ALSO
154.Xr vgl 3 ,
155.Xr syscons 4 ,
156.Xr config 8 ,
157.Xr kldload 8 ,
158.Xr kldunload 8
159.Sh STANDARDS
160.Rs
161.%T "VESA BIOS Extension (VBE)"
162.%A Video Electronics Standards Association
163.Re
164.Sh HISTORY
165The
166.Nm
167driver first appeared in
168.Fx 3.1 .
169.Sh AUTHORS
170.An -nosplit
171The
172.Nm
173driver was written by
174.An S\(/oren 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