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Diffstat (limited to 'man/3/vga')
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diff --git a/man/3/vga b/man/3/vga new file mode 100644 index 00000000..526d5231 --- /dev/null +++ b/man/3/vga @@ -0,0 +1,247 @@ +.TH VGA 3 +.SH NAME +vga \- VGA controller device +.SH SYNOPSIS +.B bind #v /dev +.PP +.B /dev/vgactl +.br +.B /dev/vgaovlctl +.br +.B /dev/vgaovl +.SH DESCRIPTION +The VGA device allows configuration of a graphics controller +on a PC (and any other platform with VGA devices). +.B Vgactl +allows control over higher-level settings such as display height, width, depth, +controller and hardware-cursor type. +Along with the I/O-port registers +provided by +.IR arch (3), +it is used to implement configuration and setup of VGA controller cards. +....This is usually performed by +.....IR vga (8). +.PP +Writing strings to +.B vgactl +configures the VGA device. +The following are valid commands. +.TP +.BI size " X" x Y x "Z chan" +Set the size of the screen image to be +.I X +pixels wide +and +.I Y +pixels high. +Each pixel is +.I Z +bits as specified by +.IR chan , +whose format is described in +.IR image (6). +.TP +.BI actualsize " X" x Y +Set the physical size of the display to be +.I X +pixels wide by +.I Y +pixels high. +This message is optional; +it is used to implement panning and to accommodate +displays that require the in-memory screen image +to have certain alignment properties. +For example, a 1400x1050 screen with a 1408x1050 in-memory image +will use +.B "size 1408x1050 +but +.BR "actualsize 1400x1050" . +.TP +.BI panning " mode" +Depending on whether +.I mode +is +.B on +or +.BR off , +enable or disable panning in a virtual screen. +If panning is on and the screen's +.B size +is larger than its +.BR actualsize , +the displayed portion of the screen will pan to follow the mouse. +Setting the panning mode after the first attach of the +.B #i +driver has no effect. +.TP +.BI type " ctlr" +Set the type of VGA controller being used. +.I Ctlr +is one of +.BR ark200pv , +.BR clgd542x , +.BR clgd546x , +.BR ct65545 , +.BR cyber938x , +.BR hiqvideo , +.BR mach64xx , +.BR mga2164w , +.BR neomagic , +.BR s3 , +and +.BR t2r4 . +.IP +Note that this list does not indicate the full set of VGA chips +supported. For example, +.B s3 +includes the 86C801/5, 86C928, Vision864, and Vision964. +It is the job of a user-level program +....IR vga (8) +to recognise which particular chip is being used and to initialize it +appropriately. +.TP +.BI hwgc " gc" +Set the type of hardware graphics cursor being used. +.I Gc +is one of +.BR ark200pvhwgc , +.BR bt485hwgc , +.BR clgd542xhwgc , +.BR clgd546xhwgc , +.BR ct65545hwgc , +.BR cyber938xhwgc , +.BR hiqvideohwgc , +.BR mach64xxhwgc , +.BR mga2164whwgc , +.BR neomagichwgc , +.BR rgb524hwgc , +.BR s3hwgc , +.BR t2r4hwgc , +.BR tvp3020hwgc , +and +.BR tvp3026hwgc . +A value of +.B off +disables the cursor. +There is no software cursor. +.TP +.BI palettedepth " d" +Set the number of bits of precision used by the +VGA palette to +.IR d , +which must be either +.B 6 +or +.BR 8 . +.TP +.B blank +Blank the screen. +This consists of setting the hardware +color map to all black as well as, on some controllers, setting the +VGA hsync and vsync signals so as to turn off +VESA DPMS-compliant monitors. +The screen also blanks after 30 minutes of inactivity. +The screen can be unblanked by moving the mouse. +.TP +.BI blanktime " minutes" +Set the timeout before the +screen blanks; the default is 30 minutes. +If +.I minutes +is zero, blanking is disabled. +.TP +.BI hwaccel " mode" +Depending on whether +.I mode +is +.B on +or +.BR off , +enable or disable whether hardware acceleration +(currently for rectangle filling and moving) +used by the graphics engine. +The default setting is +.BR on . +.TP +.BI hwblank " mode" +Depending on whether +.I mode +is +.B on +or +.BR off , +enable or disable the use of DPMS blanking +(see +.B blank +above). +.TP +.BI linear " size align" +Use a linear screen aperture of size +.I size +aligned on an +.IR align -byte +boundary. +.TP +.B drawinit +Initialize the graphics hardware. +This must be sent after setting the +.BR type . +.PP +Reading +.B vgactl +returns the current settings, one per line. +.PP +Some VGA cards support overlay graphics. +Writing strings to +.B vgaovlctl +configures such cards. +The following are valid overlay control commands: +.TP +.BI openctl +opens the overlay device. +.TP +.BI configure " w h format" +allocates resources inside the driver to support an overlay area +of width +.I w +and height +.I h +pixels. Currently, the only supported +.I format +is +.B YUYV +packed. +In +.B YUYV +two pixels are encoded by their separate Y values +and their combined U and V values. +The size of the two pixels is 32 bits. +.TP +.BI enable " x y w h" +enables drawing data on the display through the overlay mode. The data +is drawn at position +.IR x , y +and has a width and height of +.IR w , h +respectively. +.TP +.BI closectl +terminates overlay control. +.PP +Overlay data can be written to +.BR vgaovl . +.SH EXAMPLES +The following disables hardware acceleration. +.IP +.EX +echo hwaccel off > /dev/vgactl +.EE +.SH SOURCE +.B /os/pc/devvga.c +.SH SEE ALSO +.IR arch (3) +....IR vga (8) +.SH BUGS +The hardware graphics cursor on the +.B et4000 +does not work in 2x8-bit mode. |