1.\" $NetBSD: wsdisplay.4,v 1.3 2000/02/17 14:11:24 dmcmahill Exp $ 2 3.Dd March 20, 1999 4.Os 5.Dt WSDISPLAY 4 6.Sh NAME 7.Nm wsdisplay 8.Nd generic display device support in wscons 9 10.Sh SYNOPSIS 11.Cd wsdisplay* at vga? console ? 12(VGA display on ISA or PCI) 13.Cd wsdisplay* at pcdisplay? console ? 14(generic PC (ISA) display) 15.Cd wsdisplay* at tga? console ? 16(DEC TGA display, alpha only) 17.Cd wsdisplay* at pfb? console ? 18(PCI framebuffer, bebox only) 19.Cd wsdisplay0 at ofb? console ? 20(Open Firmware framebuffer, macppc only) 21.Cd wsdisplay* at nextdisplay? console ? 22(NeXT display) 23.Cd wsdisplay0 at smg0 24(VAXstation small monochrome display) 25.Cd options WSDISPLAY_DEFAULTSCREENS=N 26 27.Sh DESCRIPTION 28The 29.Nm 30driver is an abstraction layer for display devices within the 31.Xr wscons 4 32framework. It attaches to the hardware specific display device 33driver and and makes it available as text terminal or graphics 34interface. 35.Pp 36A display device can have the ability to display characters on it 37(without help of an X server), either directly by hardware or through 38software putting pixel data into the display memory. 39Such displays are called 40.Dq emulating , 41the 42.Nm 43driver will connect a terminal emulation module and provide a 44tty-like software interface. In contrary, non-emulating displays can only 45be used by special programs like X servers. 46.Pp 47The 48.Em console 49locator in the configuration line refers to the device's use as output 50part of the operating system console. A device specification containing 51a positive value here will only match if the device is in use as system 52console. (The console device selection in early system startup is not 53influenced.) This way, the console device can be connected to a known 54wsdisplay device instance. (Naturally, only 55.Dq emulating 56display devices are usable as console.) 57.Pp 58The logical unit of an independant contents displayed on a display 59(sometimes referred to as 60.Dq virtual terminal 61) is called a 62.Dq screen 63here. If the underlying device driver supports it, multiple screens can 64be used on one display. (As of this writing, only the 65.Xr vga 4 66and the 67.Tn VAX 68.Dq smg 69display drivers provide this ability.) 70Screens have different minor device numbers and separate tty instances. 71One screen posesses the 72.Dq focus , 73this means it is displayed on the display and its tty device will get 74the keyboard input. (In some cases - if no screen is set up or if a screen 75was just deleted - it is possible that no focus is present at all.) 76The focus can be switched by either special keyboard input (typically 77CTL-ALT-Fn) or an ioctl command issued by a user program. 78Screens are set up or deleted through the 79.Pa /dev/ttyEcfg 80control decice (preferrably using the 81.Xr wsconscfg 8 82utility). Alternatively, the compile-time option 83.Cd WSDISPLAY_DEFAULTSCREENS=N 84will set up N screens of the display driver's default type and using 85the system's default terminal emulator at autoconfiguration time. 86 87.Sh FILES 88.Bl -item 89.It 90.Pa /dev/ttyE* 91Terminal devices (per screen). 92.It 93.Pa /dev/ttyEcfg 94Control device. 95.It 96.Pa /usr/include/dev/wscons/wsconsio.h 97.El 98 99.Sh BUGS 100The 101.Nm 102code currently limits the number of screens on one display to 8. 103.Pp 104The terms 105.Dq wscons 106and 107.Dq wsdisplay 108are not cleanly distinguished in the code and in manual pages. 109.Pp 110.Dq non-emulating 111display devices are not tested. 112 113.Sh SEE ALSO 114.Xr wscons 4 , 115.Xr wsconscfg 8 , 116.Xr wsconsctl 8 , 117.Xr wsfontload 8 , 118.Xr vga 4 , 119.Xr pcdisplay 4 , 120.Xr tty 4 121