WSDISPLAY(4) OpenBSD Programmer's Manual WSDISPLAY(4)NAMEwsdisplay - generic display device support in wscons
SYNOPSIS
wsdisplay* at ...
option WSDISPLAY_DEFAULTSCREENS=N
DESCRIPTION
The wsdisplay driver is an abstraction layer for display devices within
the wscons(4) framework. It attaches to the hardware specific display
device driver and makes it available as text terminal or graphics
interface.
Display devices have the ability to display characters on them (without
help of an X server), either directly by hardware or through software
drawing pixel data into the display memory. The wsdisplay driver will
connect a terminal emulation module and provide a tty-like software
interface.
The console locator in the configuration line refers to the device's use
as output part of the operating system console. A device specification
containing a positive value here will only match if the device is in use
as system console. (The console device selection in early system startup
is not influenced.) This way, the console device can be connected to a
known wsdisplay device instance.
The mux locator in the configuration line refers to the wsmux(4) that
will be used to get keyboard events. If this locator is -1 no mux will
be used.
The logical unit of an independent contents displayed on a display
(sometimes referred to as ``virtual terminal'') is called a ``screen''
here. If the underlying device driver supports it, multiple screens can
be used on one display. (As of this writing, only the lcd(4) and vga(4)
display drivers provide this ability.) Screens have different minor
device numbers and separate tty instances. One screen possesses the
``focus'', this means it is displayed on the display and its tty device
will get the keyboard input. (In some cases, if no screen is set up or
if a screen was just deleted, it is possible that no focus is present at
all.) The focus can be switched by either special keyboard input
(typically CTL-ALT-Fn) or an ioctl command issued by a user program.
Screens are set up or deleted through the /dev/ttyCcfg control device
(preferably using the wsconscfg(8) utility). Alternatively, the compile-
time option WSDISPLAY_DEFAULTSCREENS=N will set up N screens of the
display driver's default type and using the system's default terminal
emulator at autoconfiguration time.
In addition and with help from backend drivers the following features are
also provided:
o Loading, deleting and listing the loaded fonts.
o Browsing backwards in the screen output, the size of the buffer for
saved text is defined by the particular hardware driver.
o Blanking the screen by timing out on inactivity in the screen holding
the input focus. Awakening activities consist of:
o pressing any keys on the keyboard;
o moving or clicking the mouse;
o any output to the screen.
Blanking the screen is usually done by disabling the horizontal sync
signal on video output, but may also include blanking the vertical
sync in which case most monitors go into power saving mode. See
wsconsctl(8) for controlling variables.
Consult the back-end drivers' documentation for which features are
supported for each particular hardware type.
IOCTL INTERFACE
The following ioctl(2) calls are provided by the wsdisplay driver or by
devices which use it. Their definitions are found in
<dev/wscons/wsconsio.h>.
WSDISPLAYIO_GTYPE (u_int)
Retrieve the type of the display. The list of types is in
<dev/wscons/wsconsio.h>.
WSDISPLAYIO_GINFO (struct wsdisplay_fbinfo)
Retrieve basic information about a framebuffer display. The
returned structure is as follows:
struct wsdisplay_fbinfo {
u_int height;
u_int width;
u_int depth;
u_int cmsize;
};
The height and width members are counted in pixels. The depth
member indicates the number of bits per pixel, and cmsize indicates
the number of color map entries accessible through
WSDISPLAYIO_GETCMAP and WSDISPLAYIO_PUTCMAP. This call is likely
to be unavailable on text-only displays.
WSDISPLAYIO_GETCMAP (struct wsdisplay_cmap)
Retrieve the current color map from the display. This call needs
the following structure set up beforehand:
struct wsdisplay_cmap {
u_int index;
u_int count;
u_char *red;
u_char *green;
u_char *blue;
};
The index and count members specify the range of color map entries
to retrieve. The red, green, and blue members should each point to
an array of count u_chars. On return, these will be filled in with
the appropriate entries from the color map. On all displays that
support this call, values range from 0 for minimum intensity to 255
for maximum intensity, even if the display does not use eight bits
internally to represent intensity.
WSDISPLAYIO_PUTCMAP (struct wsdisplay_cmap)
Change the display's color map. The argument structure is the same
as for WSDISPLAYIO_GETCMAP, but red, green, and blue are taken as
pointers to the values to use to set the color map. This call is
not available on displays with fixed color maps.
WSDISPLAYIO_GVIDEO (u_int)
Get the current state of the display's video output. Possible
values are:
WSDISPLAYIO_VIDEO_OFF The display is blanked.
WSDISPLAYIO_VIDEO_ON The display is enabled.
WSDISPLAYIO_SVIDEO (u_int)
Set the state of the display's video output. See
WSDISPLAYIO_GVIDEO above for possible values.
WSDISPLAYIO_GCURPOS (struct wsdisplay_curpos)
Retrieve the current position of the hardware cursor. The returned
structure is as follows:
struct wsdisplay_curpos {
u_int x, y;
};
The x and y members count the number of pixels right and down,
respectively, from the top-left corner of the display to the hot
spot of the cursor. This call is not available on displays without
a hardware cursor.
WSDISPLAYIO_SCURPOS (struct wsdisplay_curpos)
Set the current cursor position. The argument structure, and its
semantics, are the same as for WSDISPLAYIO_GCURPOS. This call is
not available on displays without a hardware cursor.
WSDISPLAYIO_GCURMAX (struct wsdisplay_curpos)
Retrieve the maximum size of cursor supported by the display. The
x and y members of the returned structure indicate the maximum
number of pixel rows and columns, respectively, in a hardware
cursor on this display. This call is not available on displays
without a hardware cursor.
WSDISPLAYIO_GCURSOR (struct wsdisplay_cursor)
Retrieve some or all of the hardware cursor's attributes. The
argument structure is as follows:
struct wsdisplay_cursor {
u_int which;
u_int enable;
struct wsdisplay_curpos pos;
struct wsdisplay_curpos hot;
struct wsdisplay_cmap cmap;
struct wsdisplay_curpos size;
u_char *image;
u_char *mask;
};
The which member indicates which of the values the application
requires to be returned. It should contain the logical OR of the
following flags:
WSDISPLAY_CURSOR_DOCUR
Get enable, which indicates whether the cursor is currently
displayed (non-zero) or not (zero).
WSDISPLAY_CURSOR_DOPOS
Get pos, which indicates the current position of the cursor
on the display, as would be returned by WSDISPLAYIO_GCURPOS.
WSDISPLAY_CURSOR_DOHOT
Get hot, which indicates the location of the ``hot spot''
within the cursor. This is the point on the cursor whose
position on the display is treated as being the position of
the cursor by other calls. Its location is counted in pixels
from the top-left corner of the cursor.
WSDISPLAY_CURSOR_DOCMAP
Get cmap, which indicates the current cursor color map.
Unlike in a call to WSDISPLAYIO_GETCMAP, cmap here need not
have its index and count members initialized. They will be
set to 0 and 2 respectively by the call. This means that
cmap.red, cmap.green, and cmap.blue must each point to at
least enough space to hold two u_chars.
WSDISPLAY_CURSOR_DOSHAPE
Get size, image, and mask. These are, respectively, the
dimensions of the cursor in pixels, the bitmap of set pixels
in the cursor and the bitmap of opaque pixels in the cursor.
The format in which these bitmaps are returned, and hence the
amount of space that must be provided by the application, are
device-dependent.
WSDISPLAY_CURSOR_DOALL
Get all of the above.
The device may elect to return information that was not requested
by the user, so those elements of struct wsdisplay_cursor which are
pointers should be initialized to NULL if not otherwise used. This
call is not available on displays without a hardware cursor.
WSDISPLAYIO_SCURSOR (struct wsdisplay_cursor)
Set some or all of the hardware cursor's attributes. The argument
structure is the same as for WSDISPLAYIO_GCURSOR. The which member
specifies which attributes of the cursor are to be changed. It
should contain the logical OR of the following flags:
WSDISPLAY_CURSOR_DOCUR
If enable is zero, hide the cursor. Otherwise, display it.
WSDISPLAY_CURSOR_DOPOS
Set the cursor's position on the display to pos, the same as
WSDISPLAYIO_SCURPOS.
WSDISPLAY_CURSOR_DOHOT
Set the ``hot spot'' of the cursor, as defined above, to hot.
WSDISPLAY_CURSOR_DOCMAP
Set some or all of the cursor color map based on cmap. The
index and count elements of cmap indicate which color map
entries to set, and the entries themselves come from
cmap.red, cmap.green, and cmap.blue.
WSDISPLAY_CURSOR_DOSHAPE
Set the cursor shape from size, image, mask. See above for
their meanings.
WSDISPLAY_CURSOR_DOALL
Do all of the above.
This call is not available on displays without a hardware cursor.
WSDISPLAYIO_GMODE (u_int)
Get the current mode of the display. Possible results include:
WSDISPLAYIO_MODE_EMUL
The display is in emulating (text) mode.
WSDISPLAYIO_MODE_MAPPED
The display is in mapped (graphics) mode.
WSDISPLAYIO_MODE_DUMBFB
The display is in mapped (frame buffer) mode.
WSDISPLAYIO_SMODE (u_int)
Set the current mode of the display. For possible arguments, see
WSDISPLAYIO_GMODE.
WSDISPLAYIO_GBURNER (struct wsdisplay_burner)
Retrieves the state of the screen burner. The returned structure
is as follows:
struct wsdisplay_burner {
u_int off;
u_int on;
u_int flags;
};
The off member contains the inactivity time before the screen is
turned off, in milliseconds. The on member contains the time
before the screen is turned back on, in milliseconds. The flags
member contains a logical OR of the following flags:
WSDISPLAY_BURN_VBLANK
When turning the display off, disable the vertical
synchronization signal.
WSDISPLAY_BURN_KBD
Monitor keyboard activity.
WSDISPLAY_BURN_MOUSE
Monitor mouse activity (this only works for mice using the
wsmouse(4) driver).
WSDISPLAY_BURN_OUTPUT
Monitor display output activity.
If none of the activity source flags are set, the screen burner is
disabled.
WSDISPLAYIO_SBURNER (struct wsdisplay_burner)
Sets the state of the screen burner. The argument structure, and
its semantics, are the same as for WSDISPLAYIO_GBURNER.
WSDISPLAYIO_WSMOUSED (struct wscons_event)
This call is used by the wsmoused(8) daemon to inject mouse events
gathered from serial mice, as well as various control events.
WSDISPLAYIO_GETPARAM (struct wsdisplay_param)
Retrieves the state of a display parameter. This call needs the
following structure set up beforehand:
struct wsdisplay_param {
int param;
int min, max, curval;
int reserved[4];
};
The param member should be set with the parameter to be returned.
The following parameters are supported:
WSDISPLAYIO_PARAM_BACKLIGHT
The intensity of the display backlight (usually on laptop
computers).
WSDISPLAYIO_PARAM_BRIGHTNESS
The brightness level.
WSDISPLAYIO_PARAM_CONTRAST
The contrast level.
On return, min and max specify the allowed range for the value,
while curval specifies the current setting. Not all parameters are
supported by all display drivers.
WSDISPLAYIO_SETPARAM (struct wsdisplay_param)
Sets a display parameter. The argument structure is the same as
for WSDISPLAYIO_GETPARAM, with the param and curval members filled
in. Not all parameters are supported by all display drivers.
WSDISPLAYIO_LINEBYTES (u_int)
Get the number of bytes per row when the device is in
WSDISPLAYIO_MODE_DUMBFB mode.
FILES
/dev/tty[C-F]* terminal devices (per screen)
/dev/tty[C-F]cfg control device (per screen)
/usr/include/dev/wscons/wsconsio.h
SEE ALSOintro(4), tty(4), wscons(4), wsmux(4), wsconscfg(8), wsconsctl(8),
wsfontload(8)BUGS
The wsdisplay code currently limits the number of screens on one display
to 8.
The terms ``wscons'' and ``wsdisplay'' are not cleanly distinguished in
the code and in manual pages.
OpenBSD 4.9 August 28, 2010 OpenBSD 4.9
