WSDISPLAY(4) BSD Kernel Interfaces Manual WSDISPLAY(4)NAMEwsdisplay — generic display device support in wscons
SYNOPSIS
wsdisplay* at ega? console ?
(EGA display on ISA)
wsdisplay* at vga? console ?
(VGA display on ISA or PCI)
wsdisplay* at pcdisplay? console ?
(generic PC (ISA) display)
wsdisplay* at tga? console ?
(DEC TGA display, alpha only)
wsdisplay* at pfb? console ?
(PCI framebuffer, bebox only)
wsdisplay0 at ofb? console ?
(Open Firmware framebuffer, macppc only)
wsdisplay* at nextdisplay? console ?
(NeXT display)
wsdisplay0 at smg0
(VAXstation small monochrome display)
wsdisplay* at ... kbdmux N
options WSDISPLAY_BORDER_COLOR=WSCOL_XXX
options WSDISPLAY_CUSTOM_BORDER
options WSDISPLAY_CUSTOM_OUTPUT
options WSDISPLAY_DEFAULTSCREENS=N
options WSDISPLAY_SCROLLSUPPORT
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 a text terminal or graphics
interface.
A display device can have the ability to display characters on it (with‐
out the help of an X server), either directly by hardware or through
software putting pixel data into the display memory. Such displays are
called “emulating”, the wsdisplay driver will connect a terminal emula‐
tion module and provide a tty-like software interface. In contrary, non-
emulating displays can only be used by special programs like X servers.
The console locator in the configuration line refers to the device's use
as the output part of the operating system console. A device specifica‐
tion containing a positive value here will only match if the device is in
use as the system console. (The console device selection in early system
startup is not influenced.) This way, the console device can be con‐
nected to a known wsdisplay device instance. (Naturally, only
“emulating” display devices are usable as console.)
The kbdmux 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 (some‐
times 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 vga(4) and the VAX “smg” dis‐
play drivers provide this ability.) Screens have different minor device
numbers and separate tty instances. One screen possesses the “focus”,
this means it is visible 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 CTRL-ALT-Fn, STOP-Fn
on Sun hardware, Command-Fn on ADB keyboards ) or an ioctl command issued
by a user program. Screens are created and deleted through the
/dev/ttyEcfg control device (preferably using the wsconscfg(8) utility).
Alternatively, the compile-time option WSDISPLAY_DEFAULTSCREENS=n will
also create (at autoconfiguration time) n initial screens of the display
driver's default type with the system's default terminal emulator.
Kernel options
The following kernel options are available to configure the behavior of
the wsdisplay driver:
options WSDISPLAY_BORDER_COLOR=WSCOL_XXX
Sets the border color at boot time. Possible values are
defined in src/sys/dev/wscons/wsdisplayvar.h. Defaults to
‘WSCOL_BLACK’.
options WSDISPLAY_CUSTOM_BORDER
Enables the WSDISPLAYIO_GBORDER and WSDISPLAYIO_SBORDER ioctls,
which allow the customization of the border color from userland
(after boot). See wsconsctl(8).
options WSDISPLAY_CUSTOM_OUTPUT
Enables the WSDISPLAYIO_GMSGATTRS and WSDISPLAYIO_SMSGATTRS
ioctls, which allow the customization of the console output and
kernel messages from userland (after boot). See wsconsctl(8).
options WSDISPLAY_DEFAULTSCREENS=N
Sets the number of virtual screens to allocate at boot time.
Useful for small root filesystems where the wsconscfg(8) util‐
ity is not wanted.
options WSDISPLAY_SCROLLSUPPORT
Enables scrolling support. The key combinations are LEFT SHIFT
+ PAGE UP and LEFT SHIFT + PAGE DOWN by default. Please note
that this function may not work under the system console and is
available depending on the framebuffer you are using.
Ioctls
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 (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 maxi‐
mum 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 (int)
Get the current state of the display's video output. Pos‐
sible values are:
WSDISPLAYIO_VIDEO_OFF
The display is blanked.
WSDISPLAYIO_VIDEO_ON
The display is enabled.
WSDISPLAYIO_SVIDEO (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.
WSDISPLAYOP_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 dis‐
play. The x and y members of the returned structure indi‐
cate the maximum number of pixel rows and columns, respec‐
tively, 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 applica‐
tion requires to be returned. It should contain the logi‐
cal OR of the following flags:
WSDISPLAYIO_CURSOR_DOCUR
Get enable, which indicates whether the cur‐
sor is currently displayed (non-zero) or not
(zero).
WSDISPLAYIO_CURSOR_DOPOS
Get pos, which indicates the current position
of the cursor on the display, as would be
returned by WSDISPLAYIO_GCURPOS.
WSDISPLAYIO_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-right corner
of the cursor.
WSDISPLAYIO_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.
WSDISPLAYIO_CURSOR_DOSHAPE
Get size, image, and mask. These are,
respectively, the dimensions of the cursor in
pixels, the bitmap of set pixels in the cur‐
sor 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.
WSDISPLAYIO_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:
WSDISPLAYIO_CURSOR_DOCUR
If enable is zero, hide the cursor. Other‐
wise, display it.
WSDISPLAYIO_CURSOR_DOPOS
Set the cursor's position on the display to
pos, the same as WSDISPLAYIO_SCURPOS.
WSDISPLAYIO_CURSOR_DOHOT
Set the “hot spot” of the cursor, as defined
above, to hot.
WSDISPLAYIO_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.
WSDISPLAYIO_CURSOR_DOSHAPE
Set the cursor shape from size, image, and
mask. See above for their meanings.
WSDISPLAYIO_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 argu‐
ments, see WSDISPLAYIO_GMODE.
WSDISPLAYIO_LINEBYTES (u_int)
Get the number of bytes per row, which may be the same as
the number of pixels.
WSDISPLAYIO_GMSGATTRS (struct wsdisplay_msgattrs)
Get the attributes (colors and flags) used to print console
messages, including separate fields for default output and
kernel output. The returned structure is as follows:
struct wsdisplay_msgattrs {
int default_attrs, default_bg, default_fg;
int kernel_attrs, kernel_bg, kernel_fg;
};
The default_attrs and kernel_attrs variables are a combina‐
tion of WSATTR_* bits, and specify the attributes used to
draw messages. The default_bg, default_fg, kernel_bg and
kernel_fg variables specify the colors used to print mes‐
sages, being ‘_bg’ for the background and ‘_fg’ for the
foreground; their values are one of all the WSCOL_* macros
available.
WSDISPLAYIO_SMSGATTRS (struct wsdisplay_msgattrs)
Set the attributes (colors and flags) used to print console
messages, including separate fields for default output and
kernel output. The argument structure is the same as for
WSDISPLAYIO_GMSGATTRS.
WSDISPLAYIO_GBORDER (u_int)
Retrieve the color of the screen border. This number cor‐
responds to an ANSI standard color.
WSDISPLAYIO_SBORDER (u_int)
Set the color of the screen border, if applicable. This
number corresponds to an ANSI standard color. Not all
drivers support this feature.
WSDISPLAYIO_GETWSCHAR (struct wsdisplay_char)
Gets a single character from the screen, specified by its
position. The structure used is as follows:
struct wsdisplay_char {
int row, col;
uint16_t letter;
uint8_t background, foreground;
char flags;
};
The row and col parameters are used as input; the rest of
the structure is filled by the ioctl and is returned to
you. letter is the ASCII code of the letter found at the
specified position, background and foreground are its col‐
ors and flags is a combination of ‘WSDISPLAY_CHAR_BRIGHT’
and/or ‘WSDISPLAY_CHAR_BLINK’.
WSDISPLAYIO_PUTWSCHAR (struct wsdisplay_char)
Puts a character on the screen. The structure has the same
meaning as described in WSDISPLAY_GETWSCHAR, although all
of its fields are treated as input.
WSDISPLAYIO_SSPLASH (u_int)
Toggle the splash screen. This call is only available with
the SPLASHSCREEN kernel option.
WSDISPLAYIO_SPROGRESS (u_int)
Update the splash animation. This call is only available
with the SPLASHSCREEN and SPLASHSCREEN_PROGRESS kernel
options.
WSDISPLAYIO_GET_EDID (struct wsdisplay_edid_info)
Retrieve EDID data from a driver.
struct wsdisplayio_edid_info {
uint32_t buffer_size;
uint32_t data_size;
void *edid_data;
};
The caller is responsible for allocating a buffer of at
least 128 bytes (the minimum size of an EDID block) and set
data_size to its size. If the EDID block is bigger the
call will fail with EAGAIN and the driver will set
data_size to the required buffer size. Otherwise the EDID
block will be written into the buffer pointed at by
edid_data and data_size will be set to the number of bytes
written.
WSDISPLAYIO_SETVERSION (int)
Set the wscons_event protocol version. The default is 0
for binary compatibility. The latest version is always
available as WSDISPLAYIO_EVENT_VERSION, and is currently 1.
All new code should use a call similar to the below to
ensure the correct version is returned.
int ver = WSDISPLAY_EVENT_VERSION;
if (ioctl(fd, WSDISPLAYIO_SETVERSION, &ver) == -1)
err(EXIT_FAILURE, "cannot set version");
FILES
/dev/ttyE* Terminal devices (per screen).
/dev/ttyEcfg Control device.
/dev/ttyEstat Status device.
/usr/include/dev/wscons/wsconsio.h
SEE ALSOioctl(2), pcdisplay(4), tty(4), vga(4), wscons(4), wsconscfg(8),
wsconsctl(8), wsfontload(8), wsdisplay(9)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.
“non-emulating” display devices are not tested.
BSD May 27, 2012 BSD
