WSDISPLAY(9) | Kernel Developer's Manual | WSDISPLAY(9) |
wsdisplay
,
wsdisplay_switchtoconsole
,
wsdisplay_cnattach
,
wsdisplaydevprint
,
wsemuldisplaydevprint
—
#include <dev/wscons/wsconsio.h>
#include
<dev/wscons/wsdisplayvar.h>
#include
<dev/wscons/wsemulvar.h>
#include
<dev/wscons/wsemul_vt100var.h>
void
wsdisplay_switchtoconsole
();
void
wsdisplay_cnattach
(const
struct wsscreen_descr *type,
void *cookie,
int ccol,
int crow,
long defattr);
void
wsemul_xxx_cnattach
(const
struct wsscreen_descr *type,
void *cookie,
int ccol,
int crow,
long defattr);
int
wsdisplaydevprint
(void
*aux, const char
*pnp);
int
wsemuldisplaydevprint
(void
* aux, const char
*pnp);
wsdisplay
module is a component of the
wscons(9) framework to provide
machine-independent display support. Most of the support is provided by the
wsdisplay(4) device driver,
which must be a child of the hardware device driver.
The wscons display interface is complicated by the fact that there are two different interfaces. The first interface corresponds to the simple bit-mapped display which doesn't provide terminal-emulation and console facilities. The second interface provides machine-independent terminal emulation for displays that can support glass-tty terminal emulations. These are character-oriented displays, with row and column numbers starting at zero in the upper left hand corner of the screen. Display drivers which cannot emulate terminals use the first interface. In most cases, the low-level hardware driver can use the rasops(9) interface to provide enough support to allow glass-tty terminal emulation. If the display is not the console, terminal emulation does not make sense and the display operates using the bit-mapped interface.
The wscons framework allows concurrent displays to be active. It also provides support for multiple screens for each display and therefore allows a virtual terminal on each screen. Multiple terminal emulations and fonts can be active at the same time allowing different emulations and fonts for each screen.
Font manipulation facilities for the terminal emulation interface are available through the wsfont(9) module.
int (*ioctl)(void *v, void *vs, u_long cmd, void *data, int flag, struct lwp *l); paddr_t (*mmap)(void *v, void *vs, off_t off, int prot); int (*alloc_screen)(void *, const struct wsscreen_descr *, void **, int *, int *, long *); void (*free_screen)(void *, void *); int (*show_screen)(void *, void *, int, void (*)(), void *); int (*load_font)(void *, void *, struct wsdisplay_font *); void (*pollc)(void *, int); void (*scroll)(void *, void *, int);
The ioctl member defines the function to be called to perform display-specific ioctl calls. The mmap member defines the function for mapping a part of the display device into user address space. The alloc_screen member defines a function for allocating a new screen which can be used as a virtual terminal. The free_screen member defines a function for de-allocating a screen. The show_screen member defines a function for mapping a screen onto the physical display. This function is used for switching between screens. The load_font member defines a function for loading a new font into the display. The pollc member defines a function for polling the console. The scroll member defines a function for scrolling the contents of the display.
There is a void * cookie provided by the display driver associated with these functions, which is passed to them when they are invoked.
The void *vs cookie, passed to
ioctl
() and mmap
(),
points to the virtual screen on which these operations were
executed.
const struct wsdisplay_accessops *accessops; void *accesscookie;
int console; const struct wsscreen_list *scrdata; const struct wsdisplay_accessops *accessops; void *accesscookie;
void (*cursor)(void *c, int on, int row, int col); int (*mapchar)(void *, int, unsigned int *); void (*putchar)(void *c, int row, int col, u_int uc, long attr); void (*copycols)(void *c, int row, int srccol, int dstcol, int ncols); void (*erasecols)(void *c, int row, int startcol, int ncols, long); void (*copyrows)(void *c, int srcrow, int dstrow, int nrows); void (*eraserows)(void *c, int row, int nrows, long); int (*allocattr)(void *c, int fg, int bg, int flags, long *); void (*replaceattr)(void *c, long oldattr, long newattr);
The cursor member defines a function for painting (or unpainting, depending on the on parameter) the cursor at the specified position. The mapchar member defines a function for changing the character mapped at a given position in the character table. The putchar member defines a function for writing a character on the screen, given its position and attribute. The copycols member defines a function for copying a set of columns within the same line. The erasecols member defines a function for clearing a set of columns in a line, filling the space with the given attribute. The copyrows member defines a function for copying a set of complete rows. The eraserows member defines a function for clearing a set of complete rows, filling the space with the given attribute. The allocattr member defines a function for converting an attribute specification given by its foreground color, background color and flags, to the internal representation used by the underlying graphics driver. The replaceattr member defines a function for replacing an attribute by another one across the whole visible part of the screen; this function is optional.
There is a void * cookie provided by the display driver associated with these functions, which is passed to them when they are invoked.
char *name; int ncols, nrows; const struct wsdisplay_emulops *textops; int fontwidth, fontheight; int capabilities;
The capabilities member is a set of flags describing the screen capabilities. It can contain the following flags:
int nscreens; const struct wsscreen_descr **screens;
int (*detach)(void *, int, void (*)(), void *); int (*attach)(void *, int, void (*)(), void *); int (*check)(void *); void (*destroy)(void *);
wsdisplay_switchtoconsole
()wsdisplay_cnattach
(type,
cookie, ccol,
crow, defattr)wsemul_xxx_cnattach
(type,
cookie, ccol,
crow, defattr)wsdisplaydevprint
(aux,
pnp)config_found
(). (see
autoconf(9)).wsemuldisplaydevprint
(aux,
pnp)config_found
(). (see
autoconf(9)).config_found
() to
perform the attach (see
autoconf(9)).
Display drivers which want to use the wscons terminal emulation
module must be a parent to the
wsdisplay(4) device and
provide a wsemuldisplaydev_attach_args structure
instead of the standard wsdisplaydev_attach_args to
config_found
() to perform the attach. If the display
is not the console the attachment is the same as
wsdisplaydev_attach_args.
wsdisplay_cnattach
() at console
attach time.
All display manipulation is performed by the wscons interface by
using the callbacks defined in the wsdisplay_accessops
structure. The ioctl
() function is called by the
wscons interface to perform display-specific ioctl operations (see
ioctl(2)). The argument
cmd to the ioctl
() function
specifies the specific command to perform using the data
data. Valid commands are listed in
sys/dev/wscons/wsconsio.h and documented in
wsdisplay(4). Operations
for terminal emulation are performed using the callbacks defined in the
wsdisplay_emulops structure.
wsdisplay
module itself is implemented within the file
sys/dev/wscons/wsdisplay.c. The terminal emulation
support is implemented within the files
sys/dev/wscons/wsemul_*.
ioctl(2) operations are listed in
sys/dev/wscons/wsconsio.h.
April 15, 2006 | NetBSD 9.2 |