freebsd-nq/share/man/man4/pcvt.4

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.\"  Copyright (c) 1992, 2000 Hellmuth Michaelis, Brian Dunford-Shore,
.\"                           Joerg Wunsch and Holger Veit.
.\" 
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.\"	Brian Dunford-Shore, Joerg Wunsch and Holger Veit.
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.\" Last Edit-Date: [Sun Mar 26 14:39:08 2000]
.\"
.\" $FreeBSD$
.\"
.\" Man page pcvt(4) created after pcvt_ioctl.h on 13-Jan-93
.\" by Joerg Wunsch
.\"
.Dd March 26, 2000
.Dt PCVT 4
.Sh NAME
.Nm pcvt ,
.Nm vt
.Nd VT220 virtual screen system console 
.Sh SYNOPSIS
.Cd "device vt0 at isa?"
.Sh DESCRIPTION
.Ss Overview
The
.Nm pcvt
driver provides a virtual screen handling system.
Probably most important is an emulation of a wide range
of DEC VT-220
.if t \(tm
.if n (TM)
functionality.
See
.Sx Features
for a detailed description.
.Pp
The
.Nm pcvt
driver requires the keyboard driver
.Nm atkbd
to be also configured in the kernel.
.Ss Features
.Bl -bullet
.It
Almost full DEC VT220
.if t \(tm
.if n (TM)
functionality
.Po
moving towards VT320
.if t \(tm
.if n (TM)
.Pc
.It
Completely independent virtual terminals for MDA/HGC/CGA/EGA and VGA
.It
25, 28, 35, 40, 43 or 50x80 screen resolution for each virtual screen
.It
Fully remappable keyboard to support national keyboards
.It
All VT220 character sets plus ISO Latin-1 and DEC technical supported 
.It
VT220 downloadable character set supported when run on EGA/VGA
.It
VT220 user defined keys for each virtual terminal
.It
Optional function key label support
.if t \('a
.if n 'a
la Hewlett-Packard terminals
.It
Display function codes functionality
.It
Support for MDA, CGA, EGA and VGA display adaptors
.It
Support for 132 column operation on some VGA chipsets
.It
X Window Support for XFree86 
.Po
requires
.Em XSERVER
to be defined
.Pc
.El

What it cannot:
.Bl -bullet
.It
No double wide/high characters
.It
No softscroll
.It
No inverse background
.It
No VT220 printer output support
.It
No VT52 support at all
.It
No 8-bit controls
.It
Only limited AT-keyboard
.Pq 84 keys
support
.El
.Ss Scrollback
Each virtual
.Nm
virtual terminal has 8 pages of memory attached which are used as a 
scrollback buffer.
By using
.Em SHIFT-PageUp
and
.Em SHIFT-PageDown
it is possible to scroll the screen back and forward.
.Ss Configuration
The
.Nm pcvt
console driver is available for the Intel-based FreeBSD operating
system.
It has been designed to be highly configurable in order to satisfy
everyone's needs.
The preferred way for those configurations is to
provide appropriate
.Em options
lines within the config file, possibly overriding the built-in default
values.

The following list gives a short overview of the available configuration
options.
Refer to the file
.Pa i386/isa/pcvt/pcvt_conf.h
in the kernel source tree for detailed documentation.

Note: the following conventions apply to all the Boolean options.
If an option is given with no value, a value of 1
.Pq activated
is substituted.
If an option value is given as 0, this options is
deactivated.
Any other value is substituted by 1, too.
If an option
is omitted, a built-in default is assumed.

.Bl -tag -width indent -compact

.It Em PCVT_NSCREENS
Defines the number of virtual screens.
.br
Default: 8

.It Em PCVT_VT220KEYB
If activated, a keyboard layout resembling a DEC VT200 (TM) is generated.
If deactivated, a mixture between VT220 and HP is used.
See the files
.Pa Keyboard.VT
and
.Pa Keyboard.HP
in the
.Nm pcvt
documentation directory for a full description.
.br
Default: off

.It Em PCVT_SCREENSAVER
Enables the builtin screensaver feature.
.br
Default: on

.It Em PCVT_PRETTYSCRNS
If enabled, a blinking-star screensaver is used.
If disabled, the screen
is simply blanked
.Pq which might be useful for energy-saving monitors .
.br
Default: on

.It Em PCVT_CTRL_ALT_DEL
If enabled, the key combination
.Aq Em Ctrl
.Aq Em Alt
.Aq Em Del
invokes a CPU reset.
.br
Default: off

.It Em PCVT_USEKBDSEC
Do NOT override a security lock for the keyboard.
.br
Default: on

.It Em PCVT_24LINESDEF
If enabled, the 25-line modi
.Po
VT emulation with 25 lines, and HP emulation with 28 lines
.Pc
default to 24 lines only to provide a better compatibility to the
original DEV VT220 (TM). Thus it should be possible to use the
terminal information for those terminals without further changes.
Note that this is a startup option; it is possible to toggle between
the 24- and 25-lines' display by the
.Xr scon 1
utility.
.br
Default: off

.It Em PCVT_META_ESC
If enabled, a sequence composed of
.Aq Em esc ,
followed by the normal key code is emitted if a key is pressed with the
.Aq Em Alt
key modifier.
If disabled, then normal key code with the value
.Em 0x80
added is sent.
.br
Default: off
.El

Note that there are further options available which are mainly used for
debugging purposes or as a workaround for hardware problems.
They are found in
.Pa i386/isa/pcvt/pcvt_conf.h
along with their documentation.
.Ss Internal Functions
The functionality described below may be accessed via
.Xr ioctl 2
system calls with a file descriptor opened on a device node
related to the
.Nm pcvt
driver.
To make use of them, a program should contain the following line:

.Dl #include <machine/pcvt_ioctl.h>

Any parameter definitions cited below can be found in that file.

.Em Keyboard related functions

Three functions are related to basic keyboard hardware:

.Bl -tag -width 20n -offset indent -compact
.It KBDRESET
reset keyboard, set defaults;
.It KBDGTPMAT
get current typematic value, parameter is a pointer to int where
the values is stored to;
.It KBDSTPMAT
set current typematic value, similar to above command.
.El

Symbolic values are available for the appropriate constants.
To specify the initial typematic delay time, they are
KBD_TPD250 for 250 ms through
KBD_TPD1000 for 1000 ms, in steps of 250 ms.
The typematic repeat
rates are
KBD_TPM300, specifying 30.0 characters per second through
KBD_TPM20 for 2.0 characters per second.
The intermediate values
are: 30.0, 26.7, 24.0, 21.8, 20.0, 18.5, 17.1, 16.0, 15.0, 13.3,
12.0, 10.9, 10.0, 9.2, 8.6, 8.0, 7.5, 6.7, 6.0, 5.5, 5.0, 4.6, 4.3,
4.0, 3.7, 3.3, 3.0, 2.7, 2.5, 2.3, 2.1, 2.0 characters per second.


.Bl -tag -width 20n -offset indent -compact
.It KBDGREPSW
get key repetition switch, and
.It KBDSREPSW
set key repetition switch
.El

again take a pointer to int as argument.
They manipulate the
drivers internal keyboard repetition flag, possible values are:
KBD_REPEATOFF or KBD_REPEATON.


.Bl -tag -width 20n -offset indent -compact
.It KBDGLEDS
get LED state, and
.It KBDSLEDS
set LED state manipulate the keyboard indicators, but do not influence
the drivers idea of lock key state.
.El

The int where the argument points to
may have the values
KBD_SCROLLLOCK, KBD_NUMLOCK, KBD_CAPSLOCK, which may be used in any
conjunction.

.Bl -tag -width 20n -offset indent -compact
.It KBDGLOCK
gets state of SCROLL,NUM,CAPS, and
.It KBDSLOCK
sets state of SCROLL,NUM,CAPS + LEDs
.El

should be used in a same manner to get/set the drivers internal
LED flags.


.Em Keyboard remapping

One important feature of the
.Nm pcvt
driver is its ability to overload the built in key definition.

.Bl -tag -width 20n -offset indent -compact
.It KBDGCKEY
get current key values,
.It KBDSCKEY
set new key assignment values, and
.It KBDGOKEY
get original key assignment values
.El

arrange those functions.
The take a pointer to a
.Em struct kbd_ovlkey
as argument as described below.
In addition,

.Bl -tag -width 20n -offset indent -compact
.It KBDRMKEY
removes a key assignment, taking a pointer to an int as argument which
contains the affected key number;
.It KBDDEFAULT
removes all key assignments.
.El
.Bd -literal
struct kbd_ovlkey                /* complete definition of a key */
{
    u_short keynum;                      /* the key itself */
    u_short type;                        /* type of key, see below */
    u_char  subu;                        /* subtype, ignored on write */
    char    unshift[KBDMAXOVLKEYSIZE+1]; /* emitted string, unshifted */
    u_char  subs;                        /* subtype, ignored on write */
    char    shift[KBDMAXOVLKEYSIZE+1];   /* emitted string, shifted */
    u_char  subc;                        /* subtype, ignored on write */
    char    ctrl[KBDMAXOVLKEYSIZE+1];    /* emitted string, control */
    u_char  suba;                        /* subtype, ignored on write */
    char    altgr[KBDMAXOVLKEYSIZE+1];   /* emitted string, altgr */
};
.Ed

The appropriate values for the
.Em type
field are:

.Bl -tag -width 20n -offset indent -compact
.It KBD_NONE
no function, key is disabled,
.It KBD_SHIFT
keyboard shift,
.It KBD_META
alternate shift, sets bit8 to ASCII code,
.It KBD_NUM
numeric shift, keypad numeric / application mode,
.It KBD_CTL
control code generation,
.It KBD_CAPS
caps shift - swaps case of letter,
.It KBD_ASCII
ASCII code generating key,
.It KBD_SCROLL
stop output,
.It KBD_FUNC    
function key,
.It KBD_KP
keypad keys,
.It KBD_BREAK
ignored,
.It KBD_ALTGR
AltGr translation feature,
.It KBD_SHFTLOCK
shift lock,
.It KBD_CURSOR
cursor keys, and
.It KBD_RETURN
.Dq Return
or
.Dq Enter
keys.
.El

The
.Em subtype
field contains one of the values

.Bl -tag -width 20n -offset indent -compact
.It KBD_SUBT_STR
key is bound to a string, or
.It KBD_SUBT_FNC
key is bound to a function.
.El

.Em Downloadable character set interface

EGA and VGA video adaptors provide the capability of downloadable
software fonts.
Since the
.Sq native character set
of any IBM-compatible PC video board does not allow the full interpretation
of DEC multinational character set or ISO Latin-1
.Pq ISO 8859-1 ,
this might be very useful for a U**X environment.

.Bl -tag -width 20n -offset indent -compact
.It VGASETFONTATTR
set font attr, and
.It VGAGETFONTATTR
get font attr
.El

are used to manipulate the drivers information about a downloaded
font.
The take a pointer to a
.Em struct vgafontattr
as argument:
.Bd -literal
struct vgafontattr {
    int character_set;          /* VGA character set */
    int font_loaded;            /* Mark font loaded or unloaded */
    int screen_size;            /* Character rows per screen */
    int character_scanlines;    /* Scanlines per character - 1 */
    int screen_scanlines;       /* Scanlines per screen - 1 byte */
};
.Ed

Each character of each font is to be downloaded with

.Bl -tag -width 20n -offset indent -compact
.It VGALOADCHAR
load vga char,
.El

taking a pointer to
.Em struct vgaloadchar
as its argument:
.Bd -literal
struct vgaloadchar {
    int character_set;       /* VGA character set to load into */
    int character;           /* Character to load */
    int character_scanlines; /* Scanlines per character */
    u_char char_table[32];   /* VGA character shape table */
};
.Ed

The field
.Em character_set
takes the values
CH_SET0, CH_SET1, CH_SET2, CH_SET3 on EGA's or VGA's. Since VGA's
might have up to eight simultaneously loaded fonts, they can take
CH_SET4, CH_SET5, CH_SET6, or CH_SET7, too.

Note that there's a dependence between the font size
and a possible screen height
.Pq in character rows ,
depending on the video adaptor used:
.Bd -literal
Screen size (rows) on:          EGA             VGA
Font size

8 x 8                           43              50
8 x 10                          35              40
8 x 14                          25              28
8 x 16                          not             25
                                applicable
.Ed


.Em General screen manipulation commands

.Bl -tag -width 20n -offset indent -compact
.It VGACURSOR
sets cursor shape,
.El

taking a pointer to the following structure as argument:
.Bd -literal
struct cursorshape {
    int screen_no; /* screen number for which to set,               */
                   /*  or -1 to set on current active screen        */
    int start;     /* top scanline, range 0... Character Height - 1 */
    int end;       /* end scanline, range 0... Character Height - 1 */
};
.Ed

.Bl -tag -width 20n -offset indent -compact
.It VGASETSCREEN
set screen info, and
.It VGAGETSCREEN
get screen info,
.El

provide an interface to some general driver internal variables
which might modify the behaviour of the screens,
or which might simply be used to force the driver to switch
to one certain screen.
Their argument is a pointer to the structure:
.Bd -literal
struct screeninfo {
    int adaptor_type;   /* type of video adaptor installed     */
                        /* read only, ignored on write (yet!)  */
    int totalfonts;     /* no of downloadable fonts            */
                        /* read only, ignored on write         */
    int totalscreens;   /* no of virtual screens               */
                        /* read only, ignored on write         */
    int screen_no;      /* screen number, this was got from    */
                        /* on write, if -1, apply pure_vt_mode */
                        /* and/or screen_size to current screen*/
                        /* else to screen_no supplied          */
    int current_screen; /* screen number, which is displayed.  */
                        /* on write, if -1, make this screen   */
                        /* the current screen, else set current*/
                        /* displayed screen to parameter       */
    int pure_vt_mode;   /* flag, pure VT mode or HP/VT mode    */
                        /* on write, if -1, no change          */
    int screen_size;    /* screen size                         */
                        /* on write, if -1, no change          */    
    int force_24lines;  /* force 24 lines if 25 lines VT mode  */
                        /* or 28 lines HP mode to get pure     */
                        /* VT220 screen size                   */
                        /* on write, if -1, no change          */
    int vga_family;     /* if adaptor_type = VGA, this reflects*/
                        /* the chipset family after a read     */
                        /* nothing happenes on write ...       */
    int vga_type;       /* if adaptor_type = VGA, this reflects*/
                        /* the chipset after a read            */
                        /* nothing happenes on write ...       */
    int vga_132;        /* set to 1 if driver has support for  */
                        /* 132 column operation for chipset    */
                        /* currently ignored on write          */
};
.Ed

Its field
.Em pure_vt_mode
may take the values M_HPVT for a mixed VTxxx and HP Mode, with function
key labels and a status line, or M_PUREVT for only VTxxx sequences
recognized, with no labels.

.Bl -tag -width 20n -offset indent -compact
.It VGASETCOLMS
sets the number of columns for the current screen,
.El

its parameter is a pointer to an integer containing either a value of 80,
or a value of 132.
Note that setting the number of columns to 132 is only supported on 
some VGA adaptors.
Any unsupported numbers cause the ioctl to fail with
.Em errno
.Pq see Xr intro 2
being set to
.Em EINVAL .

.Em VGA color palette interface

Only on VGA adaptors, there's a color palette register at the output.
It is responsible for the red, green and blue output voltage provided
for each of the 256 internal color codes, each lying in the range of
0 through 63 (with 63 representing the brightest value for a base color).
Thus, these adaptors map each color code to a color of a
.Dq palette
out of 262144 colors.
The commands

.Bl -tag -width 20n -offset indent -compact
.It VGAREADPEL
read VGA palette entry, and
.It VGAWRITEPEL
write VGA palette entry
.El

establish an interface to these palette registers.
Their argument is
a pointer to:
.Bd -literal
struct vgapel {
    unsigned idx;      /* index into palette, 0 .. 255 valid   */
    unsigned r, g, b;  /* RGB values, masked by VGA_PMASK (63) */
};
.Ed


.Em Driver identification

.Bl -tag -width 20n -offset indent -compact
.It VGAPCVTID
returns information if the current compiled in driver is pcvt and it's
major and minor revision numbers. the call is taking a pointer to the
following structure as argument:
.El

.Bd -literal
struct pcvtid {
#define PCVTIDNAMELN  16		/* driver id - string length */
	char name[PCVTIDNAMELN];	/* driver name, == PCVTIDSTR	*/
#define PCVTIDNAME    "pcvt"		/* driver id - string */
	int rmajor;			/* revision number, major	*/
#define PCVTIDMAJOR   3
	int rminor;			/* revision number, minor	*/
#define PCVTIDMINOR   00	
};
.Ed


.Bl -tag -width 20n -offset indent -compact
.It VGAPCVTINFO
returns information if the current compiled in driver is pcvt and it's
compile time options. the call is taking a pointer to the following
structure as argument:
.El

.Bd -literal
struct pcvtinfo {
	u_int opsys;			/* PCVT_xxx(x)BSD */
#define CONF_UNKNOWNOPSYS	0
#define CONF_386BSD		1	/* unsupported !!! */
#define CONF_NETBSD		2
#define CONF_FREEBSD		3
	u_int opsysrel;			/* Release for NetBSD/FreeBSD */
	u_int nscreens;			/* PCVT_NSCREENS */
	u_int scanset;			/* PCVT_SCANSET */
	u_int updatefast;		/* PCVT_UPDATEFAST */
	u_int updateslow;		/* PCVT_UPDATESLOW */
	u_int sysbeepf;			/* PCVT_SYSBEEPF */
	u_int pcburst;			/* PCVT_PCBURST */
	u_int kbd_fifo_sz;		/* PCVT_KBD_FIFO_SZ */

/* config booleans */

	u_long compile_opts;		/* PCVT_xxxxxxxxxxxxxxx */
};
.Ed


.Em Screen saver

Depending on the configuration of a
.Nm pcvt
driver, their might be a simple screen saver available.
It is controlled
by the command

.Bl -tag -width 20n -offset indent -compact
.It VGASCREENSAVER
set timeout for screen saver in seconds; 0 turns it off,
.El

taking a pointer to an integer as argument.
Despite of its command name,
this is available on
.Em any
kind of adaptor if configured in by the
.Xr config 8
option
.Dq PCVT_SCREENSAVER

.Em Compatibility commands for USL-style VT's

.Nm pcvt
supports a subset of the USL-style commands used to control
the virtual terminal interface.
This feature is mainly intended to allow
.Em XFree86 
to switch between virtual screens even when
running an X server.
They are ugly with respect to the implied semantics
.Pq i.\& e., they break Berkeley semantics.
See the file
.Pa i386/include/pcvt_ioctl.h
for their documentation.

.Sh FILES
.Bl -tag -width /usr/include/machine/pcvt_ioctl.h
.It Pa /usr/include/machine/pcvt_ioctl.h
Definitions for
.Xr ioctl 2
function calls
.It Pa /dev/ttyv?
.It Pa /dev/console
Device nodes to access the
.Nm pcvt
driver
.It Pa i386/isa/pcvt/pcvt_conf.h
.Pq relative to the kernel source tree
Documents the various compile-time options to tailor
.Nm pcvt .
.Sh HISTORY
The
.Nm pcvt
driver has been developed for and contributed to 386BSD 0.1.
Since then
.Nm pcvt
has become a standard part of FreeBSD, NetBSD and OpenBSD.
Since FreeBSD 5.0,
.Nm pcvt
is FreeBSD specific with support for NetBSD and OpenBSD removed to
ease further maintenance.
.Sh AUTHORS
Written by
.An Hellmuth Michaelis Aq hm@FreeBSD.org
with much help from
.An Brian Dunford-Shore Aq brian@morpheus.wustl.edu
and
.An Joerg Wunsch Aq joerg@FreeBSD.org
.Pp
This driver is based on several people's previous work, notably 
the historic 
.Xr pccons 4
implementation by
.An William Jolitz and Don Ahn Aq ljolitz@cardio.ucsf.edu
.br
and the keyboard mapping code from 
.An Holger Veit Aq veit@first.gmd.de.
.Sh SEE ALSO
.Xr cursor 1 ,
.Xr loadfont 1 ,
.Xr scon 1 ,
.Xr intro 2 ,
.Xr ioctl 2 ,
.Xr atkbd 4 ,
.Xr keyboard 4 ,
.Xr config 8 ,
.Xr ispcvt 8
.Sh BUGS
At least one left.