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[GS]ETFKEY... Definately a 2.2 Candidate a clean up of this page is to follow.... but I'm not sure I'll have it before 2.2 is to be released...
149 lines
5.0 KiB
Groff
149 lines
5.0 KiB
Groff
.\"
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.\" $Id: keyboard.4,v 1.11 1997/03/07 02:49:47 jmg Exp $
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.\"
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.Dd January 8, 1995
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.Dt KEYBOARD 4 i386
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.Os FreeBSD
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.Sh NAME
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.Nm keyboard
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.Nd pc keyboard interface
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.Sh DESCRIPTION
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The PC keyboard is used as the console character input device. The keyboard
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is owned by the current virtual console.
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To switch between the virtual consoles use the sequence
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.Ar ALT+Fn
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, which means hold down ALT and press one of the function keys. The
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virtual console with the same number as the function key is then
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selected as the current virtual console, and given exclusive use of
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the keyboard and display.
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The console allows entering values that are not physically
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present on the keyboard via a special keysequence.
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To use this facility press and hold down ALT,
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then enter a decimal number from 0-255 via the numerical keypad, then
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release ALT. The entered value is then used as the ASCII value for one
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character. This way it is possible to enter any ASCII value, not present
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on the keyboard.
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The console driver also includes a history function. It is activated by
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pressing the scroll-lock key. This holds the display, and enables the cursor
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arrows for scrolling up and down through the last scrolled out lines.
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The keyboard is configurable to suit the individual user and the different
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national layout.
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The keys on the keyboard can have any of the following functions:
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Normal key - Enter the ASCII value associated with the key.
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Function key - Enter a string of ASCII values.
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Switch Key - Switch virtual console.
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Modifier Key - Change the meaning of another key.
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The keyboard is seen as a number of keys numbered from 1 to n. This
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number is often referred to as the "scancode" for a given key. The number
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of the key is transmitted as an 8 bit char with bit 7 as 0 when a key is
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pressed, and the number with bit 7 as 1 when released. This makes it
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possible to make the mapping of the keys fully configurable.
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The meaning of every key is programmable via the PIO_KEYMAP ioctl call, that
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takes a structure keymap_t as argument. The layout of this structure is as
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follows:
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.Pp
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.Bd -literal -offset indent
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struct keymap {
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u_short n_keys;
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struct key_t {
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u_char map[NUM_STATES];
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u_char spcl;
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u_char flgs;
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} key[NUM_KEYS];
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};
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.Ed
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.Pp
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The field n_keys tells the system how many keydefinitions (scancodes)
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follows. Each scancode is then specified in the key_t substructure.
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Each scancode can be translated to any of 8 different values, depending
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on the shift, control, and alt state. These eight possibilities is
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represented by the map array, as shown below:
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alt
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scan cntrl alt alt cntrl
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code base shift cntrl shift alt shift cntrl shift
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map[n] 0 1 2 3 4 5 6 7
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---- ------------------------------------------------------
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0x1E 'a' 'A' 0x01 0x01 'a' 'A' 0x01 0x01
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This is the default mapping for the key labelled 'A' wich normally has
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scancode 0x1E. The eight states is as shown, giving the 'A' key its
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normal behavior.
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The spcl field is used to give the key "special" treatment, and is
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interpreted as follows.
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Each bit correspond to one of the states above. If the bit is 0 the
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key emits the number defined in the corresponding map[] entry.
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If the bit is 1 the key is "special". This means it does not emit
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anything, instead it changes the "state". That means it is a shift,
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control, alt, lock, switch-screen, function-key or no-op key.
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The bitmap is backwards ie. 7 for base, 6 for shift etc.
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The flgs field defines if the key should react on caps-lock (1),
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num-lock (2), both (3) or ignore both (0).
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The kbdcontrol utility is used to load such a description into/outof
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the kernel at runtime. This make it possible to change the key
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assignments at runtime, or more important to get (GIO_KEYMAP ioctl)
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the exact key meanings from the kernel (fx. used by the X server).
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The function keys can be programmed using the SETFKEY ioctl call.
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This ioctl takes a argument of the type fkeyarg_t:
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.Bd -literal -offset indent
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struct fkeyarg {
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u_short keynum;
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char keydef[MAXFK];
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char flen;
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};
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.Ed
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.Pp
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The field keynum defines which function key that is programmed.
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The array keydef should contain the new string to be used (MAXFK long),
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and the length should be entered in flen.
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The GETFKEY ioctl call works in a semilar manner, execpt it returns
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the current setting of keynum.
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The function keys are numbered like this:
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.Bd -literal -offset indent
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F1-F12 key 1 - 12
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Shift F1-F12 key 13 - 24
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Ctrl F1-F12 key 25 - 36
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Ctrl+shift F1-F12 key 37 - 48
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Home key 49
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Up arrow key 50
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Page Up key 51
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(keypad) - key 52
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Left arrow key 53
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(keypad) 5 key 54
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Right arrow key 55
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(keypad) + key 56
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End key 57
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Down arrow key 58
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Page down key 59
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Insert key 60
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Delete key 61
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Right window key 62
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Left window key 63
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Menu key 64
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.Ed
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The kbdcontrol utility also allows changing these values at runtime.
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.Pp
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.Sh AUTHOR
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S<>ren Schmidt (sos@FreeBSD.org)
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