keymap.5

操作系统设计与实现源码

.TH KEYMAP 5
.SH NAME
keymap \- keyboard maps
.SH SYNOPSIS
.B /etc/keymap
.SH DESCRIPTION
.B /etc/keymap 
is the compressed mapping from keyboard scan codes to ASCII.
It is made from a keymap source file consisting of MAP_COLS columns
(MINIX assigns the value 6 to MAX_COLS, corresponding to key pressed,
key+SHIFT, key+LEFT_ALT, key+RIGHT_ALT, key+ALT+SHIFT and key+CTRL) and 
NR_SCAN_CODES rows (MINIX assigns the value 0x80 to NR_SCAN_CODES, 
corresponding to the number of scan codes to be provided by the keyboard),
and each element is 2 bytes in length (see u16_t in type definitions). 
The low order byte corresponds to the character represented by the scan 
code, and the high order byte corresponds to the special meaning (when 
CAPS LOCK has effect, if it is a function key, etc.), which is converted to
binary keymap format using the
.BR genmap  
utility. 
.PP
.SS "Types (general): <sys/types.h>"
<sys/types.h> defines the
.B u8_t
and
.B u16_t
types, corresponding to 8 and 16 bit values.
.SS "Macros: <minix/keymap.h>"
.TP
.BI "C(" c ") - Control"
Maps to control code
.TP
.BI "A(" c ") - Alt"
Sets the eight bit
.TP
.BI "CA(" c ") - Control-Alt"
Short for
.BI "A(C(" c "))"
.TP
.BI "L(" c ") - Caps Lock"
Adds Caps Lock effect
.PP
These macros are used in a keymap source file to help define keys.  So
instead of writing
.B 032
to put a CTRL-Z in the map you write
.BR "C('Z')" .
The
.BI "L(" c ")"
macro is used in column 0 to tell that the Caps Lock key is active for this
key.  (Caps Lock should only have effect on letters.)
.SS "Definitions: <minix/keymap.h>"
<minix/keymap.h> contains a large number of definitions for special keys,
like function keys, and keys on the numeric keypad.  They are:
.PP
Escape key and modifiers:
.BR EXT ,
.BR CTRL ,
.BR SHIFT ,
.BR ALT .
.PP
Numeric keypad keys:
.BR HOME ,
.BR END ,
.BR UP ,
.BR DOWN ,
.BR LEFT ,
.BR RIGHT ,
.BR PGUP ,
.BR PGDN ,
.BR MID " (numeric '5'),"
.BR PLUS ,
.BR INSRT .
.PP
ALT + numpad key:
.BR AHOME ,
.BR AEND ", ...,"
.BR AINSRT .
.PP
CTRL + numpad:
.BR CHOME ,
.BR CEND ", ...,"
.BR CINSRT .
.PP
Lock keys:
.BR CALOCK " (Caps Lock),"
.BR NLOCK " (Num Lock),"
.BR SLOCK " (Scroll Lock)."
.PP
Function keys:
.BR F1 ", ...,"
.BR F12 .
.PP
ALT - function key:
.BR AF1 ", ...,"
.BR AF12 .
.PP
CTRL - function key:
.BR CF1 ", ...,"
.BR CF12 .
.PP
SHIFT - function key:
.BR SF1 ", ...,"
.BR SF12 .
.PP
ALT - SHIFT - function key:
.BR ASF1 ", ...,"
.BR ASF12 .
.PP
There is one key definition that isn't a key at all:
.BR EXTKEY .
This keycode is sent by the keyboard as an indicator that the next keycode
is special.  For instance both ALT keys have the same keycode, but the right
ALT key is sent by the keyboard preceded by the EXTKEY keycode.  The same is
true for the '/' key on the numeric pad versus the other '/' key on the US
keyboard.  (On other keyboards this key may have a different symbol.)  The
keyboard driver knows that a different key is presses if it is preceded by
EXTKEY.
.SS "Creating/changing keyboard mapping"
You can create your own keyboard mapping by copying one of the existing
keymap source files (Standard Minix:
.BR kernel/keymaps/*.src ,
Minix-vmd:
.BR kernel/ibm/keymaps/*.src )
and modifying the desired keys. Once this has been done, you need to
recompile the genmap.c file, either by adding a new entry to the Makefile,
or by running the following commands:
.PP
.RS
.ft B
cc -DKEYSRC=\e"\fIkeymap\fP.src\e" genmap.c
.ft P
.RE
.PP
After this, the 
.BR keymap 
file can be generated by running:
.PP
.RS
.BI "a.out > " keymap .map
.RE
.PP
The keymap can be loaded in the keyboard driver by:
.PP
.RS
.BI "loadkeys " keymap .map
.RE
.PP
It is wise to first run
.B loadkeys
on one of the maps in
.B /usr/lib/keymaps
so that you can easily revert back to a known keymap with a few taps on the
up-arrow key and pressing return.  You will otherwise have to fix the keymap
with a faulty keymap loaded into the keyboard driver, which is no fun.
.PP
When the keymap is to your satisfaction you can copy it to
.B /etc/keymap
to have it loaded automatically at reboot.
.SH FILES
.TP 15
.B /etc/keymap
Default keymap file
.SH "SEE ALSO"
.B loadkeys (1).
.SH AUTHOR
Victor A. Rodriguez - El bit Fantasma ([e-mail])