Install
misc/kbdscan and identify the key code(s) associated with the key(s) labeled
Option.
Bash:
kbdscan # Terminates itself after 5s of inactivity.
Assuming you are otherwise satisfied with the currently loaded keyboard mapping, dump it with
kbdcontrol(1).
Edit this scratch
kbdmap(5) with your favorite editor (or
ee(1)). For the standard
us.kbd this means:
Assigning unused values like the lctrl and rctrl values (unused means no other key(s) behave(s) like the Control keys) to the key code(s) you found out.
If you have defined the control keys now, overwrite the fourth column of the keyboard mapping file with scr𝑁 commands:
Code:
# alt
# scan cntrl alt alt cntrl lock
# code base shift cntrl shift alt shift cntrl shift state
# ------------------------------------------------------------------
000 nop nop nop nop nop nop nop nop O
001 esc esc esc esc esc esc debug esc O
002 '1' '!' scr01 nop '`' '`' nop nop O
003 '2' '"' scr02 nul '@' '@' nul nul O
004 '3' 0xa3 scr03 nop '#' '#' nop nop O
005 '4' '$' scr04 0xa4 '4' '$' nop nop O
006 '5' '%' scr05 nop '5' '%' nop nop O
007 '6' '^' scr06 rs '^' '^' rs rs O
008 '7' '&' scr07 nop '[' '[' esc esc O
009 '8' '*' scr08 nop '8' '*' nop nop O
010 '9' '(' scr09 nop ']' ']' gs gs O
011 '0' ')' scr10 nop '{' '{' nop nop O
Finally load the amended keyboard mapping.
You probably want to edit the
/etc/rc.conf.local file defining a
keymap rc.conf(5) value, too.