Customising keyboard maps in Linux is somewhat … confused with lots of different tools and layers to perform the same task. There are a number of tools for performing some form of keyboard mapping, but the most common ones have some disadvantages :-<\/p>\n
There is fortunately another way which is rather difficult to find information about. Which is the reason behind this posting of course.<\/p>\n
This “other method” is to use the generic input system to perform the keyboard mapping which has certain advantages over other methods. Most of the information to do this came from a README file contained within the source code<\/a>.<\/p>\n To demonstrate keyboard mapping, it is helpful to have an example keyboard with custom mappings to play with. Many of the keyboards I use this for are rather complex with\u00a0many<\/em> mappings, but I also have a mini keyboard with relatively few mappings :-<\/p>\n No great mystery as to why I want my keyboard mapped this way – I’m just fussy about keyboards.<\/p>\n In fact there is just one tool –\u00a0\/lib\/udev\/keymap<\/em> – which performs all of the relevant tasks. Before it can do anything, it needs to be provided with the path of the relevant input device. This is easiest done from the console (rather than in X) as root. The easiest way of identifying the device is to unplug the keyboard, reboot the machine, and :-<\/p>\n If you are lucky, there will be just one new input device. If not, you will have to try each one in turn. The first job is to record the keycode of each key to be customised in turn. To do this, it is necessary to run keymap<\/em> with the input device and the “-i” option, and each keystroke will result in some output :-<\/p>\n A key can<\/em> be mapped temporarily using keymap. But before that a list of possible key names is useful to have; there is one to be found in \/usr\/include\/ :-<\/p>\n The relevant name would be the part that follows the “KEY_” converted to lower-case.<\/p>\n But that is rather a temporary solution; it is better by far to create a file containing the necessary mappings to be automatically applied :-<\/p>\n The first step is to obtain some details to uniquely (or as much as possible) identify the keyboard. Run :-<\/p>\n And look through the output for the input device you previously used. Look for a ID_VENDOR_ID<\/em> and ID_MODEL_ID<\/em> that you can use.<\/p>\n Next add a rule to \/lib\/udev\/rules.d\/95-keymap.rules<\/em> along the lines of :-<\/p>\n Once this is working you may want to add it to your version of custom-filco.map<\/em> as a comment to preserve it for use after upgrades; alternatively you may wish to create a new file that will not get overwritten.<\/p>\n Before activating the new rule, remember to copy \/tmp\/custom-filco.map<\/em> into \/lib\/keymaps\/custom-filco.map<\/em>. And again keep another copy in a safe place to preserve.<\/p>\n As to how to activate, a reboot is probably the simplest way.<\/p>\n","protected":false},"excerpt":{"rendered":" Customising keyboard maps in Linux is somewhat … confused with lots of different tools and layers to perform the same task. There are a number of tools for performing some form of keyboard mapping, but the most common ones have some disadvantages :- \u00a0xkb (which is the modern X way), and\u00a0xmodmap (which is deprecated but […]<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"_share_on_mastodon":"0"},"categories":[209],"tags":[1050,109,1051],"class_list":["post-2660","post","type-post","status-publish","format-standard","hentry","category-linux-it","tag-key-mapping","tag-keyboards","tag-udev","category-209-id","post-seq-1","post-parity-odd","meta-position-corners","fix"],"share_on_mastodon":{"url":"","error":""},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p1f2KI-GU","_links":{"self":[{"href":"https:\/\/really.zonky.org\/index.php?rest_route=\/wp\/v2\/posts\/2660","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/really.zonky.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/really.zonky.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/really.zonky.org\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/really.zonky.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2660"}],"version-history":[{"count":9,"href":"https:\/\/really.zonky.org\/index.php?rest_route=\/wp\/v2\/posts\/2660\/revisions"}],"predecessor-version":[{"id":2669,"href":"https:\/\/really.zonky.org\/index.php?rest_route=\/wp\/v2\/posts\/2660\/revisions\/2669"}],"wp:attachment":[{"href":"https:\/\/really.zonky.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2660"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/really.zonky.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2660"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/really.zonky.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2660"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}The Example Keyboard<\/h2>\n
\n\n
\n Original Key<\/th>\n new function<\/th>\n<\/tr>\n \n Esc<\/td>\n Lock screen<\/td>\n<\/tr>\n \n `\/~<\/td>\n Esc<\/td>\n<\/tr>\n \n Caps Lock<\/td>\n Control<\/td>\n<\/tr>\n \n Insert<\/td>\n Delete<\/td>\n<\/tr>\n \n Delete<\/td>\n `\/~<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n The Basic “Tool”<\/h2>\n
# ls \/dev\/input\/e* > \/var\/tmp\/old.list\r\n[Plug in keyboard]\r\n# ls \/dev\/input\/e* > \/var\/tmp\/new.list\r\n# diff \/var\/tmp\/old.list \/var\/tmp\/old.list\r\n> \/dev\/input\/event13\r\n> \/dev\/input\/event14<\/pre>\n
# \/lib\/udev\/keymap \/dev\/input\/event13 -i\r\nPress ESC to finish, or Control-C if this device is not your primary keyboard\r\nscan code: 0x70029 key code: esc\r\n# \/lib\/udev\/keymap \/dev\/input\/event13 -i\r\nPress ESC to finish, or Control-C if this device is not your primary keyboard\r\nscan code: 0x70035 key code: grave\r\nscan code: 0x70039 key code: capslock\r\nscan code: 0x70049 key code: insert\r\nscan code: 0x7004C key code: delete<\/pre>\n
# grep KEY_ \/usr\/include\/linux\/input.h | less<\/pre>\n
# \/lib\/udev\/keymap \/dev\/input\/event13 0x70035 esc<\/pre>\n
# cat \/tmp\/custom-filco.map\r\n0x70029 screenlock\r\n#\tOriginal: key code: esc\r\n0x70035 esc\r\n#\tOriginal: key code: grave\r\n0x70039 leftctrl\r\n#\tOriginal: key code: capslock\r\n0x70049 delete\r\n#\tOriginal: key code: insert\r\n0x7004C insert\r\n#\tOriginal: key code: delete<\/pre>\n
Making The Mappings Permanent<\/h2>\n
# udevadm info --export-db > \/tmp\/udev-db.txt<\/pre>\n
ENV{ID_VENDOR_ID}==\"04d9\", ENV{ID_MODEL_ID}==\"2011\", RUN+=\"keymap $name custom-filco.map\"<\/pre>\n