From b2677db81994cb7b8339d9a276a25fda20b2c47c Mon Sep 17 00:00:00 2001 From: David Thurstenson Date: Thu, 7 Mar 2024 23:10:16 +0000 Subject: [PATCH] docs: add all untracked content --- home.md | 12 +++++ reference/keyboard-mapping.md | 83 +++++++++++++++++++++++++++++++++++ 2 files changed, 95 insertions(+) create mode 100644 home.md create mode 100644 reference/keyboard-mapping.md diff --git a/home.md b/home.md new file mode 100644 index 0000000..4e009eb --- /dev/null +++ b/home.md @@ -0,0 +1,12 @@ +--- +title: homepage +description: +published: true +date: 2024-03-07T22:18:27.322Z +tags: +editor: markdown +dateCreated: 2024-03-07T22:18:25.914Z +--- + +# Header +Your content here \ No newline at end of file diff --git a/reference/keyboard-mapping.md b/reference/keyboard-mapping.md new file mode 100644 index 0000000..3a5f7ef --- /dev/null +++ b/reference/keyboard-mapping.md @@ -0,0 +1,83 @@ +--- +title: Keyboard Mapping +description: Changing keyboard mapping at the hwdb level +published: true +date: 2024-03-07T22:50:17.227Z +tags: +editor: markdown +dateCreated: 2024-03-07T22:50:15.696Z +--- + +References: +- https://wiki.archlinux.org/index.php/Map_scancodes_to_keycodes +- https://github.com/Earnestly/pkgbuilds/blob/master/system-config/hwdb-capslock-as-control.hwdb + +Maping keys is pretty simple, and if it's done at the udev level, it's universal, so it doesn't require any X or Wayland specific configuration. + +As an example, I map my compose key (menu key) to right meta (aka super, logo, windows, apple, or command key), and CapsLock to left Control. + +## Get Scancode + +First, get the scancode(s) of the key(s) you wish to change. Easiest way is to use `evteest(1)`. For each keypress, you'll get information similar to the following: + +``` +Event: time 1496690003.603531, -------------- SYN_REPORT ------------ +Event: time 1496690003.723467, type 4 (EV_MSC), code 4 (MSC_SCAN), value 70065 +Event: time 1496690003.723467, type 1 (EV_KEY), code 127 (KEY_COMPOSE), value 0 +``` + +The code you will need to use in the udev hwdb config file is the `MSC_SCAN` value (in this case: 70065). + +## Get Hardware ID + +Next you will need the hardware Vendor and Product ids from `lsusb(1)`. These are two sets of four hexidecimal digits separated by a colon (:) printed right before the device name. + +``` +Bus 001 Device 005: ID 258a:1006 +``` + +In this example, the Vendor ID is `258a`, and the Product ID is `1006`. + +## Create udev hwdb Configuration + +Then create `/etc/udev/hwdb.d/61-custom-keyboard.hwdb` with the following contents: + +``` +evdev:input:b0003v258Ap1006* + KEYBOARD_KEY_70065=rightmeta + KEYBOARD_KEY_70039=leftctrl +``` + +A few notes on the format of this file: +- The format for the device identifying line for usb devices is `evdev:input:b0003vp*`. + - If `` and `` contain letters, they must be capitalized + - These scancodes can be quite device-specific, so it is wise to be specific to *at least* the vendor and product IDs + - There are methods for identifying atk keyboards as well. Check the Arch Wiki page listed in the references above for more info +- Defining a key to change is done with `KEYBOARD_KEY_=` + - `` is the code we pulled from evtest earlier + - `` is the keycode we want to emit when the key is pressed. Names of keycodes are listed in `/usr/include/linux/input-event-codes.h`, and should be all lowercased in your udev config. +- The filename `61-custom-keyboard.hwdb` is somewhat arbitrary, but make sure that you order your file *after* the existing `60-keyboard.hwdb`. + +## Update Hardware Database Index + +After changing the config files, the hwdb needs to be rebuilt: + +``` +# systemd-hwdb update +``` + +To start using this new hwdb, either reboot or tell udev to reload: + +``` +# udevadm trigger +``` + +Note that this will only work for adding or modifying existing key mappings. Deleted key mappings are kept in the kernel until a reboot. + +## Testing the New Mappings + +A simple test can be run before trying the keys directly: + +``` +# udevadm info /dev/input/by-path/*-usb-*-kbd | grep KEYBOARD_KEY +```