On my thinkpad I have an encrypted Arch installation setup similarly to my chromebook setup. Since I bought my a new wireless usb keyboard this thing never worked for decrypting the system. It perfectly works once Arch has started up, but for entering the password at boot I had to use the notebook keyboard.
Add missing modules to initramsfs
Turns out my initramfs was missing the necessary modules.
- Checkout the Arch wiki
- Find the relevant keyboard modules. In my case it was
- Edit /etc/mkinitcpio.conf and set
MODULES="hid_generic usbhid"(or whatever your modules are)
mkinitcpio -p linux