Nonfunctioning int. keyboard in initramfs solved with psmouse module

adampurkrt78 · 2025-11-08 16:29:20

I have spent almost a day figuring this out, thought I'd share. The problem was with Fujitsu Celsius H770 internal keyboard, which did not work inside mkinitcpio created initramfs, i.e. for example it was impossible to enter the passphrase for LUKS (that's where it hit me). Also, keyboard did not work when I entered emergency mode by adding "systemd.unit=emergency.target" to the kernel command line, while after full normal bootup, the keyboard worked normally. After trying lots of options, and with the help of external USB keyboard which worked out of the box, after comparing the modules loaded in the emergency state and after full bootup, the solution was adding

MODULES=(psmouse)

to /etc/mkinitcpio.conf and regenerating initramfs with "mkinitcpio -g /boot/initramfs-linux.img".

Somehow, the "psmouse" module brings the internal keyboard in my Fujitsu Celsius H770 laptop to life. Both internal keyboard and "mouse"=touchpad are on PS/2 bus, which was - perhaps - in some powersaving state or whatnot - don't know.

But finally, the internal keyboard works now.

EDIT: just for reference: kernel 6.17.7-arch1-1, mkinitcpio 40

Last edited by adampurkrt78 (2025-11-08 18:36:06)

seth · 2025-11-08 21:26:13

"psmouse" drags in "serio" and "libps2", maybe one of those is rather critical? (serio would be required for i8042)

Either way, this will eventually get lost in the forum and time, so you'd better record it at https://wiki.archlinux.org/title/Laptop/Other#Fujitsu

adampurkrt78 · 2025-11-08 21:40:36

In the default 6.17.7-arch1-1 kernel, both serio and libps2 seems to be compiled into the kernel. searching with "zless /proc/config.gz" reveals (hope these are the relevant options)

CONFIG_SERIO=y

CONFIG_SERIO_LIBPS2=y

it really seems to me that the loading of psmouse somehow triggers the functionality of ps/2 keyboard (don't know why)

EDIT: there is also

CONFIG_KEYBOARD_ATKBD=y

so the atkbd driver is built in in the kernel; still it was not enough in my case for the keyboard to work

Last edited by adampurkrt78 (2025-11-09 16:42:33)

seth · 2025-11-08 22:20:48

Indeed… makes it even more weird.
Adding modules explicitly will also explicitly load them - maybe that's the problem?
Do you have contrasting journals?

Either way, please really record this in the wiki

Arch Linux

#1 2025-11-08 16:29:20

Nonfunctioning int. keyboard in initramfs solved with psmouse module

#2 2025-11-08 21:26:13

Re: Nonfunctioning int. keyboard in initramfs solved with psmouse module

#3 2025-11-08 21:40:36

Re: Nonfunctioning int. keyboard in initramfs solved with psmouse module

#4 2025-11-08 22:20:48

Re: Nonfunctioning int. keyboard in initramfs solved with psmouse module

Board footer