This hook can be used to turn the keyboard backlight on when entering initrd. On leaving initrd, the backlight is switched off again.
Move files into /etc/initcpio
and add the hook to the HOOKS
list e.g.
HOOKS="base udev autodetect modconf block filesystems keyboard thinkpad_kbdlight keymap encrypt fsck"
Rebuild initrd:
mkinitcpio -p linux