Comment 27 for bug 1050855

The "human-keyboard screen" is in fact the boot loader, in this case syslinux. It's important to distinguish between this and the running system.

Ordinarily the fact that the keyboard works during the desktop installation (once the kernel is up) but doesn't work in d-i (the server installer) would indicate that some module is not being delivered in the appropriate udeb. However, all of hid-generic, hid-apple, and usbhid are present in the input-modules udeb, which is used by d-i.

I don't suppose any of these modules require firmware or something?