update: Basically what it says here, http://www.thinkwiki.org/wiki/Install_Classic_Keyboard_on_xx30_Series_ThinkPads
but with the spanish keyboards and some non working keys are different. I still choose to use the old keyboard because those keys are not used with VIM.
Before giving up, I used an external X220 style spanish keyboard with the X230 and it works without any modifications. some keys are not correctly mapped. I’ll put how to deal with those ones by software by now.
I needed a keyboard I could find comfortable with and I don’t have 250 euros for a second hand x220 computer so this will have to do it.
The official Lenoo BIOS checks something on the keyboard. I could turn on the computer with an english layout x220 keyboard but then it didn’t even show anything on the screen. With the spanish x220 keyboard it didn’t complain.
All the Fn keys are like in the X230 and the numeric keypad doesn’t work. The Supr, home, end, pgup, pgdown don’t work as expected. in general it works but it has issues that should be resolved using the embedded controller or using coreboot. I haven’t tried yet because the english/usa layour keyboards gave me problems.
So far it seems nothing security related has to be done and this could be easier that whitelisting wifi cards (but changing the bios for coreboot).