This is my extlinux.conf:
DEFAULT core
LABEL core
KERNEL /tce/boot/vmlinuz
APPEND initrd=/tce/boot/core.gz quiet lang=de_DE@euro waitusb=10:UUID="3b305a3c-d95b-4f80-b1fa-b7baaf7db06f" tce=UUID="3b305a3c-d95b-4f80-b1fa-b7baaf7db06f" restore=UUID="3b305a3c-d95b-4f80-b1fa-b7baaf7db06f" swapfile=UUID="3b305a3c-d95b-4f80-b1fa-b7baaf7db06f" home=UUID="3b305a3c-d95b-4f80-b1fa-b7baaf7db06f" opt=UUID="3b305a3c-d95b-4f80-b1fa-b7baaf7db06f" local=UUID="3b305a3c-d95b-4f80-b1fa-b7baaf7db06f" tz=CET-1CEST,M3.5.0,M10.5.0/3 showapps blacklist=b43,ssb,bcma noautologin
(I even left out kmap=de to not create eventual confusion; which, otoh, in any case seem to not have any effect on the console, which despite that setting still uses english/us keymap. Aterm uses the lower 128 ascii of the german keyboard, but i think, aterm is an X application and therefore controlled by the keyboard setting of X).