The another way of doing this in tc would be to first load the kmaps extension with
tce-load -iw kmaps.tcz
And then change the command line arguments for kernel when booting.
For piCore you have to do it like this.
sudo mount /dev/mmcblk0p1
cd /mnt/mmcblk0p1/
Edit cmdline.txt file, and you have to install nano before this, if you don't use vi as an text editor. Edit the file and save and reboot.
Precautions here if you change this to something wrong, your system way not boot.
sudo nano -w cmdline.txt
add this "kmap=qwerty/uk" to the line without dubble quotes.
You could also look at the faq, to see more command line arguments being used by tinycore linux dist.
http://tinycorelinux.net/faq.html