This article is from the Frequently Asked Questions for Linux, the Free/Open Source UNIX-like operating system kernel that runs on many modern computer systems. Maintained by David C. Merrill with numerous contributions by others. (v1.0).
A: For recent kernels, get /pub/Linux/system/Keyboards/kbd-0.90.tar.gz from ftp://metalab.unc.edu/. Make sure you get the appropriate version; you have to use the right keyboard mapping package for your kernel version.
For older kernels you have to edit the top-level kernel Makefile, in /usr/src /linux/.
You may find more helpful information in The Linux Keyboard and Console HOWTO, by Andries Brouwer, at ftp://metalab.unc.edu/pub/Linux/docs/HOWTO/.