Description:

The kernel-source package contains the source code files for the Linux
kernel. These source files are needed to build most C programs, since
they depend on the constants defined in the source code. The source
files can also be used to build a custom kernel that is better tuned to
your particular hardware, if you are so inclined (and you know what you're
doing).

For instructions for update, see:
http://www.mandrakesecure.net/en/kernelupdate.php

!! The tmb kernels is an experimental kernel based on the mdk kernels,
with added patches. Some of them may/will never end up in the main
mdk kernels due to their experimental nature. Some refer to this
kernel as a 'hackkernel' ...
Use these kernels at your own risk !!