Custom serial driver

Hi!

I'm currently porting a Linux kernel v2.4 to a custom PowerPC =
603e-based
board.
For decompression and starting the kernel i use U-Boot. Since I have a
non-standard serial communication-ship, I wrote a small driver for
communication with U-Boot. Everything works fine but when I start the
kernel, I get no output and it crashes somewhere.

I guess I have to add a driver for the initial console to the kernel to =
see
any output.
But where do I have to add it? I searched the net for a good tutorial, =
but
in vain.

Can anyone tell me, where I have to put this driver or to get a nice
tutorial?

Greetings,
Sebastian H=E4pe