Where do I find GPL Source Code for Dell Kace M300?

I recently acquired a Dell Kace M300 which is running what appears to be Debian Linux and uses u-boot.  Where would I find the GPL source code for u-boot and the Linux kernel used on this system?

U-Boot used is as follows:

U-Boot 1.1.4 (Jun 20 2011 - 13:16:26) Marvell version: 3.4.27
USISH-SMB Ver: kacemini-1.5

And Linux kernel is:

Linux version 2.6.31.8-kacemini-1.7 (lewinski@armcross)