Atmega644 Bootloader

Where can I download the bootloader for the Atmega644? I want to use it in some mucoming projects, but I need a bootloader.

The Sanguino board uses the 644P (that has two serial hardware channels) and they have download zip package that includes their bootloader for the 644P. The source code for the bootloader says it has been tested for both the 644 and 644P in the opening comments.