Linux Kernel
There is a set of 7 patches available sent to the linuxppc mailing list on 08 March 2007, which have to be applied to Linux 2.6.20. If you're interested in kernel development and/or adding new features, please take a look at Linux Kernel Development.
•(patch 1/7) xenon: add PCI Vendor ID: Microsoft •(patch 2/7) xenon: add platform support •(patch 3/7) xenon: udbg support (ugly) •(patch 4/7) xenon: add southbridge ethernet support •(patch 5/7) xenon: add SATA support •(patch 6/7) xenon: add SMC support •(patch 7/7) xenon: add framebuffer support (ugly)
To run linux, you need to use the Linux Bootloader available right now. To compile the kernel, you need to set up a [cross compiler] toolchain (unless you already have another PowerPC Linux machine).