Using official packages
Standard Debian kernel packages don't support OLPC yet, but the fixes for it are merged, and it is expected to be supported when Linux 2.6.26 is uploaded to sid.
Note, however, that you need a patched initramfs-tools if you use these packages (see 483431).
Current Kernel packages
http://queued.mit.edu/~dilinger/sid/ (manually selected known good build)