...was not easy. 2.6.28 will not compile with semi-recent toolchain (eldk-5.4), and it needs fixes even with older toolchain (eldk-5.2). To add difficulty, it also needs fixes to work with new make (!). Anyway, now it boots, including nfsroot. That should make userspace development possible. I still hope to get voice calls working, but it is not easy on 3.18/3.19 due to all the audio problems.