Hello,
Unfortunatelly it seems that r210 (the kconfig version bump) introduced a serious breakage in buildrom.
This is a build log where you can see the failure: http://pastebin.com/f72bc591f
Steps to reproduce: get current buildrom from svn (any revision >r210 will do) make menuconfig, select the LAB or Linux payload make build failure occurs at the kernel
Expected result: The kernel should build fine, like it does with r<=209