The ARM EABI is a new ABI for the ARM architecture which has, among other things, better system call conventions and improved floating point emulation. Unfortunately, it also requires Thumb interworking, but the Thumb instruction set is not available on armv4 cores (including the StrongARM, used in for example the Balloon Board). A set of patches to GCC can be used to enable armv4- and EABI-compatible code to be generated, at the cost of some extra instructions for each jump. This page contains the current (not-yet-working) set of patches.
This page on the Debian wiki documents these issues in significantly more detail.