icecream: make "-j" switch for cross-compiling?

Hi! I'm trying to use icecream for cross compiling for target arm and did follow your documentation steps so far. But cross-compile-toolchain (btw: which is using bitbake) does invoke compiler (linux-arm-gcc) directly instead of invoking gmake to start compiling. So I cannot give linux-arm-gcc/icecc number of parallel compile jobs to use for compile process like you can do with "make -j 4". So how can I set number of parallel compile jobs so that more than currently only _one_ compile job would be started and it would be able to transfer jobs to other nodes? Is any environment variable usable for setting number of compile jobs? regards