Is that the case under Harmattan too? I have no idea.
I'd hope that the more recent Harmattan kernel has a working armhf instruction set in the first place.

I just found that there is a patched kernel for Harmatten. [1] No idea what's been patched though.
fun fact: Since Harmattan comes with kernel 2.6.32 in the first place, the glibc hoops I had to jump through for Jessie on Maemo (2.6.28) aren't necessary.
So all you Harmattan users can create your own images the old-fashioned way "on device" without needing any other ARM hardware.


[1] http://talk.maemo.org/showthread.php?p=1259462