Good news, I got a working dt.img and a broken recovery.img.
I fixed the dt.img issue by patching the AOSP build/core/Makefile
with the Makefile from B2G.
Right now I get this error when looking into logcat:
- exec '/system/bin/sh' failed: No such file or directory (2) -
EDIT: it seems that the build doesn’t have any system/bin/
dir at all