Steps 2 to 4 comprise the link of a configurable actor; in this instance, N_iom.r. The link of a configurable actor is unusual, as instead of linking the actor in the current work directory, object files are copied into the obj directory, located in build-IOM. The actor is linked to your work directory and then copied back to the source tree.
The first step is to call genLink, which will:
Produce the sys_agglo.mk Makefile, as seen in the IOM component above.
Copy object files to the obj directory.
Generate two Makefiles in the obj directory. These Makefiles will perform the link.
Call the two Makefiles.
Copy the linked actor back to the source directory.