In iterative workflows (using incremental modifications to the AIE code and regenerating the hardware image), the graph may be recompiled to produce a new libadf.a. However, the actual AIE shim solution may remain the same as in the previous iteration. The Makefile detects any changes in the generated AIE shim solution and updates the timestamp on a file named aiesoldiff, which is later used to detect whether the platform needs to be regenerated. If the AIE shim solution is not different, then the platform will not be rebuilt, assuming the other dependencies of the platform target remain unchanged.
For example, when you try to change the datatype of the AI Engine kernel interface or functionality of the kernel, only the graph gets recompiled to produce a new libadf.a. However, changing the number of ports in the kernel interface or modifying the PLIO width of the ports leads to the change in the AIE SHIM solution which, in turn, rebuilds the platform.