By centralizing module callbacks, the gem5 module class knows when different stages of the simulation are happening and can do it's own extra checks. It also compartmentalizes modules more since the kernel object doesn't have to reach into them to enumerate ports and exports. Change-Id: I55887284af9c05150fe9d054f5b6147cad6092a1 Reviewed-on: https://gem5-review.googlesource.com/c/12610 Reviewed-by: Gabe Black <gabeblack@google.com> Maintainer: Gabe Black <gabeblack@google.com>