Packing with Boundary Constraints for a Reconfigurable Operating System

Abstract

An operating system for reconfigurable computing is responsible for dynamically placing relocatable pre-routed cores onto an FPGA at run-time. We describe an exact algorithm proposed for use in this type of OS that pre-packs cores into rectangles for subsequent placement. The algorithm not only generates feasible packings but selects those that have a minimum distance metric to optimise inter-core communication distance within the pre-packed rectangle. The algorithm works in conjunction with other software components of the OS that are responsible for partitioning large applications into manageable “space slices” and allocating area to the pre-packed rectangles from the remaining free area of the FPGA. All of these algorithms are capable of operating in a dynamic environment where applications are queued to execute on the FPGA, and then removed when completed with full area reclaim. Thus, they inherently support partial reconfiguration, dynamic reconfiguration, and multi-user operations on a reconfigurable platform.