Implementing hierarchical scheduling to support multi-mode system

Multi-mode embedded real-time systems exhibit a specific behavior for each mode and upon a mode-change request, the task-set and timing interfaces of the system need to be changed. Hierarchical Scheduling Framework (HSF) is a known technique to partition the CPU time into a number of hierarchically divided subsystems each consists of its own task set. We propose to implement a multi-mode system using a two-level HSF and provide a skeleton (framework) for an adaptive HSFs supporting multi-modes. Upon a mode-change request, the timing interface of each subsystem is changed, thus making the hierarchical scheduling adaptive in nature. We address the main goals for the implementation and describe the initial design details of the Multi-Mode Adaptive Hierarchical Scheduling Framework (MMAHSF) with the emphasis of doing minimal changes to the underlying kernel.