Hardware-in-the-loop simulation for CPU/GPU heterogeneous platforms

Multi-core CPU/GPU heterogeneous platforms became popular in embedded systems. A full system simulator is typically used to observe the internal system behavior by running complete software stacks without modification on simulation models of CPUs and other devices in the system. However, there are few known full system simulators for CPU/GPU heterogeneous platforms and existent GPU simulators are prohibitively slow for running application software. In this paper, we propose a hardware-in-the-loop simulation technique that integrates GPU hardware into a full system simulator. A novel interfacing mechanism between CPU simulator and the development board, where GPU hardware is integrated, is devised. In the experiments, we took Exynos 4412 as a case study, where gem5 simulator is used to simulate mainly a quad-core ARM CPU in the platform and an Exynos development board is used to run the Mali GPU hardware. We could successfully run Android apps on the proposed hardware-in-the-loop simulation framework with up to 1.5 M cycles per second performance.