In such a situation, managing the protection and security of the cores is key. The core has three Exception levels (ELs). EL2 is the highest level that enables a Secure enclave and separation/isolation of virtual machines for OEM code and customer code. More specifically, a Memory Protection Unit (MPU, real-time) context running at EL2 handles context switches between MPU and MMU contexts at EL1 with OEM and/or OS code while user code runs at EL0.
This means Linux can be running and when a real-time event occurs, the processor can switch to handle the real-time event, then switch back to Linux. The security enables isolation of the main firmware and enables end customers of Cortex-R82 based devices to add custom software, either real time or Linux based.
The direct addressability enables very large memory or device real-time systems and improved performance over windowing solutions. This large address space can be accessed either over AXI or CHI to enable additional capabilities including atomics and cache stashing.
The ability to run both real-time and Linux on the same core or cluster of cores is key in emerging technologies such as computational storage. The real-time capability is required for the data transfers through the SSD, but running Linux and associated software tools directly on the drive provides computational workload management and filesystem recognition. This greatly reducing data movement, latencies, and energy consumption says Werdmuller.
Using an array of R82 cores means one SoC could be used for an ordinary enterprise SSD and reconfigured for a CSD product or even be dynamically configured through software to run SSD functions during the day and switch to Computational Storage at night.