Tech musing #2: Device tree partitioning for multicore, multi-OS embedded software designs

Link: http://www.embedded.com/design/operating-systems/4436959/Device-tree-partitioning-for-multicore--multi-OS-embedded-software-designs-

Summary

The purpose of this article is to describe a resource dividing scheme for a supervised, heterogeneous multicore embedded system, where the system under consideration contains multiple instances of embedded Linux, each controlling on a dissimilar set of cores. After first reviewing the tools available currently for resource partitioning among multi OS systems, along with their limitations, a partitioning algorithm is proposed that is used to produce a filtered view of the platform for the guest operating systems in the system’s hypervisor.

Some of the key factors that drive the demand of multi-OS multicore designs in different market segments (medical/industrial/mobile/automotive) are performance, security, portability, and software consolidation. Generally speaking all of these designs are divided in two computing domains. These computing domains are classified as homogeneous and heterogeneous. The homogenous computing is recognized for the similarity in processing units that are controlled by a single instance of an OS that is able to perform all the resources in the platform. Heterogeneous computing is classified in supervised and non-supervised multicore processing. The supervised covers all the design with manager software mediating between different software stacks while the non-supervised has a manager less design where software running might assume the master role and set up work for rest of the processing units.

Embedded systems are diverse and it is impossible to satisfy the majority of requirements/constraints with a homogeneous multicore design, and this is where heterogeneous computing comes in, enabling multiple software stacks running on sets of core(s) suited to a perform a particular function.

While there are several ways by which embedded software can gather hardware information I believe that what this article shows about Flattened device trees(FDTs) is of much relevancy for a MIS professional. It demonstrates how technology in FDT is fast becoming the preferred way to provide fast enablement of Linux on hardware. A major breakthrough in the adoption of device trees that has been the inclusion in Linux kernel 3.2 for the ARM architecture; and as IT professionals, this is the kind of news we need to be up to date.