It wasn't too long ago that you had to explain to designers what the term “virtualization” was all about. That's generally not the case anymore. In fact, the number of systems that are “virtualized” as part of the design process has increased considerably.
In most cases, the systems that were candidates for virtualization were those of the high-performance variety. Today, you can make an argument to go the virtual route for almost any type of embedded system, including mobile devices. The technology that's been deployed for years in enterprise data centers can be driven down into consumer devices.
While traditional virtualization often concentrates on a high-end (even multicore) processor and chipset, mobile virtualization tends to look at the paradigm a little differently. For example, it's no surprise to see multiple chips consolidated into a unified processor, with dedicated DRAM, glue logic, and so on. At the same time, multiple functions can be ported to that single virtualized processor. While potentially increasing performance, there's a big upside in the reduced number of interconnects required. The single virtualized processor also reduces the overall memory footprint required by the system.
A side-by-side comparison of a handset that was virtualized by Open Kernel Labs (OK Labs, for short) shows a significant cost savings, up to 46% over a similar, nonvirtualized design. The biggest savings comes from being able to eliminate the applications processor, which could cost as much as $30, depending on the required performance, functionality, and feature set of the handset.
Eliminating that apps processor reduces the memory footprint, thereby savings a few dollars. The only additional cost to the BOM comes in the way of the hypervisor needed to do the virtualization, which is where OK Labs comes in. They provide that hypervisor software.
One example of a handset that was virtualized using the OK Labs technology is the Motorola Evoke. It employs an embedded hypervisor from OK Labs, called the OKL4 (note that the Motorola Evoke will be the object of an upcoming Tear Down article, where we really get into the nuts and bolts of how the handset was designed, with a particular focus on the virtualization aspect).
The bottom line is that you shouldn't dismiss virtualization technology as just being for high-end devices. You could be missing an opportunity to reduce your BOM and ultimately simplify your design, especially if your product lends itself to multiple versions/family members.
Richard Nass is editorial director of Embedded Systems Design magazine and the Embedded Systems Conferences. In a past life, he was editor in chief of Portable Design magazine and was a technology editor with Electronic Design magazine. He has a BSEE degree from the New Jersey Institute of Technology. He can be reached at .