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Microkernel boasts more “robust” SDK

Oct 21, 2008 — by Eric Brown — from the LinuxDevices Archive — 13 views

Open Kernel Labs (OK Labs) has upgraded its microkernel operating system (OS) and Linux-friendly embedded virtual machine environment, adding an improved, Linux-compatible software development kit (SDK). Another touted improvement in OKL4 3.0 is a common API across different OKL4 versions, OSes, and mobile stacks, says the company.

OKL4 is a microkernel OS that runs almost everything in userspace. The OS includes a thin hardware abstraction layer that can support Linux, Windows Mobile, Symbian, and/or other guest OSes, each running in userspace for added security. It also includes a minimal POSIX-compliant execution environment, enabling separate applications and drivers to also run in separate, isolated partitions.

OK Labs OKL4 Secure Hypercell architecture
(Click to enlarge)

The OKL4 microkernel ships in “millions of units per month,” primarily in mobile phones, and is expected to be in 250 million phones by the end of the year, claims OK Labs. OKL4 is part of multiple Linux-based handset models from Toshiba, as well as several Windows CE-based devices from HTC.

OKL4 3.0

The new OKL4 focuses primarily on easing development hassles with an improved, Linux-compatible software development kit (SDK). “Version 3.0 has a much more robust SDK,” said OK Labs CEO Steve Subar (pictured at right) in an interview.

New features include the ability for third-party developers to develop their own system-on-chip (SoC) modules for SoCs based on the ARM926 core, as an alternative to using OK Labs's supplied modules. Supported SoCs include major embedded processors from Broadcom, Freescale, Infineon, NXP, Qualcomm, and Texas Instruments (TI), says the company.

Another key new tool, said Subar, is the memory usage tool, which maps both physical and virtual memory. “Developers can now do memory mapping, so it's easier to understand what they're looking at with system configuration processes,” said Subar. “Now they can know in advance if the configuration matches the memory usage and the constraint of the design.”

Major touted features in version 3.0 of OKL4 are said to include:

  • More adaptable system security and resource allocation
  • Cross-platform API for rapid switching between high-level OS targets
  • Memory-usage tool
  • Freedom to create third-party ARM926-based SoC modules
  • SDK provides “all the header files and libraries that a developer may need”
  • Greater flexibility in integrating kernel libraries from different sources
  • Enables platform provider proprietary IP protection
  • Greater stack portability for increased code re-use

OK Labs says OKL4's API is now more consistent across different hardware platforms, enabling developers to more easily swap OSes and mobile stacks. “Designers are faced with more and more operating systems, and now we can let them switch rapidly,” said Subar. “You can replace Symbian for Linux, for example, or add Windows Mobile or switch to Android, and you don't need to re-architect the whole system.”

Secure HyperCell

The previous OKL4 2.0 release, announced in April, added major security features to bolster protection against malware and destructive hackers, while also insulating mobile phone software from the effects of poorly-behaved code like flaky drivers. The key new feature was a “Secure HyperCell” technology aimed at encapsulating and protecting critical software components from the rest of the system.

“With our Secure HyperCell technology, you can have large operating systems like Linux or Symbian, along with their drivers, and integrate them, and yet still supply full isolation for legacy code,” explained Subar. “Our handset OEM and semiconductor supplier customers are interested in protecting their legacy code. With OKL4, we are enabling them to protect this proprietary software by isolating the code from physical memory. Developers can implement it once, and then instead of writing new code, they can reuse it for other designs.”

The license isolation afforded by the OKL4 microkernel is also of “vital importance,” Subar said. “You need to be able to isolate code in a manner that is open to inspection and can be verified,” he observed.

OKLabs also launched a new “Nano” version of OKL4 3.0. Designed for low-end phones and running on only 4KB, OKL4 Nano does not run Linux or other complex OSes. However, it shares an API with the full version, so companies can use native POSIX applications such as dialers on products at a range of price points, as well as more easily upgrade low-end phones to feature phones with full OSes.


OKL4 3.0 and OKL4 Nano appear to be available now under both open source and commercial license, says OK Labs.

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