Wombat: A portable user-mode Linux for embedded systems
Embedded systems are the biggest potential market for Linux, much bigger (in terms of number as well as total value) than either the desktop or the server market. While Linux is making excellent inroads into (high-end) embedded systems, a number of challenges particular to embedded systems threaten to limit its impact. These include the requirements for hard real-time capability, extreme robustness, and, in particular, a minimal trusted computing base. The viral nature of the GPL is also frequently causing problems. We argue that a portable user-mode Linux which runs on a truly minimal kernel is the answer, and will open up application domains which would otherwise be hard to penetrate. We present such a system, called Wombat, which is a port of Linux kernel to the L4 microkernel. Wombat is readily portable between architectures (presently runs on x86, ARM and MIPS), and initial performance evaluations look promising.
Benno is a research programmer in the Embedded, Real-Time and Operating Systems program at National ICT Australia. He is interested in kernel design and has in the past invesitaged the performance of user-level device drivers on both Linux and the L4 microkernel. His current work involves running Linux in parallel with a microkernel-based real-time system.