DiSy @ CS&E . UNSW

Presently our main projects are as follows:

L4 microkernel

forms the software basis for most of our projects. We have built high-performance 64-bit implementations of L4 for the MIPS R4600 and Alpha platforms. The Alpha version features full and highly-scalable multiprocessor support. Exploratory work has been performed for StrongARM and 64-bit UltraSPARC platforms, but these activities are presently on hold. We plan to use the Alpha kernel for work on scalable SMP scheduling. L4 is the basis of a number of other projects which are still in an early state.

Mungi

is a single-address-space operating system. That means all processes share the same address space, which contains all the data in the system. Mungi provides an extensibility model which allows system services to be transparently, securely and efficiently extended at user level. Present work is on high-performance I/O, checkpointing and drivers. Mungi will be released under GPL as soon as it is ready.

Catapult

is a highly modular, generic multi-platform bootloader. It presently boots Linux on the PLEB. Work is in progress to make it boot Linux and L4 on the PLEB, the u4600 (a DiSy-built MIPS R4600 computer), Alpha-based workstations and ix86 boxes. Catapult will be released under GPL as soon as it is ready.

PLEB

is a credit-card sized computer based on the StrongARM SA-1100 processor. The goal of the PLEB project is to build an infrastructure (both hardware and software) to aid researchers and developers in the area of portable and embedded systems development. It runs Linux and L4. The hardware design is Open Source, although the license details are not yet determined.

Sulima

is a highly modular, re-targetable ISA simulator. The present version (which is close to release) simulates the MIPS R4600 ISA. A SPARC ISA module is under development. Sulima will be extended to run distributed simulations of SMP systems. Sulima will be released under some Open Source License as soon as it runs L4 without problems.

Memory management in wide address spaces

is looking at page table structures to support the use of large physical and virtual memories. We have implemented in L4/MIPS a novel page table structure efficiently supporting sparsity and superpages. A kernel containing this data structure will be released later this year.

Reduction of context-switching overhead

is a generic umbrella for a number of sub-projects. These include reduction of context switching costs in ARM-Linux, L4/ARM, IA-64 Linux as well as for systems supporting the secure execution extensions.