L4 on MIPS R4x00

This Page is no longer Maintained!

What used to be UNSW's DiSy group is now part of the Embedded, Real-Time and Operating-Systems (ERTOS) Research Program at National ICT Australia (NICTA).

Up-to-date information on our L4 activities can be found at the ERTOS L4 site.

For general information on L4 refer to L4HQ.


The R4x00 version of the L4 microkernel (L4/MIPS) used to be our main workhorse for research and teaching. It was developed at UNSW by then PhD student Kevin Elphinstone. The kernel consists of about 6,000 lines of assembler and 6,500 lines of C.

It is now superseded by our port of L4Ka::Pistachio to the MIPS64 architecture.

The kernel is stable since August 1997, with minor enhancements and bug fixes since. It has been tested on an R4600-based SGI Indy, on the Algorithmics P4000i prototyping board, as well as on the R4700-based U4600 system developed at UNSW as a research and teaching platform.


The following documentation is available:


L4/MIPS is available in source form under the terms of the GNU General Public License.