As many of you will have inferred, MIPS Technologies Inc
has been working on the MIPS/Linux kernel for the past
six months or so, driven by the need for a flexible software
platform for valdiation and characterisation of new MIPS
processor designs. Relatively early on, we made the difficult
decision not to try to track the SGI Linux repository: It was
too unstable, and the SGI activity is driven by a very
different set of goals. We therefore took the 2.2.12
kernel sources from kernel.org, and worked from there.
I've shared some of our bug findings and fixes with
the SGI mailing list, and still more of them with Ralf
directly, but a lot of other changes and improvements
have been made that will certainly be of interest to readers
of this list, particularly those targeting non-SGI platforms.
This kernel supports the new generation of 32-bit MIPS
CPUs with R4K exception models. This involved fairly
extensive changes to semaphore support and to TLB
and cache management routines. We know it works on
the MIPS 4Kc, and with appropriate additions to the
table of recognized CPUs in the (revised) CPU probe
code, it should run on the IDT 323xx, and Toshiba TX49
processor families as well.
It includes an integrated FPU emulator that handles
the full MIPS FP instruction set, and allows FPU-less
CPUs to run standard MIPS/Linux binaries.
It contains a number of endianness fixes in the kernel
and driver code, and is very stable in both configurations.
It contains platform support for the Algorithmics P-5064
and MIPS "Atlas" development boards, as well as the
This code is NOT a supported product of MIPS
Technologies Inc. It is being made available on an
"as is" basis subject to the ususal GPL. It should be
accessible via anonymous (and blind) FTP for a while at
and is archived on the Paralogos MIPS/Linux web site at
http://www.paralogos.com/mipslinux/. We'd be very interested
in any feedback, experimental results, and enhancements
that any of you may wish to provide, and I will answer
email questions to the extent that my time allows.
Kevin D. Kissell
MIPS Technologies European Architecture Lab