The Linux/MIPS FAQ

What is "Linux/MIPS"?

Linux/MIPS is a port of the LINUX Operating System to computers equipped with MIPS processors. Linux/MIPS is based on the latest sources distributed by Linus Torvalds, the author of the original Linux/i386 kernel.

To top

On what hardware will it run?

Linux/MIPS will run on most ARC (ARC = Advanced Risc Computing) compliant systems equipped with Mips R4x00 processors. A port to older MIPS microprocessors is now in progress. Ports to the following systems are in progress:

The ports to following systems are idle because of hardware and/or documentation problems:

In the meantime many other platforms turned out to be good candidates for Linux/MIPS. Although we don't have code for Mips platforms other than the systems listed above, chances are quite good that some of the following systems will be supported in future:

To top

What is the current status of Linux/MIPS?

The kernel is quite reliable and supports ext2fs and NFS filesystems. Other filesystems should also be working but are untested. Supported peripherals can be divided up in four groups:

Is Linux/MIPS little or big endian?

At least all of the ports to ARC systems will be little endian. However, it might be necessary to run older Mips systems, such as the Sony News and Mips RC3xxx, in big endian mode. If and how we can provide user code compatibility thru the whole Mips line hasn't been decided yet.

To top

Is Linux/MIPS a 64 bit OS?

Not yet. This has multiple reasons: To top

Will it run on Multiprocessor machines?

The current kernel doesn't contain very much of the special SMP stuff that is required. It will therefore only make use of one processor. Nevertheless there is
SMP support for Linux/i386.

To top

What is the state of the project?

We have a bootstrap loader which should run on most ARC systems. A network bootloader for DECstations using the MOP protocol is almost complete.
The current kernels based on Linux 1.3.57 include drivers for console, keyboard and ethernet. SCSI will be available soon. On the Acer, Olivetti and Mips boxes, the kernel boots from a floppy, and then mounts root from a NFS server. The kernel is quite reliable; my own machine has currently an uptime of over five days. The only thing that will prevent it from running longer is the fact that kernel hackers frequently reboot their machines.

A network bootloader for R3000-based DECStations using the MOP protocol is almost complete, though certain models of DECStation may be booted using tftp/bootp. Both R3000 and DECStation specific code has been written for the 1.2.11 kernel, and will be released as patches to the current 1.3.57 kernel soon. An experimental DECStation kernel image is already available. This ought to boot to the point of showing the "Calibrating delay loop..." message on most DECStations based on R3000 CPU's.

On the Linux/MIPS FTP sites is a better than nothing distribution available. It currently just a bunch of thrown-together programs and will somewhen later be replaced by a real distribution.

To top

Any support/development tools available?

Yes. We have cross compilers, assemblers and linkers ready to use for Linux/i386, SunOS 4.1.3 and Solaris 2.3. A Mips R2000/R3000 simulator (SPIM) for Linux/i386 is also ready to download. Binaries and documentation are available from the Linux/MIPS FTP sites. The current version are gcc 2.7.2 and binutils 2.6. There are patches required to both of these packages in the "src" subdirectory in the above locations. Both GCC and Binutils may be configured in four target flavours. This may be a bit confusing but is necessary since Linux/MIPS is currently migrating from a.out to ELF object format and is available for both big and little endian byte-order. The four system flavours are:

For ease of installation binaries for Linux/i386 hosts are also available. Native binaries for Linux/MIPS are included in root-0.00.tar.gz

Linux/MIPS FTP sites

This is a very incomplete list of Linux/MIPS sites. There are more available and you should try always to use the nearest site.

To top

What Literature about MIPS CPUs is available?

The book MIPS RISC Architecture from Gerry Kane is something like a bible for MIPS programmers. It covers all CPUs upto the R4000 family. The book also contains much other usefull information like the MIPS calling sequence, a list of macro instructions that expand into multiple machine instructions, examples of multiprecission arithmetic and more: There is some additional literature about available as Postscript file on SGI's FTP Server. These books contain much more details about the instruction set and hardware but don't cover software aspects very good. Another advantage is of course that these files are for free.

Is there a mailing list?

Yes, it is linux-mips@vger.rutgers.edu. To subscribe to this list, send a message to
Majordomo@vger.rutgers.edu with the command
"subscribe linux-mips _your_email_address_" in the message body. However this list is more or less dead since most people discussing Linux/MIPS are developers subscribed to another list.
Please contact linux-mips@fnet.fr for further information.

To top

Why should you use Linux/MIPS?

Just a few of the reasons that come to mind:

Can I help?

Sure! If you have a Mips box, please let us know. Eventually we find a way to include your box in the target list. And we would of course appreciate it, if you can spend some time into hacking kernel and/or user code. Please feel free to contact us at

To top

What does it cost?

Nothing, since Linux/MIPS is freely available. But the development costs -- as any development. We would appreciate any donations such as:

To top

Last changed 16-Jan-1996 Ralf Bächle Email