Linux/MIPS HOWTO
Ralf Bächle, ralf@gnu.org
v1.65, 2002-08-23
This FAQ describes the MIPS port of the Linux operating system, common
problems and their solutions, availability and more. It also tries to
be helpful to other people who might read this FAQ in an attempt to
find information that actually should be covered elsewhere.
Linux/MIPS is a port of the widespread UNIX clone Linux to the MIPS
architecture. Linux/MIPS runs on a large number of technically very
different systems ranging from small embedded systems to large
desktop machines and servers from SGI and DEC.
Here you will find links to all the resources you need
to work with Linux on MIPS, whether you are starting out getting
Linux running on your own platform, or developing an end user
application or product based on a Linux/MIPS system.
If you are looking for a commercial Linux product with associated
support, take a look at the
Commercial Linux page.
MIPS Technologies
also maintain a list of links
here to companies
providing the MIPS community with tools and services.
If you have input regarding the contents of these pages, see the
Documentation page for contact info. Webserver
contact is
webmaster@linux-mips.org.
There are two Linux/MIPS-oriented mailing lists:
-
linux-mips@linux-mips.org
This mailing list currently has the most
traffic. It is especially of interest as a good number of active developers
are subscribed to this list. Subscription to this list is handled via
Ecartis (ecartis@linux-mips.org), just send an email with the
words subscribe linux-mips. In order to unsubscribe, send
unsubscribe linux-mips. For more, information see also
http://oss.sgi.com/mips/mail.html.
The archives for this list are located at
http://oss.sgi.com/mips/archive/
-
linux-cvs@linux-mips.org
This is an announcement only mailing list
to which a message for every CVS commit into oss.sgi.com, the central CVS
archive of the Linux/MIPS community, is being sent. This allows following
the development as it happens. Subscription to this list is handled via
Ecartis (ecartis@linux-mips.org); just send an email with the
words subscribe linux-cvs. In order to unsubscribe, send
unsubscribe linux-cvs to the same address.
There is an IRC channel named #mipslinux for Linux/MIPS which may be found on
irc.openprojects.net.
The current version of the Linux kernel can be found on
kernel.org and will tend to be
somewhat ahead of the MIPS/Linux version (see CVS below) but behind in some
MIPS-specific regards. Older and more stable versions of the kernel for MIPS
are available for download - see the section on
Distributions for locations.
For those who always want to stay on the bleeding edge, and want to avoid
having to download patch files or full tarballs, we also have an anonymous
CVS server. Using CVS, you can checkout the Linux/MIPS source tree with
the following commands:
cvs -d :pserver:cvs@oss.sgi.com:/cvs login
(Only needed the first time you use anonymous CVS, the password is "cvs")
cvs -d :pserver:cvs@oss.sgi.com:/cvs co <repository>
where you insert linux, libc, gdb or faq for <repository>.
There is a mailing list for information on what gets committed to this
repository.
Via
http://oss.sgi.com/mips/cvsweb, you have
direct access to the new Linux/MIPS kernel sources, and a few other projects
hosted in the same CVS archive. The intuitive interface allows you to
follow the development at the click of your mouse.
4. Distributions.
A distribution is a complete collection of kernel, user programs, toolchain
and libraries necessary to get a system up and running. It may include an
install procedure to get the files copied correctly onto the target storage
device. See the READMEs on the links below for more information.
See the section on
commercial distributions.
A complete
distribution based on RedHat's 7.1, ported by H.J. Lu, can be found at
ftp://oss.sgi.com/pub/linux/mips/redhat/7.1/.
A little-endian only distribution is maintained by
Maciej at
ftp://ftp.ds2.pg.gda.pl/pub/macro/ or the
mirror.
MIPS maintain a version of the above, including complete installable CD-ROM
images, at
ftp://ftp.mips.com/pub/linux/mips/installation/redhat7.1/.
A Debian distribution for both little and big endian machines can be found at
http://www.debian.org/ports/mips/.
At the time of writing (January 2002) we are using a 2.4 kernel; kernel
code is shared with the ports being done by people from
MIPS Technologies, Inc.).
Algorithmics' kernels and a link to the MIPS userland can be found from a
jump page at
http://www.algor.co.uk/algor/info/linux.html. Algorithmics wrote the
floating point trap handler and emulator used in this kernel - essential for
MIPS CPUs to run floating point operations reliably and correctly.
Algorithmics also maintain a GNU
toolchain
and provide both free snapshots and a commercially supported version - worth
thinking about for commercial Linux developments. You can contact
Algorithmics at
mailto:ask@algor.co.uk.
A toolchain is a complete collection of compiler and binutils programs and
can be run either as a cross-compiler, or native on the target (if
performance allows).
5.1
Algorithmics SDE
Not a complete distribution, just a Linux toolchain. But it's a toolchain
built and maintained for MIPS with commercial support available, and free
snapshots.
Algorithmics specialize in MIPS support and maintain our own source tree for
the toolchain components. They resynchronize infrequently with mainstream
GNU releases (which inevitably have bugs for minor architectures such as
MIPS) and focus on providing the most reliable, best-performing compiler for
the largest range of MIPS CPUs.
This is the same compiler which is at the
heart of our SDE-MIPS embedded toolkit, and is fully supported for Linux
kernel and application building from
http://www.algor.co.uk/algor/info/sde5.html v5.0, out in mid 2002.
See the section on
commercial distributions -
these all include appropriate toolchain deliverables.
H.J. Lu distributes a toolchain
as part of his Red Hat 7.1 port. It can be found at
ftp://oss.sgi.com/pub/linux/mips/redhat/7.1/.
A stable set of toolchain components provided by
Maciej can be downloaded from
ftp://ftp.ds2.pg.gda.pl/pub/macro/ or the
mirror. This is based on gcc 2.95.3 (patched) and up-to-date
binutils.
The following companies provide commercial, supported
Linux/MIPS solutions for the embedded market, on a number of different
platforms.
The following webservers are relevant for Linux/MIPS developers.
-
http://oss.sgi.com/mips
This server covers most of Linux/MIPS. If you need something chances are
it's already there.
-
http://www.mips.com/devTools/devArea/Linux.html
This sites has MIPS own version of Linux/MIPS based distributions and tools
for their processors and evaluation boards.
-
http://www.debian.org/ports/mips/
This is Debian's MIPS/Linux site.
-
http://www.playstation2-linux.com
This is Sony's Linux/MIPS server for the Playstation 2.
Also in
Japanese.
-
http://www.ltc.com/~brad/mips/mips-cross-toolchain/
Bradley D. LaRonde's HowTo on building a cross toolchain for MIPS/Linux.
-
http://www.junsun.net/linux/porting-howto/
Jun Sun's porting guide has some useful information
and tips for porting to new platforms.
The primary anonymous FTP servers for Linux/MIPS are
-
ftp://ftp.linux-mips.org
This server should satisfy almost all of your Linux/MIPS related ftp
desires. Really.
-
ftp://ftp.mips.com/pub/linux
This is the server of MIPS, Inc. itself. Among other things it offers a
recent Redhat-based distribution and a support area for MIPS' evaluation
boards.
-
ftp://ftp.ds2.pg.gda.pl/pub/macro/
Maciej W. Rozycki's FTP server.
Check also the section on
Supported CPUs for which
processor types are supported,
if you are using a platform for which multiple CPU options exist.
See below for the following categories of platforms
8.1
Actively supported development boards
The following list covers development boards for which there is active
support for the port, and which are maintained continuously. Expect these
ports to work reliably. Refer also the the section on
commercial Linux ports - these companies may provide additional
hardware support.
Algorithmics P-6032 and P-6064 (and P-4032, P-5064)
Algorithmics (
http://www.algor.co.uk/) make a series of
single-board computers for MIPS prototyping, and maintain Linux kernels
for all of them:
All the boards have common I/O plus Ethernet and disk interfaces onboard,
with spare PCI slots for adding different controllers. They're highly
configurable, so will run with either byte order. All are suitable targets
for 64-bit kernels, but (so far) all the Linux work we've done has been using
32-bit code.
They're available, supported and documented with PDF manuals available
online, like
http://www.algor.co.uk/ftp/pub/doc/p6032-user.pdf
for the P-6032.
Broadcom BCM91250A
An evaluation board for the SiByteTM BCM1250 dual processor SOC (system on
chip) and is implemented in the standard ATX form factor. A high performance
board. See
http://www.broadcom.com/ for details.
MIPS Malta
The MIPS Technologies Malta board and all its CPU options are supported. See
the Developers pages under
www.mips.com.
8.2
Actively supported workstations
The following list covers machines for which there is active support for
the port, and which are maintained continuously. Expect these ports to work
reliably.
Cobalt Qube and Raq
The Cobalt Qube product series are low cost headless server systems
based on a IDT R5230. Cobalt has developed its own Linux/MIPS variant
to fit the special requirements of the Qube as well as possible. Cobalt
kernels are available from Cobalt's ftp site
http://www.cobaltnet.com.
DECstation series
The following DECstation models are actively supported:
- 2100, codename PMAX
- 5000/xx (Personal DECstation), codename MAXine
- 5000/1xx, codename 3MIN
- 5000/200, codename 3MAX
- 5000/2x0, codename 3MAX+
- 5900/2x0 (identical to the 3MAX+).
These days, most of the work is done by
Harald Koerfgen (hkoerfg@web.de) and others. On the
Internet, DECstation-related information can be found at
http://decstation.unix-ag.org/.
The DECstation family ranges from the DECstation 2100 with an R2000/R2010
chipset at 12 MHz, to the DECstation 5000/260 with a 60 MHz R4400SC. See the
section on Legacy Platforms below for other DEC machines. Note: Other x86 and
Alpha-based machines were also sold under the name DECstation.
Silicon Graphics Indy
The Indy is currently the best supported Silicon Graphics machine.
Silicon Graphics Origin 200 and 2000
Ralf Bächle (ralf@gnu.org)
and a team of SGI employees are currently working on a port to the
Origin 200. While still in it's early stages, it's running in
uniprocessor and multiprocessor mode and has drivers for the built-in IOC3
Ethernet and SCSI hostadapters.
Sony Playstation and Playstation 2
The Sony Playstation 2 has a Japanese-only port which can be found at
http://www.ps2linux.com.
The older Sony Playstation is based on an R3000 derivative and uses a set of
graphics chips developed by Sony themselves. There is no support for this
machine.
8.3
Unsupported / Legacy support only
The platforms listed here may once have been supported, but there may not have
been active maintenance for them. Expect problems with these platforms, and
consult the mailing list for information on them.
Acer PICA
The Acer PICA is derived from the Mips Magnum 4000 design.
It has a R4400PC CPU running at 133MHz or optionally 150MHz plus a 512KB
(optionally 2MB) second level cache; the Magnum's G364 gfx card was replaced
with a S3 968 based one. The system is supported with the exception of the
X server.
Baget/MIPS series
The Baget series includes several boxes which have R3000 processors: Baget
23, Baget 63, and Baget 83. Baget 23 and 63 have BT23-201 or BT23-202
motherboards with R3500A (which is basically a R3000A chip) at 25 MHz and
R3081E at 50 MHz respectively. The BT23-201 board has VME bus and VIC068,
VAC068 chips as system controllers. The BT23-202 board has PCI as internal
bus and VME as internal. Support for BT23-201 board has been done by
Gleb Raiko (rajko@mech.math.msu.su) and
Vladimir Roganov (vroganov@msiu.ru)
with a bit of help from
Serguei Zimin (zimin@msiu.ru). Support for BT23-202 is under
development along with Baget 23B which consists of 3 BT23-201 boards
with shared VME bus.
Baget 83 is mentioned here for completeness only. It has only 2MB RAM and
it's too small to run Linux. The Baget/MIPS code has been merged with the
DECstation port. The source for both is available at
http://decstation.unix-ag.org/.
DECstation
These DECstation models are orphaned because nobody is working on them,
but support for them should be relatively easy to achieve.
- 3100, identical to the 2100 except the R2000A/R2010A @ 16 MHz
- 5100, codename MIPSMATE, almost identical to the 2100 but with an
R3000/R3010 chipset.
The other members of the DECstation family, besides the x86 based ones,
should be considered as VAXen with the CPU replaced by a MIPS CPU.
There is absolutely no information available about these machines and support
for them is unlikely to ever happen unless the VAXLinux port comes back to
life. These are:
- 5400, codename MIPSFAIR
- 5500, codename MIPSFAIR2
- 5800, codename ISIS
MIPS Magnum 4000 / Olivetti M700-10
These two machines are almost completely identical. Back during the
ACE initiative, Olivetti licensed the Jazz design and marketed the machine
with Windows NT as the OS. MIPS Computer Systems, Inc. bought the
Jazz design and marketed it as the MIPS Magnum 4000 series of machines.
Magnum 4000 systems were marketed with Windows NT and RISC/os as the
operating systems.
The firmware on the machine depended on the operating system which was
installed. Linux/MIPS supports only
the little endian firmware on these two types of machines. Since the
M700-10 was only marketed as an NT machine, all M700-10 machines have this
firmware installed. The MIPS Magnum case is somewhat more complex. If
your machine has been configured big endian for RISC/os, then you need
to reload the little endian firmware. This firmware was originally
included on a floppy with the delivery of every Magnum. If you don't
have the floppy anymore you can download it via anonymous ftp from
ftp://oss.sgi.com/pub/linux/mips/misc/magnum-4000.
It is possible to reconfigure the M700 for headless operation by setting
the firmware environment variables ConsoleIn and ConsoleOut to
multi()serial(0)term(). Also, try the command listdev which will
show the available ARC devices.
In some cases, like where the G364 graphics card is missing but the console
is still configured to use normal graphics, it will be necessary to set
the configuration jumper JP2 on the board. After the next reset, the machine
will reboot with the console on COM2.
MIPS Magnum 4000SC
The MIPS Magnum 4000SC is the same as a Magnum 4000 (see above) with
the exception that it uses an R4000SC CPU.
NEC machines
The NEC uniprocessor machines are OEM Acer PICA systems, see
that section for details. The SMP systems are different from that. The
Linux/MIPS developers have no technical documentation as necessary to write
an OS. As long as that does not change, this will pretty much stay a show-
stopper, preventing a port to NEC's SMP systems.
Netpower 100
The Netpower 100 is apparently an Acer PICA in disguise.
It should therefore be supported but this is untested. If there is a
problem then it is probably the machine detection.
Nintendo 64
The Nintendo 64 is R4300-based game console with 4MB RAM. Its
graphics chips were developed by Silicon Graphics for Nintendo. Right now
this port has pipe dream status and will continue to be in that state until
Nintendo decides to publish the necessary technical information. The
question remains as to whether porting the Linux/MIPS code to this platform
is a good idea.
Silicon Graphics Challenge S
This machine is very similar to the Indy, the differences are that it doesn't
have a keyboard or graphics card, but has an additional SCSI WD33C95-based
adapter. This WD33C95 hostadapter is currently not supported.
Silicon Graphics Indigo
This machine is only being mentioned here because people have occasionally
confused it with Indys or the Indigo 2. The Indigo is a different
R3000-based architecture however, and is yet unsupported.
Silicon Graphics Indigo2
This machine is the successor to the Indigo and is very similar to the Indy.
It is now supported, but is lacking in several areas. You will have
to use serial console. If you have an Indigo2 and still want to run Linux on
it, contact either
Florian Lohoff (flo@rfc822.org) or
Klaus Naumann (spock@mgnet.de) .
Silicon Graphics Onyx 2
The Onyx 2 is basically an Origin 2000 with additional graphics
hardware. As of now, writing Linux support for the graphics hardware has
not yet been done. Aside from that, Linux should run just as well as
on a normal, headless Origin 2000 configuration.
Silicon Graphics Power Series
This is a very old series of R3000 SMP systems. There is no hardware
documentation for these machines, few of them even exist anymore, and the
hardware is weird. In short, the chances that Linux will ever run on them
are approximating zero. Not that we want to discourage any takers ...
SNI RM200C
In contrast to the RM200 (see below), this machine has EISA and PCI slots.
The RM200 is supported with the exception of the availability of the onboard
NCR53c810A SCSI controller.
SNI RM200
If your machine has both EISA and PCI slots, then it is an RM200C (please
see above). Due to the slight architectural differences of the RM200 and
the RM200C, this machine isn't currently supported in the official sources.
Michael Engel (engel@numerik.math.uni-siegen.de) has managed to get
his RM200 working partially, but the patches haven't yet been included in the
official Linux/MIPS sources.
SNI RM300C
The RM300 is technically very similar to the RM200C. It should be supported
by the current Linux kernel, but we haven't yet received any reports.
SNI RM400
The RM400 isn't supported.
SNI RW320
This machine is a OEM variant of the SGI Indigo and therefore also
unsupported.
NEC VR41xx-based platforms
The Linux VR project is porting Linux to devices based on the NEC VR41xx
microprocessors. Many of these devices were originally designed to run
Windows CE. The project has produced working kernels with basic drivers
for the Vadem Clio, Casio E-105, Everex Freestyle, and more. For more
information please see
http://linux-vr.org/.
Toshiba TMPR39xx/Philips PR31700 platforms
Similar to the VR41xx, devices with these processors were originally
intended for running Windows CE. However, there are working kernels
with basic drivers for Sharp Mobilon and the Compaq
C-Series. Support for more devices is under construction. The code is
part of the Linux VR project and as such more information can be found at
http://linux-vr.org/.
8.4
Hardware we're never going to support
IBM RS6000
As the name says, these are IBM machines which are based on the RS6000
processor series, and, as such, they're not the subject of the Linux/MIPS
project. People frequently confuse the IBM RS6000 with the MIPS R6000
architecture. However, the Linux/PPC project might support these machines.
Checkout
http://www.penguinppc.org/ for further information.
VaxStation
As the name already implies, this machine is a member of Digital Equipment's
VAX family. It's mentioned here because people often confuse it with
Digital's MIPS-based DECstation family due to the similar type numbers. These
two families of architectures share little technical similarities.
Unfortunately, the VaxStation, like the entire VAX family, is currently
unsupported.
SGI VisPC
This is actually an x86-based system, therefore not covered by this FAQ.
There is some limited Linux support available for the older Visual
Workstations. The current series of Visual Workstations is an officially
supported SGI product. Please see
http://oss.sgi.com and
http://www.sgi.com for more information.
Motorola 68k-based machines like the Iris 3000
These are very old machines, more than ten years old by now. As
these machines are not based on MIPS processors, and therefore not supported
by the Linux/MIPS project, this document is the wrong place to search for
information.
9. Supported CPUs
All CPUs and cores that conform to the MIPS32 specification, including the
MIPS 4K series, Alchemy Au1000/1500.
All CPUs and cores that conform to the MIPS64 specification, including the
MIPS 5K and 10K series, Sibyte SB1 core / SB1250 SOC.
Linux supports the R2000, R3000 family and many processors that were derived
from these the two original MIPS processors such as the R3081.
Linux supports many of the members of the R4000 family. Currently, these
are: R4000PC, R4400PC, R4300, R4600, R4700, R5000, R5230, R5260, RM7000.
The list is growing permanently.
Not supported are the R4000MC and R4400MC CPUs (that is multiprocessor
systems), as well as R5000 systems with a CPU-controlled second level cache.
This means that the cache is controlled by the R5000 itself, in contrast to
some external cache controller. The difference is important because,
unlike other systems, especially PCs, on MIPS the cache is architecturally
visible and needs to be controlled by software.
Special credit goes to
Ulf Carlsson (ulfc@engr.sgi.com) who provided the CPU module for
debugging the R4000SC / R4400SC support.
Sometimes people confuse the R6000, a MIPS processor, with RS6000, a series
of workstations made by IBM. So, if you're reading this in hope of finding
out more about Linux on IBM machines, then you're reading the wrong
document.
The R6000 is currently not supported. It is a 32-bit MIPS ISA 2 processor;
apretty interesting and weird piece of silicon. It was developed and
produced by a company named BIT Technology. Later, NEC took over
the semiconductor production. It was built using ECL technology, the same
technology that was, and still is, being used to build extremely fast chips
like those used in some Cray computers. The processor had its TLB
implemented as part of the last couple of lines of the external primary
cache, a technology called TLB slice. That means its MMU is
substantially different from those of the R3000 or R4000 series, which is
also one of the reasons why the processor isn't supported.
The R8000 is currently unsupported partly because this processor is
relatively rare and has only been used in a few SGI machines, and partly
because the Linux/MIPS developers don't have such a machine.
The R8000 is a pretty interesting piece of silicon. Unlike the other
members of the MIPS family it is a set of seven chips. It's cache and TLB
architecture are pretty different from the other members of the MIPS family.
It was born as a quick hack to get the floating point crown back to
Silicon Graphics before the R10000 is finished.
The R10000 is supported as part of the mips64 kernel which currently is
supported on the IP22 (SGI Indy, Challenge S and Indigo 2) and
Origin.
Due to the very hard-to-handle way this processor works in non-cachecoherent
systems, it will probably be some time until we support this processor
in such systems. As of today, these systems are the SGI O2 and
Indigo
For embedded purposes, there are special derivates of the above CPU
available which often lack a full TLB. We don't support those types nor
should you ever expect such support to be added.
Hackers may want to take a look at a Linux subset named Microcontroller
Linux, or short, ucLinux. This would be supportable on TLB-less processors.
Given the little difference between CPU types with and without TLB, we still
recommend that you choose a processor with TLB. It's going to save you a
lot of engineering.
Linux/MIPS version 2.4 and later feature a full FPU emulation and therefore
can support these processors while maintaining the full binary compatibility
to fpu-full versions.
NFS booting fails.
Usually, the reason for this is that people have unpacked the tar archive
under IRIX, not Linux. Since the representation of device files over NFS is
not standardized between various Unices, this fails. The symptom is that
the system dies with the error message ``Warning: unable to open an initial
console.'' right after mounting the NFS filesystem.
For now, the workaround is to use a Linux system (doesn't need to be MIPS)
to unpack the installation archive onto the NFS server. The NFS server
itself may be any type of UNIX.
Self-compiled kernels crash when booting.
When I build my own kernel, it crashes. On an Indy the crash message looks
like the following (the same problem hits other machines as well but may
look completely different):
Exception: <vector=UTLB Miss>
Status register: 0x300004803<CU1,CU0,IM4,IPL=???,MODE=KERNEL,EXL,IE>
Cause register: 0x8008<CE=0,IP8,EXC=RMISS>
Exception PC: 0x881385cc, Exception RA: 0x88002614
exception, bad address: 0x47c4
Local I/O interrupt register 1: 0x80 <VR/GIO2>
Saved user regs in hex (&gpda 0xa8740e48, &_regs 0xa8741048):
arg: 7 8bfff938 8bfffc4d 880025dc
tmp: 8818c14c 8818c14c 10 881510c4 14 8bfad9e0 0 48
sve: 8bfdf3e8 8bfffc40 8bfb2720 8bfff938 a8747420 9fc56394 0 9fc56394
t8 48 t9 8bfffee66 at 1 v0 0 v1 8bfff890 k1 bad11bad
gp 881dfd90 fp 9fc4be88 sp 8bfff8b8 ra 88002614
PANIC: Unexpected exception
This problem is caused by a still unfixed bug in Binutils newer than
version 2.7. As a workaround, change the following line in
arch/mips/Makefile from:
LINKFLAGS = -static -N
to:
LINKFLAGS = -static
Booting the kernel on the Indy fails with PROM error messages
>> boot bootp()/vmlinux
73264+592+11520+331680+27848d+3628+5792 entry: 0x8df9a960
Setting $netaddres to 192.168.1.5 (from server deadmoon)
Obtaining /vmlinux from server deadmoon
Cannot load bootp()/vmlinux
Illegal f_magic number 0x7f45, expected MIPSELMAGIC or MIPSEBMAGIC.
This problem only happens for Indys with very old PROM versions which cannot
handle the ELF binary format which Linux uses. A solution for this problem
is in the works.
Where can I get the little endian firmware for my SNI?
SNI's system can be operated in both big and little endian modes. At this
time, Linux/MIPS only supports the little endian firmware. This is somewhat
unlucky since SNI hasn't shipped that firmware for quite some time, since
they dropped Windows NT.
When running in big endian mode, the firmware looks similar to an SGI Indy
which is already supported, therefore fixing the SNI support will be
relatively easy. Interested hackers should contact
Ralf Bächle (ralf@gnu.org).
ld dies with signal 6
collect2: ld terminated with signal 6 [Aborted]
This is a known bug in older binutils versions. You will have to upgrade to
binutils 2.8.1 plus very current patches.
Missing ELF support in some PROM versions
Old PROM versions don't know about the ELF binary format which the Linux
kernel normally uses, so Linux cannot boot directly. This results in error
messages similar to this one:
>> boot -f linux root=/dev/sda1
Cannot load scsi(0)disk(1)rdisk(0)partition(8)/linux.
Illegal f_magic number 0x7f45, expected MIPSELMAGIC or MIPSEBMAGIC.
Unable to load linux: ``linux'' is not a valid file to boot.
>>
The preferable solution for this is of course a PROM upgrade but that isn't
available for all systems.
For systems which still have the sash of IRIX 5 installed it is alternativly
possible use Sash to boot the kernel. Sash knows how to load ELF binaries
and doesn't care if it's an IRIX or Linux kernel. Simply type ``Sash'' to
the PROM monitor. You'll get another shell prompt, this time from Sash.
Now launch Linux as usual.
Sash can read EFS or XFS filesystems or read
the kernel from BOOTP / TFTP.
Using the elf2ecoff tool that is shipping with the kernel source you can
convert an ELF binary into ECOFF. Or when building a kernel just run the
``make vmlinux.ecoff'' which will produce an ECOFF kernel.
My machine doesn't download the kernel when I try to netboot
Your machine is replying to the BOOTP packets (you may verify this using a
packet sniffer like tcpdump or ethereal), but doesn't download the kernel
from your BOOTP server. This happens if your boot server is running a kernel
of the 2.3 series or higher. The problem may be circumvented by doing a
"echo 1 > /proc/sys/net/ipv4/ip_no_pmtu_disc" as root on your boot server.
The kernel download from the TFTP server stops and times out
This may happen if the TFTP server is using a local port number of 32768 or
higher which usually happens if the TFTP server is running Linux 2.3 or
higher. This problem may be circumvented by doing a "echo 2048 32767 >
/proc/sys/net/ipv4/ip_local_port_range" on the server.
Bug in DHCP version 2
When using DHCP version 2 you might see the following problem: Your machines
receives it's BOOTP reply 3 times but refuses to start TFTP. You can fix
this by doing a "unsetenv netaddr" in the PROM command monitor before you
boot your system. DHCP version 3 fixes that problem.
When booting I get: Warning: unable to open an initial console.
This problem has two possible solutions. First make sure you actually have
a driver for the console of your system configured. If this is the case and
the problem persists you probably got victim of a widespread bug in Linux
distributions and root filesystems out there. The console of a Linux
systems should be a character device of major id 5, minor 1 with permissions
of 622 and owned by user and group root. If that's not the case, cd to the
root of the filesystem and execute the following commands as root:
rm -f dev/console
mknod --mode=622 dev/console
You can also do this on a NFS root filesystem, even on the NFS server
itself. However note that the major and minor ids are changed by NFS,
therefore you must do this from a Linux system even if it's only a NFS
client or the major / minor ID might be wrong when your Linux client boots
from it.
Is IRIX required for installation on SGI systems?
Various descriptions of the installation procedure use IRIX in order to
partition disks. This was required at the time of their writing as there
were no native partiting tools available. Now disks can be partitioned
using the IRIX disklabel mode which can be selected in the expert menu of
newer fdisk versions. The volume header can be manipulated using dvhtool.
Note dvhtool usage is different from IRIX.
IRIX as secondary operating systems can still be handy as it may reduce the
need to fiddle with ramdisks or nfs-root during installation. Just one word
of warning though: Be careful to not point IRIX fx(8) to disks that don't
don't contain an IRIX disklabel if you want to retain the content - IRIX may
damage the content of that disk without asking!
Can IRIX and Linux be installed on the same system
Yes. Just make sure you read the warning about IRIX's fx(8) in above
paragraph.
Insmod complains about the _gp_disp symbol being undefined
_gp_disp is a magic symbol used with PIC code on MIPS. Be happy, this error
message saved you from crashing your system. You should use the same
compiler options to compile a kernel module as the kernel makefiles do. In
particular the options -mno-pic -mno-abicalls -G 0 are important.
Serial console on SGI machines
Make sure that the kernel you're using includes the appropriate driver for a
serial interface and serial console. Set the console ARC
environment variable to either the value d1, or d2 for
Indy and Challenge S depending on which serial interface you're going
to use as the console.
If you have the problem that all kernel messages appear on the serial
console on boot-up, but everything is missing from the point when init
starts, then you probably have the wrong setup for your /dev/console. You
can find more information about this in the Linux kernel source
documentation which is in /usr/src/linux/Documentation/serial-console.txt if
you have the kernel source installed.
Strange amounts of available memory on SGI
On bootup, the kernel on the Indy will report available memory with a
message like:
Memory: 27976k/163372k available (1220k kernel code, 2324k data)
The large difference between the first pair of numbers is caused by a 128MB
area in the Indy's memory address space which mirrors up to the first 128MB
of memory. The difference between the two numbers will always be about
128MB and does not indicate a problem of any kind. Kernels since 2.3.23
don't count this 128MB gap any more.
Indy PROM related problems
Several people have reported these problems with their machines after
upgrading them typically from surplus parts. There are several PROM
versions for the Indy available. Machines with old PROM versions which have
been upgraded to newer CPU variants, like a R4600SC or R5000SC module, can
crash during the self test with an error message like:
Exception: <vector=Normal>
Status register: 0x30004803<CU1,CU0,IM7,IM4,IPL=???,MODE=KERNEL,EXL,IE>
Cause register: 0x4000<CE=0,IP7,EXC=INT>
Exception PC: 0xbfc0b598
Interrupt exception
CPU Parity Error Interrupt
Local I/O interrupt register 1: 0x80 <VR/GIO2>
CPU parity error register: 0x80b<B0,B1,B3,SYSAD_PAR>
CPU parity error: address: 0x1fc0b598
NESTED EXCEPTION #1 at EPC: 9fc3df00; first exception at PC: bfc0b598
In that case, you'll have to upgrade your machine's PROM to a newer version,
or go back to an older CPU version (usually R4000SC or R4400SC modules
should work). Just to be clear, this is a problem which is unrelated to
Linux, it is only mentioned here because several Linux users have asked
about it.
Why is so much memory reserved on my Indy?
On bootup, the `Memory: ...' message on an Indy says that there is
128MB of RAM reserved. That is ok. Just like the PC architecture has
a gap in its memory address space between 640KB and 1024KB, the Indy
has a 128MB-sized area in its memory map where the first 128MB of
its memory is mirrored. Linux knows about it and just ignores
that memory, and thus this message.
Milo is the boot loader used to boot the little endian MIPS systems with ARC
firmware, currently the Jazz family and the SNI RM 200. While Milo uses
the same name and has a similar purpose to the Alpha version of Milo, these
two Milos have nothing else in common. They were developed by different
people, don't share any code, and work on different hardware platforms. The
fact that both have the same name is just a kind of historic ``accident''.
The need for Milo has been eliminated for all ARC platforms except the RM200C
due to it's unusual firmware behavior. On all other platforms an ECOFF or
often on more modern firmware also an ELF kernel can be started directly
without the need for Milo or an equivalent. On the RM200C Milo 0.27.1 is
still required to boot the kernel.
Building Milo
The building procedure of Milo is described, in detail, in the README files
in the Milo package. Since Milo has some dependencies to kernel header
files which have changed over time, Milo often cannot be built easily.
However, the Milo distribution includes binaries for both Milo and Pandora.
Building Milo is not trivial; unless you want to modify Milo yourself the
urgent recommendation is to use the binaries shipping in the Milo
tarball.
Pandora
Pandora is a simple debugger which was primarily developed in order to
analyze undocumented systems. Pandora includes a disassembler, memory dump
functions, and more. If you only want to use Linux, then there is no need
to install Pandora, despite its small size.
Using modules on Linux/MIPS is quite easy. It should work as expected for
people who have used the feature on other Linux systems. If you want to run
a module-based system, then you should have at least kernel version 980919,
and modutils newer than version 2.1.121 installed. Older versions won't
work.
Available binaries
The easiest way to setup a cross-compiler is to just download the binaries.
For Linux/i386 hosts and big endian targets, these are the packages:
binutils-mips-linux-2.8.1-1.i386.rpm
egcs-c++-mips-linux-1.1.2-2.i386.rpm
egcs-g77-mips-linux-1.1.2-2.i386.rpm
egcs-libstdc++-mips-linux-2.9.0-2.i386.rpm
egcs-mips-linux-1.1.2-2.i386.rpm
egcs-objc-mips-linux-1.1.2-2.i386.rpm
And this is the list of packages for little endian targets:
binutils-mipsel-linux-2.8.1-1.i386.rpm
egcs-c++-mipsel-linux-1.1.2-2.i386.rpm
egcs-g77-mipsel-linux-1.1.2-2.i386.rpm
egcs-libstdc++-mipsel-linux-2.9.0-2.i386.rpm
egcs-mipsel-linux-1.1.2-2.i386.rpm
egcs-objc-mipsel-linux-1.1.2-2.i386.rpm
For 64-bit MIPS kernels, there is only one package available right now:
egcs-mips64-linux-1.1.2-2.i386.rpm
This compiler is only available in the big endian flavor as there currently
is no little endian machine supported by the 64-bit kernel. A little endian
version of the compiler will be provided as soon as there is demand for one.
It's not necessary that you install all of these packages as most people can
just omit the C++, Objective C and Fortran 77 compilers. The
Intel binaries have been linked against GNU libc 2.1, so you may have to
install that as well when upgrading.
Recommended compiler versions
Compilers older than egcs 1.1.2 are no longer supported for compiling
kernels due to bugs in the generated code. At this time, we still recommend
binutils 2.8.1 despite their age.
Building your own cross-compiler
First of all, go and download the following source packages:
- binutils-2.8.1.tar.gz
- egcs-1.1.2.tar.gz
- glibc-2.0.6.tar.gz
- glibc-crypt-2.0.6.tar.gz
- glibc-localedata-2.0.6.tar.gz
- glibc-linuxthreads-2.0.6.tar.gz
You can obtain these files from your favorite GNU archive or
oss.sgi.com. Furthermore, you'll need
patches. The unbundled patch files aren't always up-to-date and additional,
not MIPS-specific, patches may be required for building. Note that the
unbundled patch files also use a different revision numbering and it is
therefore recommended that you obtain the source and patches from the RPM
packages distributed on
oss.sgi.com.
Those are the currently recommended versions. Older versions may or may not
be working. If you're trying to use older versions, please don't send bug
reports because we don't care. When installing, please install things in
the order of binutils, egcs, then glibc. Unless you have older versions
already installed, changing the order will fail.
Disk space requirements
For the installation, you'll have to choose a directory where the files will
be installed. I'll refer to that directory below with <prefix>. To avoid
a particular problem, it's best to use the same value for <prefix> as
your native gcc. For example, if your gcc is installed in /usr/bin/gcc,
then choose /usr for <prefix>. You must use the same <prefix> value
for all the packages that you're going to install.
During compilation,
you'll need about 31MB disk space for binutils. For installation, you'll
need 7MB disk space on <prefix>'s partition. Building egcs requires
71MB, and installation 14MB. GNU libc requires 149MB disk space during
compilation, and 33MB for installation. Note, these numbers are just a
guideline and may differ significantly for different processor and operating
system architectures or compiler options.
Byte order
One of the special features of the MIPS architecture is that all processors
except the R8000 can be configured to run either in big or in little endian
mode. Byte order means the way the processor stores multibyte numbers in
memory. Big endian machines store the byte with the highest value digits at
the lowest address while little endian machines store it at the highest
address. Think of it as writing multi-digit numbers from left to right or
vice versa.
In order to setup your cross-compiler correctly, you have to
know the byte order of the cross-compiler target. If you don't already
know, check the section
Hardware Platforms for your machine's byte order.
Configuration names
Many of the packages based on autoconf support many different architectures
and operating systems. In order to differentiate between these many
configurations, names are constructed with <cpu>-<company>-<os>, or
even <cpu>-<company>-<kernel>-<os>. Expressed this way, the
configuration names of Linux/MIPS are: mips-unknown-linux-gnu for big endian
targets, or mipsel-unknown-linux-gnu for little endian targets. These names
are a bit long and are allowed to be abbreviated to mips-linux or
mipsel-linux. You must use the same configuration name for all
packages that comprise your cross-compilation environment. Also, while
other names, like mips-sni-linux or mipsel-sni-linux, are legal
configuration names, use mips-linux or mipsel-linux instead. These are the
configuration names known to other packages, like the Linux kernel sources,
and they would otherwise have to be changed for cross-compilation.
I'll refer to the target configuration name below with <target>.
Installation of GNU Binutils.
This is the first and simplest part (at least as long as you're trying to
install on any halfway-sane UNIX flavour). Just cd into a directory with
enough free space and do the following:
gzip -cd binutils-<version>.tar.gz | tar xf -
cd binutils-<version>
patch -p1 < ../binutils-<version>-mips.patch
./configure --prefix=<prefix> --target=<target>
make CFLAGS=-O2
make install
This usually works correctly. However, certain machines using GCC 2.7.x as
compiler are known to dump core. This is a known bug in GCC and can be
fixed by upgrading the host compiler to GCC 2.8.1 or better.
Assert.h
Some people have an old assert.h header file installed, probably leftover
from an old cross-compiler installation. This file may cause autoconf
scripts to fail silently. Assert.h was never necessary and was only
installed because of a bug in older GCC versions. Check to see if the file
<prefix>/<target>/include/assert.h exists in your installation. If
so, just delete the it - it should never have been installed for any version
of the cross-compiler and will cause trouble.
Installing the kernel sources
Installing the kernel sources is simple. Just place them into some
directory of your choice and configure them. Configuring them is necessary
so that files which are generated by the procedure will be installed. Make
sure you enable CONFIG_CROSSCOMPILE near the end of the configuration
process. The only problem you may run into is that you may need to install
some required GNU programs like bash or have to override the
manufacturer-provided versions of programs by placing the GNU versions
earlier in the PATH variable. Now, go to the directory
<prefix>/<target>/include and create two symbolic links named asm and
linux pointing to include/asm rsp. include/linux within your just installed
and configured kernel sources. These are necessary such that the necessary
header files will be found during the next step.
First installation of egcs
Now the pain begins. There is a so-called bootstrap problem. In our case,
this means that the installation process of egcs needs an already installed
glibc, but we cannot compile glibc because we don't have a working
cross-compiler yet. Luckily, you'll only have to go through this once when
you install a cross-compiler for the first time. Later, when you already
have glibc installed, things will be much smoother. So now do:
gzip -cd egcs-1.1.2.tar.gz | tar xf -
cd egcs-<version>
patch -p1 < ../egcs-1.1.2-mips.patch
./configure --prefix=<prefix> --with-newlib --target=<target>
make SUBDIRS="libiberty texinfo gcc" ALL_TARGET_MODULES= \
CONFIGURE_TARGET_MODULES= INSTALL_TARGET_MODULES= LANGUAGES="c"
Note that we deliberately don't build gcov, protoize, unprotoize, and the
libraries. Gcov doesn't make sense in a cross-compiler environment, and
protoize and unprotoize might even overwrite your native programs - this is
a bug in the gcc makefiles. Finally, we cannot build the libraries because
we don't have glibc installed yet. If everything went successfully, install
with:
make SUBDIRS="libiberty texinfo gcc" INSTALL_TARGET_MODULES= \
LANGUAGES="c" install
If you only want the cross-compiler for building the kernel, you're done.
Cross-compiling libc is only required to be able to compile user
applications.
Test what you've done so far
Just to make sure that what you've done so far is actually working, you may
now try to compile the kernel. Cd to the MIPS kernel's sources and type
``make clean; make dep; make''. If everything went ok do ``make clean''
once more to clean the sources.
Installing GNU libc
Note: Building glibc 2.0.6 using a compiler newer than egcs 1.0.3a is
not recommended due to binary compatibility problems which may hit certain
software. It's recommended that you either use egcs 1.0.3a or use the files
from a published binary package. Crosscompiling GNU libc is always only the
second best solution as certain parts of it will not be compiled when
crosscompiling. A proper solution will be documented here as soon as it is
available and believed to be stable. With this warning given, here's
the recipe:
gzip -cd glibc-2.0.6.tar.gz | tar xf -
cd glibc-2.0.6
gzip -cd glibc-crypt-2.0.6.tar.gz | tar xf -
gzip -cd glibc-localedata-2.0.6.tar.gz | tar xf -
gzip -cd glibc-linuxthreads-2.0.6.tar.gz | tar xf -
patch -p1 < ../glibc-2.0.6-mips.patch
mkdir build
cd build
CC=<target>-gcc BUILD_CC=gcc AR=<target>-ar RANLIB=<target>-ranlib \
../configure --prefix=/usr --host=<target> \
--enable-add-ons=crypt,linuxthreads,localedata --enable-profile
make
You now have a compiled GNU libc which still needs to be installed. Do
not just type make install. That would overwrite your host
system's files with Linux/MIPS-specific files with disastrous effects.
Instead, install GNU libc into some other arbitrary directory <somedir>
from which we'll move the parts we need for cross-compilation into the
actual target directory:
make install_root=<somedir> install
Now cd into <somedir> and finally install GNU libc manually:
cd usr/include
find . -print | cpio -pumd <prefix>/<target>/include
cd ../../lib
find . -print | cpio -pumd <prefix>/<target>/lib
cd ../usr/lib
find . -print | cpio -pumd <prefix>/<target>/lib
GNU libc also contains extensive online documentation. Your system might
already have a version of this documentation installed, so if you don't
want to install the info pages, which will save you a less than a
megabyte, or already have them installed, skip the next step:
cd ../info
gzip -9 *.info*
find . -name \*.info\* -print | cpio -pumd <prefix>/info
If you're not bootstrapping, your installation is now finished.
Building egcs again
The first attempt of building egcs was stopped by lack of a GNU libc. Since
we now have libc installed we can rebuild egcs but this time as complete as
a cross-compiler installation can be:
gzip -cd egcs-<version>.tar.gz | tar xf -
cd egcs-<version>
patch -p1 < ../egcs-1.1.2-mips.patch
./configure --prefix=<prefix> --target=<target>
make LANGUAGES="c c++ objective-c f77"
As you can see, the procedure is the same as the first time, with the
exception that we dropped the --with-newlib option. This option was
necessary to avoid the libgcc build breaking due to the lack of libc. Now
install with:
make LANGUAGES="c c++ objective-c f77" install
You're almost finished. If you think you don't need the Objective C or
F77 compilers, you can omit them from above commands. Each will save you
about 3MB. Do not build gcov, protoize, or unprotoize.
Should I build the C++, Objective C or F77 compilers?
The answer to this question largely depends on your use of your
cross-compiler environment. If you only intend to rebuild the Linux kernel,
then you have no need for the full blown setup and can safely omit the
Objective C and F77 compilers. You must, however, build the C++
compiler, because building the libraries included with the egcs distribution
requires C++.
How about float.h?
The installation of float.h is no longer necessary. Since about egcs 1.0.3a,
a proper float.h header file will automatically be generated and installed.
Known problem when cross-compiling
IRIX crashes
Origin 200 running IRIX 6.5.1 may crash when running ``make depend''
on the Linux kernel sources. IRIX 6.5 on Indy and IRIX 6.5.4 on
Origin 200 are known to work.
Resource limits on System V based hosts
Typical System V-based Unices, like IRIX or Solaris, have limits for
the maximum number of arguments to be passed to a child process which may
be exceeded when cross-compiling some software like the Linux kernel or GNU
libc. For IRIX systems, the maximum length of the argument list defaults
to 20KB, while Linux defaults to at least 128KB. This size can be modified
by the command ``systune ncargs 131072'' as root.
GDB
Building GDB as cross-debugger is only of interest to kernel developers. For
them, GDB may be a life saver. Such a remote debugging setup always consists
of two parts: the remote debugger GDB running on one machine, and the target
machine running the Linux/MIPS kernel being debugged. The machines are
typically interconnected with a serial line. The target machine's kernel
needs to be equipped with a ``debugging stub'' which communicates with the
GDB host machine using the remote serial protocol.
Depending on the target's architecture, you may have to implement the
debugging stub yourself. In general, you'll only have to write very simple
routines for the serial line. The task is further simplified by the fact
that most machines are using similar serial hardware, typically based on the
8250, 16450 or derivatives.
Choosing a processor type
R2000, R3000 family
For these processors just select the R3000 option. A kernel built for this
option will not run on any other processors than R2000 and R3000 family
members.
R4000, R5000 family
With the exception of the Nevada family these processors are all fully
compatible with rescpect to the kernel. Choose the option which matches
your processor best for optimal performance.
R6000
Linux currently doesn't support the R6000 so this paragraph is entirely
theoretical. The R6000 has it's own, rather unique if not odd cache and
MMU architecture; it also requires alot of workarounds as it's a quite
broken piece of silicon. Therefore a R6000 kernel will not work on any
other processor nor will a kernel for another processor work on the
R6000.
Nevada
The Nevada nickname stands for the QED 5230, 5231, R5260, R5261, R5270 etc.
family of CPUs. It enables the use of additional instructions which are
not supported on other processors therefore you only should choose this
opition if you indeed have one of these processors. If you're not sure
configure for R4x00 or R5000 (see above) and
SB1
Choose this option only for the Sibyte SB1 processor. A kernel built for
this processor will not work on any other processor type nor vice versa.
Being a truly bleeding edge OS Linux supports this processor even though
silicon doesn't even exist yet.
R10000
Choose this option if you want to run Linux on a R10000, R12000 or R14000
system. A kernel built with this option will not work on R4000 or R5000
family processors.
MIPS32
Choose this option if you want to run Linux on a member of the MIPS32
family.
Compatible options
The kernel configuration process doesn't make a too strong attempt at making
wrong configuration impossible. So for example an SGI Indy may never have a
framebuffer, yet it's possible to enable it which later on will result in a
compile error. This situation will improve in the future when CML2 will be
the standard kernel configuration language; for 2.2 and 2.4 you still will
have to care of your steps yourself.
Crosscompilation
The kernel has been carefully developped to ensure crosscompilation on a
non-MIPS system is possible. Once you've managed to get around the cliff of
setting up a crosscompiler crosscompiling is easy. To do so you have two
options. First you can pass CROSS_COMPILE=<target>- (note the trailing
dash) as an additional argument to your make invocations where you choose
one of mips-linux, mipsel-linux, mips64-linux or mips64el-linux depending if
your target is big or little endian, 32-bit or 64-bit. An alternate way is
setting the CONFIG_CROSSCOMPILE configuration option. The kernel will then
automatically choose the right value for CROSS_COMPILE which will keep make
command lines a bit simpler.
32-bit vs. 64-bit
By default the Linux/MIPS kernel source tree is configured to build a 32-bit
target. If you want to build a 64-bit kernel you'll have pass the
additional ARCH=mips64 argument to all you make invocations.
You can download this document in various formats:
This FAQ is also available as SGML source code via anonymous CVS from
oss.sgi.com. The archive also has a Makefile which will translate it into
various formats. An ASCII version is regularly being posted via
comp.os.linux.answers and the other Linux HOWTO channels.
Updates for this document should be sent as unified diffs against the
SGML version to
Ralf Bächle (ralf@gnu.org). Please don't updates in any
other form as that will make maintenance significantly more difficult.
Author Dominic Sweetman, Publisher Morgan Kaufmann, ISBN 1-55860-410-3.
This is intended as a pretty comprehensive guide to programming MIPS,
wherever it's different from programming any other 32-bit CPU. It's the
first time anyone has tried to write a readable, and comprehensive,
explanation and account of the wide range of MIPS CPUs available. It should
be very helpful for anyone programming MIPS who isn't insulated by someone
else's operating system. Also, the author is a free-unix enthusiast who
subscribes to the Linux/MIPS mailing list!
John Hennessey, father of the MIPS architecture, was kind enough to write
in the foreword: ``... this book is the best combination of completeness
and readability of any book on the MIPS architecture ...'';
It includes some context about RISC CPUs, a description of the
architecture and instruction set, including the "co-processor 0"
instructions used for CPU control; sections on caches, exceptions, memory
management, and floating point. There's a detailed assembly language
guide, some stuff about porting, and some fairly heavy-duty software
examples.
Available from:
and from good bookshops anywhere. It's 512 pages and costs around
$50 in the US, £34 in the UK.
I'd be inclined to list two other books too, both from Morgan Kaufmann and
available from www.mkp.com or any good bookshop:
Authors Farquhar and Bunce, Publisher Morgan Kaufmann,
ISBN 1-55860-297-6.
A readable introduction to the practice of programming MIPS at the low
level, by the author of PMON. Strengths: lots of examples; weakness:
leaves out some big pieces of the architecture (such as memory management,
floating point and advanced caches) because they didn't feature in the LSI
``embedded'' products this book was meant to partner.
Authors Hennessy & Patterson, Publisher Morgan Kaufmann,
ISBN 1-55860-329-8.
The bible of modern computer architecture and a must-read if you want
to understand what makes programs run slow or fast. Is it about MIPS?
Well, it's mostly about something very like MIPS... Its sole
defect is its size and weight - but unlike most big books it's worth
every page.
The documentation to be found at
ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/ defines many of the
MIPS specific technical standards like calling conventions, ELF properties,
and much more that is being used by Linux/MIPS, including the N32 standard.
Under
http://www.mips.com/publications there are various PDF
documents and data sheets about individual processors and cores.
NEC Electronics (
http://www.necel.com includes complete manuals
about their VR41xx processors.
While being very SGI centric
http://techpubs.sgi.com has a number
of ABI related documents online that also apply to Linux/MIPS.
Except where otherwise specified, the information in this documentation or
website is copyright (c) 1998,1999,2000,2001,2002 Ralf Bächle.
Permission is granted to copy, distribute and/or modify this document under
the terms of the GNU Free Documentation License, Version 1.1 or any later
version published by the Free Software Foundation; with the Invariant
Sections being Copyright, with no Front-Cover Texts and with no Back-Cover
Texts.
A copy of the GNU Free Documentation License is available on the World Wide
Web at
http://www.gnu.org/copyleft/fdl.html You can also obtain
it by writing to the
Free Software Foundation, Inc.
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USA
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is copyrighted work. To use the Software you must comply with the terms of
the Software's license agreement. SOFTWARE IS WARRANTED, IF AT ALL, IN
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WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
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This documentation may contain links to websites which are not under our
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