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|| [[https://buildd.debian.org/status/package.php?p=openjdk-9&suite=experimental|openjdk-9]] || [[DebianBug:841173|#841173]] || mips* || Patch available in the BTS || || [[https://buildd.debian.org/status/package.php?p=openjdk-9&suite=experimental|openjdk-9]] || [[DebianBug:841173|#841173]]/[[https://bugs.openjdk.java.net/browse/JDK-8170639|JDK-8170639]] || mips* || Patch available in the BTS, will not be upstreamed until JDK 10 ||

Debian MIPS Port

MIPS is one of the first RISC CPU architectures invented around 1985. It was a radical design which removed many features deemed unnecessary, since the goal was to get the best possible performance from a limited transistor count. Back then, MIPS were powerful general purpose CPUs, and very successful in that role, until they lost ground to systems based on cheap mass-produced Intel-compatible CPUs. Later on, the simple and elegant design allowed to create a wide range of low power CPUs targeted for embedded applications.

Today, MIPS is a popular architecture for embedded systems, with a strong presence in various networked devices.

Debian currently provides 3 ports, 'mips', 'mipsel', and 'mips64el'. The 'mips' and 'mipsel' ports are respectively big and little endian variants, using the O32 ABI with hardware floating point. They use the MIPS II ISA in Jessie and the MIPS32R2 ISA in Stretch/Sid. The 'mips64el' port is a 64-bit little endian port using the N64 ABI, hardware floating point and the MIPS64R2 ISA.

Contact

Installation

The MIPS ports can be installed via Debian Installer. Jessie images are available for the 'mips' and 'mipsel' ports, while daily images are available for 'mips', 'mipsel' and 'mips64el'.

Build daemons & porter boxes

Machine

Architecture

Memory

Sub-architecture

 Purpose

FPU?

mips-aql-01.debian.org

mips

8GB

Cavium Octeon II

buildd

No

mips-aql-02.debian.org

mips

8GB

Cavium Octeon II

buildd

No

mips-aql-04.debian.org

mips

8GB

Cavium Octeon II

buildd

No

mips-aql-05.debian.org

mips

8GB

Cavium Octeon II

buildd

No

mips-aql-06.debian.org

mips

8GB

Cavium Octeon III

buildd

Yes

mips-sil-01.debian.org

mips

8GB

Cavium Octeon III

buildd

Yes

minkus.debian.org

mips

8GB

Cavium Octeon II

porter box

No

eberlin.debian.org

mipsel/mips64el

4GB

Loongson 3A

buildd

Yes

eller.debian.org

mipsel/mips64el

8GB

Cavium Octeon III

porterbox

Yes

mipsel-aql-01.debian.org

mipsel/mips64el

8GB

Loongson 3A

buildd

Yes

mipsel-aql-02.debian.org

mipsel/mips64el

8GB

Loongson 3A

buildd

Yes

mipsel-aql-03.debian.org

mipsel/mips64el

8GB

Cavium Octeon III

buildd

Yes

mipsel-manda-01.debian.org

mipsel/mips64el

8GB

Loongson 3A

buildd

Yes

mipsel-manda-02.debian.org

mipsel/mips64el

8GB

Loongson 3A

buildd

Yes

mipsel-manda-03.debian.org

mipsel/mips64el

8GB

Cavium Octeon III

buildd

Yes

mipsel-sil-01.debian.org

mipsel/mips64el

8GB

Cavium Octeon III

buildd

Yes

Most of the machines above were donated by Imagination Technologies.

Status

Known issues

Generic issues

  • The 'mips' and 'mipsel' ports are 32-bit ports. The address space is therefore limited to 2GB per process. Unfortunately nowadays the toolchain (binutils, gcc) often need more than 2GB to build some complex code. This causes the build to abort with the "virtual memory exhausted: Cannot allocate memory" message. Adding more memory to the machine will not change anything.
  • Two packages ended-up with a corrupted data.tar.xz in the past few months: kdenlive_16.08.0-1/mipsel and gcl_2.6.12-45/mips64el. This should be investigated.

  • Since binutils 2.26 MIPS uses the DT_MIPS_RLD_MAP_REL entry to allows debugging of MIPS position independent executables and provides access to shared library information. As it is a relative entry, special care is needed when mangling the ELF headers with tools such like chrpath, cmake or meson, otherwise the resulting binaries might not work properly (mostly segmentation faults). This has been fixed in chrpath and cmake, but not yet in meson. There are still a few broken binaries in the archive. They have been identified and are currently being binNMUed.

List of packages with wrong DT_MIPS_RLD_MAP_REL entries. For tracking purposes (not really important to work on it now).

mips/sid

amarok_2.8.0-5

FTBFS, #841134

gammaray_2.4.0-1

FTBFS, investigation needed

libzypp_15.3.0-1

FTBFS, #841769

openmeeg_2.3.0~20160502-2

FTBFS, #730904

mips/experimental: None

mips/stretch

amarok_2.8.0-5

see above

iwyu_3.7-1

fixed in sid, but failed to migrate as it FTBFS on armel

pitivi_0.97.1-1

see above

(The list for mipsel and mips64el will be added when the first round of binNMUs is built)

Packages failing to build from source

Package

Bug number

Architecture

Comments

connectome-workbench

mips & mipsel

Virtual memory exhausted issue, a workaround has to be provided

ergo

mips & mipsel

Toolchain bug PR78012

flint

mips & mipsel

Toolchain bug PR78176

mono

#840494

mipsel

Investigations started by the maintainer, but help from a porter would be welcome.

ngraph-gtk

#841302

mips*

Patch available in the BTS

openjdk-8

mips

openjdk-9

#841173/JDK-8170639

mips*

Patch available in the BTS, will not be upstreamed until JDK 10

shark

#836599

mips & mipsel

Toolchain bug PR78176

gcc-7

mips64el

Toolchain issues

Package

Bug number

Comments

binutils 

#765710

It seems we still have 23 tests failing in the ld testsuite.

binutils

#834147/PR20649

Patch available but not yet committed to upstream master. Fixed in the Debian package.

binutils

#844357/PR20828

mesa's libGL.so.1 contains an invalid symbol table and is causing lots of rdeps to FTBFS

gcc

#798710

The problem seems to be solved, to be confirmed. 

gcc

PR71155

symbol in wrong section .data.rel.local on mips64el

gcc

PR78012

-mfpxx produces assembly code using odd FP registers on MIPS

gcc

PR77953

ice: insn does not satisfy its constraints - bswapsi2

gcc

PR78176

miscompiles ldxc1 with large pointers on 32-bits

gcc/go

#839132

It seems Matthias Klose has backported the libffi changes into gcc-6. To be tested.

gcc/ada

#781457/PR65618

gnat bootstrap comparison failure on mips*, Still in GCC 6

Other important bugs

Package

Bug number

Description

Comments

bind9

#778720

bind9 server hangs on mips

Patch available in the BTS

installation-guide

review sections 2.1 and 5.1 on all 3 arches for stretch

qemu

#815409

"qemu-img create -f qcow2" segfaults if fpu emulator is in use

Fixed in Linux 4.8 (FPU emulator no longer relies on an executable user-stack)

qemu

#819755

qemu-mipsel-static: "Temporary failure in name resolution"

Patch available in the BTS

qemu

#846084/LP 1643619

netlink is broken on mips big endian qemu user

strace

#841278

strace does not support mips64el

Fixed upstream, but new version not packaged yet

release-notes

#834844

document an R2 processor is required for stretch

Patch available in the BTS

Wishlist / Possible improvements

  • Add HWCAP support and/or STT_GNU_IFUNC to the GNU libc so that we can provide optimized libraries (for example MIPS32, loongson, etc...). Also add optimized versions of the string functions.
  • Add new kernel flavours: generic kernel, CI20, Routerboard
  • QEMU mips64el tcg
  • More language support: mono (mips64el), fpc, golang, java hotspot implementation
  • Valgrind / ASan

How to contribute

1. Make yourself visible/integrate yourself and learn more about the project in general

Join the projects mailing list and say hello. Feel free to ask questions.

An easy way to start contributing is to fix packages that cannot be built. The following points are related to this matter. Do not hesitate to ask the mailing list for more options if you feel like it.

2. Get a mips device or set up QEMU on your PC

Qemu is an architecture emulator and will replace your need for a mips device if you or whoever may be mentoring you cannot provide you with one.

However there is currently an issue with doing all the work with a QEMU emulated device: some functionalities may not trivially work and it may be impossible to access repositories and therefore to run any package on this virtual device. The networking part will be fleshed out as much as possible here. Future updates of this guide will hopefully be enough for newcomers to start up. If you have any insights on this matter, do not hesitate to add information or email the relevant information at this email address: jnthjackson@gmail.com

3 Download QEMU, images, kernels and set up networking

You will need images and kernels to run a version of mips Debian. You will find these at this link. Read the README for more information on how to get going with the images.

4 Learn more about package maintaining and the buildd network

How does the buildd network works:

5 Chose a package and study the failed-build log to find/fix the bug

Links to build status of packages:

Be sure to check for existing bug reports before starting to work on a package so you dont do work people have already done. You will find a "bugs" link at the top of the package web page. This is where the reports will be if any.

6 Report your progress or found bugs

If you feel like contributing in any other way, please do so and if you want to know more ways to do so, feel free to write to the mailing list.