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Building Julia on ARM

Julia has been compiled on several ARMv7 / Cortex A15 Samsung Chromebooks running Ubuntu Linux under Crouton, Raspberry Pi systems and Odroid boards. This is a work in progress - several tests are known to fail, and backtraces are not available.

Julia on ARM can be built by simply typing make, which will download all the relevant libraries. This is the recommended way, and it will take a few hours.

If you get SIGILL during sysimg.o creation, it is likely that your cpu does not support VFP. File an issue on the Julia issue tracker with the contents of /proc/cpuinfo.

This is the list of known issues on ARM: https://github.com/JuliaLang/julia/labels/arm

Build dependencies

We recommend using at least Ubuntu 14.04 and gcc 4.8, which is part of the standard build-essentials.

In case the build is failing on one of the dependent libraries, one can install various system libraries instead of building them, by adding the following lines in Make.user:

override USE_SYSTEM_BLAS=1
override USE_SYSTEM_LAPACK=1
override USE_SYSTEM_LIBM=1
override USE_SYSTEM_FFTW=1
override USE_SYSTEM_GMP=1
override USE_SYSTEM_MPFR=1
override USE_SYSTEM_ARPACK=1

The following command will install all the necessary libraries on Ubuntu.

sudo apt-get install libblas3gf liblapack3gf libarpack2 libfftw3-dev libgmp3-dev \
                     libmpfr-dev libblas-dev liblapack-dev cmake gcc-4.8 \
                     g++-4.8 gfortran libgfortran3 m4 libedit-dev

Note that OpenBLAS only supports ARMv7. For older ARM variants, using the reference BLAS may be the simplest thing to do.

ARM specific build problems

If you run into issues building LLVM, see these notes: http://llvm.org/docs/HowToBuildOnARM.html

Raspberry Pi

Note: Raspberry Pi is ARMv6, which is not well supported at the moment. However it is possible to get a working Julia build.

The Raspberry Pi ARM CPU type is not detected by LLVM. Before starting the build, it is recommended to explicitly set the CPU target by adding the following to Make.user:

JULIA_CPU_TARGET=arm1176jzf-s

It is also preferable to use various system provided dependencies on ARMv6 as described in the Build Dependencies section above.

Raspberry Pi 2

For Raspberry Pi 2, which is ARMv7, the default build should work. However, the CPU type is also not detected by LLVM. Fix this by adding JULIA_CPU_TARGET=cortex-a7 to Make.user.

Depending on the exact compiler and distribution, there might be a build failure due to unsupported inline assembly. In that case, add MARCH=armv7-a to Make.user.

If building LLVM fails, you can download binaries from the LLVM website:

  1. Download the [LLVM 3.7.0 binaries for ARMv7a] (http://llvm.org/releases/3.7.0/clang+llvm-3.7.0-armv7a-linux-gnueabihf.tar.xz) and extract them in a local directory.

  2. Add the following to Make.user (adjusting the path to the llvm-config binary):

    override USE_SYSTEM_LLVM=1
LLVM_CONFIG=${EXTRACTED_LOCATION}/bin/llvm-config

Please do let us know if you had to download a pre-built LLVM in #10235.

Chromebook

On Chromebooks, you have to first install Crouton. If you do not have an Ubuntu chroot running on your Chromebook using Crouton, you can do so by following these tutorials.

These tutorials will end up installing Ubuntu 12.04, and you have to upgrade to Ubuntu 14.04, or install Ubuntu 14.04 from scratch by finding appropriate crouton help.

Scaleway cloud hosted ARM servers

On the current Scaleway ARM servers, the Julia build works out of the box.