Tips for MacOS X

Most of the instructions for installing prerequisites and building should work on at least Linux and OS X, but assume that you’re well acquainted with your operating system’s package manager and other tools. Here are some hints that you may find helpful if you’re installing on a Mac.

This codebase has been built using either MacPorts or Homebrew. The following instructions are for MacPorts, though we’d welcome documentation contributions for other setups.

Installing the ARM GCC Toolchain

You may be tempted to use the MacPorts build of arm-none-eabi-gcc rather than ARM Ltd’s toolchain. We don’t recommend that route as subtle differences in how the toolchain is compiled can have surprisingly large effects.

Notably, when testing the MacPorts cross-compiler, it produced this error message:

/opt/local/lib/gcc/arm-none-eabi/4.7.3/../../../../arm-none-eabi/bin/ld: cannot find crt0.o: No such file or directory

Instead, we’ve had success with the MacOS build tarball of arm-gcc-embedded version 4.8-2014-q2-update.

Configuring PATH

When you install MacPorts, it adds its bin directory to your $PATH in ~/.profile, but you will also need the path to the ARM GCC toolchain and to your current version of cabal.

If you unpacked arm-gcc-embedded into your home directory, then appending this line to ~/.profile should do the trick:

export PATH="$HOME/Library/Haskell/bin:$HOME/gcc-arm-none-eabi-4_8-2014q2/bin:$PATH"

Installing GCC for OS X

In addition to the embedded toolchain, you also need a native host toolchain for compiling the various pieces of Haskell, C, and C++ code in this project. Apple’s Xcode version 5 ships with a program named gcc, but it is actually a shim wrapper around clang. Unfortunately, clang’s C preprocessor is pickier about its input than GCC’s, which triggers many warnings and may cause your compile to fail.

You can install a real GCC build and configure the Haskell Platform-installed GHC to use it.

xcode-select --install # needed for /usr/include
sudo port install gcc48
sudo port select --set gcc mp-gcc48

Next, edit /Library/Frameworks/GHC.framework/Versions/Current/usr/lib/ghc-7.6.3/settings and replace /usr/bin/gcc with /opt/local/bin/gcc.

Now you should have a working GHC installation.

Installing Python Packages

If you choose to use virtualenvwrapper as recommended in the build instructions, it’s not quite as automated in OS X as it is in most Linux distributions. You can installed the necessary pieces this way:

sudo port install py27-pip py27-virtualenvwrapper
sudo port select --set pip pip27
sudo port select --set python python27
sudo port select --set virtualenv virtualenv27

Then add this line to your ~/.profile:

. /opt/local/bin/virtualenvwrapper.sh-2.7

Finally, close any terminals you have open. When you next open a terminal you will have the virtualenvwrapper commands (mkvirtualenv, workon, etc.) available and can complete the build instructions.

Finding Serial Devices

Whether you’re using a USB FTDI serial adapter or a 3DR Radio, the path to that device will be /dev/cu.usbserial-<SERIAL>, where <SERIAL> is the manufacturer-assigned serial number. Things to note:

If you have several serial adapters or radios, each one will have a different device path. That’s important to be aware of if you’re trying to write scripts to communicate with your quadcopter.
In OS X, there is a second device node named /dev/tty.usbserial-<SERIAL>. Do not use that device with this hardware; it only works if the DCD line on the serial port is asserted, which it is not on these boards.

If you use the wrong device, the symptom will be that mavproxy/gcs can’t communicate with your vehicle.