Build an x86_64 GCC toolchain for Linux on OSX

Synopsis

This builds an x86_64 GCC toolchain for Linux on OSX.

This is based on the extremely helpful script that appears at the end of the article describing how to cross-compile a toolchain, located here: http://preshing.com/20141119/how-to-build-a-gcc-cross-compiler/

The script itself is in a Gist, located here: https://gist.github.com/preshing/41d5c7248dea16238b60

Installation notes

• You will need gettext and gnu-sed installed, plus possibly other packages (I have a load installed on my machine already, so I don't know what exactly you'll need on yours). I suggest installing using brew.
• The makefiles require gnu-sed, not the normal sed that comes with OSX. If you don't want to mess with the normal sed, perhaps add to the front of PATH the path to gnu-sed before you run this script?
  Installing using brew will result in the installation of a binary called gsed which is not what you want and you'd have to symlink to it from sed to get this to work. You can get around the problem by installing like this: brew install gnu-sed --with-default-names, which will keep the name as sed.
• Edit vars.sh first to set package versions. The versions that will result in a successful build will vary - some package versions will work, some will not.
• You will need to increase the number of open files that are permitted by OSX (check your existing limit using ulimit -a). I use 4096.
• This needs to be run/built in a case sensitive partition. You can create one using OSX's disk utility - I used a 10GB sparse image. It will be installed to a destination of your choosing, so you can delete the partition file when you're done.
• Clone this repository, change into the directory, download the packages then build.

# assumes gnu-sed v4.2.2 has been installed using brew and the default name has been kept 
export PATH=/usr/local/Cellar/gnu-sed/4.2.2/bin:$PATH
ulimit -n 4096
git clone https://github.com/johnlondon/Cross-compile-toolchain-for-linux-on-OSX.git
./download.sh
./build.sh

License

I was helped by Waldemar Brodkorb on the crosstool-ng mailing list (https://sourceware.org/ml/crossgcc/) as I couldn't get glibc to compile properly with ct-ng. He said that for x86_64 toolchain creation you are required to provide some implementation of endian.h. The files in the endian directory are taken from his OpenADK repository (http://cgit.openadk.org/cgi/cgit/openadk.git/). They are covered by a BSD license, according to the OpenADK license file.

Use this as you see fit, I hope it helps someone.