You'll need mpfr, mpc, gmp, isl, cloog, a proper build environment and anything else you don't have that's listed here.
http://gcc.gnu.org/install/prerequisites.html
You should be able to run make and when it's all done
you'll have a working arm-none-eabi-g++ toolchain with all
the fixin's. This build script uses sudo to install things
so you'll either have to type your password in from time to
time or you'll have to have NOPASSWD in your /etc/sudoers
for your login group.
Tested on Arch Linux circa end of 2012 (and again in
mid-2014). Support for building in parallel left as an
exercise. (IOW, don't do make -j.) It takes just over 35
minutes and just over 3.4 GiB on my machine from start to
finish.
vim:tw=60: