Zephyr除了官方的编译工具，还有第三方工具 arm-none-eabi-gcc 。
https://launchpad.net/gcc-arm-embedded. The source codes for both are same. Currently supports Ubuntu 10.04/12.04/14.04/14.10 32 and 64 bit.
Detailed explanations to Launchpad PPA can be found at https://help.launchpad.net/Packaging/. That website explains how a PPA is set up and how to add existing PPA and install software from it.
Here are quick steps to install toolchain from this PPA on Ubuntu before 14.04:
To update the toolchain, just repeat above step2 and step3.
Questions should be asked at https://answers.launchpad.net/gcc-arm-embedded
Bug can be filed at https://bugs.launchpad.net/gcc-arm-embedded/+filebug. It is highly encouraged to ask question first before filing a bug.