[Try to build Android 4.0.4 for Atmel sama5d3x EK board, mee following issue, which need newer git]

$ repo init -u git://github.com/Android4SAM/platform_sammanifest.git -b android4sam_v3.0

fatal: git 1.7.2 or later required

So, solve this issue with following methods.

method 1:

sudo apt-get install python-software-properties

sudo apt-get-repository ppa:git-core/ppa

sudo apt-get update

sudo apt-get install git

(某些原因，apt-get-repository仍然找不到，请使用第二种方法）

W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A1715D88E1DF1F24

solve this issue with command: sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys A1715D88E1DF1F24

method 2: 

方法来自：

 

deb  YOUR_UBUNTU_VERSION_HERE main deb-src  YOUR_UBUNTU_VERSION_HERE main