该文主要是对rocketboard教程的补充，详细教程参见https://rocketboards.org/foswiki/view/Documentation/EmbeddedLinuxBeginnerSGuide
We will be using the standard Linaro GCC toolchain for the ARMv7 instruction set to compile U-Boot (and later, the software in the root filesystem) so we need to download and extract that.
wget http://releases.linaro.org/14.09/components/toolchain/binaries/gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux.tar.xz tar -xvf gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux.tar.xz
Next we need to set up the CROSS_COMPILE environment variable. If you ever close your shell, remember to re-export this variable.
export CROSS_COMPILE=$PWD/gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux/bin/arm-linux-gnueabihf-
For 64bit Ubuntu, we need to add 32bit support, Or you will get the error message: arm-none-linux-gnueabi-gcc: No such file or directory
sudo apt-get install g++-multilib
参考文献:
http://blog.csdn.net/sqxcong/article/details/23223989
http://blog.csdn.net/qianlong4526888/article/details/8511062