What to do: install ubuntu on the computer hard drive by using wubi, Default System: WIN7 32 bit (Note: it's possible to install the ubuntu12.04 on virtual machine, however, some wired problems may occur when burning the image into the SD card)

Update software source:

# sudo apt-get upgrade  
# sudo apt-get install update  

Install text editor vim:

# sudo apt-get vim  

The ARM cross compile tool chain is required for porting kernel, use the following command to install:

# sudo apt-get install gcc-arm-linux-gnueabihf