1.download leeos_tools_for_linux rom sourceforge: http://sourceforge.net/projects/leeosbasic/
2.extract it into /usr
3.switch to supervisor mode as you need modify /etc/profile ,use instruct : su and input you password.
4.if you are using ubuntu 12.04, su may failed, so you need :sudo passwd to setup a new password for su and then try su again.
5.use command echo "PATH=$PATH:/usr/leeos_tools_for_linux/bin">>/etc/profile , do see clearly of this long command.
6.use vi /etc/profile to ensure step 5,you will see a new line PATH=$PATH:/usr/leeos_tools_for_linux/bin at the end of profile.
7.use exit command to exit from supervisor mode.
8.!!!reboot computer to use arm-elf-gcc command.