Opps, my computer system was broken again... Let's repire it.
The system of my PC is broken. I could enter the UEFI setting. So that means I coud start my PC using USB flash drive. But first of all, I need a Installer driver.
I have a xxx.iso. I need to convert it to xxx.dmg file.
hdiutil convert -format UDRW -o xxx.img xxx.iso
The process is very fast.
Firstly, unmount the target driver.
# Obtain your disk name.
diskutil list
# assuming that your USB flash driver is named disk9
diskutil unmountDisk /dev/disk9
Then, write data to this flash. Be careful not to mistake the flash name.
# The following command cost some minutes.
sudo dd if=where your img.dmg file exists of=/dev/rdisk9 bs=1m
# finally eject your flash. All done.
diskutil eject /dev/disk9
Generate Ubuntu Install Media On Mac
原文：http://www.cnblogs.com/darryo/p/Generate-Ubuntu-Install-Media-On-Mac.html