Installing/Creating Bootable USB

Creating bootable GalliumOS media is very similar to other Linux distributions. Unfortunately, that doesn't mean it's easy. The goal of this guide is to make it as straightforward as possible.

On Linux

First, you need to download the GalliumOS iso for your Chromebook.

Once the iso is finished downloading (you MUST wait for it to finish), open up your favourite Terminal emulator.

cd to the place where you downloaded the iso. It's probably ~/Downloads.

cd ~/Downloads

Plug in your USB device, identify it, and unmount it. This is a little tricky. You can use lsblk to get a list of storage devices attatched to your system. Try to find out which one is your USB flash drive. It is very important to not get this wrong, as it could cause catastrophic data loss. Once you've figured it out, make sure the USB flash drive is unmounted.

sudo umount -f /dev/sdb1

Be sure to replace sdb1 with the actual partition name as listed in lsblk. Next, use dd to copy the ISO to the USB flash drive.

dd bs=1M if=galliumos.iso of=/dev/sdb

Be sure to replace galliumos.iso with the filename of the iso you want to write. Usually typing "galliumos" and hitting tab will autocomplete it for you. Also be sure to replace sdb with the actual device as listed in lsblk. Make sure to write to the DEVICE and NOT the partition. This process can take a long time depending on the speed of your flash drive, USB connection, and hard drive. Be patient. Once the prompt comes back, the ISO should be written. If you're getting errors, try adding sudo to the beginning of the command. Before you unplug your flash drive, be sure to run sync

On Mac OS X

1. Download the GalliumOS ISO for your ChromeOS device: https://galliumos.org/download.html
2. Insert USB media into Mac OS X machine
3. Carefully determine device path for newly inserted USB media from a Terminal.app window
   bash$ diskutil list
   The device path will be something like /dev/diskN. Replace N in all steps below with the correct disk number.
   ⚡It is extremely important to determine the correct device path for your USB media in this step. Using the wrong device path in the following steps could damage your OS X install and cause irreparable data loss!
4. Unmount USB media from OS X
   
   bash$ diskutil unmountDisk /dev/diskN
5. Copy the ISO to USB media
   
   bash$ sudo dd if=./galliumos.iso of=/dev/rdiskN bs=1m
   ★Be sure to use the rdisk device name in the output file (of= parameter), and use the correct path and filename for the galliumos.iso file which you downloaded in step 1.
6. Eject USB media from OS X
   
   bash$ diskutil eject /dev/diskN
7. Remove USB media from Mac OS X machine, it's now ready for your ChromeOS device

On Windows

Try the instructions (with pictures!) from Ubuntu:

http://www.ubuntu.com/download/desktop/create-a-usb-stick-on-windows

On ChromeOS

ChromeOS is very similar to Linux, but not identical. I will write a proper guide as soon as I have access to a Chromebook (that I haven't installed GalliumOS on :P)