How to set your Acer C720 Chromebook to boot to Ubuntu by default.
- Place your closed laptop on a soft surface, upside down.
- Use a sharp knife to cut a hole in the warranty sticker (YES THIS WILL VOID THE WARRANTY).
- Remove the 13 screws with a small phillips head screwdriver (PH1 size works well). Be careful, the screws are very small and will strip easily if you use the wrong size screwdriver.
- Remove the bottom of the laptop by pulling up on it near the hinges. It takes a bit of pressure to remove, but if you lift it from the back (near the hinges) the same way you would open a laptop screen, the hooks won't break (even though they will make a loud snapping sound).
- Remove the BIOS write-protect screw. It is labeled as #7 in this image
- With the bottom off, turn over the laptop and open the screen.
- Plug the laptop in (it must be plugged in to boot with the bottom off).
- Boot to ChromeOS (Ctrl-D during white screen).
- Sign in (you may sign in as a guest and you won't be using the internet).
- Open a terminal with Ctrl-Alt-T
shelland press Enter.
sudo /usr/share/vboot/bin/set_gbb_flags.sh 0x489
- It should take a few seconds to complete and print a SUCCESS message when it's done.
- Shutdown laptop and unplug power cable.
- Close lid and place upside-down on a soft surface.
- Replace the write-protect screw.
- Replace the bottom cover.
- Screw the cover back on.
Thanks to John Lewis for the original tip on how to do this: