• to get into root: <ctrl><alt><right-arrow>
• login as root. Default password is test0000

• <ctrl><alt>t then type shell

This step will alow the quick boot of Seabios and entering the Linux distro without pressing any key shortcut

We will set these flags:

GBB_FLAG_DEV_SCREEN_SHORT_DELAY 0×00000001
GBB_FLAG_FORCE_DEV_SWITCH_ON 0×00000008
GBB_FLAG_FORCE_DEV_BOOT_LEGACY 0×00000080
GBB_FLAG_DEFAULT_DEV_BOOT_LEGACY 0×00000400

with this command: # /usr/bin/set_gbb_flags.sh 0x489 or if that doesn't work # /usr/share/vboot/bin/set_gbb_flags.sh 0x489

Your flash should have been written now.

# crossystem dev_boot_usb=1 dev_boot_legacy=1 Not really needed? but just to make sure.

• reinstall Chrome OS
• tips after install

• write protect screw
• flags
• more developer info
• fixes

• disable right-clicking by clicking on right side of touchpad: add to ~/.xsessionrc: xinput –set-int-prop $ID “Button Right Click Enable” 8 0
• disable touch to tap: add to ~/.xsessionrc: xinput –set-int-prop $ID “Tap Enable” 8 0
• note that both of the above commands assume that ID has already been set as already appears in .xsessionrc: ID=`xinput | grep cyapa | cut -f 2 | sed -e 's/id=//'`

• remove write protect screw (#7 in this photo).
• transition to developer mode:
  • with machine off hold down <refresh>(f3) and <ESC> and <POWER>
  • when you get the message Chrome is missing is damaged type <CTRL>D
  • when you get the prompt to hit space hit <ENTER>
• go through initial setup and login as guest
• <CTRL><ALT>T to get to terminal, then shell then sudo -s
• /usr/share/vboot/bin/set_gbb_flags.sh 0x489
• burn Gallium OS onto flash drive using Etcher (ubootin didn't work)
• boot from flash drive. Install
• replace write protect screw?

• everything works fine including sleep and audio.
• It *might* be necessary to not connect to the Internet when installing
• you still need to remove the write protect screw (see above obsolete section)
• you still need to install Mr. Chromebox firmware. While not required for C720 if something goes wrong it's still possible to boot Linux from USB. This does not appear to be the case with stock firmware.
• map keys correctly: touchpad and key functions
  • this seems to work only for the audio mute, - and + but not brightness
  • for brightness perhaps a bad but successful approach is to replace /usr/share/X11/xkb/keycodes/evdev with this file (remove the txt extension)

• open back
• remove write protect screw (circled below)

• optional: remove battery
• reassemble
• install Mr. Chromebox firmware with their utility script
• if wanting Gallium download Braswell