Recovery and Developer Mode

The keyboard shortcut Esc+F3+Power boots the Chromebook's recovery system; when you get there, pressing Ctrl+D – not displayed on the screen – boots into Developer mode. In the graphical login manager, log in as a guest and start a Chrome Shell (Crosh) with Ctrl+Alt+T. In a second browser tab, go to the MrChromebox [8] website, which provides the Chrome OS Device Firmware Utility Script (Listing 3), which can be downloaded using curl at the Crosh terminal (Listing 3, first line). Then proceed to install and launch (second and third line).

$ curl -LO mrchromebox.tech/firmware-util.sh
$ sudo install -Dt /usr/local/bin -m 755 firmware-util.sh
$ sudo firmware-util.sh

The largely self-explanatory utility script (Listing 4) installs either a UEFI update or a stock recovery image for Chrome OS. Some dead devices can also be persuaded to cooperate again by pressing C (Clear UEFI NVRAM) (Figure 7). Again, caution is advised; only start the firmware update if you have the correct hardware specs as identified by the script. If the aluminum rice grain is still in the right place, the script shows the note Fw WP: Disabled in the fifth line of the hardware information. Then it should run without any problems, including booting from the USB stick.

#!/bin/bash
#
# This script offers provides the ability to update the
# Legacy Boot payload, set boot options, and install
# a custom coreboot firmware for supported
# Chrome OS devices
#
# Created by Mr.Chromebox <mrchromebox@gmail.com>
#
# May be freely distributed and modified as needed,
# as long as proper attribution is given.
#
#where the stuff is
script_url="https://raw.githubusercontent.com/MrChromebox/scripts/master/"
#ensure output of system tools in en-us for parsing
export LC_ALL=C
#set working dir]\
if cat /etc/lsb-release | grep "Chrom" > /dev/null 2>&1; then
  # needed for ChromeOS/ChromiumOS v82+
  mkdir -p /usr/local/bin
  cd /usr/local/bin
else
  cd /tmp
fi
#get support scripts
echo -e "\nDownloading supporting files..."
rm -rf firmware.sh >/dev/null 2>&1
rm -rf functions.sh
 >/dev/null 2>&1
rm -rf sources.sh >/dev/null 2>&1
curl -sLO ${script_url}firmware.sh
rc0=$?
curl -sLO ${script_url}functions.sh
rc1=$?
curl -sLO ${script_url}sources.sh
rc2=$?
if [[ $rc0 -ne 0 || $rc1 -ne 0 || $rc2 -ne 0 ]]; then
  echo -e "Error downloading one or more required files; cannot continue"
  exit 1
fi
source ./sources.sh
source ./firmware.sh
source ./functions.sh
#set working dir
cd /tmp
#do setup stuff
prelim_setup
[[ $? -ne 0 ]] && exit 1
#show menu
menu_fwupdate

Figure 7: The Chrome OS Device Firmware Utility Script finds and installs the matching firmware image.

Testing and Installing Gallium

At this point, the paths with and without tinfoil meet up again; now the USB stick with GalliumOS, created earlier on, is used for booting. As with all modern Linuxes, you can see how things will work using a live system before an installation on the hard disk gives you the hard facts. This includes accessing the hard disk previously used by Chrome OS, although recovery mode has permanently deleted it for security reasons.

Anyone who decides to install GalliumOS on the hard disk will quickly find themselves at home in Ubuntu's default installer, Ubiquity. From then on, the Chromebook behaves like any other PC or laptop system. The advantage is that the Linux image is already adapted to the existing hardware, much like with Apple. Now, at last, assuming everything worked out, the aluminum rice grain has to be removed. From now on, the Chromebook will boot willingly from USB.

Xfce Desktop with HDMI Output

The Xfce desktop on GalliumOS (Figure 8) has everything a modern desktop needs. The layout and many settings are well tailored to the small display and low-powered hardware of the Acer.

Figure 8: GalliumOS comes with the lean Xfce desktop by default, a perfect choice for the ancient hardware of the Acer C710.

Having said this, the start menu already has a surprising number of entries, for example, a separate menu item for GalliumOSUpdate – a link to a root shell that executes apt -qq update (Figure 9). The -qq parameter ensures that all output except error messages is suppressed.

Figure 9: GalliumOSUpdate shows its Ubuntu/Debian roots when the updater runs sudo apt -qq update.