Every computer user is familiar with the scenario. Your favorite piece of hardware tells you "End of Support – sorry, this device is no longer supported" (Figure 1) or "This device will no longer receive software updates," followed by the laconic advice to "Please consider upgrading."

Figure 1: Is this the end of my beloved Chromebook? Or could this be the time to turn to Linux?

No software is supported forever. The continual task of coding updates and bug fixes takes time and energy, and after some predetermined support interval, the vendor just stops providing patches for old versions in order to focus on later systems.

With Chrome OS and Chromebook computers, the task of providing support is even more complicated. The term Chromebook does not define a single hardware system. Instead, Google contracts with several different hardware vendors to produce Chromebooks, including Samsung, HP, Toshiba, Asus, Dell, and many others. Google must maintain separate ISO images for each hardware system. Every Chromebook has a published expiration date, known as the Auto Update Expiration (AUE) date, which defines the last date when the operating system will receive an update. In theory, you could continue to operate the Chromebook after the AUE, but the system will be insecure, and the fact that Chromebooks are so heavily reliant on the Internet makes it even more dangerous to operate the system without security updates.

I bought my little Acer Chromebook C710 at a Walmart in 2014, and it has been a special companion ever since: under shady trees in California, on the icy Westfjords of Iceland, or in a tiny Prague hotel room the size of a double bed. Today, my Chromebook acts as a kind of media station that plays videos from YouTube, as well as from media libraries and various portals on a 40-inch HD-ready TV (Figure 2). Hard disk space or battery life are no longer important. (See Table 1 for Acer C710 hardware specs.)

Figure 2: Thanks to the Ubuntu-based GalliumOS and an external screen, the Acer C710 – bottom left in the picture – provides useful service as a media station and is also happy to play DRM-protected content.

When I got the message that the system had reached its AUE and would no longer be supported, I resolved to find another solution that would keep my Chromebook alive. All this took me quite quickly to GalliumOS [1], which is specially tailored for Chromebook users and offers images for all processor families (Listing 1). Installation is simple and makes no special demands. A recovery image of Chrome OS is available in case you need to revert to the previous system at any time.

../
TORRENTS/                            22-Dec-2019 22:17           -
CHECKSUMS-galliumos-3.1.gpg          22-Dec-2019 22:00        3364
galliumos-3.1-apollolake.iso         22-Dec-2019 20:16  1231513600
galliumos-3.1-baytrail.iso           22-Dec-2019 20:16  1231521792
galliumos-3.1-braswell.iso           22-Dec-2019 20:16  1231521792
galliumos-3.1-broadwell.iso          22-Dec-2019 20:16  1231513600
galliumos-3.1-haswell.iso            22-Dec-2019 20:16  1231523840
galliumos-3.1-kabylake.iso           22-Dec-2019 20:16  1231513600
galliumos-3.1-samus.iso              22-Dec-2019 20:16  1231697920
galliumos-3.1-sandyivy.iso           22-Dec-2019 20:16  1231513600
galliumos-3.1-skylake.iso            22-Dec-2019 20:16  1231521792
galliumos-generic-coreimage-3.1.tgz  16-Dec-2019 03:29  1160948557

GalliumOS is based on Xubuntu and uses Xfce as its desktop, which sits well with the aged Acer Chromebook and its meager hardware resources. GalliumOS for Chromebooks in version 3.x goes by the name of "Bismuth" – like chromium and gallium, bismuth is a metal in the periodic table. Version 3.1, which I use in this article, is a maintenance update.

Depends on the Hardware

The steps for installing GalliumOS on a Chromebook depend heavily on the hardware. In the simplest case, Chromebooks behave like full-fledged PCs and let you boot from a USB stick. In that case, you could install GalliumOS or any other Linux variant in much the same way you would install Linux on any computer. However, some models (like my trusty Acer, for example) require a firmware update. Check out the GalliumOS hardware compatibility list [2] to determine if your Chromebook will need a firmware update.

A sticker on the underside of your Chromebook should provide system hardware details. You can also enter the local URL chrome://system or check the menu Settings | About Chrome OS | Google Chrome OS.

Look for the model number and hardware ID, which you can use to find your device in the GalliumOS hardware compatibility list. Dual boot, virtual machine (VM), or complete replacement are possible options, but every option might not be available for every device.

ISO and Recovery Image

The first thing to do is to download the appropriate ISO file from the Gallium FTP directory [3] and drop it onto a USB stick, either using dd (Listing 2) or an alternative disk tool such as the SUSE Studio Imagewriter, Ubuntu's Startup Disk Creator, or a Windows tool like Rufus [4].

$ dd if=/home/dlittle/Downloads/galliumos-3.1-sandyivy.iso of=/dev/sdb1 status=progress

The second step is to create a backup and a recovery image. Back up any important files by moving them to a USB stick or to the cloud. Several methods are available for creating a recovery disk. Linux users can take the long route via a shell script provided by Google; however, it is better to install the browser Recovery Extension and follow the steps. Both methods have their advantages; however, keep in mind that the Chrome OS browser extension is only available if the Chromebook is still fully functional (Figure 3).

Figure 3: The Chrome Book Recovery Utility creates the recovery system for emergencies.

Firmware Update

The steps for replacing the firmware can vary depending on the hardware. On some systems (such as the small Acer), changing the firmware even requires bridging a write-protect jumper. If you don't have a suitable cover for the jumper, you can use aluminum foil and tweezers. I found a YouTube video with the necessary steps for my system [5]. Be sure you read the instructions for the firmware and device – any wrong procedure can brick your cherished hardware. Detailed documentation describes both the recovery [6] and developer modes [7].

The tools you need are a Phillips screwdriver, tweezers, and a strip of aluminum foil (about 3 centimeters long and 1 centimeter wide) (Figure 4). First, switch off the Chromebook and disconnect it from the mains. Then you have to remove the battery (the Acer Chromebook has a small lever for this) and unlock the cover at the bottom (only one screw) and pull it out. Usually, the screw is located under the sticker for the long-expired warranty ("Warranty void if seal broken.") The jumper is found under a plastic cover (Figure 5).

Figure 4: The required aluminum rice grain compared to the size of a euro cent coin.

Figure 5: The open underside of the Acer C710 with the plastic cover over the jumper (bottom left center in the picture).

Now roll up the aluminum foil and compress it to the size of a grain of rice; you can press it into the jumper with the help of the tweezers, where it bridges the contacts and thus lifts the firmware's write protection (Figure 6). This is fine for installing the new operating system, but certainly not as a permanent solution. Now you can reassemble the Chromebook, plug in the battery, connect the power supply, and start recovery mode.

Figure 6: The jumper has already been fitted with an aluminum "rice grain" for bridging.