As much of this blog, I’m writing this as a way of documenting the process I’ve done to install it, so that if I have to do it again, I can do it easily. Feel free to ask me questions in the comments, but I can’t really guarantee anything. Before we start, I want to clarify that I don’t have much against Chrome OS and that I’ll be voiding the warranty (but you can easily skip this if you want to).
Most of the information I got was from the excellent ArchWiki and the C720 thread on Arch’s bbs. Some other information I might have gotten elsewhere, please forgive if I didn’t credit something. Shoot me an e-mail and I’ll add the credits as soon as possible.
About Chrome OS
First of all, I want to tell everyone. This is not a post about how horrible ChromeOS is or anything like this. I actually LIKE ChromeOS in terms of UI/UX. This comic kinda captures the spirit of it. We use browsers for everything now. Even many “native” applications now have decent (or even good) webpage versions (Skype -> Google Talk, LibreOffice/MS Office -> Google Docs, etc). Although I dislike the idea of Google having access to all my (or anyone’s) files, I think the implementation is actually pretty good.
The OS can be used by both people that are comfortable with a computer (in which case I assume they’ll be using a browser most of the time) and people that don’t really like computers (since it abstracts a lot of “computery” stuff). In many cases, when someone asks me what kind of computer should they give their parents or grandparents, my answer is that maybe the best choice is not a computer.
I am actually pretty sad about the “desktop’s decadence” in the recent years. I really like traditional-mouse-and-keyboard computers, but the fact is that most people are not willing to “learn” how to use Linux (or Windows or anything). Some people I know don’t even like anything that involves “right-clicking”. As much as it pains me to say: tablets have been doing a much better job at this. Anyways, ChromeOS is actually good, but I need some more freedom and power. That was the reason all-along to get the C720, but as far as ChromeOS went, I actually thought it was a delightful OS.
Why might you want to void your warranty
Until you void your warranty (or the warranty expires) the device is covered by a company. This company in a sense is “responsible” for your device and, in a sense, it still “owns” it. Voiding your warranty gives you full ownership of your device. However, don’t be foolish, voiding warranties means you also take full responsibility for whatever happens next. Don’t do it unless you are either capable of fixing your device or aware of the consequences of breaking it (like having to buy a new one etc).
Now that we’ve cleared that, let’s get started.
Upgrade SSD + Removing the write-protect screw
If you are installing Arch on your laptop, you might want to upgrade the SSD. The initial 16GiB were ok for ChromeOS, but if I want to install programs locally and store larger amounts of files, I need a larger storage. Initially, I thought of getting a SDXC card or similar, but the 128GiB SSD only cost me 99USD, which is well under 1$/GiB, which I think is a pretty good price for a SSD, specially given the fact that the form factor is quite new and it is quite comparable in price with a SD card, but safer, more permanent, elegant and offering much higher perfomance than a SD.
Upgrading the SSD has been shown in several different blogs (like here, here, here, here and here), so I won’t be going into too much detail about it. The procedure is quite simple, create a recovery disk, remove the screws in the bottom (this is the bit that voids your warranty), pop the lid open, unscrew the old SSD, install the new SSD and screw it in, put the back lid again and put the screws back.
One small difference in my case is that I removed the write-protect screw (#7 in the image in this wiki). This allows us to set some flags in the C720 ROM to boot in BIOS mode automatically. After setting the flags, you should put the screw back to protect the ROM. (Actually, that’s what should happen in theory. My experience seems to show that writing the ROM with the screw in just corrupts the ROM, instead of preventing writes… Be careful while flashing the ROM, BAD BAD stuff can happen).
Enable developer mode, SeaBIOS and gbb flags
After following the instruction for upgrading the SSD, you should have a fully restored ChromeOS. We’ll have to restore ChromeOS once more. But fear not, it’ll be the last time. In this section we’ll be enabling BIOS boot and setting it as default on ChromeOS:
- Press and hold the
Esc+Refreshkeys, then press thePowerbutton - Press
Ctrl+D, this will erase your user data and enable developer mode. - Press
Ctrl+Dat the white boot splash screen to enter Chrome OS.
As soon as you enter Chrome OS, you’ll now have access to the TTY and some extra functionality.
- First, press
Ctrl+Alt+F2to go into TTY. - Use
chronosas the username, it should not prompt you for a password. - Become superuser with
sudo bash - In bash, run:
# crossystem dev_boot_usb=1 dev_boot_legacy=1 # set_gbb_flags.sh 0×489
Reinstall the write-protect screw and Install Arch
Now you can reinstall the write-protect screw and proceed to install Arch. Good luck (;