NayuOS

NayuOS is an ongoing project at Nexedi: since we mainly use Chromebooks as part of our development tools, we want to have more customizable, secure and privacy-compliant devices. We also love Free Softwares so we do want a Free alternative for Chrome OS that fits our needs.

Why choosing Chrom* OS instead of another GNU/Linux distribution?

• Security: Chrome and Chromium OS have a specific security policy, using sandboxes as a security mechanism to isolate different processes and don't let them access the file system from inside a sandbox, not having packet installation because there are web application to answer all the user's need, encrypting each user's partition independantly, ... .
• Price: Chromebooks are very cheap devices! The cheapest one is around $150.
• Freedom: There is no tying: you won't pay a Windows license and most of them are using Coreboot instead of a proprietary BIOS! But Chrome OS's sources are not open, and that is why we prefer Chromium OS.
• Speed: Chromebooks boot fast (you will mostly use the web, so there is not much on your computer anyway).
• Learning: Because you have to find how to do things on the web instead of on your machine, it is a nice way to learn modern web, and become up to date on web technologies.

For whom is Chromium OS?

For developers

Chromium OS is much more developer-friendly, since there is a large range of tools for development (Python2.7, gdb, ...) and networking (tcpdump, rsync, ...) that are not available in Chrome OS. Having Python2 means that it is easy to run an HTTP sever on the local network and develop web applications!

For people who care about privacy

Chromium OS is fully Open Source. This is necessary for better privacy and security: you don't have to trust Google, you can look at the code and ensure that the software does what you expect from it! However, it requires you to switch to developer mode, which is by default less secure (no more boot verification, shell in the browser and VT2 access, available root access with no password, ssh daemon running, ...) but allows you to use your device without restriction.

Of course, you still have to be careful with the location of the storage of your personal data (file system, Google's servers or your own, ...).

What is NayuOS and what are the benefits?

NayuOS is a customization of Chromium OS that is going to be used at Nexedi and that we want to share since it can be useful to others.

We want to improve the development environment, the usability and configuration of the system and the privacy of the users. Right now, our technical goal is to:

• ~ remove the SSH daemon running by default in Chromium OS,
• ✓ add git because we don't know any good web-based git utility allowing usual interactive commands (such as rebase -i)
• ✓ remove Google login: we prefer guest mode (this is done by default when building ChromiumOS),
• ✓ add re6st connectivity (follow instructions while running sudo grandenet in the terminal, registry to get a token),
• ~ add a HTTP server + WebDAV server with JIO for customizing stuff (it will have an access to the guest home directory and to external devices) and JavaScript development (source code),
• ✗ add Zeroconf over Babel and configure firewall to easily reach another device on a local network that runs an HTTP Server.

Be aware that, at least for now, NayuOS disables the verification usually checking the root file system at each boot.

Download the images

The build process based on Buildout in our decentralized cloud technology SlapOS makes possible to build many images for Chromium OS and our modified version NayuOS for specific boards using the latest releases of Chromium OS.

NayuOS images

board code	machine name	release R47 (latest build for this release, but a bit old)	release R48 (latest build)
auron_yuna	Acer C910 Chromebook 15
clapper	Lenovo Chromebook N20
leon	Toshiba Chromebook
lulu	Dell Chromebook 13
peppy	Acer C720 Chromebook
quawks	ASUS Chromebooks C300
swanky	Toshiba Chromebook 2
samus	Chromebook Pixel 2015

Old builds can be found in the images directory.

Verify the image

Verify the hash by checking in the hash.txt file (R47 latest, R48 latest) of the extracted image, and compare with the value of the freshly downloaded image.

      zcat your_board.nayuos.img.gz | sha512sum
    

The values should be the same.

Install the image on your Chromebook

Before doing anything, it is safer to make a recovery USB stick, just in case...

In order to install Chromium OS on you Chromebook, you will have to create a bootable USB stick. To do this, you can use:

• use the dd command on any GNU/Linux (Chrome OS included) after having unmouted the partitions of the USB stick:
  zcat your_board.nayuos.img.gz | sudo dd of=/dev/somedevice
• gunzip the downloaded file and run the UNetbootin graphical interface (but you may have some troubles).

Once you have your image, you need to activate the developer mode on your device: generally, you have to turn your Chromebook off and hit ESC + F3 (the "reload" key) + POWER button.

You should then get a screen saying that "Chrome OS is missing or damaged", this is just an dissuasive message, hit CTRL + D and confirm by hitting ENTER that you want to enable the developer mode.

Then, you need to allow your device to boot on USB. For that, get a shell:

• by typing CTRL + ALT + T in the browser to access to the "crosh" terminal, and writing the command shell
• by hitting CTRL + ALT + F2 (the "next" key), either as root or chronos

and type:

      sudo crossystem dev_boot_usb=1
    

Reboot and press CTRL + U at boot time to boot on USB. You will be on a live Chromium OS system. If you want to install it for real, open a terminal and type:

      /usr/sbin/chromeos-install
    

After that, don't try to turn the developer mode off (hitting SPACE at boot time), or you will have to reinstall the original Chrome OS!

How to build the image?

If you want to build the image yourself, you can find more informations on:

• our tutorial
• the Chromium OS quickstart and developer guides

Known issues

Some issues that may be fixed in the next versions.

• There is no dev server running that could be used for packages update or installation using gmerge (yet?).
• Because we don't use (neither even have) Google API keys, it is not possible to login with a Google account: only guest mode is working fine. But it is not a problem at all for us.
• Some packages are looking for binaries/libraries in /usr/ instead of /usr/local/:
  • Running many git fail. The reason is that git is looking for its files into /usr/something but they are located into the dev folder /usr/local/something. Solution: use git with --exec-path=/path/to/libexec/git-core/, for example:

    
                git --exec-path=/usr/local/libexec/git-core/ clone https://lab.nexedi.com/isabelle/flaskdav.git
                

  • git's pager is less, but the path is wrong also, run:

    
                git config --global core.pager '/usr/local/bin/less'
                

    to set it correctly.
  • npm is looking for node binary in /usr/bin/ instead of /usr/local/bin.

Tips and tricks

• extend the /etc/hosts (that is read-only) using the HOSTALIASES environment variable to have per-user customized IP/name conversions
• In case you get the "Chrome OS is missing or damaged" error at boot time or if you just want to go back to your original system, it is easy to make a recovery image of your original system, with the dedicated application.
• having re6st, to get IPv6 over an IPv4 network, is easy: follow instructions with the script sudo grandenet
• use the command sudo chromeos-setdevpasswd to change chronos user's password so that password is asked when using sudo and passwordless root console login is disabled.
• unzip with Python using the command: python -m zipfile -e myfile.zip outputpath
• some more information on Chromium OS website