Chromium OS

Chromium OS is a Linux distribution, unlike Google Chrome OS, the source code is freely available and usable. Chromium OS contains the substring instead of Google Chrome BSD license standing Chromium browser. New Chrome OS versions are each derived from the latest Chromium OS development and are supplemented by several commercial programs such as Google Chrome, Adobe Flash, a PDF plugin, Netflix Instant and Google Hangouts.

Chromium OS is the open source development version of Google Chrome OS. The source code for Google Chrome OS was released in November 2009 under a BSD License, named Chromium OS.

Chromium OS was built on the basis of a Linux kernel, in an Ubuntu 10.04 environment, using the official package manager of the Gentoo Linux distribution, Portage. Therefore it is a hybrid between Ubuntu and Gentoo, based on both Linux distributions.

User Interface

Chromium OS uses page tabs new:tab, included in Google Chrome, to open web applications. Chromium OS provides a clock, battery indicator and network status indicator.

The key combination Ctrl + Alt + / changes to a keyboard overlay, which shows the function of all the key combinations used in Chromium, including tasks and memory managers also found in the Google Chrome web browser, and a line interface command that accepts the common commands Linux.

The alpha release includes an application page that is launched by a button in the upper left corner of the screen. The page contains links to Google web applications such as Gmail, Google Apps, and YouTube, as well as Yahoo mail, Pandora, Hulu, Facebook, and Twitter. Chromium also contains a calculator, clock, battery indicator and network connection status indicator. Pressing the F12 function key enables multi-window mode with the ability to open additional browser windows and switch between them. The F8 key displays a keyboard layout with Short-Kat keys, including tasks and dispatchers in comparison with the Chrome browser, and even a console for interpreting commands.

Architecture

In preliminary design documents, Google describes a three-layer architecture: firmware, web browser, window manager, and a level of the user space services software system.

• The firmware contributes to time start fast because the hardware is not checked, such as floppy disks, which are not common on computers, especially netbooks. The firmware also contributes to security by verifying each step in the boot process and incorporating system recovery.
• The Linux kernel is included at the software system level, which has been patched to improve boot performance. The software in the user space has been cut to the essentials, with a management by Upstart, which can launch services in parallel, regenerate fallen jobs, and postpone the services so that the startup is faster.
• The window manager controls user interaction with multiple client windows, as do other window managers in X Window.

Builds / Compilations

In May 2010, the compiled versions of the work in progress of the source code have been downloaded from the Internet more than a million times. The most popular version entitled Chromium OS Flow was created by Liam McLoughlin, a then 17-year-old student from the University of Manchester, England, published under the name of Hexxeh. McLoughlin compilations boot from a USB stick, and include features that Google engineers had not implemented, such as support for the Java programming language.

Although Google did not expect fans to use and evaluate Chromium OS before its official launch, Sundar Pichai, vice president of product management at Google, said "what people have done, like Hexxeh, is amazing to see." Pichai said the first releases were an unwanted consequence of open source development. "If you decide to do open source projects, it has to be open all the time."

Hexxeh's work has continued in the following years. He announced the "Chromium OS Lime" in December 2010, and January 2011, published "Luigi", an application designed for "jailbreak", for the hardware prototype "Google Cr-48" Mario, and a BIOS generic installed. The developer made compilations available for the virtual machine format March 13, 2011.

Without an official version of Google's Chromium OS, the latest compiled versions of "Vanilla" by Hexxeh continue to be the main resource for people who want to try Chromium OS.

In May 2011, Dell Computer also made a new compilation for the Dell Inspiron Mini 10v netbook, following an earlier compilation published almost 18 months earlier. The compilation does not support audio, but it was bootable from a USB stick.

Prerequisites

• Having Linux installed for the development of Chromium OS, specifically:
  • Ubuntu Linux (version 10.04 - Lucid) (it may be another Linux distribution but this flavor of Linux was used).
    • A 64-bit system to perform the compilation. A 32-bit system can be supported by the way.
    • An account with access to sudo
    • Access to root, to run the command chroot and mount the assembly table.
    • + 512Mb RAM
    • An Internet connection, for the initial download of at least one 2 GB, and for subsequent updates.
  • Install the following packages to develop Chrome OS:
    • git - font control client
    • keychain - for ssh key management
    • depot_tools - Set of tools maintained by Google and used by Chromium OS
    • subversion - font control client (used by depot_tools)
    • curl - to download files from the Internet (used by cros_sdk)

Package Manager

Chromium OS uses Portage as a package manager, which consists of two main parts, the system ebuild and emerge:

• ebuild is responsible for the construction and installation of packages,
• emerge provides an interface for ebuild, managing a repository of ebuilds, solving dependencies and similar issues.

Functionalities related to system management are: allow parallel package-version of the installation, monitoring of dependencies between packages, management of a database of installed packages, providing a local ebuild repository, and synchronization of the Portage tree Local with remote repositories. Functionalities related to the installation of individual packages are: to specify the configuration of the compilation for the destination equipment and the choice of the components of the package.

In particular, it runs make_chrootto establish a Portage standard in the compilation environment and installs some building dependencies. The Portage tree contains construction recipes (called ebuilds) for packages. Unlike Debian, where the construction rules are in the source code, Portage's approach is to follow the construction instructions separately from the source code in the portage tree. It is used chromiumos_overlayto keep ebuilds new and changes in existing ebuilds separate from the original sources.

Differences to Google Chrome OS

As a basis, both projects use Chromium OS. Nevertheless, there are big differences:

• Google Chrome OS has some additional firmware features, including boot and recovery features that require the appropriate hardware specifications, and therefore do not work by default in Chromium OS builds.
• Google Chrome OS runs on specially optimized hardware.
• Google Chrome OS is supported by Google and its partners. Chromium OS is supported by the open source community.
• Google Chrome OS includes some binary packages that, for licensing reasons, should not be included in the Chromium OS project. An incomplete list gives some examples:
  • Google Play Store
  • Adobe Flash
  • Netflix Instant
  • Google Talk
  • 3G support
  • Older versions of Chrome OS may include proprietary Synaptic touchpad drivers.

In addition, Google Chrome OS has a green-yellow-red logo, while the Chromium OS consists of different shades of blue.

Free

Chromium OS is the free version of Google Chrome OS. These two projects should not be confused. Indeed, Google Chrome OS is a product, Google has designed to work with some models of computers. While Chromium OS is a community project. It is not intended for users, it is reserved for programmers who can adapt it to their needs. For example, some versions of Chromium OS offer more hardware support. By cons, Google Chrome OS is more stable and has automated updates. Another difference, Google Chrome OS can not be downloaded from the Internet, the only way to get it will be to buy a computer where it will be pre-installed, unlike Chromium OS which anyone can download the source code and make their own version.

The project also contributes to some free software on which it depends, like porting example.