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ChromeOS Explained��Robert Fekete�

12th of May 2016

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ChromeOS

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What is chromeOS?

  • Gets you online almost instantly
  • No cumbersome install and setup procedures
  • All drivers are updated seamlessly, always up to date
  • No need to update apps over time
  • No Antivirus needed, hence less risk of infection
    • well your home made photos may still be stolen online but that applies to daCloud mostly
  • No bogged down, slowed down effect over time
  • Googles ”universal syncing system” keeps sync across all devices
  • Offline capabilities, despite beeing a connected device
  • No differentiation, You will get your google desktop on any device

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Chrome OS Desktop

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Ctrl-Alt-T

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Browser Technologies

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Architecture

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ChromeOS HW

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ChromeOS Firmware

  • Based on coreboot and u-boot
  • Coreboot runs minimal hw init
    • Includes Intel provided reference code
  • U-boot payload provides flexile boot
    • Various boot media, recovery, etc
  • Root of trust for verified boot enforcement and policy

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Verified Boot

  • Only supported on ChromeOS devices
    • Other devices are in developer mode
  • Read-only firmware root of trust
    • Hw write protection
  • Verifies Bootlooader, updatable firmware,

Kernel arguments, filesystem, modules, ...

  • Root of trust owned by Google!

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Modes

  • Verified / Normal mode
    • Boots only Google signed ChromeOS images
  • Recovery mode (Esc – refresh(F3) – Power button)
    • Get back to trusted state
    • Boot signed USB image/bkp
  • Developer mode
    • Built in jailbreak mode, run chromiumOS images, root
    • Enter recovery mode, press Ctrl-D.
  • Legacy mode (Ctrl-L)
    • SeaBIOS to load alternate os, Unsupported
  • Crazy developer Mode

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Crazy Developer Mode

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Kernel

  • Patched Linux Kernel
    • Backported drivers and improvements
    • Security enhancements
    • Coreboot replace uefi, drivers needed in kernel
    • Google do not move to latest kernel too often
  • Includes drivers/API’s for all supported HW
  • Platform enablement starts here

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Userspace

  • Modified Gentoo Linux distro
  • Layers ChromiumOS on top
  • Standard Linux components
    • Upstart Init, Logging, evdev, X11(RIP),
    • OGL MESA, libdrm, network, usb, BT...
  • Only used by the Chrome Browser
  • Not accessible by other apps.

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Portage/Gentoo

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Browser

  • All system components exist to support the browser
  • API’s passed through from ChromeOS to Chrome
  • All unsandboxed native code ships with the verified OS
  • No third party OS extensions or drivers (Unlike Android)
  • All third party code runs in a sandbox, whitelist access to some ioctl’s...

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Blink

  • Web browser engine, part of the Chromium Project
  • Forked 2013 off the webcore component from Webkit
  • Uses V8 as javascript engine, same as newer Opera
    • Others are: chakra(IE), spidermonkey(firefox),nitro(Apple),...
  • Use the Fork, in order to get more power…
  • Blink's naming was influenced by the non-standard presentational <blink> html tag

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Native Client

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All is rendered by the Browser Engine

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The GFX rendering part

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Browser composition

  • Ash is the Window manager on Chromium.
  • Aura is the hardware accelerated UI framework built on CC.
  • Aura provides basic primitives like Window, Input.
  • Aura wraps native window, Ozone provides this in case of ChromiumOS.
  • Aura uses CC for window composition.

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Ozone

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Ash tray at the bottom

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How about

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X

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Chromium-freon (Chrome without X)

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Chromium-Freon Architecture

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SO�WHY

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WILL

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HTML5

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CHANGE

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EVERYTHING

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Because you don’t stumble upon a native app before installing it

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Web

  • Deep linking and index’ability (hard for native apps)
  • Integration with cloud services
  • Flexible layout primitives
  • Responsive/adaptable design, always up to date
  • One Web fits all – cross platform promise
  • Deployment and distribution model, control
  • Although Many native apps use webview to access content
  • Native apps may embrace new API’s faster though…
    • Web standardization is sloooow.

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WEB...

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emscripten

  • Emscripten is an LLVM-based project that compiles C/C++ into highly-optimizable JavaScript in asm.js format. This lets you run C/C++ on the web at near-native speed, without plugins. (http://kripken.github.io/emscripten-site/)
  • For example, emscripten converts OpenGL into WebGL among other things and uses asm.js.
  • Asm.js? an extraordinarily optimizable, low-level subset of JavaScript.  
    • It enables significant performance improvements for webapps that are written in statically-typed languages with manual memory management (such as C) and then translated to JavaScript
  • AOT: Ahead of time Compilation.....

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How fast?

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SIMD.js in V8

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ChromeOS market?

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Geographic Distribution

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Note to self! So how much does it really cost?

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ARC

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That is all for now� Thank you!

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