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<!DOCTYPE html> <head> <meta charset="utf-8"> <title>Reference</title> <link rel="stylesheet" href="/_stylesheets/@docsearch/style.css"> <link rel="stylesheet" href="/_stylesheets/default.css"> <link rel="stylesheet" href="/_stylesheets/highlight.js/github.min.css"> </head>   <script async src="https://www.googletagmanager.com/gtag/js?id=G-24XP4PG02H"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'G-24XP4PG02H'); </script> <header> <a href="/"> <img alt="the Chromium logo" src="/_assets/icon-chromium-96.png" width="48" height="48"> <h2>The Chromium Projects</h2> </a> <div id="search"></div> </header> <div id="main-wrapper"> <nav id="sidebar-left"> <section> <a href="/chromium-projects">Home</a> <a href="/Home">Chromium</a> <a href="/chromium-os">ChromiumOS</a> </section> <section> <h4>Quick links</h4> <a href="/for-testers/bug-reporting-guidelines">Report bugs</a> <a 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href="https://edit.chromium.org/edit?repo=chromium/website/main&file=site/chromium-os/developer-library/reference/index.md&ext_google.git=%7B%22repo%22%3A%22chromium%2Fwebsite%22%2C%22ref%22%3A%22main%22%2C%22file%22%3A%22site/chromium-os/developer-library/reference/index.md%22%7D">Edit this page</a> </nav> <main> <div class="breadcrumbs"> <a href="/chromium-os/developer-library">ChromiumOS</a> > </div> <h1>Reference</h1> <div class="two-column-container"> <div class="column"> <h2 id="build" tabindex="-1"><a class="header-anchor" href="#build">Build</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/build/account-management">CrOS user & group management</a></li> <li><a href="/chromium-os/developer-library/reference/build/bazel-remote-caching">Bazel remote caching</a></li> <li><a href="/chromium-os/developer-library/reference/build/faq">Build FAQ</a></li> <li><a href="/chromium-os/developer-library/reference/build/chromeos-gn">GN in ChromeOS</a></li> </ul> <h2 id="design-docs" tabindex="-1"><a class="header-anchor" href="#design-docs">Design Docs</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/design-docs/dynamic-test-suites">Dynamic test suites</a></li> <li><a href="/chromium-os/developer-library/reference/design-docs/suite_scheduler-1">Suite scheduler design doc</a></li> <li><a href="/chromium-os/developer-library/reference/design-docs/test-dependencies-in-dynamic-suites">Test dependencies in dynamic suites</a></li> </ul> <h2 id="device" tabindex="-1"><a class="header-anchor" href="#device">Device</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/device/cros-board-info">CBI: CrOS Board Info</a></li> <li><a href="/chromium-os/developer-library/reference/device/crosh">Crosh</a></li> <li><a href="/chromium-os/developer-library/reference/device/disk-format">Disk format</a></li> <li><a href="/chromium-os/developer-library/reference/device/firmware-config">Firmware Config</a></li> </ul> <h2 id="hardware" tabindex="-1"><a class="header-anchor" href="#hardware">Hardware</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/hardware/cable-and-adapter-tips-and-tricks">Cable and adapter parameters</a></li> </ul> <h2 id="kernel" tabindex="-1"><a class="header-anchor" href="#kernel">Kernel</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/kernel/kernel-scheduler">Kernel scheduler in ChromeOS</a></li> </ul> <h2 id="licensing" tabindex="-1"><a class="header-anchor" href="#licensing">Licensing</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/licensing/licensing-for-chromiumos-developers">Licensing for ChromiumOS developers</a></li> <li><a href="/chromium-os/developer-library/reference/licensing/licensing-for-chromiumos-package-owners">Licensing for ChromiumOS package owners</a></li> </ul> <h2 id="logging" tabindex="-1"><a class="header-anchor" href="#logging">Logging</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/logging/logging">Logging on ChromeOS</a></li> </ul> <h2 id="release" tabindex="-1"><a class="header-anchor" href="#release">Release</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/release/releases">ChromeOS releases</a></li> <li><a href="/chromium-os/developer-library/reference/release/understanding-chromeos-releases">Understanding ChromeOS releases</a></li> </ul> <h2 id="rotations" tabindex="-1"><a class="header-anchor" href="#rotations">Rotations</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/rotations/cros-oncall">CrOS oncall</a></li> <li><a href="/chromium-os/developer-library/reference/rotations/sheriff-details-chromium-os">Sheriff FAQ: ChromiumOS</a></li> </ul> <h2 id="style-guides" tabindex="-1"><a class="header-anchor" href="#style-guides">Style guides</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/style-guides/style-guides">Style guides in ChromiumOS</a></li> <li><a href="/chromium-os/developer-library/reference/style-guides/python">Python style guidelines</a></li> <li><a href="/chromium-os/developer-library/reference/style-guides/shell">Shell style guidelines</a></li> </ul> <h2 id="tools" tabindex="-1"><a class="header-anchor" href="#tools">Tools</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/tools/chroot-version-hooks">chroot-version-hooks</a></li> <li><a href="/chromium-os/developer-library/reference/tools/cros-deploy">cros deploy</a></li> <li><a href="/chromium-os/developer-library/reference/tools/cros-flash">cros flash</a></li> <li><a href="/chromium-os/developer-library/reference/tools/cros-tools">CrOS Tools</a></li> <li><a href="/chromium-os/developer-library/reference/tools/gsutil">gsutil</a></li> <li><a href="/chromium-os/developer-library/reference/tools/helper-scripts">Helper scripts</a></li> <li><a href="/chromium-os/developer-library/reference/tools/repo-tool">repo</a></li> <li><a href="/chromium-os/developer-library/reference/tools/xbuddy">xBuddy for Devserver</a></li> <li><a href="/developers/useful-extensions">Useful developer related Chrome extensions</a></li> </ul> <h2 id="c" tabindex="-1"><a class="header-anchor" href="#c">C++</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/cpp/intro">Intro</a></li> <li><a href="/chromium-os/developer-library/reference/cpp/cpp-memory-management">Memory Management</a></li> <li><a href="/chromium-os/developer-library/reference/cpp/cpp-patterns">Design Patterns</a></li> <li><a href="/chromium-os/developer-library/reference/cpp/cpp-mojo">Using Mojo in C++</a></li> <li><a href="/chromium-os/developer-library/reference/cpp/cpp-pref">C++ Prefs</a></li> <li><a href="/chromium-os/developer-library/reference/cpp/cpp-invariant-checks">Invariants and CHECKKs in C++</a></li> </ul> </div> <div class="column"> <h2 id="bugs" tabindex="-1"><a class="header-anchor" href="#bugs">Bugs</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/bugs/life-of-a-bug">Life of a ChromeOS Bug</a></li> </ul> <h2 id="development" tabindex="-1"><a class="header-anchor" href="#development">Development</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/development/chromium-os-faq">ChromiumOS FAQ</a></li> <li><a href="/chromium-os/developer-library/reference/development/developer-faq">Developer FAQ</a></li> <li><a href="/chromium-os/developer-library/reference/development/developer-information-for-chrome-os-devices">Developer Information for ChromeOS Devices</a></li> <li><a href="/chromium-os/developer-library/reference/development/dir-metadata">Directory metadata</a></li> <li><a href="/chromium-os/developer-library/reference/development/cros-commit-pipeline">Life of a ChromeOS commit</a></li> <li><a href="/chromium-os/developer-library/reference/development/source-layout">Local & Remote Source Tree Layouts</a></li> </ul> <h2 id="infrastructure" tabindex="-1"><a class="header-anchor" href="#infrastructure">Infrastructure</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/infrastructure/lsb-release">/etc/lsb-release File Format</a></li> <li><a href="/chromium-os/developer-library/reference/infrastructure/afe-rpc-infrastructure">AFE RPC Infrastructure</a></li> <li><a href="/chromium-os/developer-library/reference/infrastructure/autoserv-packaging">Autoserv Packaging</a></li> <li><a href="/chromium-os/developer-library/reference/infrastructure/autotest-keyvals">Autotest Keyvals</a></li> <li><a href="/chromium-os/developer-library/reference/infrastructure/os-config">ChromiumOS Configuration</a></li> <li><a href="/chromium-os/developer-library/reference/infrastructure/input-stack">ChromiumOS Input Stack</a></li> <li><a href="/chromium-os/developer-library/reference/infrastructure/collecting-stats-for-graphite">Collecting Stats for Graphite</a></li> <li><a href="/chromium-os/developer-library/reference/infrastructure/gs-offloader">GS Offloader</a></li> <li><a href="/chromium-os/developer-library/reference/infrastructure/moblab">MobLab</a></li> <li><a href="/chromium-os/developer-library/reference/infrastructure/ca-certs">Root CA Certificates on ChromiumOS</a></li> </ul> <h2 id="linux-constants" tabindex="-1"><a class="header-anchor" href="#linux-constants">Linux constants</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/linux-constants/errnos">Linux Error Number Table (errno)</a></li> <li><a href="/chromium-os/developer-library/reference/linux-constants/signals">Linux Signal Table</a></li> <li><a href="/chromium-os/developer-library/reference/linux-constants/syscalls">Linux System Call Table</a></li> </ul> <h2 id="policies" tabindex="-1"><a class="header-anchor" href="#policies">Policies</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/policies/eol-aue-process">End of Life (EOL) / Auto Update Expiration (AUE) Process</a></li> </ul> <h2 id="security" tabindex="-1"><a class="header-anchor" href="#security">Security</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/security/closed-source">Security guidelines for closed-source components</a></li> <li><a href="/chromium-os/developer-library/reference/security/firmware-updating">Peripheral firmware security</a></li> <li><a href="/chromium-os/developer-library/reference/security/fuzzer-bugs">Handling bugs found by fuzzers</a></li> <li><a href="/chromium-os/developer-library/reference/security/hardening-prioritizing-guidelines">Prioritizing security hardening bugs</a></li> <li><a href="/chromium-os/developer-library/reference/security/jit">Just-In-Time compilation in ChromeOS</a></li> <li><a href="/chromium-os/developer-library/reference/security/port-forwarding">Port forwarding and tunneling in ChromeOS</a></li> <li><a href="/chromium-os/developer-library/reference/security/review-process">The ChromeOS security review process</a></li> <li><a href="/chromium-os/developer-library/reference/security/security-whitepaper">Security in ChromeOS</a></li> <li><a href="/chromium-os/developer-library/reference/security/selinux">SELinux in ChromeOS</a></li> <li><a href="/chromium-os/developer-library/reference/security/sensitive-chromeos-packages">Security-sensitive ChromeOS packages</a></li> <li><a href="/chromium-os/developer-library/reference/security/usb4">USB4 security</a></li> <li><a href="/chromium-os/developer-library/reference/security/write-protection">Write protection</a></li> <li><a href="/chromium-os/developer-library/reference/security/cpp-security-best-practices">Security - Best Practices for C++</a></li> </ul> <h2 id="third-party" tabindex="-1"><a class="header-anchor" href="#third-party">Third party</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/third-party/archive-mirrors">ChromiumOS Archive Mirrors</a></li> </ul> <h2 id="user-sessions" tabindex="-1"><a class="header-anchor" href="#user-sessions">User sessions</a></h2> <ul> <li><a href="/chromium-os/developer-library/reference/user-sessions/user-sessions">User sessions</a></li> </ul> </div> </div> </main> </div> <script> // Configure Algolia search. let s = document.createElement('script'); s.src = '/_scripts/@docsearch/index.js'; document.head.append(s); window.addEventListener('load', () => { // Add the Algolia search widget. docsearch({ container: '#search', appId: 'RZDQYCCABX', apiKey: '98b0eabafeb13fe3e1af693d5713d8b4', indexName: 'chromium' }); }); // Configure Google Universal Analytics (the predecessor to GA4, we should // delete this when we don't need it any more). s = document.createElement('script'); s.src = 'https://www.googletagmanager.com/gtag/js?id=UA-5484340-1' s.async = true; document.head.append(s) window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'UA-5484340-1'); // Configure consent bar. s 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