---
breadcrumbs:
- - /chromium-os
  - Chromium OS
page_name: chromiumos-design-docs
title: Design Documents
---

This page has links to a preliminary set of Chromium OS design docs. (Also see
the [User Experience](/user-experience) pages.)

**Note: These designs will evolve significantly, based on implementation
challenges, community feedback, and other factors. In many cases, these design
docs represent early planning and may change direction. We'll publish more
design docs in the coming months.**

<div class="two-column-container">
<div class="column">

### General

*   [Software
            Architecture](/chromium-os/chromiumos-design-docs/software-architecture)
*   [Source Code
            Management](/chromium-os/chromiumos-design-docs/source-code-management)
*   [Upstream First](/chromium-os/chromiumos-design-docs/upstream-first)

### Security

*   [Security
            Overview](/chromium-os/chromiumos-design-docs/security-overview)
*   [Protecting Cached User
            Data](/chromium-os/chromiumos-design-docs/protecting-cached-user-data)
*   [System
            Hardening](/chromium-os/chromiumos-design-docs/system-hardening)
*   [Chaps Technical
            Design](/developers/design-documents/chaps-technical-design)
*   [TPM Usage](/developers/design-documents/tpm-usage)
*   [Verified Boot
            Presentation](https://docs.google.com/a/chromium.org/presentation/d/1HHf_0nKrceQr_NQYGMpVlYTIYF8ky-eNxP7W5Lxw94Y/present#slide=id.g341ad2000_020)
            (2014)
*   [Verified Boot
            Presentation](https://docs.google.com/presentation/d/14haBMrbpc2zlgdWmiaTlp_iDG_A8t5PTTXFMz5kqHSM/present?slide=id.g11a5e5b4cf_0_140)
            (2016)
*   [Keyboard-Controlled Reset
            Circuit](/chromium-os/chromiumos-design-docs/keyboard-controlled-reset-circuit)

### Firmware

*   [CBI: CrOS Board
            Info](/chromium-os/developer-library/reference/device/cros-board-info/)
*   [Firmware Boot and
            Recovery](/chromium-os/chromiumos-design-docs/firmware-boot-and-recovery)
*   [Disk Format](/chromium-os/developer-library/reference/device/disk-format)
            (including boot process)
*   [Developer Mode](/chromium-os/chromiumos-design-docs/developer-mode)
*   [EC-3PO](https://chromium.googlesource.com/chromiumos/third_party/hdctools/+/HEAD/docs/ec-3po-design.md)
        (EC console interpreter)
*   [Recovery Mode](/chromium-os/chromiumos-design-docs/recovery-mode)
*   [SAFT](/for-testers/saft) (semi-automated firmware test)
*   [Verified Boot](/chromium-os/chromiumos-design-docs/verified-boot)
*   [Verified Boot Crypto
            Specification](/chromium-os/chromiumos-design-docs/verified-boot-crypto)
*   [Verified Boot Data
            Structures](/chromium-os/chromiumos-design-docs/verified-boot-data-structures)

</div>
<div class="column">

### Platform

*   [Cros](/chromium-os/chromiumos-design-docs/chromium-os-libcros) (how
            Chromium talks to Chromium OS)
*   [File
            System/Autoupdate](/chromium-os/chromiumos-design-docs/filesystem-autoupdate)
*   [Kernel](/chromium-os/chromiumos-design-docs/chromium-os-kernel)
*   [User-Land Boot
            Design](/chromium-os/chromiumos-design-docs/boot-design)
*   [Library
            optimization](/chromium-os/chromiumos-design-docs/library-optimization)
*   [Login](/chromium-os/chromiumos-design-docs/login)
*   [Lucid Sleep](/chromium-os/chromiumos-design-docs/lucid-sleep)
*   [Out of memory
            handling](/chromium-os/chromiumos-design-docs/out-of-memory-handling)
*   [Partition
            Resizing](/chromium-os/chromiumos-design-docs/partition-resizing)
*   [Power
            Manager](https://chromium.googlesource.com/chromiumos/platform2/+/HEAD/power_manager/README.md)
*   [Battery Life
            Overview](/chromium-os/chromiumos-design-docs/chrome-os-battery-life-overview)
*   [Performance
            Overview](/chromium-os/chromiumos-design-docs/chrome-os-performance-overview)
*   [Printing](/chromium-os/chromiumos-design-docs/chromium-os-printing-design)
*   [Text Input](/chromium-os/chromiumos-design-docs/text-input)
*   [Timekeeping](/chromium-os/chromiumos-design-docs/timekeeping)
*   [User Accounts and
            Management](/chromium-os/chromiumos-design-docs/user-accounts-and-management)
*   [CRAS: ChromeOS Audio
            Server](/chromium-os/chromiumos-design-docs/cras-chromeos-audio-server)
*   [Chromium OS
            Cgroups](/chromium-os/chromiumos-design-docs/chromium-os-cgroups)
*   [Unified
            Builds](https://docs.google.com/document/d/1zonifFp8UpE6ISxsnzUrUb9ikx1pXeqs0UzW08ce6aY/edit#heading=h.guvbepjyp0oj)
            (Chrome OS config)

### Stateless

*   *Coming soon*

**UI**

*   [Immersive
            fullscreen](/developers/design-documents/immersive-fullscreen)
*   [Volume
            keys](/chromium-os/chromiumos-design-docs/chrome-os-volume-keys)
*   [system
            notifications](/chromium-os/chromiumos-design-docs/system-notifications)

</div>
</div>