tree: c8170ecf138c7f03f06facaedd29caeb14837d78 [path history] [tgz]
  1. assistant/
  2. attestation/
  3. audio/
  4. chromeos_strings_grd/
  5. components/
  6. constants/
  7. crosapi/
  8. cryptohome/
  9. dbus/
  10. disks/
  11. geolocation/
  12. hugepage_text/
  13. ime/
  14. lacros/
  15. login/
  16. memory/
  17. network/
  18. policy/
  19. printing/
  20. process_proxy/
  21. profiles/
  22. resources/
  23. scanning/
  24. services/
  25. settings/
  26. strings/
  27. system/
  28. test/
  29. third_party/
  30. timezone/
  31. tools/
  32. tpm/
  33. ui/
  34. BUILD.gn
  35. chromeos_export.h
  36. CHROMEOS_LKGM
  37. chromeos_strings.grd
  38. DEPS
  39. LACROS_OWNERS
  40. OWNERS
  41. README.md
  42. SECURITY_OWNERS
chromeos/README.md

Chrome OS

This directory contains low-level support for Chrome running on Chrome OS.

The Lacros project is in the process of extracting the browser-functionality into a separate binary. This introduces the following terminology and rules:

  • ash-chrome: The new name of the legacy “chrome” binary. It contains system UI and the current/legacy web browser. Code that is only used by ash-chrome should eventually be moved to //ash, have an _ash suffix in the filename, or have a (grand-)parent directory named /ash/.
  • lacros-chrome: The name of the new, standalone web-browser binary. Code that is only used by lacros-chrome should have a _lacros suffix in the filename, or have a (grand-)parent directory named /lacros/.
  • crosapi: The term “crosapi” is short for ChromeOS API. Ash-chrome implements the API, and lacros-chrome is the only consumer.
  • chromeos: The term “chromeos” refers to code that is shared by binaries targeting the chromeos platform or using the chromeos toolchain. Code that is shared by ash-chrome and lacros-chrome should have a _chromeos suffix in the filename, or have a (grand-)parent directory named /chromeos/.
  • Exception: The exception to the rule is //chrome/browser/chromeos. Following existing conventions in //chrome, the directory should refer to lacros-chrome. However, this would involve a massive and otherwise unnecessary refactor. //chrome/browser/chromeos will continue to contain code that is only used by ash-chrome. //chrome/browser/lacros will contain code used only by lacros-chrome. See this document for more details.

Many subdirectories contain Chrome-style C++ wrappers around operating system components.

For example, //chromeos/dbus contains wrappers around the D-Bus interfaces to system daemons like the network configuration manager (shill). Most other directories contain low-level utility code. For example, //chromeos/disks has utilities for mounting and unmounting disk volumes.

There are two exceptions:

  • //chromeos/services contains mojo services that were not considered sufficiently general to live in top-level //services. For example //chromeos/services/secure_channel bootstraps a secure communications channel to an Android phone over Bluetooth, enabling multi-device features like instant tethering.

  • //chromeos/components contains C++ components that were not considered sufficiently general to live in top-level //components. For example, //chromeos/components/account_manager manages the user's GAIA accounts, but is used as the backend for UI that only exists on Chrome OS devices.

Note, //chromeos does not contain any user-facing UI code, and hence it has “-ui” in its DEPS. The contents of //chromeos should also not depend on //chrome or //content.