[TOC]
Generally speaking, we talk about setup.exe
as «the installer», although
mini_installer.exe
is the thing that is delivered to devices to install
Chrome. The installer’s primary concern is putting the browser on-disk in the
proper location and registering it with Windows as a browser. It is also used to
uninstall and remove Chrome and to perform various one-off tasks.
Chrome can be installed for all users on a machine or for a single user. The former is called a «system-level» install and the latter is a «user-level» install. setup.exe defaults to performaing a user-level install (note: the Chrome download page defaults to system-level). System-level can be chosen via any of:
--system-level
on the command line,{"distribution":{"system_level":true}}
in an «initial_preferences» file
passed via the --installerdata=<PATH>
command line switch, orGoogleUpdateIsMachine=1
in the process environment block.A user-level install is always expected to be run within the context of an interactive user. A system-level install may run in the context of an interactive user (e.g., one who has downloaded Chrome’s installer and passed a UAC prompt) or in the context of a machine account such as SYSTEM (e.g., installation via msiexec.exe or an update driven by a system-level install of Google Update).
Chrome and its installer use portions of the Windows registry established by
Google Update to maintain installation-related state (not user state). This
state is saved in ...\Software\Google\Update\Clients
and
...\Software\Google\Update\ClientState
. These are unconditionally located in
the 32-bit registry hive, so KEY_WOW64_32KEY
must always be used when
accessing them.
By and large, new state should we written to Chrome’s ClientState key. The Clients key should be used for the version number and app commands (both as required by Google Update) and Chrome’s channel.
setup.exe
is run to perform a variety of one-off tasks. In all cases, these
invocations must carry certain command line switches from the original
installation. These include --system-level
, --channel=FOO
, and one of the
install mode switches, if used (e.g., --chrome-sxs
). This ensures that the
proper install is used and that metrics and crashes have the proper annotations.
setup.exe
(//chrome/installer/setup): The workhorse installer.mini_installer.exe
(//chrome/installer/mini_installer): Carries setup.exe
and the Chrome 7zip archive as resources; knows how to extract them and run
setup.exe
..exe
) installer: A self-contained executable that
installs Google Update and then runs Chrome’s mini_installer
. The tooling to
build this is not in the Chromium repository..msi
) installer: A self-contained Windows Installer
file that runs a standalone installer (yielding Google Update and Chrome). The
tooling to build this is not in the Chromium repository.From the bottom heading up:
chrome.exe
, chrome_elf.dll
, chrome.dll
,
setup.exe
, and any other binary that must be aware of install level,
channel, stats collection, etc.chrome.exe
, chrome.dll
, and setup.exe
. This is for code shared by the
browser and the installer.setup.exe
. This also has minimal
dependencies.//chrome/install_static
, //chrome/installer/util
, and
//chrome/installer/setup
.Generally, prefer //chrome/installer/setup
if the new code is only for use by
the installer. If it must be shared by Chrome, put it in
//chrome/installer/util
.