deepin-bot · Oct 15, 2026 · Oct 15, 2026
diff --git a/INSTALL.md b/INSTALL.md
@@ -2,38 +2,53 @@
 
 DDM uses CMake to configure and build the project.
 
-  1. From the project root, create a build directory: `mkdir build`
-  2. From the build directory, run cmake to the project root. Eg: `cd build && cmake ..`
-  3. To build, run `make`.
-  4. To install, run `make install`.
+  1. From the project root, configure the build directory:
+     `cmake -B build`
+  2. To build, run `cmake --build build`.
+  3. To install, run `cmake --install build`.
 
 CMake accepts a number of standard and extra arguments:
 
-  - BUILD_MAN_PAGES, pass -DBUILD_MAN_PAGES=ON to build man pages
-  - ENABLE_JOURNALD, pass -DENABLE_JOURNALD=OFF
-    to disable logging to the journal
+  - `BUILD_MAN_PAGES`, pass `-DBUILD_MAN_PAGES=ON` to build man pages. This
+    requires `rst2man` from the python `docutils` package.
+  - `WERROR`, pass `-DWERROR=ON` to build with `-Werror`.
+  - `LOGIN_DEFS_PATH`, path of `login.defs` used to autodetect `UID_MIN` and
+    `UID_MAX`. Defaults to `/etc/login.defs`.
+  - `DDM_INITIAL_VT`, the virtual terminal ddm starts on. Defaults to `1`.
+  - Install locations such as `CONFIG_FILE`, `CONFIG_DIR`, `SYSTEM_CONFIG_DIR`,
+    `STATE_DIR`, `RUNTIME_DIR`, `DATA_INSTALL_DIR`, `DBUS_CONFIG_DIR` and
+    `LOG_FILE` can be overridden in the same way.
 
-By default, a debug build is created. To build for production, use
-`cmake -DCMAKE_BUILD_TYPE=Release`.
+By default, a `Release` build is created. To build a debug build, use
+`cmake -DCMAKE_BUILD_TYPE=Debug -B build`.
 
-To see all the possible arguments, run `cmake -L ..`.
+To see all the possible arguments, run `cmake -L -B build`.
 For documentation on standard CMake variables, see:
-  http://www.cmake.org/cmake/help/v3.0/manual/cmake-variables.7.html
+  https://cmake.org/cmake/help/latest/manual/cmake-variables.7.html
 
 ### Post-installation steps
 
-By default, DDM runs as its own user. An `ddm` user needs to be created, with
-its home set to `/var/lib/ddm` by default.
+DDM runs its greeter as its own user, named **dde**. The user, its group and
+its home directory (`/var/lib/ddm` by default) are created by
+`systemd-sysusers` from the installed `dde.conf`; the runtime and state
+directories are created by `systemd-tmpfiles`. Both are installed by the
+package, so on a systemd distribution no manual step is required.
+
+DDM is started by `ddm.service`. It starts `treeland.service` for the login
+screen and requires `dde-seatd.service`. Make sure all three units and the PAM
+services (`ddm` and `ddm-autologin` in `/etc/pam.d`) are installed.
 
 ### Dependencies
 
-DDM depends on PAM for authorization and XCB to communicate with the X server.
-Apart from other things, it also depends on Qt for the user interface and event
-loop management.
-DDM can optionally make use of logind (the systemd login manager API), or
-ConsoleKit2, or upower to enable support for suspend, hibernate etc.
-In order to build the man pages, you will need `rst2man` installed. It is
-provided by the python `docutils` package
+DDM depends on PAM for authorization and on systemd-logind for opening user
+sessions, and uses libxau to write X authorization files. Apart from other
+things, it also depends on Qt 6 for its event loop and D-Bus communication.
+It uses wayland-client and the `treeland_ddm_v1` protocol from
+treeland-protocols to talk to the Treeland compositor, and dde-seatd to manage
+virtual terminals.
+
+X11 sessions additionally require an X server at runtime; the path is
+configured with the `X11.ServerPath` option.
 
-Note that DDM makes use of C++11 features for a modern and clean codebase,
-therefore it needs a recent version of GCC to compile (4.7 at least).
+DDM makes use of C++20 features, therefore it needs a recent version of GCC to
+compile.
diff --git a/README.md b/README.md
@@ -1,28 +1,65 @@
 # DDM
 
-The `ddm` project is Display Manager base `SDDM` fork.
+`ddm` (Deepin Display Manager) is the display and login manager for the
+[Treeland](https://github.com/linuxdeepin/treeland) Wayland compositor. It is based on [SDDM](https://github.com/sddm/sddm), but the
+QtQuick greeter it inherited is gone: the login screen is drawn by Treeland
+itself, and `ddm` only manages the compositor, authenticates users and starts
+their desktop sessions.
+
+See [docs/ARCHITECTURE.md](docs/ARCHITECTURE.md) for how the pieces fit together.
 
 ## Dependencies
 
-Check `debian/control` for build-time and runtime dependencies, or use `cmake` to check the missing required dependencies.
+Check `debian/control` for build-time and runtime dependencies, or use `cmake`
+to check the missing required dependencies.
+
+Core build dependencies:
+
+- Qt 6 (Core, DBus, Network), version 6.6 or newer
+- [treeland-protocols](https://github.com/linuxdeepin/treeland-protocols)
+- PAM, libsystemd, libxau and wayland-client
+- ECM (extra-cmake-modules) 1.4 or newer
+
+Runtime dependencies:
+
+- [treeland](https://github.com/linuxdeepin/treeland) — the greeter and, for
+  single-mode sessions, the compositor the user session runs in
+- [dde-seatd](https://github.com/linuxdeepin/dde-seatd) — seat and virtual
+  terminal management
+- systemd-logind, used to open user sessions
 
 ## Building
 
-Regular CMake building steps applies, in short:
+Regular CMake building steps apply, in short:
 
 ```shell
 $ cmake -Bbuild
 $ cmake --build build
 $ cmake --install build # only do this if you know what you are doing
 ```
 
+The man pages are only built with `-DBUILD_MAN_PAGES=ON`, and require `rst2man`
+from the python `docutils` package.
+
 A `debian` folder is provided to build the package under the *deepin* linux desktop distribution. To build the package, use the following command:
 
 ```shell
 $ sudo apt build-dep . # install build dependencies
 $ dpkg-buildpackage -uc -us -nc -b # build binary package(s)
 ```
 
+## Running
+
+`ddm` is meant to be started by its systemd unit as the display manager:
+
+```shell
+$ systemctl start ddm.service
+```
+
+It starts `treeland.service` for the login screen and requires
+`dde-seatd.service`. Both units, the PAM services and the `dde` greeter user
+are installed by the package.
+
 ## Getting Involved
 
 - [Code contribution via GitHub](https://github.com/linuxdeepin/ddm/)

diff --git a/README.zh_CN.md b/README.zh_CN.md
@@ -1 +1,69 @@
-TODO:
+# DDM
+
+`ddm`（Deepin Display Manager）是
+[Treeland](https://github.com/linuxdeepin/treeland) Wayland 合成器的显示与登录
+管理器。它基于 [SDDM](https://github.com/sddm/sddm)，但不再使用从
+SDDM 继承的 QtQuick greeter：登录界面由 Treeland 自己绘制，`ddm` 只负责管理
+合成器、认证用户并启动用户桌面会话。
+
+各组件之间的关系参见 [docs/ARCHITECTURE.md](docs/ARCHITECTURE.md)。
+
+## 依赖
+
+查看 `debian/control` 了解构建时和运行时依赖，或者使用 `cmake` 检查缺失的
+必要组件。
+
+核心构建依赖：
+
+- Qt 6（Core、DBus、Network），版本 6.6 或更高
+- [treeland-protocols](https://github.com/linuxdeepin/treeland-protocols)
+- PAM、libsystemd、libxau 和 wayland-client
+- ECM（extra-cmake-modules）1.4 或更高
+
+运行时依赖：
+
+- [treeland](https://github.com/linuxdeepin/treeland) —— 提供登录界面，并在
+  single 模式下作为用户会话所在的合成器
+- [dde-seatd](https://github.com/linuxdeepin/dde-seatd) —— seat 与虚拟终端管理
+- systemd-logind —— 用于打开用户会话
+
+## 构建
+
+常规的 CMake 构建步骤即可，简要如下：
+
+```shell
+$ cmake -Bbuild
+$ cmake --build build
+$ cmake --install build # 只有明确知道后果时才执行安装
+```
+
+只有传入 `-DBUILD_MAN_PAGES=ON` 才会构建 man 手册，且需要 python `docutils`
+提供的 `rst2man`。
+
+仓库提供了 `debian` 目录用于在 *deepin* Linux 发行版下打包。构建软件包使用
+以下命令：
+
+```shell
+$ sudo apt build-dep . # 安装构建依赖
+$ dpkg-buildpackage -uc -us -nc -b # 构建二进制软件包
+```
+
+## 运行
+
+`ddm` 由自身的 systemd 服务作为显示管理器启动：
+
+```shell
+$ systemctl start ddm.service
+```
+
+它会启动 `treeland.service` 以提供登录界面，并依赖 `dde-seatd.service`。
+这些服务、PAM 配置以及 `dde` greeter 用户均由软件包安装。
+
+## 参与贡献
+
+- [通过 GitHub 贡献代码](https://github.com/linuxdeepin/ddm/)
+- [在 GitHub Issues 或 GitHub Discussions 提交问题或建议](https://github.com/linuxdeepin/developer-center/issues/new/choose)
+
+## 许可证
+
+**ddm** 使用 GPL-2.0+ 许可证。详细信息参见 REUSE 文件。
diff --git a/data/man/ddm-state.conf.rst.in b/data/man/ddm-state.conf.rst.in
@@ -14,12 +14,14 @@ ddm configuration
 SYNOPSIS
 ========
 
-~ddm/state.conf
+@STATE_DIR@/state.conf
 
 DESCRIPTION
 ===========
 
 This file carries state configuration for the ddm display manager **ddm**\(1\).
+It lives in the home directory of the **dde** user, which is **@STATE_DIR@**.
+It is written by ddm and does not need to be edited by hand.
 
 OPTIONS
 =======
@@ -39,6 +41,6 @@ All options are configured in the [Last] section:
 SEE ALSO
 ========
 
-**ddm**\(1\)
+**ddm**\(1\), **ddm.conf**\(5\)
 
-The full documentation for ddm is available at https://github.com/ddm/ddm
+The full documentation for ddm is available at https://github.com/linuxdeepin/ddm
diff --git a/data/man/ddm.conf.rst.in b/data/man/ddm.conf.rst.in
@@ -55,10 +55,23 @@ OPTIONS
 
 `CursorTheme=`
 	Name of the cursor theme to be set before starting
-	the display server.
+	an X11 display server.
 
 `CursorSize=`
-	Cursor size to be set before starting the display server.
+	Cursor size to be set before starting an X11 display server.
+
+[Autologin] section:
+
+`User=`
+	User to log in automatically. An empty value disables automatic login.
+	The user must not be the greeter user **dde**.
+	Default value is empty.
+
+`Session=`
+	Session to load for automatic login. This overrides the last used
+	session. If it is empty, the session remembered in
+	**ddm-state.conf**\(5\) is used.
+	Default value is empty.
 
 [X11] section:
 
@@ -82,18 +95,16 @@ OPTIONS
 
 `SessionLogFile=`
 	Path to the user session log file, relative to the home directory.
-    Default value is ".local/share/ddm/xorg-session.log".
+	Default value is ".local/share/ddm/xorg-session.log".
 
 `DisplayCommand=`
-	Path of script to execute when starting the display server.
-	The script will be executed as root when General.DisplayServer
-	is "x11", otherwise as ddm user.
+	Path of script to execute when starting the X11 display server.
+	The script is executed as root by the ddm daemon.
 	Default value is "@DATA_INSTALL_DIR@/scripts/Xsetup".
 
 `DisplayStopCommand=`
-	Path of script to execute when stopping the display server.
-	The script will be executed as root when General.DisplayServer
-	is "x11", otherwise as ddm user.
+	Path of script to execute when stopping the X11 display server.
+	The script is executed as root by the ddm daemon.
 	Default value is "@DATA_INSTALL_DIR@/scripts/Xstop".
 
 [Wayland] section:
@@ -115,9 +126,12 @@ OPTIONS
 [Single] section:
 
 `SessionCommand=`
-	Path of script to execute when starting the user session for Treeland.
-    This script receives the value of the "Exec" setting in the ".desktop" file
-    of the selected session and run it.
+	Path of script to execute when starting the user session for a
+	single-mode Treeland session (a session whose desktop file sets
+	X-DDE-SINGLE-WAYLAND=true). Such a session runs inside the already
+	running Treeland instance instead of starting its own compositor.
+	The script receives the value of the "Exec" setting in the ".desktop"
+	file of the selected session and runs it.
 	Default value is "@WAYLAND_SESSION_COMMAND@".
 
 [Users] section:
@@ -142,6 +156,6 @@ OPTIONS
 SEE ALSO
 ========
 
-**ddm**\(1\)
+**ddm**\(1\), **ddm-state.conf**\(5\)
 
-The full documentation for ddm is available at https://github.com/ddm/ddm
+The full documentation for ddm is available at https://github.com/linuxdeepin/ddm
diff --git a/data/man/ddm.rst.in b/data/man/ddm.rst.in
@@ -19,47 +19,58 @@ ddm [OPTIONS...]
 DESCRIPTION
 ===========
 
-ddm is a display and login manager based on Qt technologies and using
-Treeland as greeter.
-
-If pam and systemd are available, the greeter will go through logind,
-which will give it access to drm devices.
-
-Distributions without pam and systemd will need to put the **ddm** user
-into the **video** group, otherwise errors regarding GL and drm devices
-might be experienced.
-
-For X11 sessions, the cookie for X authorization is written into a
-temporary file `/tmp/xauth_XXXXXX`, owned and only accessible by the
+ddm is the Deepin Display Manager, the display and login manager for the
+Treeland Wayland compositor. It authenticates users with PAM, starts their
+desktop sessions and keeps the login screen running on the initial virtual
+terminal.
+
+The login screen itself is not part of ddm: it is drawn by Treeland, which ddm
+starts as the **treeland.service** systemd unit. ddm talks to Treeland through
+the private **treeland_ddm_v1** Wayland protocol and through a local socket,
+and talks to **dde-seatd** for virtual terminal management. User sessions are
+opened through systemd-logind.
+
+X11 sessions are also supported: for those, ddm stops Treeland and starts an X
+server instead. For X11 sessions, the cookie for X authorization is written
+into a temporary file `/tmp/xauth_XXXXXX`, owned and only accessible by the
 user.
 
 OPTIONS
 =======
 
---test-mode
-	Start daemon in test mode.
-
 --example-config
-	Print the complete current configuration to stdout
+	Print the complete current configuration to stdout and exit.
 
 --help, -h
 	Show help message and exit.
 
 FILES
 =====
 
-**@SYSTEM_CONFIG_DIR@**
-	System configuration directory
+**@CONFIG_FILE@**
+	Local configuration file.
 
 **@CONFIG_DIR@**
-	Local configuration directory
+	Local configuration directory, has higher precedence than the
+	configuration file.
 
-**@CONFIG_FILE@**
-	Local configuration file for compatibility
+**@SYSTEM_CONFIG_DIR@**
+	System configuration directory, has the lowest precedence.
+
+**@STATE_DIR@/state.conf**
+	State file remembering the last user and session.
+	See **ddm-state.conf**\(5\).
+
+**@RUNTIME_DIR@**
+	Runtime directory, holds the X11 authorization file of the display
+	server.
+
+**@LOG_FILE@**
+	Log file, used when ddm does not log to the journal.
 
 SEE ALSO
 ========
 
-**ddm.conf**\(5\)
+**ddm.conf**\(5\), **ddm-state.conf**\(5\)
 
-The full documentation for ddm is available at https://github.com/ddm/ddm
+The full documentation for ddm is available at https://github.com/linuxdeepin/ddm