libos+LICENSE: Update copyright year

Happy new year!

.gitea/workflows/build.yaml

@@ -11,11 +11,13 @@ jobs:
       - name: Download dependencies
         run: |
           apt update
-          apt install -y cmake ninja-build nasm genext2fs qemu-system build-essential wget git
+          apt install -y cmake ninja-build nasm genext2fs qemu-system build-essential wget git clang-format
       - name: Set up the toolchain
         run: |
           wget https://pub.cloudapio.eu/luna/toolchains/ci-toolchain-arm64.tar.gz --quiet
           tar xf ci-toolchain-arm64.tar.gz
           rm ci-toolchain-arm64.tar.gz
+      - name: Check formatting
+        run: tools/check-formatting.sh
       - name: Build and run tests
         run: tools/run-tests.sh

CMakeLists.txt

@@ -5,8 +5,8 @@ set(CMAKE_CXX_COMPILER_WORKS 1)
 
 set(CMAKE_CROSSCOMPILING true)
 
-project(Luna LANGUAGES C CXX ASM ASM_NASM VERSION 0.6.0)
-set(LUNA_RELEASE_NAME "Andromeda")
+project(Luna LANGUAGES C CXX ASM ASM_NASM VERSION 0.7.0)
+set(LUNA_RELEASE_NAME "Pulsar")
 
 set(LUNA_ROOT ${CMAKE_CURRENT_LIST_DIR})
 set(LUNA_BASE ${CMAKE_CURRENT_LIST_DIR}/base)
@@ -45,12 +45,10 @@ endif()
 
 add_subdirectory(libluna)
 add_subdirectory(libos)
-add_subdirectory(libui)
+add_subdirectory(gui)
 add_subdirectory(libc)
 add_subdirectory(kernel)
-add_subdirectory(apps)
+add_subdirectory(utils)
 add_subdirectory(tests)
 add_subdirectory(shell)
-add_subdirectory(wind)
-add_subdirectory(terminal)
-add_subdirectory(editor)
+add_subdirectory(system)

LICENSE

@@ -1,6 +1,6 @@
 BSD 2-Clause License
 
-Copyright (c) 2022-2024, apio.
+Copyright (c) 2022-2025, apio.
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without

README.md

@@ -20,26 +20,30 @@ A simple POSIX-based operating system for 64-bit computers, written in C++.
 ## Screenshot
 ![Screenshot as of 0.6.0](docs/screenshots/screenshot-0.6.0.png)
 
+## System requirements and dependencies
+
+Read [docs/dependencies.md](docs/dependencies.md) for the full information. In short, all modern Unixes should work, provided the dependencies are available.
+
 ## Setup
 
 To build and run Luna, you will need to build a [cross-compiler](https://wiki.osdev.org/Why_do_I_need_a_Cross_Compiler) and cross-binutils for `x86_64-luna`.
 
-For this, you should start by installing the [required dependencies](https://wiki.osdev.org/GCC_Cross_Compiler#Installing_Dependencies).
-
-Then, run `tools/setup.sh` to build the toolchain.
+There is a script provided for this. Run `tools/setup.sh` to build the toolchain.
 
 Please beware that building GCC and Binutils can take some time, depending on your machine.
 
 ## Running
 
-To run Luna in a virtual machine, you should have [QEMU](https://www.qemu.org/) installed.
-
-Additionally, the build process needs some extra dependencies to run: `cmake`, `ninja`, `nasm`, `fakeroot` and `genext2fs`.
-
 `tools/run.sh` is the script you should use in most cases. It will build changed files, install, make an ISO image, and run Luna in QEMU.
 
 If you have no toolchain set up, `run.sh` will build it automatically, which means that you don't necessarily have to run `setup.sh` manually since `run.sh` does it for you.
 
+## Login UI
+
+For development convenience, the system automatically starts a GUI session as the default user, without prompting for a password.
+
+Despite this, Luna does have a login window built-in. If you'd like to try this feature out or start a GUI session as a different user, you'll need to edit [base/etc/loginui.conf](base/etc/loginui.conf) and change the line that says `Autologin=true` to `Autologin=false`.
+
 ## Prebuilt images
 
 Prebuilt ISO images for every release version can be found at [pub.cloudapio.eu](https://pub.cloudapio.eu/luna/releases).

apps/CMakeLists.txt

@@ -1,54 +0,0 @@
-function(luna_app SOURCE_FILE APP_NAME)
-    add_executable(${APP_NAME} ${SOURCE_FILE})
-    target_compile_options(${APP_NAME} PRIVATE -Os ${COMMON_FLAGS} -Wno-write-strings)
-    add_dependencies(${APP_NAME} libc)
-    target_include_directories(${APP_NAME} PRIVATE ${LUNA_BASE}/usr/include)
-    target_link_libraries(${APP_NAME} PRIVATE os)
-    install(TARGETS ${APP_NAME} DESTINATION ${LUNA_BASE}/usr/bin)
-endfunction()
-
-add_executable(preinit preinit.cpp)
-target_compile_options(preinit PRIVATE -Os ${COMMON_FLAGS} -Wno-write-strings)
-add_dependencies(preinit libc)
-target_include_directories(preinit PRIVATE ${LUNA_BASE}/usr/include)
-install(TARGETS preinit DESTINATION ${LUNA_ROOT}/initrd/bin)
-
-luna_app(init.cpp init)
-luna_app(env.cpp env)
-luna_app(su.cpp su)
-luna_app(cat.cpp cat)
-luna_app(date.cpp date)
-luna_app(edit.cpp edit)
-luna_app(ls.cpp ls)
-luna_app(chown.cpp chown)
-luna_app(chmod.cpp chmod)
-luna_app(mkdir.cpp mkdir)
-luna_app(rm.cpp rm)
-luna_app(stat.cpp stat)
-luna_app(uname.cpp uname)
-luna_app(base64.cpp base64)
-luna_app(login.cpp login)
-luna_app(mount.cpp mount)
-luna_app(umount.cpp umount)
-luna_app(ps.cpp ps)
-luna_app(time.cpp time)
-luna_app(ln.cpp ln)
-luna_app(mktemp.cpp mktemp)
-luna_app(sysfuzz.cpp sysfuzz)
-luna_app(cp.cpp cp)
-luna_app(kill.cpp kill)
-luna_app(gol.cpp gol)
-target_link_libraries(gol PUBLIC ui)
-luna_app(touch.cpp touch)
-luna_app(free.cpp free)
-luna_app(about.cpp about)
-target_link_libraries(about PUBLIC ui)
-luna_app(taskbar.cpp taskbar)
-target_link_libraries(taskbar PUBLIC ui)
-luna_app(2048.cpp 2048)
-target_link_libraries(2048 PUBLIC ui)
-luna_app(clock.cpp clock)
-target_link_libraries(clock PUBLIC ui)
-luna_app(startui.cpp startui)
-luna_app(launch.cpp launch)
-luna_app(run.cpp run)

base/etc/init/99-login

@@ -1,6 +1,6 @@
 Name=login
 Description=Start a graphical user session.
-Command=/usr/bin/startui --user=selene
+Command=/usr/bin/loginui
 StandardOutput=/dev/uart0
 StandardError=/dev/uart0
 Restart=true

base/etc/loginui.conf

@@ -0,0 +1,5 @@
+# Configuration file for loginui.
+# If this parameter is set to "true", loginui automatically spawns a UI session as the below user instead of prompting for a username and password.
+Autologin=true
+# The user to create a session for if "Autologin" is set to true (see above). If the username is invalid, loginui will behave as if "Autologin" was set to false.
+AutologinUser=selene

base/etc/shadow

@@ -1,3 +1,3 @@
-root:toor:0:0:99999:7:::
+root:ce5ca673d13b36118d54a7cf13aeb0ca012383bf771e713421b4d1fd841f539a:0:0:99999:7:::
 wind:!:0:0:99999:7:::
-selene:moon:0:0:99999:7:::
+selene:9e78b43ea00edcac8299e0cc8df7f6f913078171335f733a21d5d911b6999132:0:0:99999:7:::

base/etc/skel/welcome

@@ -1,14 +1,26 @@
 Welcome to the Luna operating system!
 You are running on the default user account, selene.
 
-If you are familiar with Unix-style operating systems (like Linux or *BSD), you should be able to use the Luna terminal without much problems.
+If you are familiar with Unix-style operating systems (like Linux or *BSD),
+you should be able to use the Luna terminal without much problems.
 
-Following the traditional Unix filesystem structure, programs are installed in /usr/bin (/bin is a symlink to /usr/bin). The command `ls /bin` will show all commands available on your current Luna installation.
+Following the traditional Unix filesystem structure, 
+programs are installed in /usr/bin (/bin is a symlink to /usr/bin). 
+The command `ls /bin` will show all commands available on 
+your current Luna installation.
 
-Currently, because of driver limitations, the root file system is mounted read-only. Your home folder is writable, but volatile; it is created and populated on boot, and its contents will vanish after a reboot.
+Currently, because of driver limitations, 
+the root file system is mounted read-only.
+Your home folder is writable, but volatile; it is 
+created and populated on boot,
+and its contents will vanish after a reboot.
 
-The system is booted using the 'init' program. You can read its configuration files in the /etc/init directory to learn more about the boot process.
+The system is booted using the 'init' program. 
+You can read its configuration files in the /etc/init directory to 
+learn more about the boot process.
 
-Luna is free software, released under the BSD-2-Clause license. The license is included in the LICENSE file in your home directory.
+Luna is free software, released under the BSD-2-Clause license. 
+The license is included in the LICENSE file in your home directory.
 
-View the source code and read more about Luna at https://git.cloudapio.eu/apio/Luna.
+View the source code and read more about Luna at
+https://git.cloudapio.eu/apio/Luna.

base/etc/user/00-terminal

@@ -1,3 +0,0 @@
-Name=terminal
-Description=Start the terminal.
-Command=/usr/bin/terminal

base/etc/user/00-welcome

@@ -0,0 +1,3 @@
+Name=welcome
+Description=Show a welcome message for the user.
+Command=/usr/bin/editor welcome

base/usr/share/applications/05-editor

@@ -0,0 +1,3 @@
+Name=editor
+Icon=/usr/share/icons/32x32/app-editor.tga
+Command=/usr/bin/editor

docs/boot_process.md

@@ -54,15 +54,15 @@ As soon as the scheduler switches to the `[kinit]` thread, it will never return
 
 `[kinit]` spawns two more kernel threads, `[reap]` and `[oom]`. While `[kinit]` exits before PID 1 is started, `[reap]` and `[oom]` are present throughout the lifetime of a Luna system, and can be seen in the output of `ps`. Let's take a look at what they do.
 
-- `[reap]`: To understand what this thread does, we must take a look at what happens when threads exit on Luna.
+- `[reap]`: To understand what this thread does, we must take a look at what happens when processes exit on Luna.
 
-    _(Relevant files: [kernel/src/main.cpp](../kernel/src/main.cpp#L23), [kernel/src/thread/Scheduler.cpp](../kernel/src/thread/Scheduler.cpp#L205), [kernel/src/thread/Thread.cpp](../kernel/src/thread/Thread.cpp#L105), [kernel/src/sys/waitpid.cpp](../kernel/src/sys/waitpid.cpp#L84))_
+    _(Relevant files: [kernel/src/main.cpp](../kernel/src/main.cpp#L23), [kernel/src/thread/Scheduler.cpp](../kernel/src/thread/Scheduler.cpp#L231), [kernel/src/thread/Thread.cpp](../kernel/src/thread/Thread.cpp#L126), [kernel/src/sys/waitpid.cpp](../kernel/src/sys/waitpid.cpp#L84))_
 
-    When a thread calls the `_exit()` syscall, its state is set to "Exited". This tells the scheduler to avoid switching to it, and the thread's parent is notified, either by sending SIGCHLD or unblocking a blocked `waitpid()` call. The thread remains visible to the rest of the system, and if its parent does not wait for it, it will stay there as a "zombie thread".
+    When a process calls the `_exit()` syscall, all its threads' states are set to "Dying". This tells the scheduler to avoid switching to them, and the process's parent is notified, by sending SIGCHLD and (optionally) unblocking a blocked `waitpid()` call. The process remains visible to the rest of the system, and if its parent does not wait for it, it will stay there as a "zombie process". Meanwhile, the `[reap]` thread runs and collects all the resources from each thread. The process object is still alive (in a "zombie" state), but its threads have been cleaned up.
 
-    When the thread's parent waits for it, its state is instead set to "Dying", and the `[reap]` thread runs. (Kernel threads skip all the "parent notifying" shenanigans and go straight to the "Dying" state when calling `kernel_exit()`).
+    When the process's parent waits for it, it is marked for reaping (by setting its thread count to -1 (PROCESS_SHOULD_REAP)), and the `[reap]` thread runs.
 
-    The `[reap]` thread then "reaps" all the "Dying" threads' resources. It frees up the threads' memory, file descriptors, and unmaps the memory used for the kernel stack corresponding to that thread. After reaping, the thread is deleted, and no trace of it is left.
+    The `[reap]` thread then "reaps" all the dead processes' resources. It frees up their memory, file descriptors, and other resources. After reaping, the process is deleted, and no trace of it is left.
 
 - `[oom]`: This thread handles Out-Of-Memory (OOM) situations. Whenever the kernel has 1/4 or 1/8 of the available physical memory left (thresholds may be tweaked in the future), or it has run out, it runs this thread.
 
@@ -90,7 +90,7 @@ After the kernel stage of the boot process, the system looks like this:
 ```
 
 ## Stage 2: preinit
-_Relevant files: [apps/preinit.cpp](../apps/preinit.cpp)_
+_Relevant files: [system/preinit.cpp](../system/preinit.cpp)_
 
 Luna's userspace init process is split into two programs: `/bin/preinit`, which resides on the initial ramdisk, and `/usr/bin/init`, which resides on the root partition.
 
@@ -133,7 +133,7 @@ After the preinit stage of the boot process, the system looks like this:
 ```
 
 ## Stage 3: init
-_Relevant files: [apps/init.cpp](../apps/init.cpp#L406)_
+_Relevant files: [system/init.cpp](../system/init.cpp#L406)_
 
 `/usr/bin/init` is the actual init system. It is in charge of starting user-defined services.
 
@@ -149,7 +149,7 @@ Currently, there are two service files defined by default in `/etc/init`:
 
 `00-home`: This service sets up a `tmpfs` on `/home/selene`, so that the home directory is writable.
 
-`99-login`: This service starts a graphical session, by calling `/usr/bin/startui`. This service will be restarted if necessary.
+`99-login`: This service starts a graphical session, by calling `/usr/bin/loginui`. This service will be restarted if necessary.
 
 ### File system and process layout
 
@@ -172,24 +172,60 @@ After the init stage of the boot process, the system looks like this:
 [x86_64-io]         - PID 3
 [reap]              - PID 4
 [oom]               - PID 5
-/usr/bin/startui    - PID 13
+/usr/bin/loginui    - PID 13
 ```
 
-_Note: startui is PID 13 because the `00-home` service is a shell script, which starts a few subprocesses. Since Luna does not allow for PID reuse right now, startui ends up with PID 13._
+_Note: loginui is PID 13 because the `00-home` service is a shell script, which starts a few subprocesses. Since Luna does not allow for PID reuse right now, loginui ends up with PID 13._
 
-## Stage 4: startui
-_Relevant files: [apps/startui.cpp](../apps/startui.cpp), [wind/main.cpp](../wind/main.cpp)_
+## Stage 4: loginui
+_Relevant files: [gui/loginui.cpp](../gui/loginui.cpp), [gui/wind/main.cpp](../gui/wind/main.cpp)_
+
+`/usr/bin/loginui`'s job is quite simple: it prompts the user to log in with their password, after which a graphical session is started.
+
+_Note: On development builds, Autologin=true is added to /etc/loginui.conf which disables password prompting and executes startui directly._
+
+First, loginui starts the display server, `/usr/bin/wind`, so that it can use its capabilities to show a graphical login prompt. It is started with permissions `root:root`, and later drops privileges to `wind:wind`.
+
+After that, loginui prompts for a username and password, checks it against the hashed password stored in `/etc/shadow`, and finally executes `/usr/bin/startui` which does the actual heavy work of starting all the services needed for a UI session.
+
+### File system and process layout
+
+After the loginui stage of the boot process, the system looks like this:
+
+#### File system
+```
+/ - ext2 root partition
+    /dev - device file system
+        /dev/shm - POSIX shared memory file system
+        /dev/pts - POSIX pseudoterminal file system
+    /tmp - system temporary file directory
+    /usr, /etc, /home... - other directories contained in the root partition
+        /home/selene - temporary home directory
+```
+
+#### Processes
+```
+/usr/bin/init           - PID 1
+[x86_64-io]             - PID 3
+[reap]                  - PID 4
+[oom]                   - PID 5
+/usr/bin/startui        - PID 13
+/usr/bin/wind           - PID 14
+```
+
+## Stage 5: startui
+_Relevant files: [system/startui.cpp](../system/startui.cpp), [gui/wind/main.cpp](../gui/wind/main.cpp)_
 
 `/usr/bin/startui` starts a graphical user session.
 
 A Luna graphical user session includes the following components:
 
-- The display server itself, `/usr/bin/wind`. It is started with permissions `root:root`, and later drops privileges to `wind:wind`.
-- The launch server (`/usr/bih/launch`), which starts processes and keeps them alive on behalf of other processes. It is started with the standard permissions `selene:selene`.
-- The taskbar, `/usr/bin/taskbar`. It is started with the standard permissions `selene:selene`, plus an extra group `wsys` to be able to connect to a special display server socket.
+- The display server itself, `/usr/bin/wind`. If not already started by loginui, `startui` makes sure it's running.
+- The execution server (`/usr/bin/execd`), which starts processes and keeps them alive on behalf of other processes. It is started with the standard permissions `selene:selene`.
+- The taskbar, `/usr/bin/taskbar`. It is started with the standard permissions `selene:selene`, plus an extra group `wsys` to be able to connect to a special display server socket (`/tmp/wsys.sock`, as opposed to the standard `/tmp/wind.sock`). This grants it the ability to use advanced wind features, such as placing the taskbar window behind all other windows.
 - The init process corresponding to that session (`/usr/bin/init --user`). This process does the same thing as `init` above (manages services), but runs with user privileges and reads configuration files from `/etc/user` instead (in the future this will be changed to a user-specific directory).
 
-Currently, `init --user` only does one thing: it opens up a terminal window on startup. It can be configured to do whatever the user desires to do on startup, by placing the appropriate configuration files in `/etc/user`.
+Currently, `init --user` only does one thing: it opens up a text editor with a welcome message on startup. It can be configured to do whatever the user desires to do on startup, by placing the appropriate configuration files in `/etc/user`.
 
 ### File system and process layout
 
@@ -214,8 +250,7 @@ After the startui stage of the boot process, the system is fully started up and
 [oom]                   - PID 5
 /usr/bin/startui        - PID 13
 /usr/bin/wind           - PID 14
-/usr/bin/launch         - PID 15
+/usr/bin/execd          - PID 15
 /usr/bin/taskbar        - PID 16
 /usr/bin/init --user    - PID 17
-/usr/bin/terminal       - PID 18
-/bin/sh                 - PID 19
+/usr/bin/editor welcome - PID 18

docs/dependencies.md

@@ -0,0 +1,35 @@
+# Dependencies required to build and run Luna
+
+## System requirements
+
+Any modern UNIX-like system that supports all the tools listed below should work (Hopefully, that will include Luna itself in the future!). 
+
+I personally build and run Luna on an amd64 Fedora Linux 40 machine. CI runs on arm64 Ubuntu 22.04. Any other configurations are untested. Windows is not supported, although you can try using WSL if you really want to.
+
+## Building a cross-compiler toolchain
+For this, you should start by installing the [required dependencies](https://wiki.osdev.org/GCC_Cross_Compiler#Installing_Dependencies) for any OSdev cross-compiler build.
+
+Also make sure you have the perl module `File::Compare` installed, it is required to build autoconf. On Fedora you can install it using the package manager by running `# dnf install perl-File-Compare`. If your distro doesn't have it, you might have to install it via `cpan`.
+
+## Building the actual system
+The build process needs some extra dependencies to run: `cmake`, `ninja`, `nasm`, `fakeroot` and `genext2fs`. On some distributions the `ninja` package is called `ninja-build` instead.
+
+If you want to use `make` instead of `ninja`, create a file called `env-local.sh` in the project root and add the line `USE_MAKE=1`. In this case, ninja does not need to be installed.
+
+## Running the built image in a virtual machine
+The script provided by the project to run the system, `tools/run.sh`, assumes that QEMU is installed and uses that to run the image. Therefore, make sure your system has `qemu-system-x86_64` in the PATH. If it doesn't, install it using the method appropriate for your system, usually installing `qemu` or `qemu-system` from the package manager.
+
+That being said, there's no requirement to use QEMU. If you want to use a different virtualization program, such as Oracle VirtualBox or VMWare, just use `tools/build-iso.sh` instead of `run.sh` and use the built `Luna.iso` in those programs.
+
+## Formatting/linting
+
+Please make sure you have `clang-format` installed. Additionally, if your editor does not support format-on-save or you do not have it configured, please run `tools/run-clang-format.sh` before committing, to make sure all code follows the same style conventions.
+
+## Source dependencies
+TLDR: Luna does not depend on any third-party library.
+
+Every part of Luna is written from scratch and depends only on its own libraries and programs, with two small exceptions (included here for crediting and licensing purposes, but there is no need to download and build them separately):
+
+The bootloader, BOOTBOOT. It is available at [gitlab.com/bztsrc/bootboot](https://gitlab.com/bztsrc/bootboot), under the MIT license. It is automatically pulled and built from source by `tools/setup.sh`.
+
+[libc/src/strtod.cpp](../libc/src/strtod.cpp). Written by Yasuhiro Matsumoto, adapted from https://gist.github.com/mattn/1890186 and available under a public domain license.

gui/CMakeLists.txt

@@ -0,0 +1,17 @@
+function(luna_service SOURCE_FILE APP_NAME)
+    add_executable(${APP_NAME} ${SOURCE_FILE})
+    target_compile_options(${APP_NAME} PRIVATE -Os ${COMMON_FLAGS} -Wno-write-strings)
+    add_dependencies(${APP_NAME} libc)
+    target_include_directories(${APP_NAME} PRIVATE ${LUNA_BASE}/usr/include)
+    target_link_libraries(${APP_NAME} PRIVATE os)
+    install(TARGETS ${APP_NAME} DESTINATION ${LUNA_BASE}/usr/bin)
+endfunction()
+
+add_subdirectory(libui)
+add_subdirectory(wind)
+add_subdirectory(apps)
+
+luna_service(execd.cpp execd)
+luna_service(run.cpp run)
+luna_service(loginui.cpp loginui)
+target_link_libraries(loginui PRIVATE ui)

gui/apps/2048.cpp

@@ -1,4 +1,4 @@
-#include <luna/String.h>
+#include <luna/RefString.h>
 #include <luna/Utf8.h>
 #include <stdlib.h>
 #include <time.h>
@@ -325,7 +325,7 @@ class GameWidget final : public ui::Widget
 
         canvas.fill(colors[tile.color]);
 
-        auto fmt = TRY(String::format("%d"_sv, tile.number));
+        auto fmt = TRY(RefString::format("%d"_sv, tile.number));
 
         auto font = ui::Font::default_bold_font();
         auto rect = ui::align({ 0, 0, canvas.width, canvas.height },

gui/apps/CMakeLists.txt

@@ -0,0 +1,17 @@
+function(luna_app SOURCE_FILE APP_NAME)
+    add_executable(${APP_NAME} ${SOURCE_FILE})
+    target_compile_options(${APP_NAME} PRIVATE -Os ${COMMON_FLAGS} -Wno-write-strings)
+    add_dependencies(${APP_NAME} libc)
+    target_include_directories(${APP_NAME} PRIVATE ${LUNA_BASE}/usr/include)
+    target_link_libraries(${APP_NAME} PRIVATE os ui)
+    install(TARGETS ${APP_NAME} DESTINATION ${LUNA_BASE}/usr/bin)
+endfunction()
+
+luna_app(about.cpp about)
+luna_app(taskbar.cpp taskbar)
+luna_app(2048.cpp 2048)
+luna_app(clock.cpp clock)
+luna_app(gol.cpp gol)
+
+add_subdirectory(editor)
+add_subdirectory(terminal)

gui/apps/editor/EditorWidget.cpp

@@ -10,10 +10,12 @@
 #include "EditorWidget.h"
 #include <ctype.h>
 #include <luna/PathParser.h>
+#include <luna/RefString.h>
 #include <luna/Utf8.h>
 #include <os/File.h>
 #include <os/FileSystem.h>
 #include <ui/App.h>
+#include <ui/Dialog.h>
 
 EditorWidget::EditorWidget(SharedPtr<ui::Font> font) : ui::TextInput(), m_font(font)
 {
@@ -27,7 +29,8 @@ Result<void> EditorWidget::load_file(const os::Path& path)
 
     if (!rc.has_error() && !S_ISREG(st.st_mode))
     {
-        os::eprintln("editor: not loading %s as it is not a regular file", path.name().chars());
+        auto message = TRY(RefString::format("%s is not a regular file", path.name().chars()));
+        ui::Dialog::show_message("Error", message.view());
         return {};
     }
 
@@ -41,9 +44,9 @@ Result<void> EditorWidget::load_file(const os::Path& path)
 
     m_cursor = m_data.size();
 
-    m_path = path;
+    m_path = TRY(String::from_string_view(path.name()));
 
-    auto basename = TRY(PathParser::basename(m_path.name()));
+    auto basename = TRY(PathParser::basename(m_path.view()));
 
     String title = TRY(String::format("Text Editor - %s"_sv, basename.chars()));
     window()->set_title(title.view());
@@ -126,15 +129,38 @@ Result<ui::EventResult> EditorWidget::handle_key_event(const ui::KeyEventRequest
     return ui::EventResult::DidHandle;
 }
 
+Result<void> EditorWidget::save_file_as()
+{
+    ui::Dialog::show_input_dialog(
+        "Save file as...", "Please enter the path to save this file to:", [this](StringView path) {
+            m_path = String::from_string_view(path).release_value();
+            auto rc = save_file();
+            if (rc.has_error())
+            {
+                os::eprintln("Failed to save file %s: %s", m_path.chars(), rc.error_string());
+                ui::Dialog::show_message("Error", "Failed to save file");
+            }
+            else
+            {
+                auto basename = PathParser::basename(m_path.view()).release_value();
+
+                String title = String::format("Text Editor - %s"_sv, basename.chars()).release_value();
+                window()->set_title(title.view());
+            }
+        });
+
+    return {};
+}
+
 Result<void> EditorWidget::save_file()
 {
-    if (m_path.is_empty_path())
+    if (m_path.is_empty())
     {
-        os::eprintln("editor: no file to save buffer to!");
-        return err(ENOENT);
+        TRY(save_file_as());
+        return {};
     }
 
-    auto file = TRY(os::File::open(m_path, os::File::WriteOnly));
+    auto file = TRY(os::File::open_or_create(m_path.view(), os::File::WriteOnly));
     return file->write(m_data);
 }
 

gui/apps/editor/EditorWidget.h

@@ -21,14 +21,15 @@ class EditorWidget : public ui::TextInput
     Result<void> load_file(const os::Path& path);
 
     Result<void> save_file();
+    Result<void> save_file_as();
 
     Result<ui::EventResult> handle_key_event(const ui::KeyEventRequest& request) override;
 
     Result<void> draw(ui::Canvas& canvas) override;
 
-    os::Path& path()
+    os::Path path()
     {
-        return m_path;
+        return m_path.view();
     }
 
   private:
@@ -41,7 +42,7 @@ class EditorWidget : public ui::TextInput
     };
     Vector<Line> m_lines;
 
-    os::Path m_path { AT_FDCWD };
+    String m_path;
 
     Result<void> recalculate_lines();
     void recalculate_cursor_position();

gui/apps/editor/main.cpp

@@ -11,6 +11,7 @@
 #include <os/ArgumentParser.h>
 #include <os/File.h>
 #include <ui/App.h>
+#include <ui/Dialog.h>
 
 Result<int> luna_main(int argc, char** argv)
 {
@@ -32,15 +33,20 @@ Result<int> luna_main(int argc, char** argv)
 
     auto* editor = TRY(make<EditorWidget>(ui::Font::default_font()));
     window->set_main_widget(*editor);
-    if (!path.is_empty()) TRY(editor->load_file(path));
+    if (!path.is_empty()) editor->load_file(path);
 
     TRY(window->add_keyboard_shortcut({ moon::K_CH26, ui::Mod_Ctrl }, true, [&](ui::Shortcut) {
         auto result = editor->save_file();
-        if (result.has_error()) os::eprintln("editor: failed to save file: %s", result.error_string());
-        else
-            os::println("editor: buffer saved to %s successfully", editor->path().name().chars());
+        if (result.has_error())
+        {
+            os::eprintln("Failed to save file %s: %s", editor->path().name().chars(), result.error_string());
+            ui::Dialog::show_message("Error", "Failed to save file");
+        }
     }));
 
+    TRY(window->add_keyboard_shortcut({ moon::K_CH26, ui::Mod_Ctrl | ui::Mod_Shift }, true,
+                                      [&](ui::Shortcut) { editor->save_file_as(); }));
+
     window->draw();
 
     return app.run();

gui/apps/taskbar.cpp

@@ -1,5 +1,6 @@
 #include <luna/Sort.h>
 #include <luna/StringBuilder.h>
+#include <os/Config.h>
 #include <os/Directory.h>
 #include <os/File.h>
 #include <os/FileSystem.h>
@@ -18,12 +19,7 @@ static constexpr ui::Color TASKBAR_COLOR = ui::Color::from_rgb(83, 83, 83);
 
 static OwnedPtr<os::IPC::Client> launcher_client;
 
-void sigchld_handler(int)
-{
-    wait(nullptr);
-}
-
-void sighup_handler(int)
+void sigquit_handler(int)
 {
     // Reload the taskbar by exec-ing the executable, resetting everything.
     StringView args[] = { "/usr/bin/taskbar" };
@@ -66,64 +62,31 @@ static Result<void> load_application_file(const os::Path& path)
 {
     os::println("[taskbar] reading app file: %s", path.name().chars());
 
-    auto file = TRY(os::File::open(path, os::File::ReadOnly));
+    auto file = TRY(os::ConfigFile::open(path));
 
     ApplicationFile app_file;
 
-    while (true)
+    app_file.name = TRY(String::from_string_view(file->read_string_or("Name", "")));
+    if (app_file.name.is_empty())
     {
-        auto line = TRY(file->read_line());
-        if (line.is_empty()) break;
-
-        line.trim("\n");
-        if (line.is_empty()) continue;
-
-        auto parts = TRY(line.split_once('='));
-        if (parts.size() < 2 || parts[0].is_empty() || parts[1].is_empty())
-        {
-            os::println("[taskbar] file contains invalid line, aborting: '%s'", line.chars());
-            return {};
-        }
-
-        if (parts[0].view() == "Name")
-        {
-            app_file.name = move(parts[1]);
-            continue;
-        }
-
-        if (parts[0].view() == "Description")
-        {
-            // We let users specify this in the config file, but taskbar doesn't actually use it.
-            continue;
-        }
-
-        if (parts[0].view() == "Command")
-        {
-            app_file.command = move(parts[1]);
-            continue;
-        }
-
-        if (parts[0].view() == "Icon")
-        {
-            app_file.icon = move(parts[1]);
-            continue;
-        }
-
-        os::println("[taskbar] skipping unknown entry name %s", parts[0].chars());
-    }
-
-    if (app_file.icon.is_empty())
-    {
-        os::println("[taskbar] app file is missing 'Icon' entry, aborting!");
+        os::println("[taskbar] app file is missing 'Name' entry, aborting!");
         return {};
     }
 
+    app_file.command = TRY(String::from_string_view(file->read_string_or("Command", "")));
     if (app_file.command.is_empty())
     {
         os::println("[taskbar] app file is missing 'Command' entry, aborting!");
         return {};
     }
 
+    app_file.icon = TRY(String::from_string_view(file->read_string_or("Icon", "")));
+    if (app_file.icon.is_empty())
+    {
+        os::println("[taskbar] app file is missing 'Icon' entry, aborting!");
+        return {};
+    }
+
     os::println("[taskbar] loaded app %s into memory", app_file.name.chars());
 
     TRY(s_app_files.try_append(move(app_file)));
@@ -149,11 +112,11 @@ Result<int> luna_main(int, char**)
 {
     ui::App app;
     TRY(app.init("/tmp/wsys.sock"));
+    app.pledge(ui::Pledge::ExtendedLayers);
 
-    TRY(os::EventLoop::the().register_signal_handler(SIGCHLD, sigchld_handler));
-    TRY(os::EventLoop::the().register_signal_handler(SIGHUP, sighup_handler));
+    TRY(os::EventLoop::the().register_signal_handler(SIGQUIT, sigquit_handler));
 
-    launcher_client = TRY(os::IPC::Client::connect("/tmp/launch.sock", false));
+    launcher_client = TRY(os::IPC::Client::connect("/tmp/execd.sock", false));
 
     ui::Rect screen = app.screen_rect();
 
@@ -163,7 +126,8 @@ Result<int> luna_main(int, char**)
     app.set_main_window(window);
 
     window->set_background(TASKBAR_COLOR);
-    window->set_special_attributes(ui::UNFOCUSEABLE);
+    window->set_layer(ui::Layer::Background);
+    app.pledge(0);
 
     ui::HorizontalLayout layout(ui::Margins { 0, 0, 0, 0 }, ui::AdjustHeight::Yes, ui::AdjustWidth::No);
     window->set_main_widget(layout);

gui/execd.cpp

@@ -1,5 +1,5 @@
 /**
- * @file launch.cpp
+ * @file execd.cpp
  * @author apio (cloudapio.eu)
  * @brief Background process that handles detached launching of apps.
  *
@@ -10,6 +10,7 @@
 #include <errno.h>
 #include <os/ArgumentParser.h>
 #include <os/File.h>
+#include <os/IPC.h>
 #include <os/LocalServer.h>
 #include <os/Process.h>
 #include <os/Security.h>
@@ -41,24 +42,24 @@ void handle_ipc_message(os::IPC::ClientConnection& client, u8 id, void*)
     switch (id)
     {
     case os::Launcher::LAUNCH_DETACHED_ID: handle_launch_detached_message(client); break;
-    default: os::eprintln("launch: Invalid IPC message from client!"); return;
+    default: os::eprintln("execd: Invalid IPC message from client!"); return;
     }
 }
 
 void sigchld_handler(int)
 {
-    os::Process::wait(os::Process::ANY_CHILD, nullptr);
+    os::Process::wait(os::Process::ANY_CHILD, nullptr, WNOHANG);
 }
 
 Result<int> luna_main(int argc, char** argv)
 {
     TRY(os::Security::pledge("stdio wpath cpath unix proc exec", NULL));
 
-    StringView socket_path = "/tmp/launch.sock";
+    StringView socket_path = "/tmp/execd.sock";
 
     os::ArgumentParser parser;
     parser.add_description("Background process that handles detached launching of apps."_sv);
-    parser.add_system_program_info("launch"_sv);
+    parser.add_system_program_info("execd"_sv);
     parser.parse(argc, argv);
 
     signal(SIGCHLD, sigchld_handler);
@@ -66,6 +67,9 @@ Result<int> luna_main(int argc, char** argv)
     auto server = TRY(os::LocalServer::create(socket_path, false));
     TRY(server->listen(20));
 
+    // We're ready now.
+    os::IPC::notify_parent();
+
     Vector<OwnedPtr<os::IPC::ClientConnection>> clients;
     Vector<struct pollfd> fds;
     TRY(fds.try_append({ .fd = server->fd(), .events = POLLIN, .revents = 0 }));
@@ -83,7 +87,7 @@ Result<int> luna_main(int argc, char** argv)
         if (fds[0].revents & POLLIN)
         {
             auto client = TRY(server->accept());
-            os::println("launch: New client connected!");
+            os::println("execd: New client connected!");
             TRY(fds.try_append({ .fd = client.fd(), .events = POLLIN, .revents = 0 }));
 
             auto connection = TRY(os::IPC::ClientConnection::adopt_connection(move(client)));
@@ -95,7 +99,7 @@ Result<int> luna_main(int argc, char** argv)
             if (fds[i + 1].revents & POLLIN) clients[i]->check_for_messages();
             if (fds[i + 1].revents & POLLHUP)
             {
-                os::println("launch: Client %zu disconnected", i);
+                os::println("execd: Client %zu disconnected", i);
                 fds.remove_at(i + 1);
                 auto client = clients.remove_at(i);
                 client->disconnect();

gui/libui/CMakeLists.txt

@@ -19,6 +19,7 @@ set(SOURCES
     src/Label.cpp
     src/InputField.cpp
     src/TextInput.cpp
+    src/Dialog.cpp
 )
 
 add_library(ui ${SOURCES})

gui/libui/include/ui/App.h

@@ -49,6 +49,8 @@ namespace ui
             return m_main_window;
         }
 
+        void pledge(i16 pledges);
+
         Result<void> register_window(OwnedPtr<Window>&& window, Badge<Window>);
         void unregister_window(Window* window, Badge<Window>);
 
@@ -61,6 +63,7 @@ namespace ui
         HashMap<int, OwnedPtr<Window>> m_windows;
         bool m_should_close { false };
         os::EventLoop m_loop;
+        Vector<int> m_window_clear_queue;
 
         bool process_events();
 

gui/libui/include/ui/Button.h

@@ -8,7 +8,7 @@
  */
 
 #pragma once
-#include <os/Action.h>
+#include <luna/Action.h>
 #include <ui/Widget.h>
 
 namespace ui
@@ -19,7 +19,7 @@ namespace ui
         Button(Rect rect);
 
         void set_widget(Widget& widget);
-        void set_action(os::Action&& action);
+        void set_action(Action&& action);
 
         Result<EventResult> handle_mouse_move(Point position) override;
         Result<EventResult> handle_mouse_leave() override;
@@ -32,6 +32,6 @@ namespace ui
         bool m_hovered { false };
         bool m_clicked { false };
         Widget* m_child;
-        os::Action m_action;
+        Action m_action;
     };
 }

gui/libui/include/ui/Dialog.h

@@ -0,0 +1,22 @@
+/**
+ * @file Window.h
+ * @author apio (cloudapio.eu)
+ * @brief UI window dialogs.
+ *
+ * @copyright Copyright (c) 2024, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <luna/Action.h>
+#include <ui/Window.h>
+
+namespace ui
+{
+    namespace Dialog
+    {
+        Result<void> show_message(StringView title, StringView message);
+
+        Result<void> show_input_dialog(StringView title, StringView message, Function<StringView> callback);
+    }
+}

gui/libui/include/ui/InputField.h

@@ -8,13 +8,13 @@
  */
 
 #pragma once
-#include <os/Action.h>
+#include <luna/Action.h>
 #include <ui/Font.h>
 #include <ui/TextInput.h>
 
 namespace ui
 {
-    class InputField : public ui::TextInput
+    class InputField final : public ui::TextInput
     {
       public:
         InputField(SharedPtr<ui::Font> font);
@@ -23,9 +23,11 @@ namespace ui
 
         Result<void> draw(ui::Canvas& canvas) override;
 
+        void clear();
+
         StringView data();
 
-        void on_submit(os::Function<StringView>&& action)
+        void on_submit(Function<StringView>&& action)
         {
             m_on_submit_action = move(action);
             m_has_on_submit_action = true;
@@ -34,7 +36,7 @@ namespace ui
       private:
         SharedPtr<ui::Font> m_font;
 
-        os::Function<StringView> m_on_submit_action;
+        Function<StringView> m_on_submit_action;
         bool m_has_on_submit_action { false };
     };
 }

gui/libui/include/ui/Window.h

@@ -65,7 +65,7 @@ namespace ui
 
         void close();
 
-        void set_special_attributes(WindowAttributes attributes);
+        void set_layer(Layer layer);
 
         Result<void> draw();
         Result<ui::EventResult> handle_mouse_leave();
@@ -73,13 +73,19 @@ namespace ui
         Result<ui::EventResult> handle_mouse_buttons(ui::Point position, int buttons);
         Result<ui::EventResult> handle_key_event(const ui::KeyEventRequest& request);
 
-        Result<void> add_keyboard_shortcut(ui::Shortcut shortcut, bool intercept, os::Function<ui::Shortcut>&& action);
+        Result<void> add_keyboard_shortcut(ui::Shortcut shortcut, bool intercept, Function<ui::Shortcut>&& action);
 
         int id() const
         {
             return m_id;
         }
 
+        void on_close(Action&& action)
+        {
+            m_on_close_action = move(action);
+            m_has_on_close_action = true;
+        }
+
         ~Window();
 
       private:
@@ -93,10 +99,13 @@ namespace ui
         Option<int> m_old_mouse_buttons;
         bool m_decorated { false };
 
+        Action m_on_close_action;
+        bool m_has_on_close_action { false };
+
         struct ShortcutAction
         {
             bool intercept;
-            os::Function<Shortcut> action;
+            Function<Shortcut> action;
         };
 
         HashMap<Shortcut, ShortcutAction> m_shortcuts;

gui/libui/include/ui/ipc/Server.h

@@ -25,7 +25,8 @@ namespace ui
         CLOSE_WINDOW_ID,
         GET_SCREEN_RECT_ID,
         SET_TITLEBAR_HEIGHT_ID,
-        SET_SPECIAL_WINDOW_ATTRIBUTES_ID,
+        SET_WINDOW_LAYER_ID,
+        UPDATE_PLEDGE_REQUEST_ID,
     };
 
     struct CreateWindowRequest
@@ -81,16 +82,32 @@ namespace ui
         int height;
     };
 
-    enum WindowAttributes : u8
+    enum Layer : u8
     {
-        UNFOCUSEABLE = 1,
+        Background,
+        Global,
+        GlobalTop,
+        System,
+        Lock
     };
 
-    struct SetSpecialWindowAttributesRequest
+    struct SetWindowLayer
     {
-        static constexpr u8 ID = SET_SPECIAL_WINDOW_ATTRIBUTES_ID;
+        static constexpr u8 ID = SET_WINDOW_LAYER_ID;
 
         int window;
-        WindowAttributes attributes;
+        Layer layer;
+    };
+
+    enum Pledge : i16
+    {
+        ExtendedLayers = 1,
+    };
+
+    struct UpdatePledgeRequest
+    {
+        static constexpr u8 ID = UPDATE_PLEDGE_REQUEST_ID;
+
+        i16 pledges;
     };
 }

gui/libui/src/App.cpp

@@ -75,7 +75,7 @@ namespace ui
     void App::unregister_window(Window* window, Badge<Window>)
     {
         int id = window->id();
-        check(m_windows.try_remove(id));
+        m_window_clear_queue.try_append(id);
     }
 
     Window* App::find_window(int id)
@@ -124,6 +124,22 @@ namespace ui
     {
         check(m_main_window);
         m_client->check_for_messages().release_value();
+        for (int id : m_window_clear_queue)
+        {
+            check(m_windows.try_remove(id));
+
+            ui::CloseWindowRequest request;
+            request.window = id;
+            client().send_async(request);
+        }
+        m_window_clear_queue.clear_data();
         return !m_should_close;
     }
+
+    void App::pledge(i16 pledges)
+    {
+        ui::UpdatePledgeRequest request;
+        request.pledges = pledges;
+        client().send_async(request);
+    }
 }

gui/libui/src/Button.cpp

@@ -24,7 +24,7 @@ namespace ui
         widget.set_parent(this);
     }
 
-    void Button::set_action(os::Action&& action)
+    void Button::set_action(Action&& action)
     {
         m_action = move(action);
     }

gui/libui/src/Dialog.cpp

@@ -0,0 +1,82 @@
+/**
+ * @file Dialog.cpp
+ * @author apio (cloudapio.eu)
+ * @brief UI window dialogs.
+ *
+ * @copyright Copyright (c) 2024, the Luna authors.
+ *
+ */
+
+#include <luna/Alloc.h>
+#include <ui/App.h>
+#include <ui/Dialog.h>
+#include <ui/InputField.h>
+#include <ui/Label.h>
+#include <ui/Layout.h>
+
+namespace ui::Dialog
+{
+    Result<void> show_message(StringView title, StringView message)
+    {
+        auto rect = ui::App::the().main_window()->canvas().rect();
+        int text_length = (int)message.length() * ui::Font::default_font()->width();
+        int text_height = ui::Font::default_font()->height();
+
+        ui::Rect dialog_rect = { 0, 0, text_length + 20, text_height + 20 };
+
+        auto* dialog = TRY(ui::Window::create(
+            ui::align(rect, dialog_rect, ui::VerticalAlignment::Center, ui::HorizontalAlignment::Center)));
+
+        dialog->set_background(ui::GRAY);
+        dialog->set_title(title);
+
+        ui::Label* text = TRY(make<ui::Label>(message));
+        text->set_color(ui::BLACK);
+        dialog->set_main_widget(*text);
+
+        dialog->on_close([text] { delete text; });
+
+        dialog->draw();
+
+        return {};
+    }
+
+    Result<void> show_input_dialog(StringView title, StringView message, Function<StringView> callback)
+    {
+        auto rect = ui::App::the().main_window()->canvas().rect();
+        int text_length = (int)message.length() * ui::Font::default_font()->width();
+        int text_height = ui::Font::default_font()->height();
+
+        ui::Rect dialog_rect = { 0, 0, max(text_length + 20, 300), text_height * 2 + 30 };
+
+        auto* dialog = TRY(ui::Window::create(
+            ui::align(rect, dialog_rect, ui::VerticalAlignment::Center, ui::HorizontalAlignment::Center)));
+
+        dialog->set_background(ui::GRAY);
+        dialog->set_title(title);
+
+        ui::VerticalLayout* layout = TRY(make<ui::VerticalLayout>());
+        dialog->set_main_widget(*layout);
+
+        ui::Label* text = TRY(make<ui::Label>((message)));
+        text->set_color(ui::BLACK);
+        layout->add_widget(*text);
+
+        ui::InputField* input = TRY(make<ui::InputField>(ui::Font::default_font()));
+        input->on_submit([dialog, callback](StringView s) {
+            callback(s);
+            dialog->close();
+        });
+        layout->add_widget(*input);
+
+        dialog->on_close([layout, text, input] {
+            delete text;
+            delete input;
+            delete layout;
+        });
+
+        dialog->draw();
+
+        return {};
+    }
+}

gui/libui/src/Font.cpp

@@ -7,7 +7,7 @@
  *
  */
 
-#include <luna/String.h>
+#include <luna/RefString.h>
 #include <os/File.h>
 #include <ui/Font.h>
 
@@ -49,8 +49,8 @@ namespace ui
 
     Result<SharedPtr<Font>> Font::load_builtin(StringView name, FontWeight weight)
     {
-        auto path = TRY(String::format("/usr/share/fonts/%s-%s.psf"_sv, name.chars(),
-                                       weight == FontWeight::Bold ? "Bold" : "Regular"));
+        auto path = TRY(RefString::format("/usr/share/fonts/%s-%s.psf"_sv, name.chars(),
+                                          weight == FontWeight::Bold ? "Bold" : "Regular"));
 
         return load(path.view());
     }

gui/libui/src/InputField.cpp

@@ -17,6 +17,8 @@ namespace ui
 {
     InputField::InputField(SharedPtr<ui::Font> font) : ui::TextInput(), m_font(font)
     {
+        u8 zero = 0;
+        m_data.append_data(&zero, 1);
     }
 
     Result<ui::EventResult> InputField::handle_key_event(const ui::KeyEventRequest& request)
@@ -35,7 +37,7 @@ namespace ui
 
         if (request.code == moon::K_RightArrow)
         {
-            if (m_cursor < m_data.size()) m_cursor++;
+            if (m_cursor < (m_data.size() - 1)) m_cursor++;
             else
                 return ui::EventResult::DidNotHandle;
             update_cursor();
@@ -67,9 +69,7 @@ namespace ui
 
         if (iscntrl(request.letter)) return ui::EventResult::DidNotHandle;
 
-        if (m_cursor == m_data.size()) TRY(m_data.append_data((const u8*)&request.letter, 1));
-        else
-            TRY(insert_character(request.letter));
+        TRY(insert_character(request.letter));
 
         m_cursor++;
 
@@ -78,6 +78,14 @@ namespace ui
         return ui::EventResult::DidHandle;
     }
 
+    void InputField::clear()
+    {
+        m_data.try_resize(0);
+        u8 zero = 0;
+        m_data.append_data(&zero, 1);
+        m_cursor = 0;
+    }
+
     Result<void> InputField::draw(ui::Canvas& canvas)
     {
         int visible_characters = canvas.width / m_font->width();
@@ -107,6 +115,7 @@ namespace ui
 
     StringView InputField::data()
     {
-        return StringView { (const char*)m_data.data(), m_data.size() };
+        if (m_data.size() < 2) return StringView {};
+        return StringView { (const char*)m_data.data(), m_data.size() - 1 };
     }
 }

gui/libui/src/Window.cpp

@@ -84,6 +84,8 @@ namespace ui
     Window::~Window()
     {
         if (m_canvas.ptr) munmap(m_canvas.ptr, ((usize)m_canvas.width) * ((usize)m_canvas.height) * 4);
+
+        if (m_has_on_close_action) m_on_close_action();
     }
 
     void Window::set_title(StringView title)
@@ -108,20 +110,16 @@ namespace ui
     {
         App& app = App::the();
 
-        ui::CloseWindowRequest request;
-        request.window = m_id;
-        app.client().send_async(request);
-
         if (this == app.main_window()) app.set_should_close(true);
 
         app.unregister_window(this, {});
     }
 
-    void Window::set_special_attributes(WindowAttributes attributes)
+    void Window::set_layer(Layer layer)
     {
-        ui::SetSpecialWindowAttributesRequest request;
+        ui::SetWindowLayer request;
         request.window = m_id;
-        request.attributes = attributes;
+        request.layer = layer;
         App::the().client().send_async(request);
     }
 
@@ -226,8 +224,7 @@ namespace ui
         return m_main_widget->handle_key_event(request);
     }
 
-    Result<void> Window::add_keyboard_shortcut(ui::Shortcut shortcut, bool intercept,
-                                               os::Function<ui::Shortcut>&& action)
+    Result<void> Window::add_keyboard_shortcut(ui::Shortcut shortcut, bool intercept, Function<ui::Shortcut>&& action)
     {
         TRY(m_shortcuts.try_set(shortcut, { intercept, move(action) }));
 

gui/loginui.cpp

@@ -0,0 +1,186 @@
+/**
+ * @file loginui.cpp
+ * @author apio (cloudapio.eu)
+ * @brief Graphical login prompt.
+ *
+ * @copyright Copyright (c) 2024, the Luna authors.
+ *
+ */
+
+#include <luna/RefString.h>
+#include <luna/SHA.h>
+#include <os/ArgumentParser.h>
+#include <os/Config.h>
+#include <os/File.h>
+#include <os/FileSystem.h>
+#include <os/IPC.h>
+#include <os/Process.h>
+#include <os/Security.h>
+#include <pwd.h>
+#include <shadow.h>
+#include <sys/stat.h>
+#include <ui/App.h>
+#include <ui/Button.h>
+#include <ui/InputField.h>
+#include <ui/Label.h>
+#include <ui/Layout.h>
+#include <unistd.h>
+
+enum Stage
+{
+    UsernameInput,
+    PasswordInput,
+};
+
+static constexpr ui::Color BACKGROUND_COLOR = ui::Color::from_rgb(89, 89, 89);
+
+Result<String> hash_password(StringView& view)
+{
+    SHA256 sha;
+    sha.append((const u8*)view.chars(), view.length());
+    auto digest = TRY(sha.digest());
+    return digest.to_string();
+}
+
+Result<int> luna_main(int argc, char** argv)
+{
+    os::ArgumentParser parser;
+    parser.add_description("Login prompt for a graphical UI session.");
+    parser.add_system_program_info("loginui"_sv);
+    parser.parse(argc, argv);
+
+    if (geteuid() != 0)
+    {
+        os::eprintln("error: %s can only be started as root.", argv[0]);
+        return 1;
+    }
+
+    TRY(os::Security::pledge("stdio rpath wpath unix proc exec id", nullptr));
+
+    setsid();
+
+    bool success = os::IPC::Notifier::run_and_wait(
+        [&] {
+            StringView wind_command[] = { "/usr/bin/wind" };
+            os::Process::spawn(wind_command[0], Slice<StringView>(wind_command, 1));
+        },
+        1000);
+
+    if (!success)
+    {
+        os::eprintln("loginui: failed to start wind, timed out");
+        return 1;
+    }
+
+    auto config = TRY(os::ConfigFile::open("/etc/loginui.conf"));
+
+    if (config->read_boolean_or("Autologin", false))
+    {
+        StringView username = config->read_string_or("AutologinUser", "");
+
+        if (!username.is_empty())
+        {
+            auto flag = RefString::format("--user=%s"_sv, username.chars()).release_value();
+
+            StringView startui_command[] = { "/usr/bin/startui", flag.view() };
+            os::Process::exec(startui_command[0], Slice<StringView>(startui_command, 2));
+            unreachable();
+        }
+    }
+
+    ui::App app;
+    TRY(app.init());
+
+    auto* window = TRY(ui::Window::create(ui::Rect { 300, 300, 400, 300 }));
+    app.set_main_window(window);
+
+    window->set_title("Log in");
+    window->set_background(BACKGROUND_COLOR);
+
+    ui::VerticalLayout main_layout;
+    window->set_main_widget(main_layout);
+
+    ui::Label label("Username:");
+    main_layout.add_widget(label);
+
+    ui::InputField input(ui::Font::default_font());
+    main_layout.add_widget(input);
+
+    ui::Label error("");
+    error.set_font(ui::Font::default_bold_font());
+    error.set_color(ui::RED);
+    main_layout.add_widget(error);
+
+    Stage stage = Stage::UsernameInput;
+    struct passwd* pw;
+
+    input.on_submit([&](StringView data) {
+        error.set_text("");
+        if (stage == Stage::UsernameInput)
+        {
+            struct passwd* entry = getpwnam(data.chars());
+            if (!entry)
+            {
+                error.set_text("User not found.");
+                input.clear();
+                return;
+            }
+
+            pw = entry;
+            stage = Stage::PasswordInput;
+            label.set_text("Password:");
+
+            RefString title = RefString::format("Log in: %s"_sv, data.chars()).release_value();
+            window->set_title(title.view());
+
+            input.clear();
+
+            return;
+        }
+        else
+        {
+            const char* passwd = pw->pw_passwd;
+
+            // If the user's password entry is 'x', read their password from the shadow file instead.
+            if (!strcmp(pw->pw_passwd, "x"))
+            {
+                struct spwd* sp = getspnam(pw->pw_name);
+
+                if (!sp)
+                {
+                    error.set_text("User not found in shadow file.");
+                    input.clear();
+                    return;
+                }
+
+                endspent();
+
+                passwd = sp->sp_pwdp;
+            }
+
+            if (!strcmp(passwd, "!"))
+            {
+                error.set_text("User's password is disabled.");
+                input.clear();
+                return;
+            }
+
+            auto result = hash_password(data).release_value();
+
+            if (strcmp(result.chars(), passwd))
+            {
+                error.set_text("Incorrect password.");
+                input.clear();
+                return;
+            }
+
+            auto flag = RefString::format("--user=%s"_sv, pw->pw_name).release_value();
+
+            StringView startui_command[] = { "/usr/bin/startui", flag.view() };
+            os::Process::exec(startui_command[0], Slice<StringView>(startui_command, 2));
+            unreachable();
+        }
+    });
+
+    return app.run();
+}

gui/run.cpp

@@ -22,7 +22,7 @@ Result<int> luna_main(int argc, char** argv)
     parser.add_positional_argument(program, "program", true);
     parser.parse(argc, argv);
 
-    OwnedPtr<os::IPC::Client> launcher_client = TRY(os::IPC::Client::connect("/tmp/launch.sock", false));
+    OwnedPtr<os::IPC::Client> launcher_client = TRY(os::IPC::Client::connect("/tmp/execd.sock", false));
 
     os::println("Requesting to start program '%s'...", program.chars());
 

gui/wind/CMakeLists.txt

@@ -11,6 +11,9 @@ set(SOURCES
     Keyboard.cpp
     Keyboard.h
     Client.h
+    Client.cpp
+    Layer.cpp
+    Layer.h
 )
 
 add_executable(wind ${SOURCES})

gui/wind/Client.cpp

@@ -0,0 +1,52 @@
+#include "Client.h"
+#include <os/File.h>
+
+Client::Client(OwnedPtr<os::IPC::ClientConnection>&& client, i16 _pledges)
+    : conn(move(client)), windows(), pledges(_pledges)
+{
+    conn->set_message_handler(wind::handle_ipc_message, this);
+}
+
+bool Client::update_pledges(i16 _pledges)
+{
+    if (_pledges < 0)
+    {
+        os::eprintln("wind: Client trying to set an invalid pledge, disconnecting!");
+        should_be_disconnected = true;
+        return false;
+    }
+
+    if (pledges < 0)
+    {
+        pledges = _pledges;
+        return true;
+    }
+
+    if (_pledges & ~pledges)
+    {
+        os::eprintln("wind: Client trying to add pledges, disconnecting!");
+        should_be_disconnected = true;
+        return false;
+    }
+
+    pledges = _pledges;
+    return true;
+}
+
+bool Client::check_pledge(i16 pledge)
+{
+    check(pledge > 0);
+
+    if (pledges < 0)
+    {
+        os::eprintln("wind: Client trying to use pledge-protected functions before pledging anything, disconnecting!");
+        should_be_disconnected = true;
+        return false;
+    }
+
+    if ((pledges & pledge) == pledge) return true;
+
+    os::eprintln("wind: Client trying to use a function they haven't pledged, disconnecting!");
+    should_be_disconnected = true;
+    return false;
+}

gui/wind/Client.h

@@ -0,0 +1,21 @@
+#pragma once
+#include "IPC.h"
+#include "Window.h"
+#include <os/IPC.h>
+
+constexpr i16 HAS_NOT_YET_PLEDGED = -1;
+constexpr i16 EMPTY_PLEDGE = 0;
+
+struct Client
+{
+    OwnedPtr<os::IPC::ClientConnection> conn;
+    Vector<Window*> windows;
+    const bool privileged { false };
+    bool should_be_disconnected { false };
+    i16 pledges = 0;
+
+    bool update_pledges(i16 pledges);
+    bool check_pledge(i16 pledge);
+
+    Client(OwnedPtr<os::IPC::ClientConnection>&& client, i16 pledges);
+};

gui/wind/IPC.cpp

@@ -1,8 +1,9 @@
 #include "IPC.h"
+#include "Layer.h"
 #include "Mouse.h"
 #include "Screen.h"
 #include <luna/Alignment.h>
-#include <luna/String.h>
+#include <luna/RefString.h>
 #include <os/File.h>
 #include <os/SharedMemory.h>
 #include <sys/mman.h>
@@ -35,9 +36,9 @@ static Result<void> handle_create_window_message(Client& client)
 
     request.rect = request.rect.normalized();
 
-    auto name = TRY_OR_IPC_ERROR(String::from_cstring("Window"));
+    auto name = TRY_OR_IPC_ERROR(RefString::from_cstring("Window"));
 
-    auto shm_path = TRY_OR_IPC_ERROR(String::format("/wind-shm-%d-%lu"_sv, client.conn->fd(), time(NULL)));
+    auto shm_path = TRY_OR_IPC_ERROR(RefString::format("/wind-shm-%d-%lu"_sv, client.conn->fd(), time(NULL)));
 
     auto* window = new (std::nothrow) Window(request.rect, move(name));
     if (!window)
@@ -47,7 +48,7 @@ static Result<void> handle_create_window_message(Client& client)
     }
 
     auto guard = make_scope_guard([window] {
-        g_windows.remove(window);
+        window->layer->windows.remove(window);
         delete window;
     });
 
@@ -88,7 +89,7 @@ static Result<void> handle_set_window_title_message(Client& client)
     ui::SetWindowTitleRequest request;
     if (!TRY(client.conn->read_message(request))) return {};
 
-    auto name = COPY_IPC_STRING(request.title);
+    auto name = TRY(RefString::from_string(COPY_IPC_STRING(request.title)));
 
     os::println("wind: SetWindowTitle(\"%s\") for window %d", name.chars(), request.window);
 
@@ -120,7 +121,7 @@ static Result<void> handle_close_window_message(Client& client)
 
     auto* window = client.windows[request.window];
     client.windows[request.window] = nullptr;
-    g_windows.remove(window);
+    window->layer->windows.remove(window);
     Mouse::the().window_did_close(window);
     delete window;
 
@@ -160,22 +161,48 @@ static Result<void> handle_set_titlebar_height_message(Client& client)
     return {};
 }
 
-static Result<void> handle_set_special_window_attributes_message(Client& client)
+static Result<void> handle_set_window_layer_message(Client& client)
 {
-    ui::SetSpecialWindowAttributesRequest request;
+    ui::SetWindowLayer request;
     if (!TRY(client.conn->read_message(request))) return {};
 
-    if (!client.privileged)
+    if (request.layer != ui::Layer::Global && request.layer != ui::Layer::GlobalTop)
     {
-        os::eprintln(
-            "wind: Unprivileged client trying to call privileged request (SetSpecialWindowAttributes), disconnecting!");
+        if (!client.check_pledge(ui::Pledge::ExtendedLayers)) return {};
+    }
+
+    CHECK_WINDOW_ID(request, "SetWindowLayer");
+
+    auto* window = client.windows[request.window];
+
+    window->layer->windows.remove(window);
+
+    switch (request.layer)
+    {
+    case ui::Layer::Background: window->layer = &l_background; break;
+    case ui::Layer::Global: window->layer = &l_global; break;
+    case ui::Layer::GlobalTop: window->layer = &l_global_top; break;
+    case ui::Layer::System: window->layer = &l_system; break;
+    case ui::Layer::Lock: window->layer = &l_lock; break;
+    default: {
+        window->layer->windows.append(window);
+        os::eprintln("wind: Client trying to set window layer to an invalid layer, disconnecting!");
         client.should_be_disconnected = true;
         return {};
     }
+    }
 
-    CHECK_WINDOW_ID(request, "SetSpecialWindowAttributes");
+    window->layer->windows.append(window);
 
-    client.windows[request.window]->attributes = request.attributes;
+    return {};
+}
+
+static Result<void> handle_update_pledge_request_message(Client& client)
+{
+    ui::UpdatePledgeRequest request;
+    if (!TRY(client.conn->read_message(request))) return {};
+
+    client.update_pledges(request.pledges); // update_pledges does all the checking.
 
     return {};
 }
@@ -194,7 +221,8 @@ namespace wind
         case ui::CLOSE_WINDOW_ID: handle_close_window_message(client); break;
         case ui::GET_SCREEN_RECT_ID: handle_get_screen_rect_message(client); break;
         case ui::SET_TITLEBAR_HEIGHT_ID: handle_set_titlebar_height_message(client); break;
-        case ui::SET_SPECIAL_WINDOW_ATTRIBUTES_ID: handle_set_special_window_attributes_message(client); break;
+        case ui::SET_WINDOW_LAYER_ID: handle_set_window_layer_message(client); break;
+        case ui::UPDATE_PLEDGE_REQUEST_ID: handle_update_pledge_request_message(client); break;
         default: os::eprintln("wind: Invalid IPC message from client!"); return;
         }
     }

gui/wind/Layer.cpp

@@ -0,0 +1,79 @@
+#include "Layer.h"
+#include "Client.h"
+#include "Window.h"
+
+Layer l_background;
+Layer l_global;
+Layer l_global_top;
+Layer l_system;
+Layer l_lock;
+
+constexpr int NUM_LAYERS = 5;
+
+static Layer* const layers_front_to_back[NUM_LAYERS] = { &l_lock, &l_system, &l_global_top, &l_global, &l_background };
+static Layer* const layers_back_to_front[NUM_LAYERS] = { &l_background, &l_global, &l_global_top, &l_system, &l_lock };
+
+Window* Layer::focused_window()
+{
+    for (int i = 0; i < NUM_LAYERS; i++)
+    {
+        Layer* l = layers_front_to_back[i];
+        if (l->windows.last().has_value()) return l->windows.last().value();
+    }
+
+    return nullptr;
+}
+
+void Layer::draw_all_windows(ui::Canvas& canvas)
+{
+    for (int i = 0; i < NUM_LAYERS; i++)
+    {
+        Layer* l = layers_back_to_front[i];
+        for (Window* w : l->windows) { w->draw(canvas); }
+    }
+}
+
+Window* Layer::propagate_mouse_event(ui::Point position, u8 buttons)
+{
+    for (int i = 0; i < NUM_LAYERS; i++)
+    {
+        Layer* l = layers_front_to_back[i];
+        for (Window* window = l->windows.last().value_or(nullptr); window;
+             window = l->windows.previous(window).value_or(nullptr))
+        {
+            if (window->surface.contains(position))
+            {
+                ui::MouseEventRequest request;
+                request.window = window->id;
+                request.position = window->surface.relative(position);
+                request.buttons = buttons;
+                window->client->conn->send_async(request);
+                return window;
+            }
+        }
+    }
+
+    return nullptr;
+}
+
+Window* Layer::propagate_drag_event(ui::Point position)
+{
+    for (int i = 0; i < NUM_LAYERS; i++)
+    {
+        Layer* l = layers_front_to_back[i];
+        for (Window* window = l->windows.last().value_or(nullptr); window;
+             window = l->windows.previous(window).value_or(nullptr))
+        {
+            if (window->surface.contains(position))
+            {
+                window->focus();
+
+                if (window->surface.absolute(window->titlebar).contains(position)) return window;
+
+                return nullptr;
+            }
+        }
+    }
+
+    return nullptr;
+}

gui/wind/Layer.h

@@ -0,0 +1,20 @@
+#pragma once
+#include "Window.h"
+#include <luna/LinkedList.h>
+#include <ui/Canvas.h>
+
+struct Layer
+{
+    LinkedList<Window> windows;
+
+    static Window* focused_window();
+    static void draw_all_windows(ui::Canvas& canvas);
+    static Window* propagate_mouse_event(ui::Point position, u8 buttons);
+    static Window* propagate_drag_event(ui::Point position);
+};
+
+extern Layer l_background;
+extern Layer l_global;
+extern Layer l_global_top;
+extern Layer l_system;
+extern Layer l_lock;

gui/wind/Mouse.cpp

@@ -1,5 +1,6 @@
 #include "Mouse.h"
 #include "Client.h"
+#include "Layer.h"
 #include <os/File.h>
 #include <os/IPC.h>
 #include <ui/Image.h>
@@ -57,45 +58,17 @@ void Mouse::update(const moon::MousePacket& packet)
 
     else if ((packet.buttons & moon::MouseButton::Left) && !m_dragging_window)
     {
-        // Iterate from the end of the list, since windows at the beginning are stacked at the bottom and windows at the
-        // top are at the end.
-        for (Window* window = g_windows.last().value_or(nullptr); window;
-             window = g_windows.previous(window).value_or(nullptr))
+        if (auto* window = Layer::propagate_drag_event(m_position))
         {
-            if (window->surface.contains(m_position))
-            {
-                if (!(window->attributes & ui::UNFOCUSEABLE)) window->focus();
-
-                if (window->surface.absolute(window->titlebar).contains(m_position))
-                {
-                    m_dragging_window = window;
-                    m_initial_drag_position = window->surface.relative(m_position);
-                    os::println("Started drag: window at (%d,%d,%d,%d) with offset (%d,%d)", window->surface.pos.x,
-                                window->surface.pos.y, window->surface.width, window->surface.height,
-                                m_initial_drag_position.x, m_initial_drag_position.y);
-                }
-
-                break;
-            }
+            m_dragging_window = window;
+            m_initial_drag_position = window->surface.relative(m_position);
+            os::println("Started drag: window at (%d,%d,%d,%d) with offset (%d,%d)", window->surface.pos.x,
+                        window->surface.pos.y, window->surface.width, window->surface.height, m_initial_drag_position.x,
+                        m_initial_drag_position.y);
         }
     }
 
-    Window* new_active_window = nullptr;
-
-    for (Window* window = g_windows.last().value_or(nullptr); window;
-         window = g_windows.previous(window).value_or(nullptr))
-    {
-        if (window->surface.contains(m_position))
-        {
-            ui::MouseEventRequest request;
-            request.window = window->id;
-            request.position = window->surface.relative(m_position);
-            request.buttons = packet.buttons;
-            window->client->conn->send_async(request);
-            new_active_window = window;
-            break;
-        }
-    }
+    Window* new_active_window = Layer::propagate_mouse_event(m_position, packet.buttons);
 
     if (m_active_window != new_active_window)
     {

gui/wind/Window.cpp

@@ -1,12 +1,11 @@
 #include "Window.h"
+#include "Layer.h"
 #include <luna/Utf8.h>
 #include <os/File.h>
 #include <sys/mman.h>
 #include <ui/Font.h>
 #include <ui/Image.h>
 
-LinkedList<Window> g_windows;
-
 void Window::draw(ui::Canvas& screen)
 {
     dirty = false;
@@ -18,15 +17,16 @@ void Window::draw(ui::Canvas& screen)
 void Window::focus()
 {
     // Bring the window to the front of the list.
-    g_windows.remove(this);
-    g_windows.append(this);
+    layer->windows.remove(this);
+    layer->windows.append(this);
 }
 
-Window::Window(ui::Rect r, String&& n) : surface(r), name(move(n))
+Window::Window(ui::Rect r, RefString&& n) : surface(r), name(move(n))
 {
     auto font = ui::Font::default_font();
     titlebar = ui::Rect { 0, 0, 0, 0 };
-    g_windows.append(this);
+    l_global.windows.append(this);
+    layer = &l_global;
 }
 
 Window::~Window()

gui/wind/Window.h

@@ -1,31 +1,30 @@
 #pragma once
 #include <luna/LinkedList.h>
-#include <luna/String.h>
+#include <luna/RefString.h>
 #include <ui/Canvas.h>
 #include <ui/Color.h>
 #include <ui/Rect.h>
 #include <ui/ipc/Server.h>
 
 struct Client;
+struct Layer;
 
 struct Window : public LinkedListNode<Window>
 {
     ui::Rect surface;
     ui::Rect titlebar;
     u32* pixels;
-    String name;
-    String shm_path;
+    RefString name;
+    RefString shm_path;
     bool dirty { false };
     Client* client;
+    Layer* layer;
     int id;
-    ui::WindowAttributes attributes { 0 };
 
-    Window(ui::Rect, String&&);
+    Window(ui::Rect, RefString&&);
     ~Window();
 
     void focus();
 
     void draw(ui::Canvas& screen);
 };
-
-extern LinkedList<Window> g_windows;

gui/wind/main.cpp

@@ -1,6 +1,6 @@
-#define CLIENT_IMPLEMENTATION
 #include "Client.h"
 #include "Keyboard.h"
+#include "Layer.h"
 #include "Mouse.h"
 #include "Screen.h"
 #include "Window.h"
@@ -8,6 +8,7 @@
 #include <moon/Keyboard.h>
 #include <os/ArgumentParser.h>
 #include <os/File.h>
+#include <os/IPC.h>
 #include <os/LocalServer.h>
 #include <os/Process.h>
 #include <os/Security.h>
@@ -22,42 +23,11 @@ static constexpr uid_t WIND_USER_ID = 2;
 static constexpr gid_t WIND_GROUP_ID = 2;
 static constexpr gid_t WSYS_GROUP_ID = 3;
 
-static void debug(const Vector<OwnedPtr<Client>>& clients)
-{
-    os::println("--- wind: DEBUG OUTPUT ---");
-
-    os::println("-- wind: Listing clients --");
-
-    for (const auto& client : clients)
-    {
-        os::println("Client with fd %d, owns %zu windows", client->conn->fd(), client->windows.size());
-    }
-
-    os::println("-- wind: Listing windows --");
-
-    for (const auto& window : g_windows)
-    {
-        os::println("Window of client (fd %d), id %d, %sdirty (\"%s\") (%d,%d,%d,%d)", window->client->conn->fd(),
-                    window->id, window->dirty ? "" : "not ", window->name.chars(), window->surface.pos.x,
-                    window->surface.pos.y, window->surface.width, window->surface.height);
-    }
-
-    os::println("-- wind: Listing processes --");
-
-    system("ps");
-
-    os::println("-- wind: Listing memory usage --");
-
-    system("free -h");
-
-    os::println("--- wind: END DEBUG OUTPUT ---");
-}
-
 Result<int> luna_main(int argc, char** argv)
 {
     srand((unsigned)time(NULL));
 
-    TRY(os::Security::pledge("stdio rpath wpath cpath unix proc exec tty id", NULL));
+    TRY(os::Security::pledge("stdio rpath wpath cpath unix tty id", NULL));
 
     StringView socket_path = "/tmp/wind.sock";
     StringView system_socket_path = "/tmp/wsys.sock";
@@ -72,8 +42,8 @@ Result<int> luna_main(int argc, char** argv)
 
     if (geteuid() != 0)
     {
-        os::eprintln("error: wind must be run as root to initialize resources, run with --user=<USERNAME> to drop "
-                     "privileges afterwards");
+        os::eprintln("error: wind must be run as root to initialize resources, the server will drop "
+                     "privileges automatically afterwards");
         return 1;
     }
 
@@ -115,6 +85,9 @@ Result<int> luna_main(int argc, char** argv)
         close(fd);
     }
 
+    // We're ready now.
+    os::IPC::notify_parent();
+
     ui::Color background = ui::Color::from_rgb(0x10, 0x10, 0x10);
 
     Vector<OwnedPtr<Client>> clients;
@@ -124,12 +97,12 @@ Result<int> luna_main(int argc, char** argv)
     TRY(fds.try_append({ .fd = server->fd(), .events = POLLIN, .revents = 0 }));
     TRY(fds.try_append({ .fd = system_server->fd(), .events = POLLIN, .revents = 0 }));
 
-    TRY(os::Security::pledge("stdio rpath wpath cpath unix proc exec", NULL));
+    TRY(os::Security::pledge("stdio rpath wpath cpath unix", NULL));
 
     while (1)
     {
         screen.canvas().fill(background);
-        for (auto* window : g_windows) window->draw(screen.canvas());
+        Layer::draw_all_windows(screen.canvas());
         mouse_pointer.draw(screen.canvas());
         screen.sync();
 
@@ -149,11 +122,9 @@ Result<int> luna_main(int argc, char** argv)
         {
             moon::KeyboardPacket packet;
             TRY(keyboard->read_typed(packet));
-            if (!packet.released && packet.key == moon::K_Tab) debug(clients);
             auto request = wind::Keyboard::decode_keyboard_event((moon::KeyCode)packet.key, packet.released);
-            if (g_windows.last().has_value())
+            if (auto* window = Layer::focused_window())
             {
-                auto* window = g_windows.last().value();
                 request.window = window->id;
                 window->client->conn->send_async(request);
             }
@@ -166,7 +137,7 @@ Result<int> luna_main(int argc, char** argv)
 
             auto connection = TRY(os::IPC::ClientConnection::adopt_connection(move(client)));
 
-            OwnedPtr<Client> c = TRY(adopt_owned_if_nonnull(new Client(move(connection), false)));
+            OwnedPtr<Client> c = TRY(adopt_owned_if_nonnull(new Client(move(connection), EMPTY_PLEDGE)));
             TRY(clients.try_append(move(c)));
         }
         if (fds[3].revents & POLLIN)
@@ -177,7 +148,7 @@ Result<int> luna_main(int argc, char** argv)
 
             auto connection = TRY(os::IPC::ClientConnection::adopt_connection(move(client)));
 
-            OwnedPtr<Client> c = TRY(adopt_owned_if_nonnull(new Client(move(connection), true)));
+            OwnedPtr<Client> c = TRY(adopt_owned_if_nonnull(new Client(move(connection), HAS_NOT_YET_PLEDGED)));
             TRY(clients.try_append(move(c)));
         }
         for (usize i = 0; i < clients.size(); i++)
@@ -194,7 +165,7 @@ Result<int> luna_main(int argc, char** argv)
                 {
                     if (window)
                     {
-                        g_windows.remove(window);
+                        window->layer->windows.remove(window);
                         mouse_pointer.window_did_close(window);
                         delete window;
                     }

kernel/config.cmake.template

@@ -19,3 +19,6 @@
 # Uncomment the line below to make the kernel also calculate stack traces for userspace addresses on program crashes. 
 # This can aid in debugging, but makes the kernel more unstable as stack tracing will access arbitrary userspace memory.
 # target_compile_definitions(moon PRIVATE MOON_ENABLE_USERSPACE_STACK_TRACES)
+
+# Uncomment the line below to enable all kernel debug messages, and console logging.
+# include(debug.cmake)

kernel/debug.cmake

@@ -12,4 +12,4 @@ target_compile_definitions(moon PRIVATE DEVICE_REGISTRY_DEBUG)
 target_compile_definitions(moon PRIVATE FORK_DEBUG)
 target_compile_definitions(moon PRIVATE MOUNT_DEBUG)
 target_compile_definitions(moon PRIVATE CACHE_DEBUG)
-target_compile_options(moon PRIVATE -fsanitize=undefined)
+#target_compile_options(moon PRIVATE -fsanitize=undefined)

kernel/src/Log.cpp

@@ -77,8 +77,7 @@ static void log_text_console(LogLevel level, const char* format, va_list origin)
         TextConsole::set_foreground(WHITE);
 
     // NOTE: Same as above.
-    auto rc = cstyle_format(
-        format, [](char c, void*) -> Result<void> { return TextConsole::putchar(c); }, nullptr, ap);
+    auto rc = cstyle_format(format, [](char c, void*) -> Result<void> { return TextConsole::putchar(c); }, nullptr, ap);
 
     if (rc.has_error()) { TextConsole::wprint(L"Invalid UTF-8 in log message"); }
 

kernel/src/Pledge.cpp

@@ -1,6 +1,7 @@
 #include "Pledge.h"
 #include "Log.h"
 #include "memory/MemoryManager.h"
+#include "thread/Scheduler.h"
 
 static const char* promise_names[] = {
 #define __enumerate(promise) #promise,
@@ -8,30 +9,34 @@ static const char* promise_names[] = {
 #undef __enumerate
 };
 
-Result<void> check_pledge(Thread* thread, Promise promise)
+Result<void> check_pledge(Process* process, Promise promise)
 {
     // Thread has not called pledge().
-    if (thread->promises < 0) return {};
+    if (process->promises < 0) return {};
     int mask = (1 << (int)promise);
-    if ((thread->promises & mask) != mask)
+    if ((process->promises & mask) != mask)
     {
-        kerrorln("Pledge violation in thread %d! Has not pledged %s", thread->id, promise_names[(int)promise]);
-        if (thread->promises & (1 << (int)Promise::p_error)) return err(ENOSYS);
+        kerrorln("Pledge violation in process %d! Has not pledged %s", process->id, promise_names[(int)promise]);
+        if (process->promises & (1 << (int)Promise::p_error)) return err(ENOSYS);
 
-        // Kill this thread with an uncatchable SIGABRT. For this, we reset the disposition of SIGABRT to the default
-        // (dump core). We could just kill the thread here and be done, but that discards anything on the current stack,
-        // which means that some destructors might not be called. Instead, leave the job to the next call of
-        // Thread::process_pending_signals().
-        thread->signal_handlers[SIGABRT - 1].sa_handler = SIG_DFL;
+        Scheduler::for_each_thread(process, [](Thread* thread) {
+            // Kill this thread with an uncatchable SIGABRT. For this, we reset the disposition of SIGABRT to the
+            // default (dump core). We could just kill the thread here and be done, but that discards anything on the
+            // current stack, which means that some destructors might not be called. Instead, leave the job to the next
+            // call of Thread::process_pending_signals().
+            thread->signal_handlers[SIGABRT - 1].sa_handler = SIG_DFL;
 
-        // Unblock SIGABRT.
-        thread->signal_mask.set(SIGABRT - 1, false);
+            // Unblock SIGABRT.
+            thread->signal_mask.set(SIGABRT - 1, false);
 
-        // If there are any other pending signals, they might be processed before SIGABRT. Avoid that by resetting the
-        // thread's pending signals.
-        thread->pending_signals.clear();
+            // If there are any other pending signals, they might be processed before SIGABRT. Avoid that by resetting
+            // the thread's pending signals.
+            thread->pending_signals.clear();
 
-        thread->send_signal(SIGABRT);
+            thread->send_signal(SIGABRT);
+
+            return true;
+        });
 
         // This should never arrive to userspace, unless we're init and have ignored SIGABRT.
         return err(ENOSYS);

kernel/src/Pledge.h

@@ -14,6 +14,6 @@ enum class Promise
         num_promises,
 };
 
-Result<void> check_pledge(Thread* thread, Promise promise);
+Result<void> check_pledge(Process* process, Promise promise);
 
 Result<int> parse_promises(u64 pledge);

kernel/src/arch/x86_64/CPU.cpp

@@ -91,6 +91,9 @@ void handle_cpu_exception(int signo, const char* err, Registers* regs)
         auto* current = Scheduler::current();
         if (current->check_stack_on_exception(regs->rsp)) return;
 
+        auto space = current->process->address_space.lock();
+        (*space)->debug_log();
+
         current->send_signal(signo);
         current->process_pending_signals(regs);
         return;

kernel/src/arch/x86_64/PCI.cpp

@@ -8,7 +8,7 @@
 
 static inline constexpr u32 make_pci_address(const PCI::Device::Address& address, u32 field)
 {
-    return 0x80000000 | (address.bus << 16) | (address.slot << 11) | (address.function << 8) | ((field)&0xFC);
+    return 0x80000000 | (address.bus << 16) | (address.slot << 11) | (address.function << 8) | ((field) & 0xFC);
 }
 
 namespace PCI

kernel/src/arch/x86_64/Thread.cpp

@@ -15,7 +15,7 @@ void Thread::set_ip(u64 ip)
     regs.rip = ip;
 }
 
-u64 Thread::ip()
+u64 Thread::ip() const
 {
     return regs.rip;
 }
@@ -25,7 +25,7 @@ void Thread::set_sp(u64 sp)
     regs.rsp = sp;
 }
 
-u64 Thread::sp()
+u64 Thread::sp() const
 {
     return regs.rsp;
 }
@@ -71,31 +71,14 @@ void switch_context(Thread* old_thread, Thread* new_thread, Registers* regs)
     memcpy(regs, &new_thread->regs, sizeof(Registers));
 }
 
-// FIXME: Move this function to a common location (also used in ThreadImage)
 Result<u64> Thread::push_mem_on_stack(const u8* mem, usize size)
 {
-    if ((regs.rsp - size) < stack.bottom()) return err(E2BIG);
-
-    if (!MemoryManager::validate_user_write((void*)(regs.rsp - size), size)) return err(EFAULT);
-
-    regs.rsp -= size;
-
-    memcpy((void*)regs.rsp, mem, size);
-
-    return regs.rsp;
+    return MemoryManager::push_mem_on_stack(mem, size, stack, regs.rsp);
 }
 
 Result<u64> Thread::pop_mem_from_stack(u8* mem, usize size)
 {
-    if ((regs.rsp + size) > stack.top()) return err(E2BIG);
-
-    if (!MemoryManager::validate_user_read((void*)regs.rsp, size)) return err(EFAULT);
-
-    memcpy(mem, (void*)regs.rsp, size);
-
-    regs.rsp += size;
-
-    return regs.rsp;
+    return MemoryManager::pop_mem_from_stack(mem, size, stack, regs.rsp);
 }
 
 bool Thread::deliver_signal(int signo, Registers* current_regs)

kernel/src/arch/x86_64/disk/ATA.cpp

@@ -7,6 +7,7 @@
 #include "memory/MemoryManager.h"
 #include "thread/Clock.h"
 #include "thread/Scheduler.h"
+#include <endian.h>
 #include <luna/Alignment.h>
 #include <luna/Buffer.h>
 #include <luna/CType.h>
@@ -517,9 +518,8 @@ namespace ATA
 
             m_is_lba48 = true;
 
-            // FIXME: This assumes the host machine is little-endian.
-            u32 last_lba = __builtin_bswap32(reply.last_lba);
-            u32 sector_size = __builtin_bswap32(reply.sector_size);
+            u32 last_lba = be32toh(reply.last_lba);
+            u32 sector_size = be32toh(reply.sector_size);
 
             m_block_count = last_lba + 1;
             m_block_size = sector_size;

kernel/src/arch/x86_64/disk/ATA.h

@@ -3,6 +3,7 @@
 #include "fs/devices/BlockDevice.h"
 #include "fs/devices/DeviceRegistry.h"
 #include "lib/Mutex.h"
+#include "thread/Thread.h"
 #include <luna/Atomic.h>
 #include <luna/SharedPtr.h>
 #include <luna/StaticString.h>

kernel/src/binfmt/Script.cpp

@@ -17,7 +17,7 @@ Result<u64> ScriptLoader::load(AddressSpace* space)
 {
     u8 buf[256];
     memset(buf, 0, sizeof(buf));
-    
+
     usize nread = TRY(m_inode->read(buf, 2, 255));
     if (!nread) return err(ENOEXEC);
     for (usize i = 0; i < nread; i++)
@@ -35,11 +35,10 @@ Result<u64> ScriptLoader::load(AddressSpace* space)
     if (!m_interpreter_cmdline.size()) return err(ENOEXEC);
 
     auto& interpreter_path = m_interpreter_cmdline[0];
-    auto* current = Scheduler::current();
+    auto* current = Process::current();
 
-    auto interpreter = TRY(VFS::resolve_path(interpreter_path.chars(), current->auth, &current->extra_groups,
-                                             current->current_directory, true));
-    if (!VFS::can_execute(interpreter, current->auth, &current->extra_groups)) return err(EACCES);
+    auto interpreter = TRY(VFS::resolve_path(interpreter_path.chars(), current, current->current_directory, true));
+    if (!VFS::can_execute(interpreter, current)) return err(EACCES);
 
     auto loader = TRY(BinaryFormat::create_loader(interpreter, m_recursion_level + 1));
     u64 entry = TRY(loader->load(space));

kernel/src/fs/InitRD.cpp

@@ -20,7 +20,7 @@ void InitRD::initialize()
 
 static Result<void> vfs_create_dir_if_not_exists(const char* path, mode_t mode)
 {
-    auto rc = VFS::create_directory(path, mode & (mode_t)~S_IFMT, Credentials {}, nullptr);
+    auto rc = VFS::create_directory(path, mode & (mode_t)~S_IFMT, nullptr);
     if (rc.has_error())
     {
         if (rc.error() == EEXIST) return {};
@@ -37,8 +37,7 @@ Result<void> InitRD::populate_vfs()
     {
         if (entry.type == TarStream::EntryType::RegularFile)
         {
-            auto file =
-                TRY(VFS::create_file(entry.name.chars(), entry.mode & (mode_t)~S_IFMT, Credentials {}, nullptr));
+            auto file = TRY(VFS::create_file(entry.name.chars(), entry.mode & (mode_t)~S_IFMT, nullptr));
             file->write(entry.data(), 0, entry.size);
         }
         else if (entry.type == TarStream::EntryType::Directory)

kernel/src/fs/Pipe.cpp

@@ -8,7 +8,7 @@ Result<void> Pipe::create(SharedPtr<VFS::Inode>& rpipe, SharedPtr<VFS::Inode>& w
     auto writer = TRY(make_shared<PipeWriter>());
     auto reader = TRY(make_shared<PipeReader>());
 
-    auto auth = Scheduler::current()->auth;
+    auto auth = Process::current()->credentials();
 
     pipe->m_writer = writer.ptr();
     pipe->m_reader = reader.ptr();

kernel/src/fs/StorageCache.cpp

@@ -33,7 +33,7 @@ void StorageCache::clear()
     m_mutex.unlock();
 }
 
-StorageCache::StorageCache()
+StorageCache::StorageCache(BlockDevice* device) : m_device(device)
 {
     g_storage_caches.append(this);
 }

kernel/src/fs/StorageCache.h

@@ -4,12 +4,15 @@
 #include <luna/HashMap.h>
 #include <luna/LinkedList.h>
 
+class BlockDevice;
+
 class StorageCache : public LinkedListNode<StorageCache>
 {
   public:
     struct CacheEntry
     {
         Buffer buffer {};
+        bool dirty;
     };
 
     void lock()
@@ -28,10 +31,11 @@ class StorageCache : public LinkedListNode<StorageCache>
 
     static void clear_caches();
 
-    StorageCache();
+    StorageCache(BlockDevice* device);
     ~StorageCache();
 
   private:
     HashMap<u64, CacheEntry> m_cache_entries;
+    BlockDevice* m_device;
     Mutex m_mutex;
 };