fix: comprehensive boot warnings and exceptions — fixable silenced, unfixable diagnosed

Build system (5 gaps hardened):
- COOKBOOK_OFFLINE defaults to true (fork-mode)
- normalize_patch handles diff -ruN format
- New 'repo validate-patches' command (25/25 relibc patches)
- 14 patched Qt/Wayland/display recipes added to protected list
- relibc archive regenerated with current patch chain

Boot fixes (fixable):
- Full ISO EFI partition: 16 MiB → 1 MiB (matches mini, BIOS hardcoded 2 MiB offset)
- D-Bus system bus: absolute /usr/bin/dbus-daemon path (was skipped)
- redbear-sessiond: absolute /usr/bin/redbear-sessiond path (was skipped)
- daemon framework: silenced spurious INIT_NOTIFY warnings for oneshot_async services (P0-daemon-silence-init-notify.patch)
- udev-shim: demoted INIT_NOTIFY warning to INFO (expected for oneshot_async)
- relibc: comprehensive named semaphores (sem_open/close/unlink) replacing upstream todo!() stubs
- greeterd: Wayland socket timeout 15s → 30s (compositor DRM wait)
- greeter-ui: built and linked (header guard unification, sem_compat stubs removed)
- mc: un-ignored in both configs, fixed glib/libiconv/pcre2 transitive deps
- greeter config: removed stale keymapd dependency from display/greeter services
- prefix toolchain: relibc headers synced, _RELIBC_STDLIB_H guard unified

Unfixable (diagnosed, upstream):
- i2c-hidd: abort on no-I2C-hardware (QEMU) — process::exit → relibc abort
- kded6/greeter-ui: page fault 0x8 — Qt library null deref
- Thread panics fd != -1 — Rust std library on Redox
- DHCP timeout / eth0 MAC — QEMU user-mode networking
- hwrngd/thermald — no hardware RNG/thermal in VM
- live preload allocation — BIOS memory fragmentation, continues on demand

local/recipes/qt/qtwayland/source/examples/wayland/spanning-screens/CMakeLists.txt

@@ -0,0 +1,48 @@
+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+cmake_minimum_required(VERSION 3.16)
+project(spanning-screens LANGUAGES CXX)
+
+set(CMAKE_AUTOMOC ON)
+
+if(NOT DEFINED INSTALL_EXAMPLESDIR)
+    set(INSTALL_EXAMPLESDIR "examples")
+endif()
+
+set(INSTALL_EXAMPLEDIR "${INSTALL_EXAMPLESDIR}/wayland/spanning-screens")
+
+find_package(Qt6 REQUIRED COMPONENTS Core Gui Qml)
+
+qt_add_executable(spanning-screens
+    main.cpp
+)
+
+set_target_properties(spanning-screens PROPERTIES
+    WIN32_EXECUTABLE TRUE
+    MACOSX_BUNDLE TRUE
+)
+
+target_link_libraries(spanning-screens PUBLIC
+    Qt::Core
+    Qt::Gui
+    Qt::Qml
+)
+
+# Resources:
+set(spanning-screens_resource_files
+    "main.qml"
+)
+
+qt6_add_resources(spanning-screens "spanning-screens"
+    PREFIX
+        "/"
+    FILES
+        ${spanning-screens_resource_files}
+)
+
+install(TARGETS spanning-screens
+    RUNTIME DESTINATION "${INSTALL_EXAMPLEDIR}"
+    BUNDLE DESTINATION "${INSTALL_EXAMPLEDIR}"
+    LIBRARY DESTINATION "${INSTALL_EXAMPLEDIR}"
+)

local/recipes/qt/qtwayland/source/examples/wayland/spanning-screens/doc/src/spanning-screens.qdoc

@@ -0,0 +1,60 @@
+// Copyright (C) 2021 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
+
+/*!
+ * \title Spanning Screens
+ * \example spanning-screens
+ * \examplecategory {Embedded}
+ * \brief Spanning Screens is an example that demonstrates how to let Wayland clients span multiple screens.
+ * \ingroup qtwaylandcompositor-examples
+ *
+ * \section1 Introduction
+ *
+ * Spanning screens is a Wayland compositor example that maximizes clients across a top and a bottom
+ * screen.
+ *
+ * \image spanning-screens.jpg
+ *
+ * For an introduction to the basic principles of creating a \l{Qt Wayland Compositor} with Qt,
+ * see the \l{Minimal QML}{Minimal QML example}.
+ *
+ * \section1 Supporting Multiple Screens
+ *
+ * In \l{Qt Wayland Compositor} a screen is represented by a \l{WaylandOutput}, and a \l Window is
+ * used to contain the \l{Qt Quick} scene representing both clients and the compositor's UI.
+ *
+ * In this example, a multi-screen setup is emulated by creating two windows on the primary screen,
+ * but the code can easily be modified to target multiple physical screens.
+ *
+ * \snippet spanning-screens/main.qml enable screens
+ *
+ * Since each \l Window represents an isolated \l{Qt Quick} scene, this means we need a trick to
+ * have the same client content display inside both windows. The way to do this in
+ * \l{Qt Wayland Compositor} is to create two views of the same client content: One for the "top"
+ * window and one for the "bottom". The views share a reference to the same underlying graphics buffer.
+ * This allows us to copy different areas of the client's surface onto each of the windows.
+ *
+ * \snippet spanning-screens/main.qml create items
+ *
+ * When the client connects to the \l{Shell Extensions - Qt Wayland Compositor}{shell extension}
+ * \l{XdgShell}, we create two references to the surface. One of them is added to the "top" output,
+ * and the second to the "bottom". The item on the bottom output also gets an offset corresponding
+ * to the height of the top output. This ensures that the part of the client surface showing on
+ * the bottom output starts where the top output ends.
+ *
+ * \snippet spanning-screens/main.qml size
+ *
+ * In addition, we tell the client to resize its surface so that it fills both the top and bottom
+ * window. The end result is a client that spans two windows, or "screens".
+ *
+ * Referencing the same client surface from multiple items is a tool which can be used for many
+ * things. For a demonstration of a desktop-style compositor where windows can be moved from screen
+ * to screen, take a look at the \l{Multi Screen}{Multi Screen example}.
+ *
+ * The \l{Multi Output}{Multi Output example} shows how client surfaces can be displayed on multiple
+ * outputs with different sizes and other properties.
+ *
+ * \note In order to support multiple Wayland outputs in the same compositor, the
+ * \l Qt::AA_ShareOpenGLContexts attribute must be set before the \l QGuiApplication
+ * object is constructed.
+ */

local/recipes/qt/qtwayland/source/examples/wayland/spanning-screens/main.cpp

@@ -0,0 +1,20 @@
+// Copyright (C) 2017 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+#include <QtCore/QUrl>
+#include <QtCore/QDebug>
+
+#include <QtGui/QGuiApplication>
+
+#include <QtQml/QQmlApplicationEngine>
+
+int main(int argc, char *argv[])
+{
+    // AA_ShareOpenGLContexts is required for compositors with multiple outputs
+    QCoreApplication::setAttribute(Qt::AA_ShareOpenGLContexts, true);
+    QGuiApplication app(argc, argv);
+
+    QQmlApplicationEngine appEngine(QUrl("qrc:///main.qml"));
+
+    return app.exec();
+}

local/recipes/qt/qtwayland/source/examples/wayland/spanning-screens/main.qml

@@ -0,0 +1,90 @@
+// Copyright (C) 2018 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
+
+import QtQuick
+import QtQuick.Window
+import QtWayland.Compositor
+import QtWayland.Compositor.XdgShell
+
+WaylandCompositor {
+    WaylandOutput {
+        sizeFollowsWindow: true
+        window: Window {
+            id: topSurfaceArea
+
+            property int pixelHeight: screen.devicePixelRatio * height
+            property int pixelWidth: screen.devicePixelRatio * width
+
+            width: 1024
+            height: 768
+            visible: true
+            color: "#1337af"
+
+            Text { text: "Top screen" }
+
+            // ![enable screens]
+            // Enable the following to make the output target an actual screen,
+            // for example when running on eglfs in a multi-display embedded system.
+
+            // screen: Qt.application.screens[0]
+            // ![enable screens]
+        }
+    }
+
+    WaylandOutput {
+        sizeFollowsWindow: true
+        window: Window {
+            id: bottomSurfaceArea
+
+            property int pixelHeight: screen.devicePixelRatio * height
+            property int pixelWidth: screen.devicePixelRatio * width
+
+            width: 1024
+            height: 768
+            visible: true
+            color: "#1abacc"
+
+            Text { text: "Bottom screen" }
+
+            // Enable the following to make the output target an actual screen,
+            // for example when running on eglfs in a multi-display embedded system.
+
+            // screen: Qt.application.screens[1]
+        }
+    }
+
+    Component {
+        id: chromeComponent
+        Item {
+            property alias shellSurface: ssi.shellSurface
+            ShellSurfaceItem {
+                id: ssi
+                onSurfaceDestroyed: destroy()
+            }
+        }
+    }
+
+    XdgShell {
+        onToplevelCreated: (toplevel, xdgSurface) => {
+            const shellSurface = xdgSurface;
+
+            // ![create items]
+            const topItem = chromeComponent.createObject(topSurfaceArea, {
+                shellSurface
+            });
+
+            const bottomItem = chromeComponent.createObject(bottomSurfaceArea, {
+                shellSurface,
+                y: Qt.binding(function() { return -topSurfaceArea.height;})
+            });
+            // ![create items]
+
+            // ![size]
+            const height = topSurfaceArea.pixelHeight + bottomSurfaceArea.pixelHeight;
+            const width = Math.max(bottomSurfaceArea.pixelWidth, topSurfaceArea.pixelWidth);
+            const size = Qt.size(width, height);
+            toplevel.sendFullscreen(size);
+            // ![size]
+        }
+    }
+}

local/recipes/qt/qtwayland/source/examples/wayland/spanning-screens/spanning-screens.pro

@@ -0,0 +1,14 @@
+QT += gui qml
+
+SOURCES += \
+    main.cpp
+
+OTHER_FILES = \
+    main.qml
+
+RESOURCES += spanning-screens.qrc
+
+target.path = $$[QT_INSTALL_EXAMPLES]/wayland/spanning-screens
+sources.files = $$SOURCES $$HEADERS $$RESOURCES $$FORMS spanning-screens.pro
+sources.path = $$[QT_INSTALL_EXAMPLES]/wayland/spanning-screens
+INSTALLS += target sources

local/recipes/qt/qtwayland/source/examples/wayland/spanning-screens/spanning-screens.qrc

@@ -0,0 +1,5 @@
+<RCC>
+    <qresource prefix="/">
+        <file>main.qml</file>
+    </qresource>
+</RCC>