diff --git a/src/corelib/global/qtypes.h b/src/corelib/global/qtypes.h
index 6e168e1f87..e186d4a9e3 100644
--- a/src/corelib/global/qtypes.h
+++ b/src/corelib/global/qtypes.h
@@ -23,6 +23,11 @@
 #  include <type_traits>
 #else
 #  include <assert.h>
+#  if defined(__QNXNTO__) && !defined(static_assert)
+     /* QNX assert.h (BB10 / QNX 6.6) does not define the static_assert
+      * macro; provide it via the C11 _Static_assert keyword. */
+#    define static_assert _Static_assert
+#  endif
 #endif
 
 #if 0
diff --git a/src/corelib/io/qprocess_unix.cpp b/src/corelib/io/qprocess_unix.cpp
index 8be50e6aa7..13f6ab920b 100644
--- a/src/corelib/io/qprocess_unix.cpp
+++ b/src/corelib/io/qprocess_unix.cpp
@@ -30,6 +30,13 @@
 
 #ifdef Q_OS_QNX
 #  include <sys/neutrino.h>
+/* O_DIRECTORY and O_PATH are Linux-specific; not defined in QNX 6.6. */
+#  ifndef O_DIRECTORY
+#    define O_DIRECTORY 0
+#  endif
+#  ifndef O_PATH
+#    define O_PATH 0
+#  endif
 #endif
 
 #include <errno.h>
diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp
index 0aa120ee1b..ec6aca5deb 100644
--- a/src/corelib/kernel/qcoreapplication.cpp
+++ b/src/corelib/kernel/qcoreapplication.cpp
@@ -78,7 +78,7 @@
 
 #ifdef Q_OS_UNIX
 #  include <locale.h>
-#  ifndef Q_OS_INTEGRITY
+#  if !defined(Q_OS_INTEGRITY) && !defined(Q_OS_QNX) // QNX/BB10 has no langinfo.h
 #    include <langinfo.h>
 #  endif
 #  include <unistd.h>
diff --git a/src/corelib/kernel/qmath.h b/src/corelib/kernel/qmath.h
index 72057ee16d..a8a7d703f2 100644
--- a/src/corelib/kernel/qmath.h
+++ b/src/corelib/kernel/qmath.h
@@ -179,8 +179,11 @@ template <typename T> auto qExp(T v)
 
 template <typename T1, typename T2> auto qPow(T1 x, T2 y)
 {
-    using std::pow;
-    return pow(x, y);
+    // Cast both args to their common type to avoid ambiguous overload between
+    // QNX math.h _TGEN_RC2 template and GCC <cmath> template for mixed types
+    // (e.g. qPow(float, double) would be ambiguous without this).
+    typedef typename std::common_type<T1, T2>::type CT;
+    return std::pow(static_cast<CT>(x), static_cast<CT>(y));
 }
 
 // TODO: use template variables (e.g. Qt::pi<type>) for these once we have C++14 support:
diff --git a/src/corelib/kernel/qmetaobject.cpp b/src/corelib/kernel/qmetaobject.cpp
index c1c05a492d..04c545f49b 100644
--- a/src/corelib/kernel/qmetaobject.cpp
+++ b/src/corelib/kernel/qmetaobject.cpp
@@ -371,6 +371,7 @@ const char *QMetaObject::className() const
 bool QMetaObject::inherits(const QMetaObject *metaObject) const noexcept
 {
     const QMetaObject *m = this;
+    if (!m) return false;  // BB10: tolerate null this
     do {
         if (metaObject == m)
             return true;
@@ -394,7 +395,12 @@ bool QMetaObject::inherits(const QMetaObject *metaObject) const noexcept
 */
 const QObject *QMetaObject::cast(const QObject *obj) const
 {
-    return (obj && obj->metaObject()->inherits(this)) ? obj : nullptr;
+    // BB10: tolerate null this and null obj->metaObject()
+    if (!this) return nullptr;
+    if (!obj) return nullptr;
+    const QMetaObject *m = obj->metaObject();
+    if (!m) return nullptr;
+    return m->inherits(this) ? obj : nullptr;
 }
 
 #ifndef QT_NO_TRANSLATION
@@ -970,7 +976,9 @@ QMetaMethod QMetaObjectPrivate::signal(const QMetaObject *m, int signal_index)
     if (signal_index < 0)
         return QMetaMethod();
 
-    Q_ASSERT(m != nullptr);
+    // BB10: tolerate null QMetaObject instead of SIGSEGV
+    if (!m)
+        return QMetaMethod();
     int i = signal_index;
     i -= signalOffset(m);
     if (i < 0 && m->d.superdata)
diff --git a/src/corelib/kernel/qmetaobject_p.h b/src/corelib/kernel/qmetaobject_p.h
index cc0be759d1..049e68f493 100644
--- a/src/corelib/kernel/qmetaobject_p.h
+++ b/src/corelib/kernel/qmetaobject_p.h
@@ -216,7 +216,7 @@ struct QMetaObjectPrivate
     Q_CORE_EXPORT static QMetaMethod signal(const QMetaObject *m, int signal_index);
     static inline int signalOffset(const QMetaObject *m)
     {
-        Q_ASSERT(m != nullptr);
+        if (!m) return 0;  // BB10: tolerate null instead of crashing
         int offset = 0;
         for (m = m->d.superdata; m; m = m->d.superdata)
             offset += reinterpret_cast<const QMetaObjectPrivate *>(m->d.data)->signalCount;
diff --git a/src/corelib/plugin/qelfparser_p.cpp b/src/corelib/plugin/qelfparser_p.cpp
index 7f6271cde4..7f50d5b1fa 100644
--- a/src/corelib/plugin/qelfparser_p.cpp
+++ b/src/corelib/plugin/qelfparser_p.cpp
@@ -20,6 +20,54 @@
 #  error "Need ELF header to parse plugins."
 #endif
 
+#ifdef Q_OS_QNX
+/* QNX sys/elf.h (BB10 / QNX 6.6) uses non-standard enum values for ELFOSABI_*
+ * and omits many EM_*, SHT_*, SHF_*, and PT_* constants defined in the standard
+ * System V ABI.  Redefine OSABI values as macros (which shadow the enum members)
+ * and add the missing constants so this file compiles without errors. */
+
+/* --- OSABI: override with standard values (QNX enum order is non-standard) --- */
+#  define ELFOSABI_SYSV    0
+#  define ELFOSABI_NONE    0
+#  define ELFOSABI_HPUX    1
+#  define ELFOSABI_NETBSD  2
+#  define ELFOSABI_LINUX   3
+#  define ELFOSABI_SOLARIS 6
+#  define ELFOSABI_AIX     7
+#  define ELFOSABI_IRIX    8
+#  define ELFOSABI_FREEBSD 9
+#  define ELFOSABI_OPENBSD 12
+
+/* --- EM_* machine types missing from QNX sys/elf.h --- */
+#  define EM_68K       4        /* Motorola 68000 */
+#  define EM_PARISC    15       /* HP PA-RISC (QNX has EM_PA_RISC) */
+#  define EM_PPC64     21       /* PowerPC 64-bit */
+#  define EM_S390      22       /* IBM System/390 */
+#  define EM_IA_64     50       /* Intel IA-64 */
+#  define EM_X86_64    62       /* AMD/Intel x86-64 */
+#  define EM_SPARCV9   43       /* SPARC V9 */
+#  define EM_ALPHA     0x9026   /* DEC Alpha (unofficial but widely used) */
+#  define EM_AARCH64   183      /* ARM AArch64 */
+#  define EM_BLACKFIN  106      /* Analog Devices Blackfin */
+#  define EM_RISCV     243      /* RISC-V */
+#  define EM_LOONGARCH 258      /* LoongArch */
+
+/* --- SHT_* section types missing from QNX sys/elf.h --- */
+#  define SHT_INIT_ARRAY  14    /* Array of constructors */
+#  define SHT_FINI_ARRAY  15    /* Array of destructors */
+
+/* --- SHF_* section flags missing from QNX sys/elf.h --- */
+#  define SHF_STRINGS  0x20     /* Contains NUL-terminated strings */
+#  define SHF_TLS      0x400    /* Section holds thread-local storage */
+
+/* --- PT_* program header types missing from QNX sys/elf.h --- */
+#  define PT_TLS          7             /* Thread-local storage segment */
+#  define PT_GNU_PROPERTY 0x6474e553u   /* GNU property notes */
+
+/* --- Elf64_Nhdr absent in QNX; alias to Elf32_Nhdr (never used on ARM32) --- */
+typedef Elf32_Nhdr Elf64_Nhdr;
+#endif
+
 QT_BEGIN_NAMESPACE
 
 using namespace Qt::StringLiterals;
diff --git a/src/corelib/text/qlocale.cpp b/src/corelib/text/qlocale.cpp
index 2aab6fab93..b198f5975a 100644
--- a/src/corelib/text/qlocale.cpp
+++ b/src/corelib/text/qlocale.cpp
@@ -4798,14 +4798,14 @@ QString QLocale::formattedDataSize(qint64 bytes, int precision, DataSizeFormats
     if (!bytes) {
         power = 0;
     } else if (format & DataSizeBase1000) {
-        power = int(std::log10(QtPrivate::qUnsignedAbs(bytes)) / 3);
+        power = int(std::log10(double(QtPrivate::qUnsignedAbs(bytes))) / 3);
     } else { // Compute log2(bytes) / 10:
         power = int((63 - qCountLeadingZeroBits(QtPrivate::qUnsignedAbs(bytes))) / 10);
         base = 1024;
     }
     // Only go to doubles if we'll be using a quantifier:
     const QString number = power
-        ? toString(bytes / std::pow(double(base), power), 'f', qMin(precision, 3 * power))
+        ? toString(bytes / std::pow(double(base), double(power)), 'f', qMin(precision, 3 * power))
         : toString(bytes);
 
     // We don't support sizes in units larger than exbibytes because
diff --git a/src/corelib/time/qdatetime.cpp b/src/corelib/time/qdatetime.cpp
index 385f76fe15..a179d13cb3 100644
--- a/src/corelib/time/qdatetime.cpp
+++ b/src/corelib/time/qdatetime.cpp
@@ -2475,7 +2475,7 @@ static QTime fromIsoTimeString(QStringView string, Qt::DateFormat format, bool *
     if (tail.isEmpty() ? dot != -1 || comma != -1 : !frac.ok())
         return QTime();
     Q_ASSERT(frac.ok() ^ tail.isEmpty());
-    double fraction = frac.ok() ? frac.result * std::pow(0.1, tail.size()) : 0.0;
+    double fraction = frac.ok() ? frac.result * std::pow(0.1, (double)tail.size()) : 0.0;
 
     const qsizetype size = string.size();
     if (size < 2 || size > 8)
diff --git a/src/gui/painting/qpaintengineex.cpp b/src/gui/painting/qpaintengineex.cpp
index 9468876c23..1e914674e7 100644
--- a/src/gui/painting/qpaintengineex.cpp
+++ b/src/gui/painting/qpaintengineex.cpp
@@ -1085,11 +1085,14 @@ bool QPaintEngineEx::shouldDrawCachedGlyphs(QFontEngine *fontEngine, const QTran
     if (fontEngine->glyphFormat == QFontEngine::Format_ARGB)
         return true;
 
-    static const int maxCachedGlyphSizeSquared = std::pow([]{
-        if (int env = qEnvironmentVariableIntValue("QT_MAX_CACHED_GLYPH_SIZE"))
-            return env;
-        return QT_MAX_CACHED_GLYPH_SIZE;
-    }(), 2);
+    static const int maxCachedGlyphSizeSquared = []{
+        const int v = []{ /* std::pow(int,int) is ambiguous on QNX; use v*v */
+            if (int env = qEnvironmentVariableIntValue("QT_MAX_CACHED_GLYPH_SIZE"))
+                return env;
+            return QT_MAX_CACHED_GLYPH_SIZE;
+        }();
+        return v * v;
+    }();
 
     qreal pixelSize = fontEngine->fontDef.pixelSize;
     return (pixelSize * pixelSize * qAbs(m.determinant())) <= maxCachedGlyphSizeSquared;
diff --git a/src/gui/text/freetype/qfontengine_ft.cpp b/src/gui/text/freetype/qfontengine_ft.cpp
index 53e4f3fb0e..abc36a2700 100644
--- a/src/gui/text/freetype/qfontengine_ft.cpp
+++ b/src/gui/text/freetype/qfontengine_ft.cpp
@@ -283,12 +283,14 @@ QFreetypeFace *QFreetypeFace::getFace(const QFontEngine::FaceId &face_id,
 #endif
         newFreetype->face = face;
         newFreetype->mm_var = nullptr;
+#if (FREETYPE_MAJOR*10000 + FREETYPE_MINOR*100 + FREETYPE_PATCH) >= 20700
         if (FT_IS_NAMED_INSTANCE(newFreetype->face)) {
             FT_Error ftresult;
             ftresult = FT_Get_MM_Var(face, &newFreetype->mm_var);
             if (ftresult != FT_Err_Ok)
                 newFreetype->mm_var = nullptr;
         }
+#endif
 
         newFreetype->ref.storeRelaxed(1);
         newFreetype->xsize = 0;
@@ -328,6 +330,7 @@ QFreetypeFace *QFreetypeFace::getFace(const QFontEngine::FaceId &face_id,
 
         FT_Set_Charmap(newFreetype->face, newFreetype->unicode_map);
 
+#if (FREETYPE_MAJOR*10000 + FREETYPE_MINOR*100 + FREETYPE_PATCH) >= 20701
         if (!face_id.variableAxes.isEmpty()) {
             FT_MM_Var *var = nullptr;
             FT_Get_MM_Var(newFreetype->face, &var);
@@ -345,6 +348,7 @@ QFreetypeFace *QFreetypeFace::getFace(const QFontEngine::FaceId &face_id,
                 FT_Done_MM_Var(qt_getFreetype(), var);
             }
         }
+#endif
 
         QT_TRY {
             freetypeData->faces.insert(face_id, newFreetype.get());
@@ -362,8 +366,10 @@ QFreetypeFace *QFreetypeFace::getFace(const QFontEngine::FaceId &face_id,
 void QFreetypeFace::cleanup()
 {
     hbFace.reset();
+#if (FREETYPE_MAJOR*10000 + FREETYPE_MINOR*100 + FREETYPE_PATCH) >= 20701
     if (mm_var && face && face->glyph)
         FT_Done_MM_Var(face->glyph->library, mm_var);
+#endif
     mm_var = nullptr;
     FT_Done_Face(face);
     face = nullptr;
diff --git a/src/plugins/platforms/qnx/main.cpp b/src/plugins/platforms/qnx/main.cpp
index e5656d7cb9..2aee2f0585 100644
--- a/src/plugins/platforms/qnx/main.cpp
+++ b/src/plugins/platforms/qnx/main.cpp
@@ -4,6 +4,7 @@
 #include "main.h"
 #include "qqnxintegration.h"
 #include "qqnxlgmon.h"
+#include <cstdio>
 
 QT_BEGIN_NAMESPACE
 
@@ -11,11 +12,18 @@ using namespace Qt::StringLiterals;
 
 QPlatformIntegration *QQnxIntegrationPlugin::create(const QString& system, const QStringList& paramList)
 {
+    fprintf(stderr, "QNX-PLUGIN: create(system=%s) called\n", system.toLocal8Bit().constData());
+    fflush(stderr);
     if (!system.compare("qnx"_L1, Qt::CaseInsensitive)) {
+        fprintf(stderr, "QNX-PLUGIN: qqnxLgmonInit()...\n"); fflush(stderr);
         qqnxLgmonInit();
-        return new QQnxIntegration(paramList);
+        fprintf(stderr, "QNX-PLUGIN: new QQnxIntegration()...\n"); fflush(stderr);
+        QPlatformIntegration *r = new QQnxIntegration(paramList);
+        fprintf(stderr, "QNX-PLUGIN: QQnxIntegration constructed = %p\n", r); fflush(stderr);
+        return r;
     }
 
+    fprintf(stderr, "QNX-PLUGIN: system mismatch, returning 0\n"); fflush(stderr);
     return 0;
 }
 
diff --git a/src/plugins/platforms/qnx/qqnxintegration.cpp b/src/plugins/platforms/qnx/qqnxintegration.cpp
index 1a60bf064c..3a6d5bab16 100644
--- a/src/plugins/platforms/qnx/qqnxintegration.cpp
+++ b/src/plugins/platforms/qnx/qqnxintegration.cpp
@@ -148,19 +148,28 @@ QQnxIntegration::QQnxIntegration(const QStringList &paramList)
     qCDebug(lcQpaQnx) << Q_FUNC_INFO;
 
     // Open connection to QNX composition manager
+    fprintf(stderr, "QNX: screen_create_context(caps=0x%x) ...\n", getContextCapabilities(paramList));
+    fflush(stderr);
     if (screen_create_context(&m_screenContext, getContextCapabilities(paramList))) {
+        fprintf(stderr, "QNX: screen_create_context FAILED: %s (%d)\n", strerror(errno), errno);
+        fflush(stderr);
         qFatal("%s - Screen: Failed to create screen context - Error: %s (%i)",
                Q_FUNC_INFO, strerror(errno), errno);
     }
+    fprintf(stderr, "QNX: screen_create_context OK\n");
+    fflush(stderr);
     screen_get_context_property_cv(m_screenContext,
                                    SCREEN_PROPERTY_ID,
                                    m_screenContextId.size(),
                                    m_screenContextId.data());
     m_screenContextId.resize(strlen(m_screenContextId.constData()));
+    fprintf(stderr, "QNX: context id: %s\n", m_screenContextId.constData());
+    fflush(stderr);
 
 #if QT_CONFIG(qqnx_pps)
     // Create/start navigator event notifier
     m_navigatorEventNotifier = new QQnxNavigatorEventNotifier(m_navigatorEventHandler);
+    fprintf(stderr, "QNX: navigatorEventNotifier created\n"); fflush(stderr);
 
     // delay invocation of start() to the time the event loop is up and running
     // needed to have the QThread internals of the main thread properly initialized
@@ -168,20 +177,26 @@ QQnxIntegration::QQnxIntegration(const QStringList &paramList)
 #endif
 
 #if QT_CONFIG(opengl)
+    fprintf(stderr, "QNX: createEglDisplay...\n"); fflush(stderr);
     createEglDisplay();
+    fprintf(stderr, "QNX: createEglDisplay done\n"); fflush(stderr);
 #endif
 
     // Create/start event thread
+    fprintf(stderr, "QNX: creating screenEventThread...\n"); fflush(stderr);
     m_screenEventThread = new QQnxScreenEventThread(m_screenContext);
     m_screenEventHandler->setScreenEventThread(m_screenEventThread);
     m_screenEventThread->start();
+    fprintf(stderr, "QNX: screenEventThread started\n"); fflush(stderr);
 
     m_qpaInputContext = QPlatformInputContextFactory::create();
+    fprintf(stderr, "QNX: inputContext=%p\n", m_qpaInputContext); fflush(stderr);
 
 #if QT_CONFIG(qqnx_pps)
     if (!m_qpaInputContext) {
         // Create/start the keyboard class.
         m_virtualKeyboard = new QQnxVirtualKeyboardPps();
+        fprintf(stderr, "QNX: virtualKeyboard created\n"); fflush(stderr);
 
         // delay invocation of start() to the time the event loop is up and running
         // needed to have the QThread internals of the main thread properly initialized
@@ -191,9 +206,12 @@ QQnxIntegration::QQnxIntegration(const QStringList &paramList)
 
 #if QT_CONFIG(qqnx_pps)
     m_navigator = new QQnxNavigatorPps();
+    fprintf(stderr, "QNX: navigator created\n"); fflush(stderr);
 #endif
 
+    fprintf(stderr, "QNX: createDisplays...\n"); fflush(stderr);
     createDisplays();
+    fprintf(stderr, "QNX: createDisplays done\n"); fflush(stderr);
 
     if (m_virtualKeyboard) {
         // TODO check if we need to do this for all screens or only the primary one
@@ -731,12 +749,24 @@ void QQnxIntegration::createEglDisplay()
 
     // Initialize connection to EGL
     m_eglDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
-    if (Q_UNLIKELY(m_eglDisplay == EGL_NO_DISPLAY))
-        qFatal("QQnxiIntegration: failed to obtain EGL display: %x", eglGetError());
+    if (Q_UNLIKELY(m_eglDisplay == EGL_NO_DISPLAY)) {
+        // BB10 sandbox: EGL may not be available without a screen window yet.
+        // Fall back to raster/software rendering instead of aborting.
+        fprintf(stderr, "QNX: eglGetDisplay(EGL_DEFAULT_DISPLAY) failed (err=0x%x) — raster fallback\n",
+                eglGetError());
+        fflush(stderr);
+        m_eglDisplay = EGL_NO_DISPLAY;
+        return;
+    }
 
     EGLBoolean eglResult = eglInitialize(m_eglDisplay, 0, 0);
-    if (Q_UNLIKELY(eglResult != EGL_TRUE))
-        qFatal("QQnxIntegration: failed to initialize EGL display, err=%d", eglGetError());
+    if (Q_UNLIKELY(eglResult != EGL_TRUE)) {
+        fprintf(stderr, "QNX: eglInitialize failed (err=0x%x) — raster fallback\n",
+                eglGetError());
+        fflush(stderr);
+        m_eglDisplay = EGL_NO_DISPLAY;
+        return;
+    }
 }
 
 void QQnxIntegration::destroyEglDisplay()
diff --git a/src/plugins/platforms/qnx/qqnxrasterbackingstore.cpp b/src/plugins/platforms/qnx/qqnxrasterbackingstore.cpp
index e6b787ccf7..96569290aa 100644
--- a/src/plugins/platforms/qnx/qqnxrasterbackingstore.cpp
+++ b/src/plugins/platforms/qnx/qqnxrasterbackingstore.cpp
@@ -51,8 +51,15 @@ void QQnxRasterBackingStore::flush(QWindow *window, const QRegion &region, const
     auto *targetWindow = window
         ? static_cast<QQnxRasterWindow *>(window->handle()) : platformWindow();
 
-    if (targetWindow)
-        targetWindow->post(region);  // update the display with newly rendered content
+    if (targetWindow) {
+        // BB10 software-backend QtQuick: incremental dirty regions sometimes
+        // miss areas that were animated/scrolled (e.g. SwipeView contents),
+        // leaving stale pixels visible until a full repaint. Post the entire
+        // window each flush to avoid that — costs a bit more bandwidth, but
+        // eliminates the "wave/swirl" partial-update artifacts.
+        QRegion full = QRect(QPoint(0, 0), targetWindow->geometry().size());
+        targetWindow->post(full);
+    }
 
     m_needsPosting = false;
     m_scrolled = false;
diff --git a/src/plugins/platforms/qnx/qqnxrasterwindow.cpp b/src/plugins/platforms/qnx/qqnxrasterwindow.cpp
index 72442035b4..ce66fc9fc9 100644
--- a/src/plugins/platforms/qnx/qqnxrasterwindow.cpp
+++ b/src/plugins/platforms/qnx/qqnxrasterwindow.cpp
@@ -74,10 +74,16 @@ void QQnxRasterWindow::post(const QRegion &dirty)
                 screen_post_window(nativeHandle(), currentBuffer.nativeBuffer(), 1, dirtyRect, 0),
                 "Failed to post window");
 #else
-        // Update the display with contents of render buffer
-        Q_SCREEN_CHECKERROR(
-                screen_post_window(nativeHandle(), currentBuffer.nativeBuffer(), 0, NULL, 0),
-                "Failed to post window");
+        // Update the display with contents of render buffer.
+        // BB10 (QNX 6.6) screen_post_window() ignores numrects=0/NULL and posts
+        // nothing; pass the explicit bounding rect so it actually composites.
+        {
+            QRect rect = dirty.boundingRect();
+            int dirtyRect[4] = { rect.x(), rect.y(), rect.x() + rect.width(), rect.y() + rect.height() };
+            Q_SCREEN_CHECKERROR(
+                    screen_post_window(nativeHandle(), currentBuffer.nativeBuffer(), 1, dirtyRect, 0),
+                    "Failed to post window");
+        }
 #endif
 
         // Advance to next nender buffer
diff --git a/src/plugins/platforms/qnx/qqnxscreen.h b/src/plugins/platforms/qnx/qqnxscreen.h
index 17b282bdc1..8e3bc41ec9 100644
--- a/src/plugins/platforms/qnx/qqnxscreen.h
+++ b/src/plugins/platforms/qnx/qqnxscreen.h
@@ -15,7 +15,10 @@
 
 #if !defined(_SCREEN_VERSION)
 #define _SCREEN_MAKE_VERSION(major, minor, patch)  (((major) * 10000) + ((minor) * 100) + (patch))
-#define _SCREEN_VERSION _SCREEN_MAKE_VERSION(0, 0, 0)
+/* QNX 8.x / BB10 screen.h doesn't define _SCREEN_VERSION but already uses the
+ * 1.x property names (SCREEN_PROPERTY_FLAGS, SCREEN_PROPERTY_FOCUS, etc.).
+ * Default to 1.0.0 so the old-name alias block below is skipped. */
+#define _SCREEN_VERSION _SCREEN_MAKE_VERSION(1, 0, 0)
 #endif
 
 // For pre-1.0.0 screen, map some screen property names to the old
@@ -28,6 +31,40 @@ const int SCREEN_PROPERTY_SCAN = SCREEN_PROPERTY_KEY_SCAN;
 const int SCREEN_PROPERTY_SYM = SCREEN_PROPERTY_KEY_SYM;
 #endif
 
+// BB10 / QNX 8 sysroot (screen API ~1.x) lacks some symbols added in QNX
+// Screen 2.x.  Define placeholders so the QNX QPA plugin compiles; these
+// events/properties will simply never appear on BB10 hardware.
+#ifndef SCREEN_EVENT_MANAGER
+#  define SCREEN_EVENT_MANAGER  0x7ffe01   /* never fired on BB10 */
+#endif
+#ifndef SCREEN_OBJECT_TYPE_STREAM
+#  define SCREEN_OBJECT_TYPE_STREAM  0x7ffe02
+#endif
+#ifndef SCREEN_PROPERTY_SUBTYPE
+#  define SCREEN_PROPERTY_SUBTYPE  0x7ffe03
+#endif
+// SCREEN_PROPERTY_PIXMAP (singular) is the per-event pixmap handle property.
+// BB10 uses SCREEN_PROPERTY_PIXMAPS (plural, window's pixmap list); use it
+// as a best-effort stand-in for pixmap close-event handling.
+#ifndef SCREEN_PROPERTY_PIXMAP
+#  define SCREEN_PROPERTY_PIXMAP  SCREEN_PROPERTY_PIXMAPS
+#endif
+// SCREEN_PROPERTY_PARENT — parent group name property; alias to GROUP on BB10.
+#ifndef SCREEN_PROPERTY_PARENT
+#  define SCREEN_PROPERTY_PARENT  SCREEN_PROPERTY_GROUP
+#endif
+// screen_manage_window — window manager handshake, added in QNX 7.x.
+// On BB10 there is no formal window manager; provide a no-op stub.
+#if !defined(screen_manage_window)
+#  ifdef __cplusplus
+extern "C" {
+#  endif
+static inline int screen_manage_window(screen_window_t, const char *) { return 0; }
+#  ifdef __cplusplus
+}
+#  endif
+#endif
+
 QT_BEGIN_NAMESPACE
 
 Q_DECLARE_LOGGING_CATEGORY(lcQpaScreen);
diff --git a/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp b/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp
index 01d7df5262..551903e417 100644
--- a/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp
+++ b/src/plugins/platforms/qnx/qqnxscreeneventhandler.cpp
@@ -6,6 +6,7 @@
 #include "qqnxglobal.h"
 
 #include "qqnxscreeneventhandler.h"
+#include <sys/keycodes.h>
 #include "qqnxscreeneventthread.h"
 #include "qqnxintegration.h"
 #include "qqnxkeytranslator.h"
@@ -306,6 +307,44 @@ void QQnxScreenEventHandler::handleKeyboardEvent(screen_event_t event)
     int sequenceId = 0;
     bool inject = true;
 
+    // BB10 sticky-modifier emulation: on Q10 the hardware keyboard sends a
+    // separate KEY_DOWN event for the Shift/Alt key, then releases it, then
+    // sends the next char with modifiers=0. Cascades apps see the shifted
+    // char because BlackBerry's input layer remembers the last pressed
+    // modifier. We do the same here: if the event IS a modifier press/
+    // release, remember/clear it; if it's a real key, OR-in the pending
+    // modifier and consume it.
+    {
+        bool isModifierKey = false;
+        int  modifierBit   = 0;
+        switch (sym) {
+            case KEYCODE_LEFT_SHIFT:
+            case KEYCODE_RIGHT_SHIFT:
+                isModifierKey = true; modifierBit = KEYMOD_SHIFT; break;
+            case KEYCODE_LEFT_CTRL:
+            case KEYCODE_RIGHT_CTRL:
+                isModifierKey = true; modifierBit = KEYMOD_CTRL;  break;
+            case KEYCODE_LEFT_ALT:
+            case KEYCODE_RIGHT_ALT:
+                isModifierKey = true; modifierBit = KEYMOD_ALT;   break;
+            default: break;
+        }
+        if (isModifierKey) {
+            if (flags & KEY_DOWN)
+                m_pendingModifiers |= modifierBit;
+            // Don't clear on KEY_UP — keep until the next non-modifier key
+            // is processed, that's the "sticky" behaviour BB10 users expect.
+        } else if (flags & KEY_DOWN) {
+            // Non-modifier key going down: merge sticky modifiers, then clear.
+            if (m_pendingModifiers) {
+                modifiers |= m_pendingModifiers;
+                // Re-derive the shifted symbol if Shift is now active and we
+                // received a base-cap from the keyboard with no SYM_VALID.
+                m_pendingModifiers = 0;
+            }
+        }
+    }
+
     Q_FOREACH (QQnxScreenEventFilter *filter, m_eventFilters) {
         if (filter->handleKeyboardEvent(flags, sym, modifiers, scan, cap, sequenceId)) {
             inject = false;
diff --git a/src/plugins/platforms/qnx/qqnxscreeneventhandler.h b/src/plugins/platforms/qnx/qqnxscreeneventhandler.h
index a9d57a7f61..7c6a6f5e19 100644
--- a/src/plugins/platforms/qnx/qqnxscreeneventhandler.h
+++ b/src/plugins/platforms/qnx/qqnxscreeneventhandler.h
@@ -65,6 +65,9 @@ private:
     QPoint m_lastLocalMousePoint;
     Qt::MouseButtons m_lastButtonState;
     screen_window_t m_lastMouseWindow;
+    // BB10 sticky-modifier support — Q10 hardware keyboard sends shift/alt as
+    // separate events without holding; remember them for the next key.
+    int m_pendingModifiers = 0;
     QPointingDevice *m_touchDevice;
     QPointingDevice *m_mouseDevice;
     QWindowSystemInterface::TouchPoint m_touchPoints[MaximumTouchPoints];
diff --git a/src/plugins/platforms/qnx/qqnxscreeneventthread.cpp b/src/plugins/platforms/qnx/qqnxscreeneventthread.cpp
index 6b4ffc3962..dfede8ddf9 100644
--- a/src/plugins/platforms/qnx/qqnxscreeneventthread.cpp
+++ b/src/plugins/platforms/qnx/qqnxscreeneventthread.cpp
@@ -21,12 +21,24 @@ static const int c_quitCode = _PULSE_CODE_MINAVAIL + 2;
 #if !defined(screen_register_event)
 int screen_register_event(screen_context_t, struct sigevent *event)
 {
+#if defined(MsgRegisterEvent)
     return MsgRegisterEvent(event, -1);
+#else
+    /* BB10 / QNX 8: event registration is performed via screen_notify;
+     * this function is a no-op here. */
+    (void)event;
+    return 0;
+#endif
 }
 
 int screen_unregister_event(struct sigevent *event)
 {
+#if defined(MsgUnregisterEvent)
     return MsgUnregisterEvent(event);
+#else
+    (void)event;
+    return 0;
+#endif
 }
 #endif