First guess at making eglfs_kms use 16-bit framebuffers

eglfs_kms_16bit.patch

diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmintegration.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmintegration.cpp
index 1c0a8e1b5fc1..6b1dd875fb7e 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmintegration.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmintegration.cpp
@@ -90,7 +90,7 @@ EGLNativeWindowType QEglFSKmsGbmIntegration::createNativeOffscreenWindow(const Q
     qCDebug(qLcEglfsKmsDebug) << "Creating native off screen window";
     gbm_surface *surface = gbm_surface_create(static_cast<QEglFSKmsGbmDevice *>(device())->gbmDevice(),
                                               1, 1,
-                                              GBM_FORMAT_XRGB8888,
+                                              GBM_FORMAT_RGB565,
                                               GBM_BO_USE_RENDERING);
 
     return reinterpret_cast<EGLNativeWindowType>(surface);
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp
index 7a17b60a5e7a..07494257e1a3 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms/qeglfskmsgbmscreen.cpp
@@ -80,7 +80,7 @@ QEglFSKmsGbmScreen::FrameBuffer *QEglFSKmsGbmScreen::framebufferForBufferObject(
 
     QScopedPointer<FrameBuffer> fb(new FrameBuffer);
 
-    int ret = drmModeAddFB(device()->fd(), width, height, 24, 32,
+    int ret = drmModeAddFB(device()->fd(), width, height, 16, 16,
                            stride, handle, &fb->fb);
 
     if (ret) {
@@ -132,7 +132,7 @@ gbm_surface *QEglFSKmsGbmScreen::createSurface()
         m_gbm_surface = gbm_surface_create(static_cast<QEglFSKmsGbmDevice *>(device())->gbmDevice(),
                                            geometry().width(),
                                            geometry().height(),
-                                           GBM_FORMAT_XRGB8888,
+                                           GBM_FORMAT_RGB565,
                                            GBM_BO_USE_SCANOUT | GBM_BO_USE_RENDERING);
     }
     return m_gbm_surface;
diff --git a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.cpp b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.cpp
index e6b256f6b2e2..c86e9c17dd99 100644
--- a/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.cpp
+++ b/src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.cpp
@@ -108,12 +108,12 @@ QRect QEglFSKmsScreen::geometry() const
 
 int QEglFSKmsScreen::depth() const
 {
-    return 32;
+    return 16;
 }
 
 QImage::Format QEglFSKmsScreen::format() const
 {
-    return QImage::Format_RGB32;
+    return QImage::Format_RGB16;
 }
 
 QSizeF QEglFSKmsScreen::physicalSize() const