KMSDRM doesn't have a window manager, so all windows are fullscreen
diff --git a/src/video/SDL_video.c b/src/video/SDL_video.c
index d750a35..8786bbd 100644
--- a/src/video/SDL_video.c
+++ b/src/video/SDL_video.c
@@ -1480,6 +1480,13 @@ SDL_CreateWindow(const char *title, int x, int y, int w, int h, Uint32 flags)
return NULL;
}
+ /* Some platforms don't have a window manager */
+ if (SDL_strcmp(_this->name, "KMSDRM") == 0) {
+ if (!(flags & SDL_WINDOW_FULLSCREEN)) {
+ flags |= SDL_WINDOW_FULLSCREEN;
+ }
+ }
+
/* Some platforms have OpenGL enabled by default */
#if (SDL_VIDEO_OPENGL && __MACOSX__) || (__IPHONEOS__ && !TARGET_OS_MACCATALYST) || __ANDROID__ || __NACL__
if (!_this->is_dummy && !(flags & SDL_WINDOW_VULKAN) && !(flags & SDL_WINDOW_METAL) && !SDL_IsVideoContextExternal()) {