UIWindow layout issue on ios7.1 with xcode 6.0

I created a project on xcode 6.0 and I've been running the project on ios8 simulator however when I tried run it on iphone5s ios7.1 simulator the UIWindow frame became to 320x480...

self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.backgroundColor = [UIColor whiteColor];
self.window.rootViewController = self.navigationController;
[self.window makeKeyAndVisible];

above is how I create UIwindow

enter image description here

What shall I do?

Solution

You must add correct size iphone/ipad default images, your problem will be solved. , see this link for further details Launch images screen size for iphone