Users can also switch between the open and closed modes (e.g. between a 'community' kernel and Nokia's kernel), so that after working in the open mode, users can return to the DRM-protected mode to play some music. If the application doesn't use the protected storage but just stores its data as plain files in the file system, like most non-commercial applications will do, those files are accessible in both modes. Switching modes requires rebooting the device, though, because the checks for the integrity of the software are done by the boot loader.