tinycore has had (u)efi support for some time now, see:
http://forum.tinycorelinux.net/index.php/topic,19364.msg119228.html#msg119228
http://forum.tinycorelinux.net/index.php/topic,20939.msg130829.html#msg130829
http://forum.tinycorelinux.net/index.php/topic,19364.msg119228.html#msg119228
http://forum.tinycorelinux.net/index.php/topic,20939.msg130829.html#msg130829