pwrap_init_chip_select_ext
pwrap_init_chip_select_ext(wrp, 15, 15, 15, 15);
pwrap_init_chip_select_ext(wrp, 0, 4, 2, 2);
pwrap_init_chip_select_ext(wrp, 0, 4, 0, 0);
pwrap_init_chip_select_ext(wrp, 4, 0, 2, 2);
pwrap_init_chip_select_ext(wrp, 5, 0, 2, 2);