Just for completeness, this is the default one from a fresh RetroPie v4.0.2 image
dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait quiet loglevel=3 consoleblank=0 quiet init=/usr/lib/raspi-config/init_resize.sh
Don't know how make it look like a code line