RPi cmdline.txt

This file is for passing arguments to the Linux kernel and it can be found in /boot/

Default options:
 * dwc_otg.lpm_enable=0
 * console=ttyAMA0,115200
 * kgdboc=ttyAMA0,115200
 * console=tty1
 * root=/dev/mmcblk0p2
 * rootfstype=ext4
 * elevator=deadline
 * rootwait

some common options:
 * dwc_otg.speed=1
 * USB v1 speed
 * smsc95xx.turbo_mode=N
 * if the raspberrypi freezes after filling the log withe kevent dropped.
 * dwc_otg.microframe_schedule=1
 * console=ttyAMA0,115200
 * usbhid.mousepoll=8