Operation Manual

root file system is available. Without this option, the Pi can get stuck as it begins to boot before the relatively slow SD card is
fully ready for access.
With the exception of the dwc_otg setting, none of these kernel parameters are unique to the Pi. The bootloader configuration of
any Linux distribution will include a list of options very similar to those of cmdline.txt.
Typically, you should leave the cmdline.txt alone. It’s created by the distribution maintainers specifically for that version of
Linux, and may differ from one distribution to the next. Entries that work on Fedora Remix may not work on Debian, and vice
versa. The options available to cmdline.txt depend on what kernel the distribution is using and what features were included
when the kernel was built.
If you’re a kernel developer, you can use cmdline.txt to pass parameters for enabling or disabling new functionality that
you’ve compiled into the kernel. As with config.txt, any changes require a reboot to take effect.