* <code>./flash.sh gecko</code> : update the b2g runtime
* <code>./flash.sh gaia</code> : update the gaia apps and data
In addition, you can run the following non-standard update commands
* <code>./flash.sh boot</code> : update the RPi firmware, bootloader files, and kernel
* <code>./flash.sh kernel</code> : update the kernel only
You can also flash your SD card anew at any time by following the instructions above. But this should usually not be necessary.