How to update the Beaglebone Black Firmware
For some reason everything I found on the web and even the Beaglebone Org documentation was crazy out of date so…

It’s very easy to do this.
Get the latest image from http://beagleboard.org/latest-images
Note the tiny little note at the bottom. Once you’ve written the image to an SD card you have to mount it on a Linux system (Windows couldn’t read the format) and then edit the file boot/uEnv.txt to remove the hash mark (#) and uncomment the programming line that looks like this
#cmdline=init=/opt/scripts/tools/eMMC/init-eMMC-flasher-v3.sh
Then just power off your Beaglebone, insert the SD card, power it on so it boots from SD and it will automatically flash the eMMC.
Doh.
While it’s flashing the lights will cycle left-right. Once it finishes flashing it will power down the system.

