To perform an automatic software update at boot, you need to place 2 files on the root directory of the ACA:
The firmware image to be loaded.
A text document called ‘startup.txt’ which points to the firmware image to be loaded.
The text file needs to contain the following content: ‘autoUpdate=<software file name>’
(Example with the firmware to be loaded renamed to ‘firmware.bin’)
Then you can insert the ACA to the device and (re-) boot it. The firmware mentioned will automatically be loaded and updated on the device.