The default internal drive of a Douro's Aaeon tablet can be susceptible to data corruption upon repeated unexpected power loss. However, the Aaeon can be run fully off of a USB flash drive with no performance impact, which is more resilient against data corruption than its internal drive.
If you need to reimage, or as a preventative measure, use this article to switch to running from a USB drive instead.
What you'll need
- USB keyboard
- 32GB USB 3.0 flash drive
- A second USB flash drive (any size)
- Laptop (macOS, Windows, or Linux)
Creating a Linux utility drive
In order to run the tablet solely from a USB drive, we need to wipe the data from its internal drive, so it's no longer tempted to boot from it. First, we'll create a Linux utility drive and boot from it in order to wipe the internal drive.
Download this image file: TinyCore-current.iso
Burn it to the USB drive (that isn't the 32GB USB 3.0 one) using balenaEtcher.
After burning, plug the USB drive into the top of the tablet along with a USB keyboard.
Press the power button on the tablet, then immediately and repeatedly press the keyboard's DEL button until the tablet's BIOS screen appears as in the video below.
Follow the steps in the video below to disable the internal drive ('mSATA mini'), select the USB drive as the boot drive, then 'Save changes and reset'.
Wiping the internal drive with the Linux utility drive
When the 'TinyCore' boot screen comes up, use the keyboard arrow to select 'Boot Core (command-line only)' and hit Enter.
At the following command prompt, type the below and hit enter. It may take up to 10 minutes to complete, and it won't show a message until then:
sudo dd if=/dev/zero of=/dev/sda bs=1M
Once complete, power off the tablet by holding down on its power button and remove the USB drive.
Downloading the Lamassu disk image
Choose the appropriate disk image based on your Douro's tablet model.
An ACP-1104 tablet has one blue USB 3.0 port at the top near its power button. If this is your tablet, download this image: dd-v7.4.9-acp-1104-2020.07.24.img.xz
An ACP-1103 tablet has all black USB 2.0 ports, and a mini-HDMI port next to its power button. If this is your tablet, download this image: dd-v7.4.9-acp-1103-2020.07.24.img.xz
Creating a bootable system drive
Burn the above image to the 32GB USB 3.0 drive using balenaEtcher.
Then, connect it to the tablet's USB port (its blue 3.0 port if available) and ensure it is selected as the boot device in the tablet's BIOS settings, as when booting from the previous USB drive.
After saving the configuration and restarting, it should boot only from the USB drive. If you ever need to replace the drive, you can burn a new USB drive and swap this one without wiping or reimaging.
You should see a screen with 'Congratulations' and an 'INIT' button. Press the INIT button and pair with your admin using a new pairing code.
The image above contains Crafty Chnemu v7.3, though we'll want to update it to Defiant Dingirma v7.4.
Once initialised and paired to the server, please let us know the output of the server command lamassu-devices, and we'll look for the new machine online and update it.