UP Squared sporadically booting into the BIOS only

AdnanAdnan New Member Posts: 1

can you possibly help with the following problem one of our customers experiences with an UP Squared board, P/N: UPS-GWS01P4-A20-0864?

Here is the customer's problem description:

There is a Linux system installed, which did not cause any problems in the beginning. This system is installed in our measuring instruments.

Currently we have the following problem:
We use the device with the Linux system installed and switch it off after the measuring process is finished.
At the next boot the UP-Squared starts directly into the BIOS and not into our Linux system as usually.
However, this does not happen every time, but sporadically.
The measuring device was not moved at the time when the error started to turn up.
To solve the problem, we have to restart from the BIOS and then start "normally" into the Linux system.

Enclosed Photo1 of the "faulty" start directly into the BIOS.

And Photo2 after the restart and afterwards manual procedure into the BIOS.

According to that this sounds like the issue turns up on cold boots only and only sporadically. According to the provided pictures the boot order is automatically changed and the USB boot device is taken out from the first position in the boot order.
Could this be a BIOS problem? The picture shows BIOS 2.18.1263, but strangely the issue turned up only after using the board for a while…

I'm grateful for any hints
Thank you.


  • snuhgsnuhg New Member Posts: 14
    edited July 5

    Take this with a grain of salt, but to me your description reminds me of a problem other users have reported on this forum. These reports vary in some of the details but the common symptom is always the same. Namely, at boot-up the system is unable to detect/initialize the eMMC storage device. This results in the system not finding the files needed to complete the boot process and by default the system resorts to opening the BIOS pages.

    When looking at your first picture (where the system failed to boot) you can see that there is no additional info for {Hard Disk} in the list of boot device options. That means the system was unable to initialize/detect a hard disk (i.e. the eMMC on the UP2 board). When such a failure occurs there are also error messages during boot-up to the effect off something like "error xyz, unable to initialize eMMC". I am not sure if these messages are included in the system logs (probably not). In contrast, the second picture (where the boot-up was successful) shows a hard disk entry in the list of boot devices which also contains info about the OS (debian) and the type of storage device (M...., which would probably read MMC if there were more space on the screen to show the complete list entry).

    Why does your system fail to detect the hard disk and why does it occur randomly? Only AAEON knows the complete answer, but discussions on this forum seem to suggest bad electrical contacts, i.e. poor soldering, as the underlying problem. The resulting effect will vary from board to board, depending on quality control in the factory and how good or bad an individual soldering contact on a particular board is. In the worst case, initialization of the MMC will always fail, so it is not even possible to install an OS in the first place. In less severe cases it is possible to install an OS, but the boot process might randomly fail at later times. I am not an expert on soldering and/or PCBs, but I can imagine that a bad contact might get worse with time and/or show different behavior depending on ambient conditions (temperature, ....) and God knows what else.

    Mind you, there are also reports on this forum concerning an issue that may be characterized as "random reboots". That's a different case from yours because these boards were randomly rebooting, i.e. after boot-up they would run for a while and then suddenly reboot. The cause was found to be a software bug, I believe, and I think it was an issue with the original UP-board only and not the UP2.

  • ApeiChenApeiChen New Member, Moderator, AAEON Posts: 14 mod


    May I know if you update the BIOS to the latest version the problem still occur or not?

  • AntoineAntoine New Member Posts: 6

    @ApeiChen said:

    May I know if you update the BIOS to the latest version the problem still occur or not?

    Yes it does :(

    Our BIOS info : UP-APL01 R4.2 (UPA1AM42 ) (03/12/2019)

    I don't think that your BIOS version is 2.18.1263, I believe this is just the Aptio Setup Utility version.
    The BIOS version is showed in the "Main" tab.

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