"Data abort" Brick unresponsive after completing program

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"Data abort" Brick unresponsive after completing program

Postby Nathan1123 » Sat May 05, 2018 6:34 pm


I was just running some debug code in my program to test for memory capacity, as it was filling up too quickly.

However, as soon as the program ended I got the following error message:

Data abort
PC 001040B0
AASR 0000005A
ASR 00020202
DEBUG1 00000000
DEBUG2 00000000

And its unresponsive. Oddly enough, the light sensor still seems to be on, and its making a constant "clicking" noise.

Is there a way I can safely force restart the brick? According to your help guide, it should only run into this issue if it tries to execute a non LeJOS program. However, that is not what happened.

I read online I can do a hard reset of the brick, but that would delete all the files from it. There is one file on that I don't have on my computer, so if there was a way to recover the brick without wiping it out I would prefer that. Furthermore, I have no idea what caused it. I am concerned that hard-resetting and reinstalling the firmware will just result in the exact same thing again when I inevitably want to test my code as I was trying to originally.

Any ideas?

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Re: "Data abort" Brick unresponsive after completing program

Postby gloomyandy » Sat May 05, 2018 8:47 pm

You should just be able to reflash leJOS to it, make sure you use the same version, there is an option not to reformat the file system, so you may be able to recover your file, but it is never a good idea to not have a backup of data on the NXT. See NXJFlashG here:
http://www.lejos.org/nxt/nxj/tutorial/P ... ITools.htm

It is very rare to have a data abort, but it usually indicates that either you ran a corrupt leJOS program or you have hit a bug in the leJOS VM or linker, it can also be caused by a hardware problem with the brick itself. If you do manage to recover your file I would recommend that you reformat the file system on the NXT after you have made a copy of your file to your PC. It is possible to debug data aborts, but it is a tricky process and you really need to be very familiar with the VM code and have all of the needed tools available. Unfortunately I no longer have those tools easily at hand and given that the good weather has just arrived here, I'm more inclined to go out and ride my bike than spend time re-installing them! Sorry!
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Re: "Data abort" Brick unresponsive after completing program

Postby Nathan1123 » Sun May 06, 2018 6:59 am

Ok, I was able to do as you said, and immediately copied the file in question on my PC.

I was able to debug out the data abort issue by just tapping the reset button on the brick. That seems to cause it to restart without resetting the firmware.

However, I was not able to determine exactly how the Data Abort happened. I just rewrote the algorithm of my code and it went away.

Thank you so much :)

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