Ah well, just as I feared. If I remember correctly back in the day Linux on ARM used to work in such a way that unaligned memory accesses (trying to access for example 32-bit data that is not in 32-bit aligned address) caused trap in the kernel and depending on options the kernel either fixed up the access or raised SIGBUS as it's usually a bug and slow in any case and older ARM processors didn't support unaligned access at all.
I made a short test program that does exactly this and it works on both my Raspberries (Pi 4 running 64-bit and Pi 3 running 32-bit RaspberryOS). It needs to be renamed to unaligned.c (forum doesn't allow .c files) and compiled with -O0 or the compiler optimizes the access away and just prints the value. It should print "Value 0x8010203". This might be totally red herring and have nothing to do with the issue, but checking that on the problematic platforms would at least narrow the search a bit.
I get Value 0x8010203.
on Ubuntu 20.04.4 LTS
Linux 4.9.312-125 aarch64. arm64
120 MM Skywatcher Esprit on Celestron CGX, ZWO ASI 224MC guiding, Pegasus FocusCube v2+PPBA
Nikon Z7 8256 x 5504, 35.9 x 23.9mm 4.34 um. Triad Ultra Quad NB Filter
1) Odroid-N2 Ubuntu-mate 20.04.4 2) StellarMate RPI4 8G
The good, the bad, the ugly at sciencedowneast.no-ip.ca/zenphoto/
This is the line in my log file:
[2022-07-26T21:47:14.018 MST DEBG ][ org.kde.kstars.indi] - INDI Server: "2022-07-27T04:47:13: Driver indi_asi_ccd: indi_asi_ccd: symbol lookup error: indi_asi_ccd: undefined symbol: _ZN4INDI3CCD15addFITSKeywordsEP8fitsfilePNS_7CCDChipE"
The undefined symbol error is common for having a 3rd-party driver and base INDI library out of sync (C++ is notorious for introducing ABI-incompatibilities when pretty much anything in the base class changes), recompiling the 3rd-party driver fixes it.
I am running Ubuntu 20.04 LTS --- bleeding ...
I'm a bit confused... and a new moon is going to waste.
I think the indi_asi_ccd dirver is closed source and we are dependant on ZWO to fix this.Please confirm.
If I am mistaken and a compile from source will fix this, then I need to verify that this URL links to the latest source building instructions for my architecture. indilib.org/forum/general/210-howto-buil...st-libindi-ekos.html
... finally, Is there a simple way to switch to an earlier INDI version that will allow me to use a 6200MC camera with a CEM40 mount.
No, indi_asi_ccd is open source, but it links against the binary-only libASICamera2, which seems to be the cause of the crashes. So yes, ZWO has to fix this. Recompiling everything yourself won't.
Until then, on aarch64 you need to downgrade to an earlier version of that library (1.22 is safe).
In doubt set your package manager to keep downloaded packages, so you can easily downgrade in case of issues. Can't give you guides to that though, as I'm RPM-based....
If you can compile yourself, it is enough to compile libasi from indi-3rdparty. You just need to check out a version with the proper lib (that would be commit 33bb2a3ec71)
openSUSE Tumbleweed KStars git INDI git
GPDX+EQMOD, CEM60EC, ASI2600/1600/290mini+EFW+EAF