[ 20.900878] device eth0.1 entered promiscuous mode
[ 20.905758] device eth0 entered promiscuous mode
[ 20.940478] br-wlan: port 1(eth0.1) entered forwarding state
[ 20.946310] br-wlan: port 1(eth0.1) entered forwarding state
[ 22.939289] br-wlan: port 1(eth0.1) entered forwarding state
[ 24.809528] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: 8701d944
[ 24.823293] Rebooting in 3 seconds..
This Kernel panic is a known bug of the closed source MediaTek WiFi driver. Now we know it can not manage if there is a WiFi AP in the neighborhood with some Unicode character in its SSID.
Onion @administrators deeply kept silent about this bug.
It seems Onion's new WARP CORE driver (also closed source ???) can manage this situation.
Unfortunately Onion @administrators do not say too much about this bug feature (as usual ;-).
@György-Farkas kernel was corrupted for sure, that's something I can tell you with honesty. The device was literally dead, only after inserting a microSD card with a new firmware my device was able to update itself and become functional.
Well... no one but you should know if this correct (or not ;-)
Thank you @Zheng-Han - a little out of my depth with that for now :( I think I must rather focus on my original issue with the i2c driver freezing up randomly when fetching data from the arduino. I need to find a way to restart the driver without having to resort to a reboot and losing data.
Duh. Solved the problem... I had a script in /etc/init.d that wasn't backgrounding properly, so the system wasn't actually booted all the way; as a result, the button wasn't working. Fixed that script, and the button now works as expected.
Anyway, I confirmed the script in /etc/rc.button/reset does work, and you can replace the reboot line with whatever you want. I hope that helps someone.
The omega bootloader (uboot) has a small http server built-in, which can run and accept a new firmware over ethernet (but not WiFi) completely independently from OpenWrt - this allows to recover even seriously mis-flashed units.
This feature saved my Omega a few times back when I just had started to build my own OpenWrt images and got important details wrong in the first few attempts...
I just noticed that even when you don't have the ethernet expansion, but a second Omega with dock, you can use that to reflash, see here