I have been struggling getting a new device working, and because it's a sealed unit (with battery), I really don't have any serial port access - so when it hangs on boot, I'm flying blind ... . But I don't think this issue is necessarily limited to this device - rather any device where a serial port is not accessible (or just not practical).
I tried to get netconsole working, but no luck. Has anyone been able to get the kernel log (console) output to some sort of persistent storage, like USB, microSD, or whatever? I know there can be flash wearout issues ... but for debugging, that's a don't care ... Thoughts?