Some vital information there, but I can hold off on questions for awhile.
Ah, well, one question:
Do you have ssh (or telnet) setup over USBnet?
If so, then I may have a list of small questions for things in the kernel's dynamic part of the file system.
Observations at first glance:
* A very unusual start address for an embedded Linux kernel.
* U-boot is certainly stripped down
* Why would the init scripts be looking for our dropbear installation, unless it intended to do it harm? (which is a criminal offense in the USA).
* Others, not as trivial. Will need more study.
Would someone run off the same outputs from 5.2.0 before up-grading please.
Note that the above requires the serial port connection.