I'm having trouble testing my initial build. Via UART, u-boot zips by any opportunity to choose boot options. I suspect bootdelay is set to 0 as described for the xiaomi 4a:
Xiaomi Mi Router 4A Gigabit Edition (R4AG/R4A Gigabit) -- fully supported and flashable with OpenWRTInvasion,
My ch341a programmer is not detecting the flash chip and I suspect it is bad (there was a spark and the connect led became abnormally hot). I've ordered a new one, but for now, I can't change the u-boot environment commands.
I also can't connect via ssh or telnet. Trendnet's GPL'd source download does not contain telnet or openssh.
The device has a http recovery loader (hold reset during power on x 5 seconds) at 192.168.10.1 as described for another Trendnet device:
Unfortunately, attempting to load my build via the http recovery loader fails - unable to get specific error messages. My other Trendnet device has a cameo signature appended and I pasted the code from an OEM update image onto my image and renamed it factory. It also failed.
Specific to this device, I see a couple of pathways: Hacking u-boot as was done with the Xiaomi, Look into the OpenWrt Invasion program and modifying the sysupgrade.bin image into a factory.bin.
The later looks to be the safest path - I'll split off a thread as it could apply to other devices.