I'm heading out soon...this is all standard tftp stuff, you should be able to find online resources for it.
once you get that booted, you'll need to use sysupgrade to flash the actual firmware file. This was compiled with the patch needed to boot this device.
Okay they're on the same network, however when I boot up with the TTL connected, it defaults to 192.168.10.1 rather than the gateway my network uses (192.168.1.1). Do you know how to change this default IP within the boot process?
Alright I was able to change the IP address and get it to pull the 3 files from my TFTP server. I'm at a standstill now:
on that first uboot screen, choose option 5 "load image"
enter the IP the device should use
enter its subnet mask
enter the IP of your tftp server
enter the file name
let it load, then answer "Y" to run this image
once it's up, make sure br-lan has an IP in your lan range. it will come up with 192.168.1.1 by default
you can temporarily change it for this part "ifconfig eno1 [ip address] netmask [subnet mask]
then use pscp(or maybe windows has scp now?) to copy the openwrt-wavlink.bin file from your windows machine to /tmp
flash the image "sysupgrade -n /var/tmp/openwrt-wavlink.bin"
it will reboot and then you will have a running openwrt system
amazing how much you can figure out by yourself, when you try things, instead of just having people telling you what to do 
I'm still stuck on the screenshot above. for some reason, it can't find the tftp server on my network now. I'm doing everything the same as I was before, but it fails when I try to load the file through TFTP.
you had already loaded an image, what's changed ?
I reset the unit and when I tried to reload the image, it failed and fails every time now.
here's my variables. my network base is 192.168.1.1, and when i boot the unit up with default firmware, it shows 192.168.1.50 by DHCP. But when I boot with U-BOOT, and set it to that IP, the TFTP fails now. 
FTP transfer's failing....
is the IP of the TFTP host correct ?
is the IP/interface correct in TFTPd64 ?
is the file name correct ?
did you connect the two devices directly, or via some other device ?
Yes, host IP is same as it was the time it worked (192.168.1.100 - the PC running the TFTP server software).
Yes, I believe so. Same as it was when it worked the first time (192.168.1.50)
Yes, initramfs.bin.
Switch -> PoE Injector -> Unit
I was going to ask about a firewall on the TFTPd host, but I assume it's the same host ?
was it a VM back then too ?
TFTP server is running on my Windows 11 system that's on the same network (plugged into the same switch as the PoE injector going to the unit), on 192.168.1.100.
VM? You mean the Virtual Eth Adapter? Yes
not what I asked ...
Okay, well then I didn't understand your question.
are you using the same "host", as when the TFTP transfer worked ?
Yes. Everything I am aware of is the exact same.
out of ideas, I'd boot openwrt off a flash drive, then tcpdump the traffic, see if u-boot is sending the TFTP requests to 192.168..x.y
or if you already have a Linux system somewhere, do it from there.
wireshark on Windows works too, obviously.
