@Jeremy Good — that rules out the firewall/permissions angle cleanly, thanks for actually checking rather than taking my word for it.
The new symptom is a different failure than before, and it’s outside anything FOG serves: looping on BOOTP with no attempt at Retrieving file... means it’s failing at DHCP/BOOTP negotiation, a step before pxe get would ever run. FOG can’t see that far back — the board never gets far enough to ask FOG anything.
You’ve also moved to a materially different boot path than what we’d been testing: cardless, via the Pi’s own network-boot EEPROM, rather than typing commands by hand at the U-Boot prompt. That matters here, because the EEPROM’s automatic network-boot flow runs its own boot sequence, built into that U-Boot, not necessarily the dhcp / pxe get / pxe boot lines from earlier in this thread — those were for a manually-typed bootcmd. If the EEPROM path uses bootp instead of dhcp, or expects OPNsense to hand it specific DHCP options, that’s a different thing to get right than what we tested manually.
Two things I’d need to actually say anything useful here, since I can’t see either from where I’m sitting:
What’s the board actually running right now — did the nano edit touch a persisted bootcmd (printenv bootcmd), or is this the EEPROM’s own default network-boot sequence with nothing custom in the loop at all? In OPNsense’s DHCP config for that subnet, what are options 66 (next-server) and 67 (filename / bootfile-name) set to? The EEPROM’s PXE client needs those to know where to send its own request in the first place — if they’re pointing at the wrong place, or missing, U-Boot never gets the chance to see FOG at all, and that would produce exactly a BOOTP loop with nothing after it.That’ll tell us whether this is a boot-script problem (fixable on your end) or a DHCP-options problem (fixable in OPNsense) — right now I genuinely can’t tell which from here.