FOG Project Image Capture on Raspberry Pi 4 (ARM64) via U-Boot

[Jeremy]

@Tom-Elliott

I checked both database entries for hostKernelArgs, and isdebug=yes was indeed not present there.

Regarding the U-Boot wget error, I followed your suggestion and went to the U-Boot prompt (=>) on the Raspberry Pi. When I type wget, it responds with:
Unknown command wget try help

So it seems the U-Boot build on these Raspberry Pis does not have the wget command compiled into it at all. What would be the recommended fallback or alternative method to fetch the script from FOG in this case (e.g., using TFTP or an alternative command if available)?"

[Tom Elliott]

@Jeremy Good, that narrows it down — no wget at all in this build, not just the older syntax. Two ways to close that:

Rebuild U-Boot with wget compiled in (keeps you on the dynamic per-host endpoint). CONFIG_CMD_WGET is a plain menuconfig option — you don’t need the HTTPS variant, which pulls in the whole lwIP/mbedTLS stack, just plain HTTP:

make rpi_4_defconfig
make menuconfig # Command line interface -> Network commands -> wget
make

Reflash the resulting u-boot.bin. Since dhcp already works for you, the network stack is there — this just turns on the one command. Once it’s in, the sequence from before should work as documented.

Or skip the dynamic endpoint and hand-roll a static boot.cmd — which is exactly what already worked for your capture: plain tftp for kernel/initrd/dtb, fixed bootargs with the task’s mac=, osid=, type=, img=, etc. baked in. The real tradeoff: tftp doesn’t ask FOG anything, so that config is identical for every board that boots it. Fine if every Pi runs the same task; not fine if you need FOG to decide per-host. boot.php exists specifically to answer “what does this MAC need right now” dynamically, and there’s currently no TFTP equivalent of it for boards that can’t do HTTP — that’s a real gap on FOG’s side, not something you’re doing wrong.

For 100+ boards I’d lean toward rebuilding U-Boot rather than going static, since you keep per-host tasking either way — but that’s your call based on how uniform the fleet’s deployment actually needs to be.

[Jeremy]

@Tom-Elliott "Hi again,

Following your instructions, I checked the U-Boot prompt. When typing wget, it responds with:
Unknown command wget try help
So the U-Boot build on these boards does not include the wget command.

Also, for context on how the board behaves at boot, here is what happens visually during the startup sequence (attached photo): it tries to boot locally, times out on storage (mmc / usb), and then falls back to a standard network BOOTP broadcast loop (Retry time exceeded).

Given that U-Boot lacks wget and relies on standard BOOTP/PXE broadcast rather than direct HTTP fetching, what is the recommended way or fallback mechanism to have these boards pull their configuration from FOG?"

[Tom Elliott]

@Jeremy Good news on the wget front — I closed that gap I mentioned. FOG can
now serve boards with no wget at all, over plain TFTP instead of HTTP.

U-Boot’s pxe get command doesn’t need wget — every U-Boot build has it,
and unlike wget it isn’t configurable: it always fetches
pxelinux.cfg/01-<mac, dash-separated, lowercase> by TFTP from whatever
server your board’s serverip points at. FOG now keeps a real file at that
path for every host, kept in sync automatically whenever a task is queued,
completed, or canceled — so your boot sequence becomes just:

dhcp
pxe get
pxe boot

No URL, no query string, nothing for the “bad port”/no-wget class of problem
to trip over — the filename is fixed by the MAC, so there’s nothing to
substitute.

This just merged into working-1.6 — same branch you’re already tracking
(you quoted 1.6.0-beta.4707 a few hours ago; this landed after that), so
running your update again should pick it up. Two things to check once you
have:

• Settings → FTP/TFTP needs a TFTP host/username/password configured — same
  connection FOG already uses to upload your ARM kernel, so if that’s
  already working for you, you’re set.
• I still don’t have a Pi to test this against, same as everything else in
  this thread — if pxe get doesn’t find the file, or finds one FOG didn’t
  mean to serve, that’s exactly the kind of thing I need you to report back.

One thing from your last post I want to flag separately, because it looks
like a different problem from the wget one: the boot sequence you
described — times out on local storage, then falls into a BOOTP broadcast
loop that gives up with “Retry time exceeded” — reads like U-Boot’s own
default bootcmd running, not a custom one. That’s the standard
Raspberry Pi fallback behavior when nothing else answers, and it wouldn’t
run dhcp / pxe get / pxe boot at all, custom or not.

Everything you’ve described testing so far — the wget/pxe boot sequence,
the curl check, now pxe get — sounds like it’s been typed by hand at the
=> prompt each time. That proves the commands work, but it can’t be “fully
automated,” which was the goal from your very first post: nothing runs
automatically unless it’s persisted as bootcmd, either with
setenv bootcmd '...'; saveenv on the board itself, or as a boot.scr /
extlinux.conf your SD card or TFTP server hands U-Boot on its own at power-on.

Can you confirm which of those two you actually have in place right now? If
the answer is “neither yet — I’ve only been testing at the prompt,” that’s
probably the real blocker to automation, independent of wget vs. TFTP, and
worth sorting out before we look any further at the fetch mechanism itself.

[Jeremy]

@Tom-Elliott

"To answer your question directly: yes, so far I have only been testing manually at the U-Boot prompt (=>).

My main concern right now is scalability. Since I need to deploy this across a fleet of 100 to 200 Raspberry Pi units, configuring each SD card manually or typing commands at the prompt for every single machine is not an option.

What is the recommended best practice in FOG working-1.6 to handle automation for a large fleet? Can the bootcmd be permanently stored in the Pi’s onboard EEPROM once, or can U-Boot fetch a boot script via TFTP automatically without manual card preparation?"

[Jeremy]

@Tom-Elliott

"Hi again! Great news regarding the new TFTP fallback mechanism.

I tested it manually by setting the IP addresses:
Plaintext

setenv ipaddr 192.168.203.50
setenv serverip 192.168.203.113
pxe get

What happened:

U-Boot successfully found the correct path generated by FOG based on the MAC address (Retrieving file: pxelinux.cfg/01-88-a2-9e-53-34-c0).

However, the download times out (Loading: T T T T T T) and results in a Retry count exceeded.

For context: a deployment task was explicitly active and queued in the FOG web interface before running the test, so the file should be there.

Is there a specific TFTP block size or setting required in working-1.6 for U-Boot’s pxe get to successfully pull the file without timing out, or could it be related to firewall/TFTP service configuration on the server side?"

[Tom Elliott]

@Jeremy That’s real progress — pxe get finding pxelinux.cfg/01-88-a2-9e-53-34-c0 by MAC means the naming convention and the file-generation side both work end to end. That’s the part I couldn’t test myself, so thank you for actually running it.

On the timeout itself: “found the file, then hung mid-transfer” (Retrieving file: ... succeeding, then Loading: T T T T T T / Retry count exceeded) points at TFTP’s own connection model, not at FOG. TFTP’s initial request goes to port 69, but the server then hands the rest of that transfer off to a different, randomly chosen UDP port for the actual data — so if there’s a firewall between the Pi and your FOG server that only allows port 69 through, the request succeeds (that’s why U-Boot found the file) and every packet after it gets silently dropped. That matches your symptom closely enough that I’d check it first: either open the OS’s ephemeral UDP range to your TFTP daemon, or (simpler if this is on the same box) confirm nothing’s filtering loopback/LAN traffic to it at all. If you’ve got shell on the FOG server, tcpdump -ni <iface> port 69 or portrange 32768-60999 while you retry pxe get should show the request going out and then nothing coming back, which would confirm it.

Separately — while looking into this I found a real gap on FOG’s side and fixed it regardless of whether it’s your actual cause: the file pxe get downloads wasn’t having its permissions set after upload, so if your TFTP daemon reads as a different user than the account FOG uploads over SFTP with, that alone could produce exactly this symptom (found the file, denied reading it). That fix is in the same working-1.6 branch now, so another update will pick it up. Worth ruling both things out — they’re not mutually exclusive.

On your scalability question: for 100–200 units, don’t script the SD card at all — the RPi 4’s own boot EEPROM supports network boot as the first boot mode, ahead of SD/USB, which is exactly what you want instead of the local-storage-timeout-then-BOOTP-fallback sequence you saw. rpi-eeprom-config (or the raspi-config boot order menu) lets you set that once, and once it’s set it’s a firmware-level property of the board, not something FOG or an SD card image controls — one flash per unit, and after that every power-on goes straight to network boot, no bootcmd persistence step needed on your end at all. I’d flash that as part of whatever imaging/provisioning process gets each Pi ready before it ever talks to FOG the first time, rather than trying to solve it per-deployment.

I don’t have a Pi 4 here to confirm the exact EEPROM boot-order syntax for your firmware revision, so double-check against Raspberry Pi’s own EEPROM config docs before you commit to a fleet-wide flash — but the “make network boot the default at the firmware level” shape of the answer is what actually gets you out of typing anything at the prompt.

[Tom Elliott]

@Jeremy Correction on the firewall angle: if your server went through FOG’s own installer on ufw or firewalld, that’s actually less likely to be it than I made it sound — the installer already handles the exact “TFTP works for the request but the reply is on a random port” problem for both of those (a named tftp service on firewalld, and nf_conntrack_tftp loaded for ufw), specifically because it’s bitten people before.

So rather than “check your firewall” in general, four narrower things:

1. Which firewall are you actually running — ufw, firewalld, or plain iptables? The installer only auto-configures the first two; if it’s bare iptables, my original theory stands and you’d need to allow the ephemeral UDP range by hand.
2. If it’s ufw: lsmod | grep tftp — the installer tries to load nf_conntrack_tftp but silently continues if that fails, so it’s worth confirming it’s actually loaded rather than assumed.
3. Is BOOT_external_tftp_server set to “yes” in your FOG settings? If so and your TFTP is actually running on the FOG box itself, firewalld would have skipped opening it for you.
4. Are the Pi and the FOG server on the same subnet/VLAN, or is there a router, switch ACL, or (if this is a VM/cloud box) a security group between them? None of the above touches anything outside this box.

If you’ve got shell on the FOG server, tcpdump -ni <iface> port 69 or portrange 32768-60999 while you retry pxe get is still the fastest way to see whether the request goes out and nothing comes back (firewall/network) versus the request itself failing (something else entirely).