FreeBSD network boot on Raspberry Pi 4

[Denis Polygalov]

Hi,

I'm trying to boot FreeBSD 12.1-RELEASE over network
on Raspberry Pi 4 Model B.
Well, the '12.1-RELEASE' doesn't matter here because
seems like loader.efi cannot find and load kernel yet.

I'm using RPi4 UEFI v 1.17:
https://github.com/pftf/RPi4/releases/tag/v1.17

and here is what I see on a serial console:

ESC (setup), F1 (shell), ENTER (boot)..
 >>Start PXE over IPv4.
   Station IP address is 192.168.10.201

   Server IP address is 192.168.10.10
   NBP filename is boot/loader.efi
   NBP filesize is 610056 Bytes
  Downloading NBP file...

   NBP file downloaded successfully.
Consoles: EFI console
FreeBSD/arm64 EFI loader, Revision 1.1

    Command line arguments: loader.efi
    EFI version: 2.70
    EFI Firmware: https://github.com/pftf/RPi4 (rev 1.00)
    Console: efi (0)
    Load Path:
(few minutes time delay here)
bootp: no reply
No response for RARP request
net_open: RARP failed
bootp: no reply

Seems like the loader.efi is get executed but not all
necessary parameters are passed to it...

The host machine I'm using for testing is designated for
network boot of various ARM based boards and I'm quite
sure tftpd/dhcpd/nfsd configuration is correct.
Here is relevant output of Nanopi-NEO2 board
network boot performed on the same host machine:

... skipped ...
## Starting EFI application at 40080000 ...
Consoles: EFI console
     Reading loader env vars from /efi/freebsd/loader.env
FreeBSD/arm64 EFI loader, Revision 1.1

    Command line arguments: loader.efi
    EFI version: 2.70
    EFI Firmware: Das U-Boot (rev 8217.1024)
    Console: efi (0)
    Load Path: /dtb\allwinner\sun50i-h5-nanopi-
    Load Device: 
/VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/MAC(0201579f3216,0x1)
Setting currdev to net0:
net0: cannot set rx. filters (status=3)
Loading /boot/defaults/loader.conf
Loading /boot/device.hints
Loading /boot/loader.conf
Loading /boot/loader.conf.local
Autoboot in 8 seconds, hit [Enter] to boot or any other key to stop
Loading kernel...
/boot/kernel/kernel text=0x93a61c data=0x1914c8+0x84ab1c 
syms=[0x8+0x138810+0x8+0x124a28]
Loading configured modules...
... skipped ...

is there anything I can do in order to get my RPi 4 booted over network?

Best Regards,
Denis.