[HOWTO] Install OPNsense 25.1 on Silver Peak FWA-ASP1012 EC-XS-Security Appliance

[rumshot]

Hello Team,

I bought a EC-XS too and could figure out most of the steps, until arrive this thread.
My issue is due to the fact the device is not detecting my usb stick and im unable to boot from it and install opnsense.
I was wondering if someone face that or would have a tip to give me.
I could potentially install the opnsense in another computer with ec-xs hd, but i dont know if when i swap it back to ec-xs it will detect the interfaces and so on.
Any guidance its welcome.
ps.: im mac user, then maybe im struggling a little bit and not sure if my usb stick its really booting.

[ThornB52]

Had a similar problem with the earlier version of this product [FW-7551a-SV1] when trying to boot from the -serial image.  Just went unrecognized.  The -nano image written to a USB stick did however boot.  The BIOS in the 7551 includes "UEFI" in it's name but surprisingly neither the SSD (SATA3 in this case) and the CF card in the case were EFI/GPT partitioned. YMMV

[RentedVista]

Had a similar problem with the earlier version of this product [FW-7551a-SV1] when trying to boot from the -serial image.  Just went unrecognized.  The -nano image written to a USB stick did however boot...

I'm entirely new to OPNsense and I'm the same shoes. I recently purchased an FW-7551A-SV1.

• Disabled watchdog timer in BIOS.
• Set console port speed to 115,200 in BIOS.
• Used Rufus 4.14p to write OPNsense 26.1.6 amd64/serial to USB flash drive. I noted in Disk Management that the flash drive partition style was GPT.
• In BIOS, changed boot order to boot first to USB. FW-7551A-SV1 wouldn't boot from flash drive.
• Wrote OPNsense 26.1.6 amd64/nano to flash drive instead and noted that the flash drive partition style is now MBR. FW-7551A-SV1 booted with no problems.
• Logged in as root/opnsense, selected 8 (shell), and entered opnsense-installer at the prompt.
• Completed installation wizard, including selecting to install to internal ~120 GB SSD, set root password, and halted system when finished.
• Changed boot order to boot first from SSD, saved changes and reset. FW-7551A-SV1 won't boot, with error, "Reboot and Select proper Boot device or Insert Boot Media in selected Boot device and press a key."

So, I think I was confused about how nano is intended to work. My understanding now is that it isn't intended to be installed to internal devices such as SSD disks. I would really like to figure out how to get the amd64/serial image installed to the internal SSD. In BIOS, I see:
UEFI 2.3; PI 1.2
American Megatrends
Core Version 5.008
Doing a bit of searching, I think this BIOS version should support GPT partition style / UEFI booting, but I'm seeing nothing related to configure in the BIOS, such as legacy/UEFI/CSM boot, etc.
I have experience with pfSense, and it sounds like others have installed pfSense on the FW-7551A-SV1, but I'm not ready to go that route. I really want to use OPNsense in this instance. I would appreciate your suggestions/input!