Experimental POPS UDPFS / BDM-UDPFS Assault

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Experimental in official POPSLoader 1.2.3; not hardware-certified.
The Ethernet mode selector, UDPFS VCD browser, and embedded POPSTARTER driver
staging are implemented. Cross-compilation and automated regression checks have
passed, but physical PS2 launch compatibility is Unknown (verify on hardware).
Official release 1.2.3 includes the opt-in Ethernet SMBv1 / USB + UDPFS picker and embedded Okeanos fallback staging, but does not certify real-console launch or device compatibility.

Experimental implementation

The POPSLoader feature branch implements the planned Ethernet protocol picker:
select SMBv1 to use the existing SMB browsing and network-streaming modules,
or USB + UDPFS to use a read-only udpfs:/POPS/ game list and Okeanos's
POPSTARTER runtime fallback. This implementation is also included in official 1.2.3 as an experimental opt-in option, not as hardware-verified compatibility. Do not advertise stable support
until the release matrix records hardware validation.

USB + UDPFS configuration

Start udpfsd or udpfs_server.py on the same LAN with POPS/<title>.VCD
in the server's exported folder. The extension must be uppercase .VCD for
the upstream POPSTARTER driver.
In Settings → SMB / Network, disable DHCP and enter the console's static
PS2 IP and Netmask, and optionally its gateway. The in-game Okeanos
driver and the menu-side UDPFS filesystem must use the same console IP.
The gateway is ignored by the driver; the server must be on the same subnet.
Put a USB drive with a POPS/ directory in the console. On launch,
POPSLoader checks existing POPS/IPCONFIG.DAT on every detected USB volume:
if addresses disagree, it cancels without overwriting the user's file; if
missing, it generates one using the configured static address.
POPS/UDPFSCONFIG.DAT is optional and is not automatically modified;
create one containing the server IPv4 address to bypass discovery.
Select Ethernet → USB + UDPFS. The network game page can list VCDs
without an SMB login. Press R1 to rescan after starting/restarting the
server.
Choose a game. POPSLoader resolves POPSTARTER.ELF from a local device
(never from the network filesystem), prepares the USB settings, and equips
the embedded usbd.irx.udpfs / usbhdfsd.irx.udpfs pair on the memory
card as POPSTARTER/usbd.irx and POPSTARTER/usbhdfsd.irx.
The XX.<title>.ELF mass selector starts the USB-first / UDPFS-fallback
read path after POPSTARTER's IOP reset. Do not expect the in-menu
udpfs: filesystem to survive that reset.

SMB and the UDPFS ministack cannot share the PS2's network adapter at once.
To change from one protocol to the other after a connection, restart
POPSLoader / reset the IOP. There is intentionally no attempt to reflash
any adapter firmware, change the UDPFS server implementation, or forcibly
unload the resident network IRX modules.

The binary pair is pinned from the RiptOPL copy of Okeanos's Alpha release;
the menu filesystem modules are pinned from its Neutrino bundle. The upstream
license notices and configuration reference are mirrored under
docs/third_party/okeanos_udpfs/.
Build success is not hardware compatibility proof. Verify physical PS2
USB enumeration, UDPFS directory scanning, launch, return/restart behavior,
and SMBv1 regression before a public release.

How USB + UDPFS works

The upstream BDM-UDPFS Assault Alpha
is a POPSTARTER-specific, read-only network fallback. POPSTARTER first checks
for the VCD on USB and then, if absent, looks for the same file under POPS/
(or upstream-supported POPS0/ … POPS9/) on a UDPFS server. It is not
the Neutrino PS2 game transport and does not add UDPBD image mode to POPSTARTER.

The feature branch implements this through the existing Ethernet tile:
choose SMBv1 or USB + UDPFS. To configure the UDPFS choice, use
Settings → SMB / Network, turn DHCP off, and enter a valid static PS2 IP
and contiguous subnet mask. Those settings supply the menu-side UDPFS
ministack and the USB POPS/IPCONFIG.DAT used by Okeanos's POPSTARTER driver.
An existing file must agree with the settings; POPSLoader does not overwrite
conflicting user files. POPS/UDPFSCONFIG.DAT is optional and stays under
the user's control, with broadcast discovery used when appropriate.

When a UDPFS title launches, POPSLoader stages the matching Okeanos driver
pair on the memory card regardless of the global Adaptive BDMA setting.
It resolves POPSTARTER.ELF from persistent local storage, never udpfs:/,
because the temporary browsing filesystem disappears on the IOP reset.
SMBv1 keeps its existing module, share, and POPSTARTER launch workflow.

Upstream driver names (manual-install reference)

Upstream file	POPSTARTER destination
`bdm_udp_fs_assault.irx`	`mc?:/POPSTARTER/usbd.irx`
`usbd_bd_assault.irx`	`mc?:/POPSTARTER/usbhdfsd.irx`

These are the upstream names; the feature branch embeds the corresponding
renamed driver images. See the mirrored upstream configuration reference
and license notices.

Scope and current availability

Upstream Okeanos Alpha: publicly available as a standalone driver.
POPSLoader SMBv1 / USB+UDPFS picker, VCD browsing and automatic staging:
included as an experimental feature in official 1.2.3 and further developed on dev; game launch on physical PS2 remains unverified.
Dedicated POPS UDPFS settings editor: not implemented or required; the
feature branch uses the existing SMB / Network static address fields.
Hardware compatibility: Unknown (verify on hardware). A passing
build and host test are not PS2 hardware confirmation.

Credits

Okeanos developed BDM-UDPFS Assault, the POPSTARTER-specific read-only UDPFS fallback. It builds on israpps / El_isra's BDM Assault and the wider PS2SDK ecosystem. POPSTARTER itself is by krHACKen; the udpfsd server is by pcm720. All retain their own project and licensing credits.

POPSLoader's official stable integration remains pending hardware validation. This documentation is not a claim that any of these authors supplied or verified the integrated POPSLoader build.

An official release requires documented PS2 hardware test results, regression checks for existing SMB/USB modes, working binaries, and complete packaging/license notices.