Follow-up to OpenIPC/firmware#2410, which left MT7601U as the only in-tree USB
Wi-Fi stack on hi3518ev300. RTL8188EU lands here as a camera profile, splitting
the two adapters across the two repositories.
hi3518ev300_lite_generic-rtl8188eu builds the driver INTO the kernel rather than
shipping it as a module: a profile whose only Wi-Fi is that driver has no reason
to carry it as loadable code, and the rootfs is the partition under pressure.
The out-of-tree rtl8188eus-openipc cannot make that move -- it is an external
kernel-module package, never linked into vmlinux -- so this uses the in-tree
staging driver at CONFIG_R8188EU=y through a variant kernel config, the same
shape as gk7205v200.generic-otg.config.
Built in, the driver also has no modprobe problem: as a module it was
unreachable, because /etc/wireless/usb's rtl8188eu-generic profile modprobes
'8188eu' while the in-tree module is 'r8188eu'. Linked into the kernel it binds
off its own USB device table at boot.
CONFIG_R8188EU selects WIRELESS_EXT, so the wext ABI firmware#2410 dropped comes
back on this variant only. It requests rtlwifi/rtl8188eufw.bin, so
linux-firmware-openipc comes with it. Registered in .github/firmware-drift.json
against the firmware blob it derives from.
MEASURED in CI, against the module-based version of the same profile:
uImage [1873KB/2048KB] -> [1991KB/2048KB] 56KB free
rootfs.squashfs [5084KB/5120KB] -> [4728KB/5120KB] 392KB free
Also drops excludes entries firmware now handles upstream: r8188eu.ko from
xiaomi-mjsxj02hl, and r8188eu.ko + scsi_mod.ko + sd_mod.ko from
yuancam-dgk423403. Both cameras build green; both run out-of-tree Realtek
drivers over nl80211 and are otherwise unaffected.
Not tested on a camera. This changes which 8188EU driver is used -- mainline
staging rather than the Realtek vendor fork -- so it wants confirmation that a
dongle is detected at boot without a modprobe, associates, and streams.
