Adding support for FiberHome AN5506-04-FAT GPON ONU

I have a FiberHome AN5506-04-FAT GPON ONU that an ISP abandoned, and I want to know if I can put OpenWrt on it. I understand this requires both a way to flash it, and an understanding of what firmware to flash it with. Here are some photos, and I hope that based on these photos folks here can help me figure this out.

Notes: I have logged into the admin interface, using the default credentials printed on the device, and the admin interface is extremely basic -- for example, no option to disable DHCP nor an option to upgrade firmware.

Intended use: The most immediate use is as a wired and wireless switch. In other words, if the fiber optic port, phone ports, and USB ports don't work, that's ok for now. I just want to disable DHCP and setup WiFi to my choosing, and plug it in via ethernet cable to the LAN in an office network.

Bonus use:

  • Having the option to reconfigure one of the LAN ports as a WAN port.
  • Working fiber optic port.
  • Working USB ports.

Photos (or look at them as an album here):

Top of the PCB:

Detail of the top:

Detail GPON of the top:

Detail ELEC of the top:

Bottom of the PCB:

Ports:

Model and power info, with a glimpse of the fiber optic port (blue):

Model info and default access info:

More version info:

It look like it uses Hisilocon SD5115 chipset.