I'm writing this post in hopes that I could get some help and pointers in getting this device supported to an extent.
The RP-WD009 is a MediaTek MT7628AN-based portable travel router slash file hub slash backup solution. It's a lot of functions slapped into a single device. It's a quite handy solution for those on the move a lot, especially if they prefer a nice, portable backup solution.
However the stock firmware is utter garbage. Maybe due to the HooToo heritage (most RP-WD devices are rebranded HooToo units), or the utter incompetence at RAVPower HQ, but it simply just... Sucks.
The hardware on the other hand is quite capable. The main SoC is a MediaTek MT7628AN, paired with an MT7610E (for 5GHz WiFi), 16MB flash, and 64MB RAM. Sure, it won't be driving a full residential home, or a small office, but it does not have to. The main purpose is still to provide a WiFi network, and connect to an uplink via either Ethernet, WiFi, or USB tethering.
Luckily, I stumbled upon both the FCC approval photos (internal and external), and after a bit of fighting in email, RAVPower has also shared their GPL sources with me - including their whole build system, some precompiled binaries (mostly their own tools for managing e.g. LED status), and of course the web interface. I could spend some days or weeks coming up with a better solution based on the stock firmware, but in my opinion it's not worth the hassle. I'd rather use something that is more mainstream, like OpenWRT.
Another OpenWRT user has made some progress in testing the waters out - according to the published request to add the sub-page, the MT7628 evaluation board image boots, and generally works on the WD007 (a practically identical model to the WD009, with some design changes on the PCB, mainly to reduce heating), with the exception of 5GHz WiFi (I suppose the MT7610 needs some extra initialisation), SD card reader (possibly a DTS change is required for proper pinouts), and LEDs (the official firmware uses a custom utility to control LED status, but based on the board, it is supposed to be nothing more than 7 LEDs (both the power and SD card icons have a secondary red LED to indicate malfunction or low battery) connected to 7 GPIO ports - at least hopefully.
I would be more than happy to start working on at least some minimal support on OpenWRT side. The original sources are based on Linux kernel 2.6.36, so unfortunately no DTS available for this board, however based on the experiments done before, the MT7628AN eval board's config should be a good starting point. The bootloader is U-Boot 1.1.3, which is also quite old, but not ancient like the kernel. It comes with the standard TFTP based recovery, so as long as the bootloader doesn't fail, the device should be reflashable with ease.
I'd gladly test out builds, or even make them, however my experience with OpenWRT is quite limited, and could definitely use some pointers on how to set certain things up, especially with a brand new device being added.