OpenWrt support for Zyxel PMG5617GA, first GPON support !?

Awesome stuff. Regarding tclinux, that's a toolchain TrendChip and its descendants SoC (Ralink, Econet, Mediatek, Airoha) use to build and decompose firmware as discussed in here. A variant of it named tcrevange (github page here) is used but from what i've heard it's mostly unmaintained. I've tried emailing Airoha if they can provide some SDKs/Toolchains to help but to no avail so far so we have to make use of what we have.