Hi, I recently got my hands on a Zyxel VMT4005-B50B VDSL modem. The hardware runs on a Broadcom BCM63138 SOC. I see some people have worked on ports in the past with little success, and I was wondering how I could help get OpenWRT ported to this device.
There is a UART on the board, and connecting to it I can see the bootup process with the CFE bootloader. I'm not sure how to get further to tell it to boot a TFTP image, it looks like it requires setting some magic bits or flags to enable booting from a TFTP image. I did find the command to flash an image over TFTP, but I wanted to make sure there's a working image first before I commit to flashing.