Hey Tommylight — thanks for the reply just to close the loop on that earlier issue
I did get past the firmware/install side in the end. After a few messy attempts, I wiped everything and went with a fresh Debian 12 install, then installed LinuxCNC separately (rather than relying on bundled firmware paths). That got the 7i76EU fully detected, firmware loaded cleanly, and all stepgens running perfectly.
Where I’m stuck now is further downstream: the limit/prox inputs. The board, smart-serial, and motion side are all behaving exactly as expected, but the GPIO inputs appear frozen and don’t update in HAL even when shorted directly to GND.
So the original “missing firmware” problem is solved — this is a new issue on the input side, which is what I’m trying to chase down now.
I created a fresh topic on it to try and nail it down as its hopefully my final port of call for a while.