Its difficult,but that is why its a challenge.
I am doing it mostly because of the NAND driver,I gotta look if we have some more 8devices Rambutan boards at work as those are the only ones with NAND I have access to.
Nice development that you started to port the WNDR4300 to ath79. I also use this router. I was also thinking in looking into porting it to ath79 but I don’t have serial access to the device so I can’t see the booting process. @hertog_jan Is serial access really necessary or is it possible to just use the builtin tftp upload a new firmware and start over if the router doesn’t boot?
I have managed to find working values so both network PHYs are recognised, meaning both WAN and LAN ports are working, although they use random mac addresses because there is no way to read those from NAND currently.
FYI - if you change KERNEL_PATCHVER to 4.19 for the ath79 Makefile, you may find the NAND driver to be MUCH easier now.
Try taking a look at the GL.iNet AR300M NAND configs for inspiration.
I have a question (which is likely needed for GL-AR750S) - do either of you know what the replacement for the "ubinize" INI files for the WNDR4300 v1 is in the ath79 tree?
The GL.iNet NAND devices use these in GL.iNet's modified OpenWRT source, but I can't find any equivalent to these in ath79. This hasn't been a huge issue for AR300M because kernel and source are both on the same device, however in the AR750S, it appears that kernel is always in NOR and rootfs location depends on whether you're a NOR or NAND build.