Is it possible to support Netgear R6400? Thanks.
Possible but unlikely to happen.
Based on wikidevi the device seems to be BCM47xx device, and that target has not got much development activity here. https://wikidevi.com/wiki/Netgear_R6400_v1
And as the router has been release already in 2015 and so far nobody has been interested enough to add support for it, it is unlikely to happen... unless you do that.
dd-wrt and Tomato seem to have some support for R6400.
This is ARM, so it's bcm53xx target, not brcm47xx one.
Provide me boot log and output of "nvram show | grep gpio", I can get a basic image working.
I've just bought one
Board: Netgear R6400 v1
nvram show | grep gpio
size: 31576 bytes (99496 left)
Looks like there's no match when searching that (while running dd-wrt on the r6400).