On further thought I dont think the OpenWRT build root can produce factory upgrade images.
The factory image is lay out like below and will need binary parts included.
Uboot Loader
Uboot Binary ? 2nd stage loader
Kernel
File system
PID, KFS checksum and ImageChecksum.
Empty Code
The 2nd stage loader is a binary blob with not source, Its used for recovery and loading the kernel and computing checksums. Its not updated on flashing but is included with the image.
I might just put instructions on the Wiki page on how to generate an factory image image with the netgear source.
Edit: I can just pad out the Uboot and 2nd stage loader as there not updated. Will submit a patch shortly.
(Last edited by andytara12 on 16 Dec 2012, 08:33)