As a stop-gap measure, I managed to get a ramdisk version of OpenWrt modified to boot Debian on the external USB drive. After testing via TFTP a few times, I looked at the U-Boot source from Netgear to find the info on which area of flash to use. The NOR flash made it easy -- just burned the UImage ramdisk image to the place that originally had the Squashfs. -- 0xBf070000As far as getting Debian on to the external USB drive, I used the 'foreign' debootstrap approach. Here's a nice description for the Sheevaplug, but it was pretty close to what I did for the WNDR3700.