[reiter1a]

I would like to share my experience with flashing the Belkin Share F7D3302 v1  router. After hours of probes and errors I managed to flash the router and have the rndis support and usb internet connection through my htc hd2. Here are the steps I have preformed:
A. Flashing the firmware with DD-WRT v24-sp2 (04/13/11) mega (SVN revision 16785)
First to mention - the hard reset 30/30/30 is not working on these router!

1. Press reset button and unplug and plug the power cable still holding reset button for 7 sec. The power led blink short and turn off and the router is in Cli or mini server mode and listening on 192.168.2.1.
2. Make manually the connection ( assigning IP 192.168.2.10, subnet 255.255.255.0, Gateway 192.168.2.1 on lan card connected to one of wired port of router.).
3. In browser's address field type 192.168.2.1.
4. Through web interface choose the firmware file.
Initially I used the mini build – dd-wrt.v24-15337_NEWD-2_K2.6_mini_f7d3302.bin. I'm not sure waiting 5 min after successfully flashing is necessary but better wait.
5. Then unplug and plug power cable. If dd-wrt does not boot then perform step 1 to 3. In web interface choose restore or refresh nvram. DD-WRT should appear. (here I spent a lot of hours until recognising what the problem is, because my router did not boot. I thought I have bricked the router but it was not!)
6. In DD-WRT interface (logging through dhcp) go to firmware upgrade and install DD-WRT v24-sp2 (04/13/11) mega (SVN revision 16785).

B. Enabling the RNDIS support
here are the post I followed:
http://www.dd-wrt.com/phpBB2/viewtopic.php?p=544418

1. Download the kernel modules usb-rndis-lite.zip (post 1)
2. Enable jffs in DD-WRT
3. scp the unzipped modules to /jffs/tmp
4. telnet to 192.168.2.1
5. Insmod the modules

insmod /jffs/tmp/usbnet.ko
insmod /jffs/tmp/cdc_ether.ko
insmod /jffs/tmp/rndis_host.ko
5. Connect the phone and enable USB internet sharing
6. ifconfig rndis0 up
7. udhcpc -i rndis0 -s /tmp/udhcpc (obtain IP from phone)
8. Now the router has internet connection

C. Routing the connection between rndis0 and lan/wlan
http://www.dd-wrt.com/wiki/index.php/Cellular_Phone/USB_Modem_as_WAN_connection

1. Here I found real problems. nvram setting didn’t work for me nor iptables setting alone.
2. I must perform iptables -F. Then
iptables -I FORWARD -i br0 -o rndis0 -j ACCEPT

iptables -t nat -A POSTROUTING -o rndis0 -j MASQUERADE
3. Internet connection is available on lan/wlan.

Surely that is not a for daily use solution. After phone disconnect all setting must be set again manually trough ssh or telnet.
So I hope that this functionality will be implemented in future DD-WRT builds.