Add more information on how to enable internet over USB

README.md

@@ -33,6 +33,7 @@ sudo btmgmt --index 0 public-addr 00:11:22:33:44:55
 NOTE: `bluez-btmgmt` must be installed
 
 ## Enable Internet over USB
+(see https://wiki.postmarketos.org/wiki/USB_Internet)
 ### Host
 ```bash
 sysctl net.ipv4.ip_forward=1
@@ -41,6 +42,17 @@ iptables -A FORWARD -s 172.16.42.0/24 -j ACCEPT
 iptables -A POSTROUTING -t nat -j MASQUERADE -s 172.16.42.0/24
 iptables-save
 ```
+### Device
+```bash
+ip route add default via 172.16.42.2 dev usb0
+echo nameserver 1.1.1.1 > /etc/resolv.conf
+echo 'ip route add default via 172.16.42.2 dev usb0' > /etc/local.d/usb_internet.start
+chmod +x /etc/local.d/usb_internet.start
+rc-update add local
+```
+
+## Notes
+- Regarding GPI DMA issue: https://oftc.irclog.whitequark.org/linux-msm/2023-11-26 (and following days)
 
 ## Misc. Links
 - https://softhandtech.com/what-is-ffbm-mode-in-android/