USB in ITOS 2008

Initially posting this via Maemo Blogger on osgiliath.

One of the most useful improvements in ITOS 2008 is the proper support for USB Host mode. Unlike previous versions where one had to jump through hoops to even get USB devices recognized, Host mode is now as simple as sending a value over to the appropriate /sys entry.

Here's a quick-and-dirty script which I simply call usb (compiled from various sources) that not only allows you to select between Host and On-The-Go (OTG) modes, it even allows for USB networking.

#!/bin/sh

MODE=$1
if [ "$MODE" == "net" ]; then
 LOADED=`lsmod | grep g_ether | grep -v grep`
 if [ "$LOADED" == "" ]; then
   insmod /mnt/initfs/lib/modules/2.6.21-omap1/g_ether.ko
   ifup usb0
 fi
 IP=`getip usb0 2>/dev/null`
 echo "IP is $IP"

elif [ "$MODE" == "file" ]; then
 ifdown usb0
 rmmod g_ether

elif [ "$MODE" == "host" -o "$MODE" == "otg" ]; then
 if [ "$MODE" == "otg" ]; then
   echo peripheral > /sys/devices/platform/musb_hdrc/mode
 fi
 echo $MODE > /sys/devices/platform/musb_hdrc/mode
 echo USB mode set to $MODE

else
 echo "Specify 'host', 'otg', 'net', or 'file'"
 IP=`getip usb0 2>/dev/null`
 if [ "$IP" == "" ]; then
   CUR=`cat /sys/devices/platform/musb_hdrc/mode`
   echo "Current mode is $CUR."
 else
   echo "Current mode is net, IP $IP"
 fi
fi

The helper script getip is just

#!/bin/sh

DEV=$1
if [ "$DEV" == "" ]; then
 DEV=wlan0
fi
IP=`ifconfig $DEV |head -2 |tail -1 |awk '{print $2}' |cut -d: -f2`
echo -n $IP

Basically, you just call it as usb host or usb otg; or as usb net or usb file. I haven't fully tested these scripts, but they work for me. YMMV.

Here's a shot of an N800 xterm showing my 12GB Devant HD, and the 2GB SD from my camera in a card reader. The df command was typed from a USB keyboard connected to the same powered hub. I used a cheap CA408 AF/AF USB adaptor from CDR King to connect the hub.