DroidMod

There is no original content here, I’m simply mirroring an already widely known method for rooting the Bionic (and pretty much every other Motorola Android device, for that matter).

Open an adb shell, and:

mv /data/local/12m /data/local/12m.bak
ln -s /data /data/local/12m

Now reboot the phone. When it comes back up, one of the init scripts will recursively chmod the symlink you’ve created, thus giving you write access to modify /data/local.prop:

rm /data/local/12m
mv /data/local/12m.bak /data/local/12m
mv /data/local.prop /data/local.orig.prop
cat > /data/local.prop <<EOF
ro.sys.atvc_allow_netmon_usb=0
ro.sys.atvc_allow_netmon_ih=0
ro.sys.atvc_allow_res_core=0
ro.sys.atvc_allow_res_panic=0
ro.sys.atvc_allow_all_adb=1
ro.sys.atvc_allow_all_core=0
ro.sys.atvc_allow_efem=0
ro.sys.atvc_allow_bp_log=0
ro.sys.atvc_allow_ap_mot_log=0
ro.sys.atvc_allow_gki_log=0
EOF

Now reboot again. The o.sys.atvc_allow_all_adb property will prevent the phone from dropping its root privileges on startup, so the next time you open an adb shell you will be root. I recommend installing a proper su/Superuser.apk pair at this point.

mount -o remount,rw /dev/null /system
cat /path/to/Superuser.apk > /system/app/Superuser.apk
cat /path/to/su > /system/bin/su
chmod 4755 /system/bin/su
mount -o remount,ro /dev/null /system

And that’s all there is to it! Enjoy your rooted Bionic. Be careful with what you modify in /system, until we find a proper way to recover the phone.