I am assuming that you are using the Andrew Henderson's 3.8 Kernel + Android JB configuration. As I understand the adb as it is intend is not functional in this configuration. Nikolay Elenkov in is blog has the following work around. Following is a direct word to word copy from the his blog
Configure FunctionFS support in the kernel
(CONFIG_USB_FUNCTIONFS=y):
Device Drivers -> USB Support ->
USB Gadget Support -> USB Gadget Driver -> Function Filesystem
Modify the boot parameters in uEnv.txt to set the vendor and product IDs, as well as the device serial number
g_ffs.idVendor=0x18d1 g_ffs.idProduct=0x4e26 g_ffs.iSerialNumber=
Setup the FunctionFS directory and mount it in your init.am335xevm.usb.rc file:
mkdir /dev/usb-ffs 0770 shell shell
mkdir /dev/usb-ffs/adb 0770 shell shell
mount functionfs adb /dev/usb-ffs/adb uid=2000,gid=2000
on fs
Delete all lines referencing /sys/class/android_usb/android0/*. (Those nodes are created by the native Android gadget driver and are not available when using FunctionFS.)
Please review this blog for detail infomation
http://nelenkov.blogspot.be/2013/07/building-wireless-android-device.html