How to connect i.MX51 and Ubuntu using USB cable: i.MX51 Side Plug in USB cable. getprop debug.adb.usb - Shows that debug.adb.usb are not set by default setprop persist.service.adb.enable 0 -> disable adb setprop debug.adb.usb 1 - adb will be through USB (for Ethernet, use setprop debug.adb.usb 0) setprop persist.service.adb.enable 1 -> enable adb Example: # getprop debug.adb.usb  # # # setprop persist.service.adb.enable 0 disabling adb # adb_release android_usb gadget: high speed config #1: android setprop debug.adb.usb 1 # # setprop persist.service.adb.enable 1 enabling adb # adb_open adb_release adb_open android_usb gadget: high speed config #1: android # Ubuntu Side On Ubuntu side, the most important tip is regarding permission. ADB server MUST be started with root right. Example of right mistake: $ sudo <AND_SDK_DIR>/android-sdk-linux_86/tools/adb devices List of devices attached ????????????    no permissions  $ sudo <AND_SDK_DIR>/android-sdk-linux_86/tools/adb shell error: insufficient permissions for device How to proceed to get permission: $ sudo <AND_SDK_DIR>/android-sdk-linux_86/tools/adb kill-server $ sudo <AND_SDK_DIR>/android-sdk-linux_86/tools/adb start-server * daemon not running. starting it now * * daemon started successfully * $ sudo <AND_SDK_DIR>/android-sdk-linux_86/tools/adb devices List of devices attached 0123456789ABCDEF    device  $ sudo <AND_SDK_DIR>/android-sdk-linux_86/tools/adb shell ADB over Ethernet/Wi-Fi To make ADB work in i.MX51 using TCP: In your host machine: - Install Android SDK - export ADBHOST=BOARD_IP (setenv ADBHOST=xxx.xxx.xxx.xxx) - adb kill-server In your board: - make sure that ro.secure property is *not* set when the adbd daemon is launched, so edit the file default.prop - make sure that /dev/android_adb or /dev/android do *not* exist - stop adbd - start adbd Now you will be able to list the device: hamilton@saygon:/opt/work/androidsdk/android-sdk-linux_86/tools$ ./adb kill-server hamilton@saygon:/opt/work/androidsdk/android-sdk-linux_86/tools$ ./adb devices * daemon not running. starting it now * * daemon started successfully * List of devices attached emulator-5554   device