Installing CyanogenMod on Samsung Galaxy s2 i777 (AT&T)

*Note, I am NOT an Android developer. This documentation is for my own reference as much as anything else. There is a second Galaxy s2 that I’ll need to tackle at some point.

My device, the  Samsung Galaxy s2 i777 (AT&T) running Android 4.1.2 (but connected with T-Mobile since I got crabby with AT&T). Since I’m well off warranty, a nice clean install of Android was highly tempting. We have two of these phones in our household, so below is the second, clean install I completed. The meandering of the first attempt is outlined in more detail below.


  1. Charged phone
  2. external sd card in phone
  3. usb cable
  4. Windows 7 computer


  1. Charge the phone and remove it from its case.
  2. Change the phone settings to allow transferring the files (if not already possible). I used Settings->Wireless and networks->USB utilities when Windows Explorer was not displaying the phone. This was not always necessary.
    • I also changed Security->Unknown sources for application installs, but I’m not sure this was necessary.
  3. Move (the Clockwork file) using whatever mechanism you prefer to the external sd card for the phone. This was the second of two phone drives visible in Windows Explorer for me when using the USB utility or simply the “card” when phone immediately displayed in Windows Explorer. Eject the phone from the computer if possible (icon usually in lower righthand corner of computer screen).
  4. Turn the phone fully off.
  5. Restart the phone in recovery mode by holding down the up and down volume buttons and the power button until “Samsung” displays on the screen. Quickly release them to get into a Recovery screen.
    1. Move through the screens using the volume rocker and power button to select.
    2. In retrospect, I’m not sure if this was necessary since I repeated it below.
    3. Select: “apply update from external storage” and then (the file you added)
    4. Select: “install zip from sd card” and then “apply /sdcard/”
    5. I also did a factory reset at this point, but I’m not sure it was necessary.
    6. Reboot using the menu option
  6. Attach phone to computer again with USB cable.
  7. Transfer (again using Windows Explorer in my case) and gapps zip files. Probably could have just done this in step 3 above.
  8. Turn off and restart in recovery mode. Follow step six above so that the right version of clockwork mod is running. Then repeat for the cyanogen and gapps zip files.
  9. Reboot the phone
  10. In my case the CyanogenMod loading animation hung. I then restarted again and it booted up nicely.
  11. Start setting up your new phone!

ADB push

I totally disregarded the adb push instruction the second time

  1. In a command window, change directory (cd) to the abd directory and push the modified cyanogenmod and gapps zip files. For whatever reason, abd push did not work after I had unzipped (flashed?) the cyanogenmod file on the first phone, so I’m carefully pushing both of them now.

I first tried to use the simple, lazy person install of CyanogenMod, and had it fail. It seemed like it should work, but failed on step 4 in fall 2013 (when on AT&T) and in March 2014 (When on T-Mobile) with an “unsupported device” alert.

I then moved onto the wiki for the i777 installation.

A few things I learned:

  • Recovery mode: volume up/down and power. Nav: volume up/down and power for enter
  • “Flashing” appears to mean unzipping a file
  • Finally figured out checksums using the Microsoft utility fciv.ext
  • Not sure I ever got running right, but could fire it off from recover mode
  • Need Java Development Kit  to run ADK
  • Eventually just moved the zip files to the external card using file manager (ignoring
  • cyanomod only installed after remove the version check:
  • gapps had a metadata failure: Successfully installed after the supposed cyanomod install
  • Stuck in the cyanomod loading animation
  • Booted into recovery mode.
    • Noticed running clockwork mode, not which is the approved version for i777. Read some errors.
    • Did a restore
    • INstalled original
    • rebooted
    • Seems to be working
  • Discovered installed wrong version of Google Apps  for the version of CyanogenMod I’m running on my phone.
  • Couldn’t convince adb to push the correct gapps version (tried the Developer settings — 7 clicks on version and activating various debugging, restarting), ended up transferring with Windows Explorer. Restarted in recover/reboot mode, shifted to  the correct, and the unpacked the hand transferred gapps. Worked fine.


Other resources


Original time estimate: 2 hours.
Actual time: 4+ hours