El Capitan OS X 10.11 Guide to Updating Android OS Marshmallow

marshmallow nexus el capitan osx flash

Well this was a nightmare for me. Learning how to add Marshmallow from my El Capitan mac on my Nexus 6 At&t was not easy. There are no OTA updates on At&t so I had to take the splash. I recently switched to a Nexus 6 from the world of iPhone. I’m really happy with the switch and all the crazy stuff I can easily do, but the phone drastically needed an updated to Marshmallow to help with battery life on the giant phablet and it was a sneaky feat on El Capitan.

El Capitan is the latest Apple Mac OS X update (OSX 10.11). It has some drastic changes to security of the file structure at the root level. This was something I had to learn the hard way after trying to get the “adb” and “fastboot” tools installed at the root level.

Thankfully my pain is your gain! Follow the steps below to get your OS updated and root your Android devices.

  1. Important first step that has not made it to other guides yet. You will need to authorize your mac to allow writing to the root level. Restart your mac in Recovery mode. At boot chime hold down the keys Command and R. After some time the computer will start to show the progress meter for the booting. You can let go of the keys when you see the progress meter.
  2. After it boots into recovery mode click on the “Tools” at the top and click “Terminal”. Inside the Terminal window type csrutil disable and hit the enter/return key.
  3. Reboot your mac normally.
  4. While it is rebooting you need to enable your Android device to allow USB debugging and unlock the OEM. On your 4.2 or higher Android device go to Menu > Settings > About Phone. Scroll down to Build Number. Tap on the Build Number section 7 times. After the 7th tap it says something like “Congrats you’re a developer!” Now press back and there will be a new area called { } Developer Options.
  5. Tap on Developer Options and enable the OEM unlocking and USB debugging.
  6. Now download the proper Android image for your device. I have a Nexus 6 so I downloaded the 6.0.1 image under “shamu” for Nexus 6. All Nexus device images are found here from Google.
  7. Download this zip file and unzip it to your desktop. The zip contains the “adb” and “fastboot” tools and uses a simple script to place them into your /usr/bin/ folder so they can be used in any directory in Terminal.
  8. Open a Terminal window. I like to use the shortcut Command + Spacebar and type in Terminal and hit the Return key.
  9. Now you need to navigate to your desktop and the Android folder you unzipped in step 4. Simple ways to navigate Terminal are to do the following steps: type cd ~ and press return. Now type ls and press return. You should see all the files/folders in your personal directory. If you don’t see the desktop listed you are in the wrong directory.
  10. If you see the desktop listed enter the following. cd desktop/Android and press return. Congrats you are now in the correct folder.
  11. Now type ./ADB-Install-Mac.sh and press return. This script now generates some text to say that adb and fastboot were moved to “usr/bin” which is correct.
  12. Plug in your your Android device into your Mac’s USB port. Let’s test to make sure things are installed correct. Type adb devices into the Terminal and press return. A list of attached devices should appear. If you get an error it means either the device was not powered on or the adb and fastboot did not install correctly. Make sure you followed all the steps above for El Capitan.
  13. This install will wipe your device. I used an app called SMS Backup + created by Jan Berkel. Use it to backup your SMS and call data.
  14. Now let’s start installing the new image. Unzip the image you downloaded from Google. It is likely in your Download folder. I suggest renaming the folder to something easy like shamu. Now go back to Terminal and type cd ~ and press return. Type  cd Downloads/ and press return.
  15. Type ls and press return. You should see all of your downloads and your new newly renamed unzipped folder shamu.
  16. Type cd shamu and press return. You can use the ls command if you want to see the list of files and folders in that directory. You should see a couple of files. The most important one for step 19 is the flash-all.sh file.
  17. While in the directory type adb reboot bootloader and press return.
  18. Next you need to type fastboot oem unlock and press return. Take a look at your Android device. Follow the onscreen directions to erase everything on your Nexus device. This could take a couple minutes.
  19. Now you are going to flash the new image onto the device. In Terminal type ./flash-all.sh and press return. This will start the installation of the new image. It will take a while. Do not unplug your phone while it is flashing the rom. Your device will restart when it is done.
  20. Now we will lock the bootloader back for security. Type adb reboot bootloader and press return. Now type fastboot oem lock  and press return. Thing will restart and you will have a fresh new build of Marshmallow on your Nexus device! **NOTE** When I upgraded to 6.0.1 I had to go through the setup on my Nexus 6 and perform steps 4 and 5 again to get the device to be seen through usb on the mac.
  21. Now repeat steps 1-3 except type csrutil enable into the Terminal in the Recovery mode to return your root security to normal.

Twenty one steps later… Let us know what you think!