[Fire HD 8 and HD 10 Android Development] jammyjammers:
Rooting and Post-Rooting

I did it! Struggled with my device all day and I finally got it to work. Below are the details of my success story.

DEVICE INFO

Amazon Fire HD 8 G090-G8XX-XXXX-XXXX

KFMEWI, Thebes, armv7I

ROOTING

1) Set up ADB drivers in Windows and on the device.

2) Download appropriate firmware (5.1.2, not 5.1.2.1; my .bin file was called update-kindle-32.5.4.2_user_542168620.bin) from links located in the index of these forums.

3) Reboot to recovery (volume down and power... make sure you know which one is volume down, haha)

4) Wipe user data and factory reset: I have heard that your device might connect to a network during installation and recover OS files, so to get around this, I wiped and reformatted entirely. This deleted saved network passwords, so the device shouldn't automatically connect to the Internet. Reinstalling the OS without wiping saved other user data as well, such as desktop appearance and folders. Wiping also decreased issues with Kingroot for me. In my opinion, it's best to wipe and start fresh.

5) Install fireOS 5.1.2 (update-kindle-32.5.4.2_user_542168620.bin), wait 25 min or so for installation to complete.

6) On device, allow debugging

7) On device, allow installation of outside apps

8) Turn on wifi (kingroot doesn't work without it for me)

9) Install Kingroot on windows desktop (i used v3.2)

10) Install Kingroot APK to device (i used v4.9)

11) At this point, rooting the device with Kingroot took me 4 or 5 tries. I alternated installs between the device and the desktop. First, I tried to install Kingroot from the device. It failed around 30%. Then I tried to install from the desktop. It failed around 35%. I went back and forth, alternating install between device and desktop. Each time, the failure would happen at a slightly higher percentage. On my second try on the desktop, it failed at 50%. Then on my third try installing Kingroot on the device, it finally succeeded. If you're having issues with Kingroot (e.g. it can't find the device or gives you an error before it tries to root), don't be afraid to wipe and start over. I also reinstalled Kingroot on my desktop a couple times throughout the day. Who knows why it is so finicky.

POST-ROOTING

1) WARNING - Installing SuperSU through SuperSU Me...

I had a problem here. I used SuperSU Me and it seemed to work fine until SuperSU tried to update the binaries. My device just hung during the boot / amazon splash screen. I eventually had to reinstall the OS and start over. My second time around, I chose to just leave KingRoot and not bother with SuperSU or FlashFire. I'll wait until a more stable process crops up.

2) Enable Google services....

Install four apps from APK: Google Login Services, Google Play Store, Google Account Manager, Google Service Framework. Then open up a command window in windows and use the following commands:

A) adb devices (did it return the device's serial number? Good!)

B) adb shell

C) pm grant com.google.android.gms android.permission.INTERACT_ACROSS_USERS

D) exit

If you receive "error: closed," which I did, it means you stupidly turned off the device to run the ADB command from the bootloader. Don't do that. Note that Google Play Store will ultimately NEVER work, which I didn't know. However, installing these four apps allows you to run other Google apps, like Gmail, youtube, calendar, etc. Use the Play store after initial installation to login to your Google services account, but don't bother downloading or updating apps from it. If the Play store doesn't open after your shell command, try reinstalling the Play store APK and then opening it. You can also use '1Mobile Market' instead of the Play store to manage your apps. In accessibility options, make sure to allow 1mobile market to install applications.

3) Disable Lockscreen Ads...

Install ES File Explore, enable root access or exploring, and move OTAcerts.zip located in /system/etc/security/ to a safe place (this disables automatic updates)

4) Replace Fire Launcher with preferred home screen launcher....

Install nova launcher prime (or your favorite launcher app). Open nova launcher to get it fully installed. Then install titanium backup pro (you'll need the paid version to do the following...). In titanium, search for Fire Launcher and freeze it. Now your home button will revert to nova launcher.