[Kindle Fire HDX 7" & 8.9" Q&A, Help & Troubleshoot] Rvby1:
Thor (kindle fire hdx7) & apollo (kindle fire hdx8 gen3) 4.4.4 & 4.4.3 guide to flash

As a huge ode of thanks to all your help and the work of yourself and many users here, I wanted to give something back to the community. SO, here is a guide of sorts. Let me know if I should post this somewhere outside of this thread, or feel free to do it yourself with a simple link to this post, or something.

THOR (KINDLE FIRE HDX7) & APOLLO (KINDLE FIRE HDX8 GEN3) 4.4.4 & 4.4.3 GUIDE TO FLASH READINESS​

Disclaimers​

Neither I nor anyone on this board is responsible for any damage to your device. Make absolutely certain that you follow these instructions properly and READ THROUGH IT ALL A FEW TIMES BEFORE YOU EVEN START SO YOU KNOW WHAT TO EXPECT. If you are unsure about something, search then post before rushing in! There is likely someone who can help you.

For Thor and Apollo 4.4.4 and 4.4.3, but this guide should be adaptable to any level as long as you can get to 3.2.8.

This is a documentation of the process that worked for me on Thor 4.5.4; it might not work as smoothly, or at all, for you. For example, I have heard the rollback method that will be used here hasn't worked for various users on 4.5.4. Sorry for any such problems.

Finally, I especially cannot guarantee the quality of this guide for Apollo devices. I've been told it works with a different file set, so I have generalized the guide to attempt including these different files sets; however, there may still be issues. Sorry. ​

Prerequisites:

Thor(Kindle HDX7) OR Apollo (Kindle HDX8 Gen3)

Thor 4.5.4 or 4.5.3/ Apollo 4.5.4 or 4.5.3. If you’re already on 4.5.2, skip to step 15.

A USB to tether your kindle to a windows-based computer.

Process:

In settings, enable apps from unknown sources and adb editing.

Download the 13.3.2.8 FireOS update here. You can do this on your device or computer. If you use your computer, move the file to the root--the "internal storage" when you have the USB plugged in(tethered). If you used your device, put the file on the highest level you can go to (/sdcard, I think).

IF YOU HAVE ANY VALUABLE FILES ON THE DEVICE, BACK THEM UP. THE KINDLE WILL HAVE ALL OF ITS DATA RESET.

Turn on airplane mode and disable Wifi. Reboot.

Go to Settings > Device > System Update and wait until it sees the update file; it will be pretty clear that it does.

Once it does, tell it to go through with it. On 4.5.4, there is apparently a chance the update will fail and give you an error message; despite this, it’s worth a shot, as a failure won’t damage the device. Stop here if it fails. Sorry!

If you successfully roll back to 3.2.8, IMMEDIATELY ENABLE AIRPLANE MODE AND DISABLE WIFI. IF YOU GET AN OTA—OVER THE AIR UPDATE—YOUR DEVICE WILL UNRECOVERABLY BRICK. DO NOT FORGET THIS.

Take a breather. Now that Wifi is disabled, you are safe for a moment.

Back on your computer, download the HDX Toolkit here. This program, so far as I know, only works on Windows. With it downloaded, unzip the file.

Tether your kindle. Run the HDX Toolkit program.

You will come to a screen with options. If you don't have ADB drivers installed, click 1 and go through with it. These are needed.

(Optional, but recommended) Once they install, choose option 8 to Towelroot. This may require a momentary internet connection, but it did not for me. If it does, only enable it for 5-10 seconds, then disable it again; DO NOT KEEP IT ON LONG ENOUGH TO LET AN UPDATE DOWNLOAD. This allows for more options in case something goes wrong.

On your computer, download the 4.5.2 bin here. Once it’s downloaded, sideload the .bin onto your device in the root folder (definition above). DO NOT ENABLE WIFI TO DOWNLOAD ON YOUR KINDLE. Reboot. Go to System > Device > System Update and wait for the file to be recognized. Give it 10-15 minutes.

Once it’s recognized, allow it to update. IF YOU SOMEHOW LOOSE YOUR AIRPLANE MODE AND WIFI DISABLING AFTER UPDATING, REENABLE IT IMMEDIATELY.

Congrats! You’re now on 4.5.2. Take another quick breather.

Because you updated, your device is no longer rooted. Let’s fix that. There are two methods, but first, we’ll need a file explorer.

Download the ES File Explorer apk to your computer here.

Go through the process for installing Android SDK on your computer. Documentation here.

Open up CMD and navigate to where you installed the user tools for SDK. Default should be C:\Users\USERNAME\AppData\Local\Android\sdk\platform-tools. To change directory, use "cd <path>" as the command.

I recommend renaming ES File Explorer to ES. Now find the path to ES File Explorer. Let’s say it’s C:\Users\USERNAME\Downloads. For that path, you would enter this: adb install C:\Users\Daniel\Downloads\ES.apk. It should now attempt to install. If you see success, you’re good.

Now let's get on to the actual rooting process. NOTE THAT I DO NOT KNOW IF THESE WILL WORK FOR APOLLO. YOU MAY HAVE TO FIND METHODS ON YOUR OWN FOR NOW. (Feedback pending) There are two current rooting methods:

(ROOT METHOD #1) cve20147911. Download to your computer here.

[*]i. IMPORTANT: activate developer controls. To do this, refer here. Once activated, activate “mock locations.” under the new Developer Settings tab.

[*]ii.	Sideload cve20147911 onto the device. Path doesn't matter.

[*]iii.	Open up ES File Explorer. (Won’t appear right away. You need to go to applications, filter it to device, and then click on it in that menu.).

[*]iv.	Navigate to the cve20147911 apk, click it to trigger its install, install it, and then run it. Click the button twice. Your device will reboot and say it’s updating. This freaked me out, but don’t worry about it.

[*]v.	Reboot the device once yourself.

[*]vi.	Check root with ES File Explorer. To do this, go to root explorer under one of the ribbons on the side and attempt to activate it. If it lets you flip it to "on," you're rooted.

[*]vii. If you get a popup from SuperSU asking to grant permissions to ES File Explorer, do it.​

(ROOT METHOD #2) Kingroot. I don’t know how to use this method, so you’ll have to trudge through this on your own. Sorry. I would recommend the method I went over.

Congrats. You are rooted! You now have two options: stay on FireOS or Flash your device to a ROM. If you choose to stay on FireOS… block OTA updates and install GAPPS using this as a reference. You’re good to go!

Want a ROM? Let's continue! Keep in mind that I will be going over getting the Nexus ROM. I'm not sure if the process for CM-11 is the same.

Please look into these threads a bit (1) (2) before moving on. They’ll give you an overview of the process, and I’ll be referencing links therein. Great place to ask questions, too; you’ll likely get a response.

Download the right SafeStrap 4.01 for your device here, Nexus ROM here, and GAPPS ROM here. KEEP THE LATTER TWO ZIPPED. Sideload all three onto the root (refer back for definition).

Install SafeStrap 4.01 by clicking on the apk and clicking install. Open it. Grant SafeStrap SuperSU access when asked and agree to the terms. Click Install Recovery. Once it finishes, reboot to recovery should become clickable. Click it. Safestrap recovery should come up—it’ll say “Safestrap 4.01 (TWRP v2.7.1.0) on top.

From here, click on install. Scroll to the Nexus ROM.zip, click it, and flash it. Use the recruiting arrow in the bottom right to go back, then click on install, navigate to the GAPPS ROM.zip, and flash it.

Go back using the recruiting arrow.DO NOT FORGET THIS. Click on Wipe and swipe the bottom bar to factory reset. DO NOT CHANGE ANY OTHER SETTINGS IN FACTORY RESET.

Go back using the recruiting arrow. Click on Reboot and then System.

The device will restart and boot up to a screen with a robot. Just let it progress into the system start up after ten seconds.

You will be presented with a new start up splash screen. Let it take you to setup. Perform setup. Feel free to choose a Wi-Fi network now. (am I right in that being okay?)

When you finally finish up, a pop up will come up asking you if you want Explorer3 or a Google application. I went for Explorer3.

CONGRATULATIONS! You now have a fully functioning, flashed Kindle Fire HDX. Enjoy!

If anyone notices any problems grammatically or technically, please let me know as soon as possible. Further, if you have any suggestions to make this look better, please let me know about those too. Thanks!

Sources:

Rollback information and files.

HDX Toolkit.

Kingroot.

Nexus and GAPPS ROMS.

Safestrap.

Some instructions and inspiration.

(Deutsch)Rooting process and very general explanation of rolling back.

General thread where I learned a lot through Davey's help and example of a possible outcome.