[Kindle Fire HDX 7" & 8.9" Q&A, Help & Troubleshoot] p-4:
[Solved] Manual install CM11 & Original Thread: How to install CM 11.1 on Fire HDX 7?

Hello,

as I just managed to install CM 11 on my Fire HDX 7 (3rd Gen) (thanks a lot to @Cl4ncy, @Davey126 and @EncryptedCurse) I want to share the information I got during the process.

Note: This manual might be outdated if you read it. So check if there is a newer manual You could break your device if you dont do everything correctly. I am not responsible for breaking your device! If you have a question just ask! It could be that i forgot something.

When I started my Fire HDX 7" had Fire OS 4.5.5.

Note: CM 12 is not available yet for Safestrap v4. If you want CM 12 you need an unlocked bootloader. You can't do it if your version is above Fire OS 3.2.3.2. And you are not able to downgrade below 3.2.8 due to rollback protection by Amazon.

Some preperations:

- connect your Fire HDX to your PC (if your PC doesnt recognize your Fire HDX then install the USB drivers. If that doesn't work deinstall the actual Fire HDX driver and try it again.)

- copy every folder from the Fire HDX storage to your PC (backup music, ....)

- install (Holo Backup and click on every Backup Button (in my version there were 5 buttons))

- install minimal adb + fastboot

Download these files and save them on your PC:

- ES Explorer

- KingRoot

- Safestrap v4

- a Safestrap v4 compatible ROM (CM11 or Nexus v4)

- SuperSU if you want root - Download the .zip file from here: https://download.chainfire.eu/696/SuperSU/UPDATE-SuperSU-v2.46.zip //Check if there is a newer Version

- GApps if you want the Google Apps (the right things should be already selected. If not select: ARM, 4.4, nano) -> the name should be sth like: "arm 4.4 nano 30 September 2015"

Thanks to @Davey126 and @Cl4ncy:

- Turn Wifi Off and flightmode on (you might need to enable Wifi, when you root your device with KingRoot)

- rollback to FireOS 3.2.8

// you do that by copying the file into the 'Internal storage folder' of your Fire HDX (not in a subfolder, just copy it where the DCIM, Document, Download, kindle, ... folder are.). Now wait a few minutes and go to Settings -> Device -> System Updates -> Tap Update

- upgrade to FireOS 4.5.2

// do it as before

- install ES Explorer and KingRoot with minimal ADB + Fastboot

- make sure that only the Fire HDX 7" is connected

- run this Code to see the connected devices

adb devices

- install the ES Explorer and KingRoot by using minimal ADB + Fastboot

- replace "C:\users\p-4\es.apk" with your own path and do the same for KingRoot

adb install C:\users\p-4\es.apk

- root with KingRoot or another method (i didn't find another one) //if it doesn't work directly just try it again (I tried it 10 times). If it still doesn't work just try another Wlan (that nothing gets blocked) or wait a week.

- block OTA (over-the-air updates) - only step#1 //you don't have to install the GApps because you will flash them with the ROM

- install Safestrap v4

- Copy the installation files (ROM, SuperSU, Gapps) to your Fire HDX into the /sdcard folder. (There the files won't get deleted if you wipe). If there folder isn't available then create one. But normally there should be one. Make sure you have your Fire HDX rooted. Only then you can see the folder with ES Explorer. In my case the "/sdcard" folder was the normal one, where i stored my Music, Documents, ... so had didn't have to do sth.

- Reboot

- Make a backup of the 'Stock-Slot'

- Copy the backup to your PC

- flash a Safestrap v4 compatible ROM to the ROM-Slot-1 , 2, 3 or 4 (currently CM11 or Nexus v4)

Safestrap v4 Tutorials:

(https://www.youtube.com/watch?v=K6fPF5UZsWw) General Safestrap usage

(https://www.youtube.com/watch?v=xR0WXCITq2Q) Specifically how to install a custom ROM

Notes: If you use a secondary slot the biggest possible Data Size is 16GB and your battery won't last long. You have to charge the Fire HDX very often.. If you use the Stock Rom Slot you will have the whole storage of your device.

Congratulations you successfully installed CM11 if you did everything right.

But as I mentioned before the performance is not very good, because the ROM is installed on a secondary slot.

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To get the best performance and a very good battery life you have to install the ROM on the 'stock-slot'.

Thanks to @Cl4ncy and @Davey126 :

For that just:

- Reboot and go to the Safestrap Menu

- check if the installation files (ROM, Gapps, SuperSU) are in the "/sdcard" folder press "..." in the installtion menu to go up the path. There should be the "/sdcard" folder.

- Delete the secondary ROM-Slots

- Go into the Wipe Menu and Swipe to perform a factory reset (only a simple one - no advanced wipe)

- Go to install and add the ROM File

- add Gapps

- add SuperSU if you want root

- perform the flash

- if it was successfull Reboot otherwise DON'T Reboot. Just wipe again and flash the files again.

Note: If something went wrong with the stock-ROM don't reboot directly. Just install a ROM on a secondary slot and reboot then.

// The Original Post:

Hello,

since it is possible to download prime videos on any android device i would like to install Cyanogenmod 12.1 on my fire hdx 7.

I found this Cm 12.1 Port.

Is there a step by step manual how to install such a rom, because i never did that before and i have heard that if you do something wrong your device is broken.

Because I neither know how to get an unlock bootloader or what a TWRP is. Furthermore i also dont know how to flash the ROM.

In some forum posts i read, that it is possible to go from Cyanogenmod back to FireOS (unbrick). For now i dont want to go back from Cyanogenmod to FireOS, but i think it would be good to have such a possibility.

Do I have to take precautions for that?

And how do I make backups?

Info:

Kindle Fire HDX 7" (3. Generation): Fire OS 4.5.5

Thanks a lot

p-4