[Fire Original Android Development] Doggy77:
Today, I successfully flashed a two 8Gb and one 16GB variant of the fire tablet. One 8GB model was delivered with fireOS 5.0.1, the other two tablets were delivered with fireOS 5.1.3. The method described here worked with all tablets.

tl;dr: Flashing this fine ROM works also with 16GB-model. Downgrade 5.1.3 => 5.1.2 with well known amazon firmware 5.1.2 works also on 16GB model.

I used this method here:

I used the following prerequisites:

+ VMware player 12 on a Windows machine

+ a virtual machine using Linux (I used "Linux mint 17.2") with adbtools installed. make sure "adb version" shows 1.0.32. Please use Google to find out how to install the correct adbtools with your specific linux distribution.

+ Knowledge how to open a terminal and enter "adb version"

+ download inside the linux system the files needed (rootjunkys supertool, the CM12-image and the "openGapps ARM 5.1 pico").

+ prepare a micro-SD-card containing the files "cm-12.1-20160710-UNOFFICIAL-ford.zip" and "open_gapps-arm-5.1-pico-20160713.zip".

Follow these steps:

- insert SD card into tablet

- Power up tablet, do not connect it to Wifi now, do not enter any account data and check the fireOS version installed: Go to "Settings => software update". It shows the version that is currently installed. Flash downwards with ADB sideload to 5.1.2 using the usual image from amazon. The rootjunkys supertool (or more precise "kingroot" for rooting) does not work with 5.1.3 or higher. If coming from 5.1.3 or higher, never ever go lower as 5.1.2 or you will brick your device. Also never ever change anything if you are lucky enough to have a version below 5.1.2 of fireOS (i.e. version 5.0.1). To sideload this please power down the tablet. Disconnect USB. Hold "Power" and "Vol-Down" buttons until the "recovery mode" appears. Using the volume buttons navigate the white bar to "apply update from adb". Accept with the power button. Connect the USB cable to the device and connect it into the VMware. In the linux terminal on the VMware enter "adb sideload ./Downloads/fire-OS-5.1.2-update-kindle-global-37.5.4.2_user_542168620.bin". If the filename is not found please check where it was saved at downloading. It shuld begin the transfer. This step needs about 30 minutes.

- Use rootjunkys supertool for rooting. Installs Kingroot. Before starting the rooting process two things had to be done:

- - disconnect USB cable (with USB connected it won't root here)

- - connect to WiFi. Kingroot works only with wifi connected.

- attached tablet back to the computer

- continue rootjunkys supertool for kingroot to be removed and be replaced by supersu.

- on computer copy flashfire 0.51 to internal memory to "downloads" and install it. The 0.50 variant from the rootjunky supertool ddn't want to start here.

- Install flashfire from "downloads".

- start Flashfire.

- - Add "Wipe", tick "System data", "3rd party apps", "Dalvik Cache", "internal storage", "cache partition".

- - Add "Flash ZIP or OTA". in Headline switch to "External SD card". Select "cm-12.1-20160710-UNOFFICIAL-ford.zip". Leave ticks as they are ("Auto-mount" unticked, "Mount /system read/write" ticked, "Preserve recovery" unticked).

- - Add "Flash ZIP or OTA". in Headline switch to "External SD card". Select "open_gapps-arm-5.1-pico-20160713.zip". Leave ticks as they are ("Auto-mount" unticked, "Mount /system read/write" ticked, "Preserve recovery" unticked).

- - Move Wipe-Action to TOP of the List! (This is important!)

- - Optional: If desired go to "EverRoot" and add the tick "Inject SuperSu". This is not necessary, because the ROM has "su" (for beginners: this means "have root") built in but deactivated. Some prefer "SuperSU" as app for managing the root access. To enable "Root" without SuperSU follow the steps below.

- After all is set up hit the "Flash" button. Now wait till the device reboots.... First the amazon-logo from bootloader appears. After this the "Cyanogen-face" should flash. This step may need some minutes (up to 10 minutes). Et voila, you're done.

There is no real need to flash every update that is provided by OP. Just be lucky to have freed this fine hardware.

As promised here the steps for enabling root without supersu:

- Go to "settings => About tablet".

- Tap 7 times on the entry "Build number". Message appears "You have enabled developer settings".

- Go back using the arrow in top left corner. Admire the beauty of the new entry "Developer options".

- open these developer options. Tap on "Root access"

- Choose "Apps only". You get a warning message that apps requiring root access may damage the device. If you are aware of this accept with "OK".

- Still in developer options look out for the entry "local terminal". Enable it.

- Reboot the device. This step is important, root access is only active if device is rebooted!

- After reboot go to the app overview (list of all apps) and open up the "Terminal". The screen goes all black and "scary hacker symbols" are shown. ;) (it says here "u0_a55@ford:/ $"). the "$" sign at the end shows "you are not root, you are in safe userland".

- Enter the command "su" and hit enter. A security question appears. This is important, please take a short time to read this paragraph to understand the meaning of this question! Any App that wants to change/damage the system and asks for root has to be allowed by the user. If this security question appears "out of the nowhere while working" you may be attacked by the website or the app you are using. If you are aware "yes, I am INDEED doing some system related thingys" for example flashing a rom or doing other "nasty things" you may answer "yes, please do it, I grant you root access". If you are unsure from where this comes, always answer "no" and stay safe and ask at an appropriate xdadevelopers forum. Here in this situation we will allow it. If the reading of these sentences has needed too long and the dialog has disappeared re-enter "su" as command and allow it.

- The "scary hacker symbols" are changing to "root@ford:/ #". The hash tag at the end of the line indicates "Hi user, be careful. You are now working as root and you may damage the system severely. Don't shoot yourself!". To exit this mode just enter "exit" and you are back in the "safe userland with the Dollar-sign". One more "exit" and the terminal is closed.

- congratulations, you have now been "root" and also know about the meaning of the warning dialogue "grant root access to the app XYZ? yes or no".

If you found this explanation a bit useful please feel free to hit the "Thank you" button. This also applies to the posts of other users that are contributing to your knowledge or your pleasure: ggow as provider of the roms, rootjunky as provider of the supertool, davey126 and sd_shadow as "main supporter" in this forum and all other persons I forgot to mention.

Greets,

Doggy77