Recently there was a sale on this Fire hd 8 gen 7 for $20 at Woot so I brought it so I tried to hack. It is hard to find a one with the firmware 5.6.4.0 or lower so this is how I got it to work. Honorable mention to Opec who actually got the instructions right so I modified his instructions a little to fit everything in.
A) amonet-douglas-v1.2.zip from first Page of this Thread:
https://forum.xda-developers.com/...p.4845269/
Unpack the Archive to a separate Folder.
B) brick-douglas.zip from first Page of this Thread:
https://forum.xda-developers.com/...p.4825253/
Unpack the Archive to a separate Folder.
1) Boot from a live version of linux (I used Ubuntu mate Lts 20.04) or you can install linux in your computer.
2) Run the following commands to install tools;
sudo apt update
sudo add-apt-repository universe
sudo apt install python3 python3-serial adb fastboot dos2unix
3) Disable modem manager
sudo systemctl stop ModemManager
sudo systemctl disable ModemManager
4) Reboot FireHD8 to Recovery (Power Off device, then hold VolUp + Power)
5) Select Factory Reset then Wipe Cache
6) Reboot to Bootloader. You will see the black screen with "Fastboot" in the lower corner.
7) Connect your usb cable to the tablet.
8) Open Terminal from "brick-douglas" folder an enter "sudo ./brick.sh (note that you are actually bricking your fire tablet in order to recover)
9) Check Display output for the "Disconnect USB and Powerdown" Message and do so when prompted. Proceed to step 10 if there no problems, but it didn't work for me.
*** Note if you see an error and the FireHD Reboot and do the "Apps and Data Optimization" at the Welcome Install Screen Powerdown the FireHD and enter Bootloader again.
a) repeat steps 4-7
b) Enter "sudo ./brick-8920.sh" instead of brick.sh
c) You should see Display output for the "Disconnect usb and powerdown" message and do so when prompted.
10) Open Terminal from "amonet-douglas-v1.2" foder.
11) Enter "sudo ./bootrom-step.sh"
12) Reconnect USB while your tablet is off.
13) Wait until the bootrom step is finished
14) Enter "sudo ./fastboot-step.sh"
15) You will end up in TWRP
16) Prepare a microsd card with Lineage OS 15.1 or 14.1 with the rom and gapps and install Lineage OS.
https://forum.xda-developers.com/...1.4328503/
https://forum.xda-developers.com/...1.4195349/
This comment here was all I needed, the OP had me a bit confused thanks much.
Its crazy to think that I had this tablet as a paper weight for all these years, all of the sudden it is a rooted android tablet, I was playing a few games perfectly, running extensions in my browser, cant believe how useful it is now! Thanks to everyone!!!
P.S. You should not need one with 5.6.4.0 or lower. I had the firmware from 2019 which was the last time I used it (5.6.4.0) and it would not work for me until I upgraded to the newest firmware then I booted it into fastboot and ran the ./brick-8920.sh as the other did not work. Also I decided to just make a quick USB stick with Ubuntu 20 and do it that way just because it was written that this might not work on wsl.
THANKS!