Finally I got myself to root and unlock bootloader of my Thor Kindles. I've been lurking for few years. Here is the steps:-
1. Install Kingroot from Kingroot website (
https://kingroot.net/) and root the phone. I got it first try. But some people are saying they need 8 tries to work. Some even report success after 20 tries.
2. Flash TWRP and Unlock bootloaders. Instruction in
https://xdaforums.com/kindle-fire-h...r-firmware-t3463982/post70881555#post70881555. Instruction in this post is better than the first post (OP) in the thread. The step is:-
a) install ADB driver and install Kindle Fire USB driver
b) put get_code.bat and unlock.bat in adb.exe directory. Put aboot and cubed twrp in /sdcard/
b) create unlock.code with get_code.bat
c) flash aboot and cubed twrp with this command in DOS command prompt in adb.exe directory:-
d) make sure check the Android ADB Composite driver is properly install in Device Manager
e) execute unlock.bat
f) reboot, press UP + power to boot into TWRP
g) wipe, then flash your ROM using adb sideload or normal flashing if you already have the rom in your device earlier. Then wipe again.
Tips:-
1. Make sure the driver is Android ADB Composite Driver is properly install or the unlock bootloader (unlock.bat) won't work
2. Installing Rom, press UP+POWER to go into TWRP, download the ROM to PC, then enable ADB side in TWRP, follow up with ADB sideload command in PC. Wipe before and after. :-
https://xdaforums.com/kindle-fire-hdx/orig-development/rom-fire-nexus-rom-ktu84q-t3322931
3. Safe Strap is not supported in 4.5.5.2
4. Copy ROM zip file to /sdcard/ before doing the above to skip the adb sideload step and you can directly flash the rom from TWRP only.
5. Can't boot into 4.5.5.2 after unlock bootloader. I've tried issuing "fastboot -i 0x1949 oem idme bootmode 4000" and then "fastboot -i 0x1949 reboot" command but it does not work.
Added another instructions from another forumer who think my instructions is not complete:-