Amazon Fire 7 Inch Tablet
For $35.33 I got a tangerine Fire Tablet on amazon prime day.
At that price, I figured I could afford to experiment with all the nasty rooting and modding hacks described in the xda Amazon Fire Forums
The tablet arrived with 5.1.3 already installed and 5.1.4 ready and anxious to auto install the next time it thinks it has enough spare time and power.
Since (as near as I can tell from the forums) neither 5.1.3 nor 5.1.4 can be rooted, the first order of business is to try downgrading to 5.1.2.
First Try
This post has links to the different versions of firmware:
I downloaded update-kindle-global-37.5.4.2_user_542168620.bin which is supposed to be 5.1.2 and compared the checksums (which matched).
Now I need to "sideload" it, not that I have any idea what the hell that means or how to do it...
The quest for that arcane knowledge led me here: Sideloading Fire Firmware
Apparently that means I need to get adb working (by frantically clicking on serial number under the device options in settings, then enabling usb/adb connection when developer options appears).
Download the .bin file (did that above)
Hold volume down and power button at same time to boot into recovery.
Connect to pc
Select "apply update from adb" in recovery options
(actually you need to connect to the pc, *after* selecting that option, then see that "adb devices" says there is a sideload device out there).
I also had to try this twice, it failed the first time, so I got a better USB cable and did not go through a hub on 2nd try.
use the "adb sideload <filename>" command wait 10 minutes or so
when recovery comes back, wipe data and cache
reboot
wait a long time
should be running 5.1.2 now.
Ta-Da! That all worked and I am indeed running 5.1.2 now.
In theory, I can now root this thing.
Several searches point to KingRoot which has a homepage where you can download the .apk file then use adb install to install it.
That worked on the 2nd try so I have a kind of root access now.
I also needed the play store to be working, so I unpacked the AmazonFire5thGenSuperTool.zip and manually did some of the things in the script. [This was probably a mistake, I didn't bother with it on the 2nd try I'll get to below].
I installed FlashFire from the play store and it only wants SuperSu, so since I'm not worried about random corruption I went ahead and downloaded the supersu-me-v6.7.apk and installed it via adb and ran it. Seemed to work OK right up till I rebooted: I appear to be stuck in the fire logo and never finish booting.
Time to start over and re-install 5.1.2 I guess :-).
Second Try
Power off tablet (have to hold power a long time since it is stuck booting).
Hold down power and vol down (farthest away from power) till the recover screen comes up.
Push vol up once to select "apply update from adb" and press power button to start process.
Plug in usb cable to computer
run "adb devices" and see that it says there is a device ready for a sideload.
run "adb sideload <filename>" to load the 5.1.2 rom.
That runs for a while (if all goes well) then the recovery screen comes back.
Now select "wipe cache partition" and hit power key
Then select "wipe data/factory reset" and hit power key
Then select reboot and it should come up in 5.1.2 after a long boot process.
Yep, 5.1.2 is now back and boots OK.
Time to adb install NewKingrootV4.95_C149_B283_en_release_2016_07_05_105203.apk
It installed and I ran it to root the tablet. It took about 4 tries this time, but finally got rooted.
This time use the AmazonFire5thGenSuperTool.zip scripts as a guide to switch to supersu (seems to have worked - I was able to reboot).
The supersu interface seems to work.
Time to try flashfire again... This time just download the .apk and install with adb, don't bother getting play store to work.
To do that, I visit CM Rom which has the instructions for installing CM and open_gapps. I did that and they appeared to install and booted up in the new rom.
I'm somewhat worried about the stuff saying I have to fastboot if I ever shutdown the tablet (but not to worry, all those fastboot comments in the thread are apparently old - the tablet boots just fine with no fastboot required).
Conclusions
Sure the screen resolution sucks on this tablet, but for a little over 30 bucks, it is a pretty darn nice tablet once you get the amazon ecosystem off of it. It isn't bad for watching videos, but I wouldn't want to do a lot of reading on it.
The fact that it has an SD card slot makes it pretty unique these days. I added the old 32Gb card I used to have in a phone before they stopped making phones with SD card slots, so that gave me lots more storage.
I was shocked to discover that the TiVo app works on it, and I was able to stream videos from my Roamio. No complaints about a rooted device or non-standard kernel.
I installed MX Player as well, and it also seems to work. I tested playing videos from the removable SD card with no problems. I also use MX Player to play videos via http from my desktop's web server.
I even reinstalled some of the amazon apps, like amazon underground which I used to install prime video, and prime video works well.