How to downgrade after forced upgrade to 15.6.4?

[Kindler123]

I was ecstatic when I heard about LanguageBreak and was able to successfully jailbreak Paperwhite gen 12 (PW5) with ver 15.6.2.1.1 software. I installed mrpi, kual, koreader and other tools available and was learning about my now significantly expanded new features. I installed the jailbreak hot fix and clicked on prevent installing ota on kual. I thought I was safe from upgrade.

Next day I connected to Wi-Fi and was immediately upgraded to 15.6.4 by Amazon. It appears that the jailbreak survived, but clicking on kual does not work (application error: the selected application cannot be started) and re-installing anything with mrpi doesn’t see to work.

Am I doomed? Is it possible to downgrade the version? How?

IF I can downgrade, how should I protect kindle from the upgrade in the future?

[Daviteusz]

What extension did you use to block ota?

[mergen3107]

Your cause isn’t lost if you had a properly installed JB!
Follow this post from Step 13: https://www.mobileread.com/forums/sh...19#post4374819

Go into Airplane first, do NOT do any other updates or factory resets before you restore JB.

[mergen3107]

After you downgrade to 5.16.2, make sure to install AND run renameOTAbin from KUAL. This will prevent sporadic updates in the future.

[Kindler123]

Forgive me, which one of the NiLuJe's K5 Jailbreak package should I use? I unziped all of the packages on this page and did not find emergency-bridge-recovery.zip in any one of them here: https://www.mobileread.com/forums/sh...d.php?t=225030

[Kindler123]

@mergen3107 Never mind, I found it here: https://www.mobileread.com/forums/sh....php?p=4375594

Should I follow @pierexx suggestions and edit sh file etc or just follow your steps?

[Kindler123]

@mergen3107, I found the file here: https://www.mobileread.com/forums/sh....php?p=4375594

Should I follow your steps or the ones outlined by @pierexx?

[Kindler123]

OK. I tried both @mergen3107 and @pierexx methods. Neither seem to work.
On restart I see a message on the bottom of the screen **** SQUASH JB **** which I assume comes from amazon. After applying emergency-bridge-recovery the file file /mnt/us/version.txt.backup does not appear in either method.

What can I try next?

[j.p.s]

Originally Posted by Kindler123

OK. I tried both @mergen3107 and @pierexx methods. Neither seem to work.
On restart I see a message on the bottom of the screen **** SQUASH JB **** which I assume comes from amazon. After applying emergency-bridge-recovery the file file /mnt/us/version.txt.backup does not appear in either method.

What can I try next?

I can't address the rest of your question, but I strongly doubt that "**** SQUASH JB ****" came from amazon.

[mergen3107]

@Kindler123 ,
SQUASh JB - is the message from the JB that tries to survive. Please restart your Kindle again and tell me what does it say this time around.

[Kindler123]

After multiple trials and restarts here is what I think worked at the end:

1. Move 4 files from emergency-bridge-recovery (NiLuJe's K5 Jailbreak) I found here after I edited emergency.sh file with the code provided by Marek (according to that page), which appears to be the same code as in the the RUNME.sh file in step 16 by @mergen3107 to the top kindle folder, then restart kindle

I attached these 4 files with edits to emergency.sh to this post.

2. I was unable to install NiLuje's Hotfix after this as mrpi did not seem to work at this stage (as it has been suggested by @mergen3107 in step 14 and 15 here)

3. I copied the official update_kindle_all_new_paperwhite_11th_5.16.2.1.1 file to the top kindle folder and restarted the kindle. This worked and allowed me to downgrade kindle to 5.16.1.1 and keep the jailbreak (it appears that it also worked to @pierexx here, but it took me multiple trials/restarts for me to make this work - not sure why.

4. At this stage I was able to install mrpi, followed by kual, koreader and renameotabin.

Appreciate your help @mergen3017 and @pierexx!

Last question - if I ran rename from kual (renameotabin), am I completely safe from Amazon attempt to upgrade me in the future, and thus can use WiFi or there are some other security measures I should implement?

[Kindler123]

My reply / post is waiting approval by the moderator, but in the meantime I found @megen3107 answer to my question re: renameOTAbin reliability in preventing Amazon updates. I have installed both renameOTAbin and kual helper (enabled “Prevent OTA”).

I cannot find how I can disable Amazon logging
I also found BackDoorLock hack here and wonder if you would recommend to install it too.

[mergen3107]

Originally Posted by Kindler123

My reply / post is waiting approval by the moderator, but in the meantime I found @megen3107 answer to my question re: renameOTAbin reliability in preventing Amazon updates. I have installed both renameOTAbin and kual helper (enabled “Prevent OTA”).

I cannot find how I can disable Amazon logging
I also found BackDoorLock hack here and wonder if you would recommend to install it too.

Activate renameOTAbin too! ASAP!

[mergen3107]

Congrats on restoring JB!

[mergen3107]

In the steps above, you mixed all things together.

Here is wait you should have done (after unexpected Firmware upgrade to >5.16.2):
1) Put the four emergency files, then restart Kindle.
2) They should disappear- that means JB was restored.
3) Install Hotfix from NiLuJe’s Snapshots with “Update Your Kindle”.
4) Restart Kindle TWICE.
5) Put the RUNME.sh file with downgrader code - run this with “;log runme” command.
6) This creates this version.txt.bak and allows to downgrade.
7) Put the lower FW bin file and restart - Kindle will downgrade.
8) Install again Hotfix from NiLuJe with UYK.
9) Restart Kindle TWICE.
10) Install AND activate renameOTAbin.