PW4 MY Kpw4's FW revert to 5.10.1.3 from 5.12.2

[Tsiung]

I don't know if it is a special case or not，but I think sharing it is beneficial.Maybe，someone will learn something from it.

I JailBreaked your KPW4 using Factory JailBreak (Factory FW) from here.
https://www.mobileread.com/forums/sh...&postcount=455

But Updata fireware to 5.12.2, my Kpw4 lost JB，the";log mrp" do not work.
Before Updata，I flashed the newest ‘hotfix’ （2019-Oct-11 23:23:06）using '；log mrpi'. After the operation, I found out that it is a wrong operation. the ';log mrpi' has't work. But I can still perform the correct operation.
I flashed the newest ‘hotfix’ （2019-Oct-11 23:23:06）using "Update Your Kindle" to my kpw4. it work，but ";log mrpi" still don't work.Finally I put Factory JailBreak (Factory FW) in my kpw4 and update。After reboot，My kpw4's FW revert to 5.10.1.3，and '；log mrpi' work.

[hius07]

As the latest hotfix sets the flag PRE_GM_DEBUGGING_FEATURES_ENABLED__REMOVE_AT_GMC, we can assume that the function of this flag (allow downgrade) has been restored in 5.12.
Need more confirmation from users.

[hius07]

Great!
Confirmed downgrading PW3 from 5.12.2 to the factory 5.9.6.1.

[Uphantom89]

Is it possible to apply for non-jailbreak device to upgrade to 5.12.2 and downgrade 5.9.6.1?

[hius07]

Originally Posted by Uphantom89

Is it possible to apply for non-jailbreak device to upgrade to 5.12.2 and downgrade 5.9.6.1?

No, you should install the hotfix (or manually set the flag in the system area) prior to downgrade.

[trcm]

Should I (at 5.10.1.3) install this updated hotfix, are there any downsides to this PRE_GM_DEBUGGING_FEATURES_ENABLED__REMOVE_AT_GMC flag being set ?

[hius07]

Originally Posted by trcm

Should I (at 5.10.1.3) install this updated hotfix, are there any downsides to this PRE_GM_DEBUGGING_FEATURES_ENABLED__REMOVE_AT_GMC flag being set ?

The flag will be set on 5.12.* only.
Everyone should install the latest hotfix asap.

[Uphantom89]

Yes, my pw3 is on 5.12.1, but not jb yet, can I downgrade?

[hius07]

Originally Posted by Uphantom89

Yes, my pw3 is on 5.12.1, but not jb yet, can I downgrade?

No, you can't.

[MrTick]

I'm wondering if this approach can be used in my particular situation:
- I had a factory-jailbroken PW4, updated to 5.11.something
- For some reason I had to do a factory reset, then reinstalled most of the hacks (but not the hotfix)
- It was living in an airplane mode ever after.
- One day I've disabled the airplane mode to sync time...
- OTA to 5.12.2 happened.

Now the hotfix instalation (via Update my Kindle) throws 007 error.

But maybe there are some JB leftovers that'll allow me to enable PRE_GM_DEBUGGING_FEATURES_ENABLED__REMOVE_AT_GMC and downgrade to factory image.

I'm just wondering how risky is the attempt to downgrade. Should it fail right in the beginning, or it'll attempt to flash something and leave me in bricky state?...

[hius07]

@MrTick, reset + firmware update = jb lost definitely
You can try to put initial factory firmware 5.10.1.3 to the usb-root and reboot but chances are close to zero.

[MrTick]

Originally Posted by hius07

@MrTick, reset + firmware update = jb lost definitely
You can try to put initial factory firmware 5.10.1.3 to the usb-root and reboot but chances are close to zero.

Roger. So I think I'll stick to the evil 5.12 for now...

[Schattenjager]

I just successfully recovered lost jailbreak on PW3 after update to 5.12.2 and rolled back to factory firmware.
Maybe this will help someone.

After upgrading to 5.12.2, I could not install the latest hotfix and use the ;log mrpi command.
Before that, I had all the most recent at that time (2019-Oct-01, I think, not yet supporting firmware 5.12.2) snapshots installed, including the Rescue Pack and Coward's Rescue Pack.

Rescue Pack must be installed on the device!
Installed Coward's Rescue Pack is also desirable - if not, see step 1.2.

I did the following:
1.1. Rebooted PW3 with the USB cable connected to the PC
1.2. If you have not installed the Coward's Rescue Pack, just create the empty file ENABLE_DIAGS without extension on the device and reboot it
2. PW3 booted in Diags mode
3. Enabled USB device mode
4. Extracted all contents of kindle-5.4-jailbreak.zip from kindle-jailbreak-1.16.N-r16552.tar.xz on PW3
5. Ejected PW3 from PC, USB cable remained connected
6. Entered Misc individual diagnostics -> Utilities -> Enable USBnet
7. On PC edited new USB Ethernet connection - set IP address to 192.168.15.201 and network mask to 255.255.255.0
8. In the terminal emulator connected to PW3 via SSH
ssh root@192.168.15.244
any password - just hit enter
9. Mount root filesystem in read/write mode
mntroot rw
10. Allow firmware downgrade
touch /PRE_GM_DEBUGGING_FEATURES_ENABLED__REMOVE_AT_GMC
11. Executed the jailbreak
cd /mnt/us
sh jb.sh
12. Exited to the root of the Diags menu
13. Entered Device Settings
14. Exited to the root of the Diags menu
15. Entered Reboot or Disable Diags -> Disable Diagnostics
16. After PW3 has booted successfully installed latest hotfix through UYK
17. Then installed factory image 5.9.6.1
18. Applied factory jailbreak via ;merchant
19. Installed consumer firmware 5.9.6.1
20. Installed KUAL via ;log mrpi
21. And so on...

P.S.: Not sure if steps 6, 9, 10 are necessary.

This instruction is not intended to be complete, I can forget or miss something.
Also, my English writing skills are not very good, so Google Translate helped me a lot.

[Schattenjager]

Updated previous post

[hius07]

@Schattenjager, have you installed the latest hotfix before upgrading to 5.12.2?

It is interesting, why someone can install the hotfix after upgrade, and someone cannot.