PW3 I just bricked my kindle ;P

[Vlash]

Yeah, I just did it, on the second day fiddling with my kindle. II'll be detailed and describe everything I did here, step-by-step, but TL;DR is:
I used Popcorn Jailbreak on my PW3, then after I did a factory reset, JB hotfix refused to install normally (update firmware was greyed out), I tried installing it with MRPI again, it it downright failed, two packages I forgot about went through (RescuePack and CowardRescue Pack) and the PW3 instantly died, no longer boots after that.


FULL STORY:
When I first jailbroke it, everything worked fine. I installed the hotfix via the "Update firmware" menu, Kual, Koreader and everything worked fine.
Except the NiJuLe's downgrader extension, it never showed up in KUAL.

My problems began when I asked whether it was possible to downgrade to 5.9.7 and someone recommended me to:
1. Clear internal storage then factory reset
2. Reinstall the hotfix (that's when problems started)
3. Reboot twice
4. Reinstall everything
5. Downgrade

I did the following:
1. Formatted internal memory but then t
2. Factory reset
3. Reboot twice
4. The hotfix refused to install via the kindle "update firmware" menu. So I:
5. Installed it again via MRPI
6. Reinstalled everything
7. Noticed half the Kual extensions didn't work, koreader, helper, and Kual+ didn't launch, MRPI didn't work from inside Kual

Since the Downgrader from the snapshots thread didn't even show up, I tried downgrader 2.0
When I tried it I noticed that:
Update failed with error 12 HOWEVER, using kterm I could check the /etc/versions.txt file was indeed changed to a version number that according to Amazon Source Code notices, correspondes to the first PW3 firmware. I wasn't able to downgrade though. I also noticed I wasn't able to reinstall the same firmware I'm on (FW 5.15.1). IDK if that was possible before, but I tried, it failed.

Upon failing to downgrade and seeing that something was messed up with the kual extensions, I did another factory reset. Again, JB hotfix didn't install normally, I tried installing it via MRPI, it installed but the bugs persisted.
So I:
1. Tore down the PW3 again, did the SDP trick and reflashed Popcorn Jailbreak, thinking it would erase the old firmware or something
2. Installed kual and everything, same issues popped up again (Koreader, KUAL+, Helper, neither of them was working, MRPI just worked by calling it directly using ;log mrpi)

So now I thought it might be a good idea to try and use USB network to SSH into the Kindle and hopefully fiddle with the /etc/versions.txt OR the backup the script made.

So here I had a bit of trouble, because instructions aren't as clear as other tutorials, or maybe it doesn't work on this FW.

I was able to get the driver working, get the NDIS interface up, etc, I was able to assign an IP and to ping it normally. However, I created the SSH keys, put the public key in the kindle, under "/mt/us/usbnet/etc/authorized_keys" (used Notepad++ to select LF line endings). I also had a hard time figuring the authorized_keys file(a file that's talked about a lot but there's no template of it anywhere. Luckily on the PC SSH used that file too). Then I tried using the key I generated with PuTTy, WinSCP, CLI SCP and CLI SSH, all gave me a "connection refused" error.

Then I switched to Linux so I could try. However, there the NDIS interface doesn't have an ip, and the usbnet command mentioned is something that comes from a kernel module that's disabled by default on linux, so (as mentioned in USBNET README) you have to compile your own kernel to see if it will work. As the tutorial is quite a bit old and I didn't know if that was the reason I couldn't get an IP address for the Kindle's NDIS interface, I gave up.

Then I did another factory reset and left the Kindle as is, thinking once amazon releases a new FW I'll install it to get rid of JB completely.

After this, I read about rescue pack and coward's rescue pack and that they might be useful to enter SSH. I installed mrpi and dropped them into the mrpackages folder, THEN I FORGOT about them, I had dinner and all, I came back and remembered I had to reinstall the JB hotfix, put in on the top folder of internal storage and went to settings, update option was greyed out.

So what I did next is what killed it. I dropped the JB hotfix thing inside the mrpackage folder without opening it, unplugged and typed ;log mrpi in the searchbar. The JB Hotfix package just failed and showed an exclamation mark, then the other 2 packages went through and the Kindle didn't reboot properly. It's now stuck in the "Kid under the tree" image, with the LEDs full on.

If I force reset it, it the same happens again and again...

[NiLuJe]

Originally Posted by Vlash

Except the NiJuLe's downgrader extension, it never showed up in KUAL.

I... don't have a Downgrader KUAL extension?

I have a very, very, very old hack that is explicitly aimed at pre-5.6.0 FW and making the "let's unplug from usbms like a savage" trick a bit safer, but it has nothing to do with KUAL?

[NiLuJe]

Originally Posted by Vlash

I also noticed I wasn't able to reinstall the same firmware I'm on (FW 5.15.1). IDK if that was possible before, but I tried, it failed.

According to my notes, that hasn't been possible since 5.12.2.1.1 (not accounting for downgrader playing yo-yo with the OTA build number, as I have no experience with that myself).

[NiLuJe]

Originally Posted by Vlash

I dropped the JB hotfix thing inside the mrpackage folder

Hotfix packages are *specifically* built for UYK, *NOT* MRPI. It's usually mostly harmless, unless your build numbers are screwed up enough that it makes the version check fail in MRPI, too.

If you want to install the JB bridge via MRPI.... use the JB bridge package, which *is* packaged more leniently for MRPI usage (but is otherwise the exact same payload as the jb hotfix).

(In any case, a bridge failure is "harmless", and doesn't affect RP/CRP).

[NiLuJe]

I'd be inclined to say either RP/CRP tripped and your diags is borked somehow, or upstart is falling on its ass somewhere. Are you booting with a cable plugged in?

(IIRC, there *have* been reports of diags builds with serial-only output).

Since you've obviously opened the device up before, I'd just plug a serial adapter in there and actually check what's happening?

[Vlash]

Originally Posted by NiLuJe

I'd be inclined to say either RP/CRP tripped and your diags is borked somehow, or upstart is falling on its ass somewhere. Are you booting with a cable plugged in?

(IIRC, there *have* been reports of diags builds with serial-only output).

Since you've obviously opened the device up before, I'd just plug a serial adapter in there and actually check what's happening?

Hi, NiJuLe, thanks for the answer. When i mentioned the downgrader, thought it was yours bc there's a downgrader in the snapshots thread. Either way, that one is not what I used.

From what you say my intuition is that:
1. When I used Downgrader 2.0 , the changes it made to /etc/version.txt prevented installing JB-Hotfix via UYK
2. RP/CRP didn't work properly due to lack of it
3. Bricked Kindle ;D

Answering your other question, it doesn't boot with or without a cable. In any case I'll get a serial adapter and try using that.

[NiLuJe]

Originally Posted by Vlash

2. RP/CRP didn't work properly due to lack of it

Nope. The only relationship between the two is that you need JB keys to install the packages. That's it.

[Vlash]

Originally Posted by NiLuJe

Nope. The only relationship between the two is that you need JB keys to install the packages. That's it.

Ok then, thanks for the clarification..

Originally Posted by NiLuJe

I'd be inclined to say either RP/CRP tripped and your diags is borked somehow, or upstart is falling on its ass somewhere. Are you booting with a cable plugged in?

(IIRC, there *have* been reports of diags builds with serial-only output).

Since you've obviously opened the device up before, I'd just plug a serial adapter in there and actually check what's happening?

Regarding this serial thing, I have a few questions:
1. would any USB to Serial adapter work? I'm also afraid because most of them have no brand, how am I suppose to get drivers for those things?

2. What voltage should I choose? I just found 3.3/5v adapters in local stores. I've seen people here mentioning the Kindle needs 1.8v, others saying you can do without plugging VCC at all.

If the latter is true, I'm just gonna grab any adapter, otherwise I'll have to import a 1.8v adapter.

3. Am I able to downgrade the Kindle firmware using Serial? The whole reason why I messed with my kindle was to get rid of the latest firmware. I wanted to go as far back as 5.9.7, last good firmware IMO.

[katadelos]

Originally Posted by Vlash

1. would any USB to Serial adapter work? I'm also afraid because most of them have no brand, how am I suppose to get drivers for those things?

2. What voltage should I choose? I just found 3.3/5v adapters in local stores. I've seen people here mentioning the Kindle needs 1.8v, others saying you can do without plugging VCC at all.
...
3. Am I able to downgrade the Kindle firmware using Serial? The whole reason why I messed with my kindle was to get rid of the latest firmware. I wanted to go as far back as 5.9.7, last good firmware IMO.

Any of the 1.8v or 3.3v adapters should work, you can get away with connecting only the RX/TX wires if your Kindle is plugged into the same PC via USB (common ground). The whole "3.3v serial will fry your device" is BS in my opinion, you'll be fine as long as you don't connect the voltage output of the serial adapter to anything.

You can downgrade over serial using the steps here as long as you have the 5.9.7 firmware to unpack: https://www.mobileread.com/forums/sh...d.php?t=343385

[Vlash]

Originally Posted by katadelos

Any of the 1.8v or 3.3v adapters should work, you can get away with connecting only the RX/TX wires if your Kindle is plugged into the same PC via USB (common ground). The whole "3.3v serial will fry your device" is BS in my opinion, you'll be fine as long as you don't connect the voltage output of the serial adapter to anything.

You can downgrade over serial using the steps here as long as you have the 5.9.7 firmware to unpack: https://www.mobileread.com/forums/sh...d.php?t=343385

Ok, that was very clarifying, thanks.

Other doubts arised now:

1. The tutorial you linked refers to flashing the roots partition, but it doesn't mention the kernel or uboot. Does that mean that flashing just roots is enough?

2. Is it possible to edit this rootfs image (specifically to remove root password from /etc/passwd) or is it signed or something?

3. Another unrelated question. I used your Popcorn jailbreak on my PW3. I later tried to flashing uboot/uimage extracted from the stock firmware in SDP mode, but i was only able to flash Popcorn images using SDP. Why is that?

[katadelos]

Originally Posted by Vlash

Ok, that was very clarifying, thanks.

Other doubts arised now:

1. The tutorial you linked refers to flashing the roots partition, but it doesn't mention the kernel or uboot. Does that mean that flashing just roots is enough?

2. Is it possible to edit this rootfs image (specifically to remove root password from /etc/passwd) or is it signed or something?

3. Another unrelated question. I used your Popcorn jailbreak on my PW3. I later tried to flashing uboot/uimage extracted from the stock firmware in SDP mode, but i was only able to flash Popcorn images using SDP. Why is that?

I would approach this by working out what caused your device to brick using the output from the serial port, fixing the issue and only then proceeding to carry out the downgrade.

Once you're at that point, then yeah - flashing a rootfs is the only thing that you should need to do to downgrade the firmware. The kernel/u-boot image never changes in almost all cases that I'm aware of and you only need to flash those if you're intended on messing around with the kernel or u-boot.

The rootfs image isn't signed and you can make whatever changes you think are needed.

You probably had issues attempting to load images over SDP as the uboot used for Popcorn is different to the stock one (it uses a separate DCD table to initialise the device and is set up to load the uImage loaded into RAM at a certain address by imx_usb_loader.) Note that Popcorn doesn't flash anything to the device, everything happens in RAM - you need to use fastboot mode to flash stuff to the device.