Re: 5.12.2 jailbreak steps done - downgrade now?

letshin · 12-10-2020, 05:00 AM

Hi,

I've read through the various posts and done the following (mainly https://www.mobileread.com/forums/sh...d.php?t=267541) with some minor modifications. I've detailed what I've done in case it helps someone else.

Set up a 1.8v serial to usb device
Removed my KT2 device from its frame and expose its serial debug slot
Manually held pins down with my hand onto the Tx/RX points (making sure to only touch the plastic bits). I taped ground to one of the heatsinks.
Connected via Putty after changing baud rate
Pressed 'd'- diagnostics inaccessible. So 'exit login' brings up the username/pw prompt
Accessed root after figuring out my password (not necessarily fionaxxx, I've found) and changed /tmp/main/etc/passwd
Ran jb.sh from "kindle-jailbreak-1.16.N-r17396" in the folder "JailBreak\kindle-5.4-jailbreak"
Installed "KUAL-KDK-2.0.azw2", "Update_KUALBooklet_hotfix_v2.7.24_install.bin ", and after that MRPI from "kual-mrinstaller-1.7.N-r17940".
Added the partial download folder to Kindle root and disabled on the air update through KUAL helper

Q1. Context: I wish to use the KT2 with WiFi on as I want to use Python to display images being pushed from a webserver (I already have python and usbnetwork installed). My question is that since I am on 5.12.2 is the KUAL helper and partial download folder enough to stop updates or should I downgrade the firmware?

Q2. If so, I've been through the factory downgrade instructions but this isn't clear I think. I've downloaded "update_KT2_5.6.0_initial.bin" and from what I understand I should run this as 'update you kindle device'.

Q3. Also, before I write it, does anyone have a Python script that pulls images from a webserver? I've found that pjimenezmateo has an interesting github project here "https://github.com/pjimenezmateo/kindle-wallpaper/" that does something similar.

Thanks.

Edit: Wow. First post since I joined in 2010...

JSWolf · 12-10-2020, 06:32 AM

You should upgrade the firmware.

letshin · 12-10-2020, 08:01 AM

Everything I've read seems to suggest downgrading to avoid the frequent potentially forced updates to the firmware. Can you help me understand why you are suggesting upgrading instead?

JSWolf · 12-10-2020, 08:39 AM

Quote:

Originally Posted by letshin

Everything I've read seems to suggest downgrading to avoid the frequent potentially forced updates to the firmware. Can you help me understand why you are suggesting upgrading instead?

Bug fixes, new features, and maybe more.

I see no reason to downgrade. It just gets you old code that may have problems that have been fixed in the new code.

In fact 5.13.4 has just been released.

https://www.mobileread.com/forums/sh...d.php?t=335509

pdurrant · 12-10-2020, 08:43 AM

Quote:

Originally Posted by JSWolf

Bug fixes, new features, and maybe more.

I see no reason to downgrade. It just gets you old code that may have problems that have been fixed in the new code.

In fact 5.13.4 has just been released.

Jon, this thread in in the Kindle Developer's Corner.

I suspect that someone having fun with tweaking what the Kindle can do will be less concerned than most users with latest bug fixes, and more concerned about the possibility of being locked out of their hardware by a firmware update that invalidates the jailbreak.

Perhaps you should consider your audience before you reply?

JSWolf · 12-10-2020, 08:45 AM

I do tweak but when new firmware is released, I wait for the what needs to be made compatible and once done, I tweak again.

NiLuJe · 12-10-2020, 09:30 AM

A1. I don't *quite* recall the cut-off point, but either 5.10.x or 5.11.x *should* be okay as far as the "OTA Block" KUAL button goes.... But....

A2. The issue is that you're not going to be able to downgrade to the factory image, because you're already running something > 5.6.0, and I don't think there's an exception for the KT2 on that front. (Someone will chime in if there is, and/or check the wiki).

Which means you'd have to do it by hand, over serial, in diags. I think there's a fairly recent success story about that somewhere around here, though.

A2b: Which means the path of least resistance, since you've already cleared the hurdle of JB via serial, would simply be to stay on your current FW version, and just mangle the OTA process to prevent updates. There are a few "recent" threads about the various ways you can achieve that (mainly by mangling the various ota binaries/scripts/upstart jobs one way or another).

NiLuJe · 12-10-2020, 09:32 AM

A3. One of the many various weather station thingy might be doing it one way or another, but most were probably written before I started bundling requests in the Python packages, so, eh, it might not be pretty

. (Hence the server/client design in the stuff you linked, wereas you really shouldn't require anything else than the Kindle).

So, provided you have basic Python knowledge, requests + fbink ought to do it.

(Depending on your use-case, the usual hurdle is SVG. Although, on Kindle, there's the remnant of a GTK stack, so I think at least one of those managed to bring in a librsvg binary without too much trouble. Otherwise, as long as there are no text paths, nanosvg and some code might do the trick).

ilovejedd · 12-10-2020, 09:44 AM

Quote:

Originally Posted by JSWolf

I do tweak but when new firmware is released, I wait for the what needs to be made compatible and once done, I tweak again.

That's on Kobo, though.

With Kindle, one wrong move and potentially no more tweaking allowed.

j.p.s · 12-11-2020, 01:05 PM

Quote:

Originally Posted by JSWolf

Bug fixes, new features, and maybe more.

I see no reason to downgrade. It just gets you old code that may have problems that have been fixed in the new code.

In fact 5.13.4 has just been released.

On the other hand:

Quote:

Originally Posted by ilovejedd

I just received a PM from @hius07 that the current PW4 JB method doesn't appear to be working on the latest FW 5.13.4 OTA update. There's only been one case thus far and we haven't tested it ourselves.

To be safe though, if you wish to be able to jailbreak your PW4 make sure to enable airplane mode so it doesn't automatically update to 5.13.4.

letshin · 12-11-2020, 01:23 PM

Thanks everyone for chiming in.

@NiLuJe
A2b: Cool, I think I've found what you are talking about (https://www.mobileread.com/forums/sh...d.php?t=327879). I'll try this out.

A3. New-ish to Python (more at script kiddie level right now) but I have some experience coding so I'll manage. Sorry, this is going to be a bit of a stupid follow up question. For the Python script, would I call it through SSH (for terminal access), having uploaded the script to root? Automation I suppose I could do either with a timer within the Python script or with Cron? Requests and FBink are the network and display libraries respectively - so helpfiles will tell me all I need to know to interface with these.

Asking to determine current best practices for Kindle hacking.

NiLuJe · 12-11-2020, 02:12 PM

A2b: that's one of these yeah (possibly the earliest, if memory serves).

A3: Not necessarily in the rootfs (especially since it's ro by default, and wiped by updates), but that's a fairly minor detail. Depending on how you handle power management (i.e., if it's to be plugged in, you can forget about every low-level potential mishaps and just keep it running), a crontab will only work as long as the device is not alseep. Otherwise, you enter the fun realm of rtc wake alarms.

letshin · 12-15-2020, 06:28 PM

Thanks, I'll have a look and play around with these as a Christmas project. Season's greetings to all!

12-10-2020, 05:00 AM	#1
letshin Junior Member Posts: 8 Karma: 10 Join Date: Nov 2010 Device: Desire	Re: 5.12.2 jailbreak steps done - downgrade now? Hi, I've read through the various posts and done the following (mainly https://www.mobileread.com/forums/sh...d.php?t=267541) with some minor modifications. I've detailed what I've done in case it helps someone else. Set up a 1.8v serial to usb device Removed my KT2 device from its frame and expose its serial debug slot Manually held pins down with my hand onto the Tx/RX points (making sure to only touch the plastic bits). I taped ground to one of the heatsinks. Connected via Putty after changing baud rate Pressed 'd'- diagnostics inaccessible. So 'exit login' brings up the username/pw prompt Accessed root after figuring out my password (not necessarily fionaxxx, I've found) and changed /tmp/main/etc/passwd Ran jb.sh from "kindle-jailbreak-1.16.N-r17396" in the folder "JailBreak\kindle-5.4-jailbreak" Installed "KUAL-KDK-2.0.azw2", "Update_KUALBooklet_hotfix_v2.7.24_install.bin ", and after that MRPI from "kual-mrinstaller-1.7.N-r17940". Added the partial download folder to Kindle root and disabled on the air update through KUAL helper Q1. Context: I wish to use the KT2 with WiFi on as I want to use Python to display images being pushed from a webserver (I already have python and usbnetwork installed). My question is that since I am on 5.12.2 is the KUAL helper and partial download folder enough to stop updates or should I downgrade the firmware? Q2. If so, I've been through the factory downgrade instructions but this isn't clear I think. I've downloaded "update_KT2_5.6.0_initial.bin" and from what I understand I should run this as 'update you kindle device'. Q3. Also, before I write it, does anyone have a Python script that pulls images from a webserver? I've found that pjimenezmateo has an interesting github project here "https://github.com/pjimenezmateo/kindle-wallpaper/" that does something similar. Thanks. Edit: Wow. First post since I joined in 2010... Last edited by letshin; 12-10-2020 at 05:04 AM.

12-10-2020, 09:32 AM	#8
NiLuJe BLAM! Posts: 13,506 Karma: 26047190 Join Date: Jun 2010 Location: Paris, France Device: Kindle 2i, 3g, 4, 5w, PW, PW2, PW5; Kobo H2O, Forma, Elipsa, Sage, C2E	A3. One of the many various weather station thingy might be doing it one way or another, but most were probably written before I started bundling requests in the Python packages, so, eh, it might not be pretty . (Hence the server/client design in the stuff you linked, wereas you really shouldn't require anything else than the Kindle). So, provided you have basic Python knowledge, requests + fbink ought to do it. (Depending on your use-case, the usual hurdle is SVG. Although, on Kindle, there's the remnant of a GTK stack, so I think at least one of those managed to bring in a librsvg binary without too much trouble. Otherwise, as long as there are no text paths, nanosvg and some code might do the trick). Last edited by NiLuJe; 12-10-2020 at 09:35 AM.

12-11-2020, 01:23 PM	#11
letshin Junior Member Posts: 8 Karma: 10 Join Date: Nov 2010 Device: Desire	Thanks everyone for chiming in. @NiLuJe A2b: Cool, I think I've found what you are talking about (https://www.mobileread.com/forums/sh...d.php?t=327879). I'll try this out. A3. New-ish to Python (more at script kiddie level right now) but I have some experience coding so I'll manage. Sorry, this is going to be a bit of a stupid follow up question. For the Python script, would I call it through SSH (for terminal access), having uploaded the script to root? Automation I suppose I could do either with a timer within the Python script or with Cron? Requests and FBink are the network and display libraries respectively - so helpfiles will tell me all I need to know to interface with these. Asking to determine current best practices for Kindle hacking. Last edited by letshin; 12-11-2020 at 01:26 PM.

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12-10-2020, 06:32 AM	#2
JSWolf Resident Curmudgeon Posts: 79,064 Karma: 144284144 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	You should upgrade the firmware.

12-10-2020, 08:01 AM	#3
letshin Junior Member Posts: 8 Karma: 10 Join Date: Nov 2010 Device: Desire	Everything I've read seems to suggest downgrading to avoid the frequent potentially forced updates to the firmware. Can you help me understand why you are suggesting upgrading instead?

12-10-2020, 08:45 AM	#6
JSWolf Resident Curmudgeon Posts: 79,064 Karma: 144284144 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	I do tweak but when new firmware is released, I wait for the what needs to be made compatible and once done, I tweak again.

12-10-2020, 09:30 AM	#7
NiLuJe BLAM! Posts: 13,506 Karma: 26047190 Join Date: Jun 2010 Location: Paris, France Device: Kindle 2i, 3g, 4, 5w, PW, PW2, PW5; Kobo H2O, Forma, Elipsa, Sage, C2E	A1. I don't quite recall the cut-off point, but either 5.10.x or 5.11.x should be okay as far as the "OTA Block" KUAL button goes.... But.... A2. The issue is that you're not going to be able to downgrade to the factory image, because you're already running something > 5.6.0, and I don't think there's an exception for the KT2 on that front. (Someone will chime in if there is, and/or check the wiki). Which means you'd have to do it by hand, over serial, in diags. I think there's a fairly recent success story about that somewhere around here, though. A2b: Which means the path of least resistance, since you've already cleared the hurdle of JB via serial, would simply be to stay on your current FW version, and just mangle the OTA process to prevent updates. There are a few "recent" threads about the various ways you can achieve that (mainly by mangling the various ota binaries/scripts/upstart jobs one way or another).

12-11-2020, 02:12 PM	#12
NiLuJe BLAM! Posts: 13,506 Karma: 26047190 Join Date: Jun 2010 Location: Paris, France Device: Kindle 2i, 3g, 4, 5w, PW, PW2, PW5; Kobo H2O, Forma, Elipsa, Sage, C2E	A2b: that's one of these yeah (possibly the earliest, if memory serves). A3: Not necessarily in the rootfs (especially since it's ro by default, and wiped by updates), but that's a fairly minor detail. Depending on how you handle power management (i.e., if it's to be plugged in, you can forget about every low-level potential mishaps and just keep it running), a crontab will only work as long as the device is not alseep. Otherwise, you enter the fun realm of rtc wake alarms.

12-15-2020, 06:28 PM	#13
letshin Junior Member Posts: 8 Karma: 10 Join Date: Nov 2010 Device: Desire	Thanks, I'll have a look and play around with these as a Christmas project. Season's greetings to all!

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