PW2 My (still WIP) journey of forcing the PW2 to run 5.14.1 against its will.

[hanakomisa]

A few disclaimers!

- This thread is very much a work in progress, I'm just documenting things (and asking questions to the more experienced members). I wouldn't recommend anyone attempting what I'm doing.

- You will probably brick your Kindle a lot. I know I bricked mine a few times last night messing around with different things. Make backups. You'll be thanking yourself when you need it. I just used knc1's script (https://www.mobileread.com/forums/sh...d.php?t=289690) to back everything up twice and checking the md5 to make sure they're good. As for the user partition I just used dd to back it up just in case..

- According to katadelos, the PW2 (and by extension, KT2) will run 5.14.1 just fine as long as you're using the old UI (https://www.mobileread.com/forums/sh...3&postcount=12), the memory exhaustion only becomes a problem when you're trying to run the React Native (new) UI. That said it isn't impossible to make it run at least on the KT2. (https://www.reddit.com/r/kindle/comm...newest_update/)

- The Paperwhite 2's partition layout is different to the other imx6_wario devices, All of them (KT2, KV, PW3) has mmcblk0p1 the size of ~440MiB, except the Paperwhite 2, which is ~350MiB. (This is where I'm stumped on..)

With all that out of the way, let's get to the main meat and potato.

The actual thread.

Last week, I decided to buy an FT232RL adapter, and a 1.8v regulator since I had some left over eBay points I got from selling things. It arrived, is all and well, so I soldered 3v3 to the right leg, GND to the left, and then the middle leg to VCC of the board. Then RXD to RX of the Paperwhite 2, TXD to TX, and GND to a shield, you know the drill.



(Not my finest soldering job, but it'll hold.)

From there, I plugged it in to my screw-around-and-find-out laptop(s) and thankfully it didn't blow up in my face. Red power light and both the green LEDs were lit up so I fired up Tera Term, set baud to 115200, then rebooted my Kindle, got to uboot, sent "bootm 0xE41000" and... it did not boot into DIAGS. it would just kernel panic.

Hmm, well that's not good, is that why I couldn't install the rescue pack before? It did say something about not being able to change password but I'm not entirely sure.
It was at this point I decided to look through katadelos' threads and posts, and turns out he did have his own snapshot thread, with a DIAGS partition for the PW2.
I grabbed that, then knc1's backup script, ran it once, copied files to pc, ran it again, copied files, compared MD5, it was all good. Now to try and flash katadelos' DIAGS partition.
I used TobiasWooldridge's fork of yifanlu's fastboot-kindle (https://github.com/TobiasWooldridge/Fastboot-Kindle) since the Makefile included there supported Linux, which certainly helped a linux beginner like me and avoid having to reboot to my macOS partition on my main pc/hackintosh. Then flashed diags image to well, diags. Rebooted it, interrupted and gave it the diags boot command again. This time it actually booted into diags properly!
From there, I checked that everything was working properly and that my battery was above 80%. Now to drop into the login prompt.

"Login incorrect"

Well. that's bad. I checked the password using kindletool's info, and used my serial number, but the password just wasn't correct. I thought "Maybe it's because I'm using katadelos' DIAGS instead of mine, and thus the password would match a serial of his. But how am I supposed to know his PW2's serial number?", then I googled and scoured through the forum, seeing if there is a way to somehow crack the root password. Then I found that on some Kindles there's an account called "framework" with the password "mario", and thankfully, this DIAGS partition did have it.
I looked through /etc/, and found that I can expose the contents inside of both passwd and shadow using cat. And from there I found out that you can use a tool called John the Ripper to decipher the password for me. I also stumbled upon a filelist for all the possible fiona password combinations (https://www.mobileread.com/forums/sh...d.php?t=160490) which was helpful. I grabbed the contents inside both passwd and shadow, combined them with unshadow, then used John to crack the code. It was indeed another password that's different from my serial number. And from there I was finally able to log into the system as root in DIAGS.



I've never been more happy to see that notice. Now, NOW I can finally try the sacred, PW3's rootfs. I followed the "How to boot 5.14.1 on KV" thread (https://www.mobileread.com/forums/sh...d.php?t=343385) and obviously, I didn't think to check the partition layout first.

I followed it right up to DDing the image, I did that thing until I noticed DD was saying it ran out of space. Panicking, I decided to check "fdisk -l" and then reality hit me in the face. Obviously it's never gonna be that easy for me. my mmcblk0p1 is only 350M in size, while the rootfs image of PW3's 5.14.1 is 440M. Just to check my sanity, I downloaded the update image for the KT2 and KV to check what size it has, and it was also 440M. At this point, my kindle was "bricked", but thankfully I was able to restore my mainsys.bin using DD and have it booted up all fine and dandy again.

So now, I'm currently very stumped on what to do next. If I want to continue, I'll probably have to repartition the eMMC, increasing the size of mmcblk0p1 to 440M, and shift all the other partitions (and reducing the size of mmcblk0p4) accordingly. I don't know how I should go about it though.

My current idea is to delete all the partitions except p1 using fdisk in main mode, recreate them again but with the space increase needed for p1 accounted for, reflash p2 with the diags, p3 with local, but I don't know yet what to do with p4 since I would need it to transfer files using USBMS.
Skipping the last part, assuming it'll all work properly, I boot into diags, extend the p1 partition, make sure it still boots up and everything, then try and flash 5.14.1 and see how things go. From this part I would need help from people with more experience doing Linux stuff (and Kindle Linux stuff) than me. Feel free to post down your thoughts and help (and prayers ) in this thread, I'll respond to them when I can.

Also, thanks to all the amazing members of this community for making modding the Kindles possible. I'm looking forward to do more with it and hopefully also grow a collection of the hardware.

Hopefully my wall of text didn't disorient anyone, if I did, oops, sorry. I'm still not really used to BB Code formatting.

[katadelos]

Originally Posted by hanakomisa

[SIZE="5"]
So now, I'm currently very stumped on what to do next. If I want to continue, I'll probably have to repartition the eMMC, increasing the size of mmcblk0p1 to 440M, and shift all the other partitions (and reducing the size of mmcblk0p4) accordingly. I don't know how I should go about it though.

My current idea is to delete all the partitions except p1 using fdisk in main mode, recreate them again but with the space increase needed for p1 accounted for, reflash p2 with the diags, p3 with local, but I don't know yet what to do with p4 since I would need it to transfer files using USBMS.

Bad idea, the bootloader + a few places in Upstart etc expect the partitions to be located at particular memory offsets. Screwing with this without making sure that you've accounted for every instance that they're used is likely to be.. painful.

The important thing is not the overall size of the partition, it's the size of the contents of the image:

/dev/loop23     430M  358M   50M  88% /tmp/pw3/mnt
/dev/loop28     341M  302M   32M  91% /tmp/pw2/mnt

You could probably trim away enough fat from the PW3 image by removing the new UI from the image (with appropriate Upstart tweaks to ensure that nothing is too broken afterwards).

Beware though, even if you can make the image fit, even the old UI will still be somewhat broken on KT2/PW2 - the old UI uses absolute sizes for UI icons meaning that assets taken from PW3 will be hilariously oversized on KT2/PW2. These assets need to be scaled to match the resolutions of the latter devices.

If you're intent on achieving this, save yourself the pain and see if you can figure out NFS boot - you'll save a lot of time by cutting out the whole "change/flash/test" cycle.

[hanakomisa]

Originally Posted by katadelos

Bad idea, the bootloader + a few places in Upstart etc expect the partitions to be located at particular memory offsets. Screwing with this without making sure that you've accounted for every instance that they're used is likely to be.. painful.

The important thing is not the overall size of the partition, it's the size of the contents of the image:

/dev/loop23     430M  358M   50M  88% /tmp/pw3/mnt
/dev/loop28     341M  302M   32M  91% /tmp/pw2/mnt

You could probably trim away enough fat from the PW3 image by removing the new UI from the image (with appropriate Upstart tweaks to ensure that nothing is too broken afterwards).

Beware though, even if you can make the image fit, even the old UI will still be somewhat broken on KT2/PW2 - the old UI uses absolute sizes for UI icons meaning that assets taken from PW3 will be hilariously oversized on KT2/PW2. These assets need to be scaled to match the resolutions of the latter devices.

If you're intent on achieving this, save yourself the pain and see if you can figure out NFS boot - you'll save a lot of time by cutting out the whole "change/flash/test" cycle.

1. Honestly, I'm not surprised that there's something like that regarding the memory locations. It was one of the reasons I haven't gone ahead with repartitioning yet.

2. I'll look into trimming the fat, but at the same time I do also want to see the new UI on this device so that might be my last resort if nothing else works.

3. I saw from your reddit posts with your KT2 running the newer firmwares. I think it looks hilarious and to be fair, my end goal was more of "it is possible" and less of "I want it to be usable" so I'm totally fine with it, and as you said, could probably do with scaling the assets down to make it look native.

4. I'll look into figuring out NFS boot, I have a friend who's way more knowledgeable at Linux (and some embedded devices) than me so I'm sure we can think of something.

Lastly, Thank you so much for your contribution to the community. Without WatchThis I would've probably never bought a Kindle and get my start in messing around with embedded hardware like this. Sent you a little cup of joe through your donate button, it's not much but it's what I can do.

[Badcatalex]

The title here is the best thing I've seen all day, I wish you the best of luck! You're doing some excellent stuff.

[hanakomisa]

Originally Posted by Badcatalex

The title here is the best thing I've seen all day, I wish you the best of luck! You're doing some excellent stuff.

Thank you, I didn't know what else to make as a title and then thought of that one, was like "eh good nuff" and posted, waited a day for the mod to approve my post and here we are.

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In case anyone is wondering about any progress: none. I really haven't done much with it since IRL is getting in the way with me applying for driver's license and things. I promise I'll get it done one day though. I have no ETAs.