K5 Backporting a newer version of the Kindle firmware/GUI from Paperwhite to Touch

[WaseemAlkurdi]

P.S.
1. I still believe till now that the kernel versions will turn out to be the same. Or is it wishful thinking?
2. @NiLuJe ... I don't think that what I'm proposing would work, but just for the sake of confirmation: can't we just trick the old man sitting on the armchair in the porch by patching the assertion?

[WaseemAlkurdi]

P.P.S.
Looking at screenshots of 5.4.4.2 online, it seems that it is older than the new UI that I wanted. It seems that the new UI debuted on the 5.9.x series ... which might be within reach if 5.4.4.2 was done.
Still, only a little disappointing, but not enough to kill the project, since I really believe that it's possible.

[NiLuJe]

Probably no: you'd risk random segfaults because of ABI breaks.

And I'd wager > 5.6 is definitely out: it never came out for the PW1. So, different platform.

[WaseemAlkurdi]

Originally Posted by NiLuJe

Probably no: you'd risk random segfaults because of ABI breaks.

And I'd wager > 5.6 is definitely out: it never came out for the PW1. So, different platform.

Good. So there we go ... I'll download 5.6 and get working post haste!

[WaseemAlkurdi]

Surprise! It turns out to run the same
A quick Google search reveals this. Quoting from this tutorial:

You now have a file named ~/gplrelease/linux/linux-2.6.31-rt11-lab126.tar.gz containing the kernel and modules (mine is attached 'linux-2.6.31-rt11-lab126.tar.gz', don't blame me if you use it). I will edit to add how to load this onto your kernel shortly, but if you are doing this process you really should know how already.

It's 2.6.31, too! The version string is identical: 2.6.31-rt11-lab126.

[NiLuJe]

That's not terribly surprising .

[WaseemAlkurdi]

So I have downloaded the Paperwhite 1 5.6.1.1 firmware package and extracted it, then mounted the resultant rootfs.img.
However, I'd like to ask a few things first:

- Can I get to monitor the boot process, possibly using dmesg, over USB alone? (I can't do serial)

- Can I 'netboot' the Kindle without serial too?

- I've seen that the Kindle retrieves each and every splash screen from /opt/amazon/low_level_screens/600x800/* on the Touch, while the Paperwhite uses /opt/amazon/low_level_screens/* (no resolution). In theory, that would mean that the Touch would fail to even start booting because the boot pictures are mislocated. I'm copying those over from the Touch to the Touch path in the Paperwhite image.
The question is: are there more resolution- or device-specific files in the rootfs image that I should pay attention to?

- I've found and flashed (using dd on the Kindle's main system) a modified diags (mmcblk0p2) partition for SSH access (first thought of modifying it by hand, but then got too lazy). However, mount -o rw,remount /dev/mmcblk0p4 / && touch /ENABLE_DIAGS && reboot doesn't seem to work. I don't have a Windows machine (Linux only), so I can't use MfgTool to "select boot". What do I do?

[WaseemAlkurdi]

Originally Posted by WaseemAlkurdi

So I have downloaded the Paperwhite 1 5.6.1.1 firmware package and extracted it, then mounted the resultant rootfs.img.
However, I'd like to ask a few things first:

- Can I get to monitor the boot process, possibly using dmesg, over USB alone? (I can't do serial)

- Can I 'netboot' the Kindle without serial too?

- I've seen that the Kindle retrieves each and every splash screen from /opt/amazon/low_level_screens/600x800/* on the Touch, while the Paperwhite uses /opt/amazon/low_level_screens/* (no resolution). In theory, that would mean that the Touch would fail to even start booting because the boot pictures are mislocated. I'm copying those over from the Touch to the Touch path in the Paperwhite image.
The question is: are there more resolution- or device-specific files in the rootfs image that I should pay attention to?

- I've found and flashed (using dd on the Kindle's main system) a modified diags (mmcblk0p2) partition for SSH access (first thought of modifying it by hand, but then got too lazy). However, mount -o rw,remount /dev/mmcblk0p4 / && touch /ENABLE_DIAGS && reboot doesn't seem to work. I don't have a Windows machine (Linux only), so I can't use MfgTool to "select boot". What do I do?

P.S. Never mind the last point (scratched out) in the question I asked above. I've been able to boot to diags using imx_usb. Do you know what it feels like when something hides in plain sight? Yep, that's the feeling.

Another point I noticed is that "diags" boot has a slightly different splash screen (older "Amazon Kindle" vs. newer "Kindle" logo). And it happens that the "diags" system is based on the Kindle 5.0.1 firmware. That seems to confirm that yep, the splash is loaded from /opt/ ... and that the loss of the splash screen (or something possibly more important) due to the path change might be problematic.

[WaseemAlkurdi]

@NiLuJe @knc1
I'm ready and waiting for your response to start the rootfs transplant. How do you suppose I could monitor the boot process over USB?

[NiLuJe]

I tend not to respond when I have no idea .

Random somewhat related comments:

* Patching diags to get SSH in there and make it stick is kind of the RescuePack's sole purpose in life .

* I don't think anyone ever attempted anything related to USBSerial (I'm not even sure the kernels support that gadget). So, yeah, monitoring would be far more reliable over serial.
If it does boot, the kernel logs are somewhat sanely archived by the logging system, although this sometimes goes a bit wonky.

[WaseemAlkurdi]

Originally Posted by NiLuJe

I tend not to respond when I have no idea .

Random somewhat related comments:

* Patching diags to get SSH in there and make it stick is kind of the RescuePack's sole purpose in life .

* I don't think anyone ever attempted anything related to USBSerial (I'm not even sure the kernels support that gadget). So, yeah, monitoring would be far more reliable over serial.
If it does boot, the kernel logs are somewhat sanely archived by the logging system, although this sometimes goes a bit wonky.

Ah, good for making that known! I thought you gave up on this

I did know that there was something "called" a Rescue Pack (specifically, it's when I noticed this in your Snapshots thread), but I thought it was for bricked Kindles, and didn't read the thread. And I wish I had read this, because it would have saved me a whole load of effort (half of which has been head-scratching because ENABLE_DIAGS did nothing on a Kindle w/o Rescue Pack

So, do you think I should jump right in?
I'm going to dd if=rootfs.img of=/dev/mmcblk0p4 bs=4096 via a SSH session from diags, then copy /opt/amazon/low_level_screens/* from the Touch rootfs and reboot.
If that doesn't work, I'm going to throw in the contents of /lib/modules/* as well [1]
Anything I should know?

P.S.
[1]: I thought about this because of this quote by @knc1:

The Linux kernel (as used in the Kindles) is not a monolithic, self-contained, kernel image.
Some of its services are provided by dynamically loaded "kernel modules" (things like the e-ink display drivers).
"kernel modules" live inside of the file system image.

Translation: You must use "matched pairs" of a file system image (the loadable modules ++ other stuff) and a kernel image.

[WaseemAlkurdi]

P.P.S.
In post #4 in this thread, @geekmaster says:

NOTE: After installing SSH into diags, it should be a bit safer to mess with main and not worry so much about bricking it (to a certain degree)

Why does he use 'a bit' and 'to a certain degree'?
Provided that we have both SSH in diags and fastboot/imx_usb, what is left to be concerned about?

[knc1]

Because it is a dual boot system, not a concurrent boot system.
(gm probably will not answer you, he passed away last summer.)

[NiLuJe]

CRP also helps in that you don't even have to have access to the FS anymore: boot with a cable plugged in => diags.

Although, IIRC, that doesn't actually work all that well on the Touch, so, just saying that for future ref ;p.

[WaseemAlkurdi]

Originally Posted by knc1

Because it is a dual boot system, not a concurrent boot system.
(gm probably will not answer you, he passed away last summer.)

Oh .. that makes two of the elite devs ... ixtab and geekmaster ...
May their souls rest in peace, they've certainly been a helping hand to lots of people out there ...
It's really touching when you re-read the words of a person you've thought to be alive, after you get the news of their death ... it's almost like you've known them in person.

Originally Posted by NiLuJe

CRP also helps in that you don't even have to have access to the FS anymore: boot with a cable plugged in => diags.

Although, IIRC, that doesn't actually work all that well on the Touch, so, just saying that for future ref ;p.

Exactly ... it didn't work at all on my Touch.

To update you on my progress, I have done the transplant. And as you have expected, it didn't boot.
Initially, I flashed my own fixed-up version of rootfs.img. I basically mounted it, searched for files with yoshime in their names, and replaced them with Kindle Touch versions.

This is the list of files from the Touch that had yoshi in their names:

./opt/amazon/ebook/config/framework.yoshi.conf
./opt/ar6k/target/AR6003/hw2.1.1/bin/athwlan.bin.yoshi
./var/local/java/default/7/content/com/amazon/ebook/booklet/reader/impl/ui/resources/assets/yoshime3
./var/local/java/default/7/content/com/amazon/ebook/booklet/reader/impl/ui/resources/assets/yoshi
./var/local/java/default/7/content/com/amazon/ebook/booklet/reader/impl/ui/resources/assets/en/yoshime3
./var/local/java/default/7/content/com/amazon/ebook/booklet/reader/impl/ui/resources/assets/en/yoshi
./etc/modules.yoshi
./etc/kdb.src/yoshi (in reality, /etc/kdb.src*)
./lib/firmware/zforce/yoshi_2.0b0r12.hex

This is the list of files from the Paperwhite image that had yoshime* in their names:

./lib/modules/2.6.31-rt11-lab126/kernel/drivers/usb/gadget/arcotg_udc_yoshime.ko
./opt/ar6k/target/AR6003/hw2.1.1/bin/yoshime3
./opt/amazon/ebook/config/framework.yoshime3.conf
./etc/modprobe.d/yoshime3.conf

I replaced the yoshime* files with their yoshi counterparts, then added the yoshi files that did were absent from the PW image.

That did not work. Nor did flashing the verbatim image from the Paperwhite
In both cases, it's stuck at the tree with the 'Kindle' logo. No signs of life, nothing when plugging USB.
The power button would trigger the LED when pressed.

Note that I have not flashed the Paperwhite kernel. I feared that the Paperwhite kernel might do something nasty and permanent to the hardware ... and on Android devices, this happens.

What now?