PW4 Hardware Mod Discussion

[AbdulHamdy]

Hello everyone,

first post here.. I have been lurking around and decided to make this post because I think the pieces are here, it's just that no one has put them together yet..

I do NOT like Calibre or all of the available Library managment software and would just rather copy the whole thing or be able to access it over ftp/smb from the Kindle..

So, this brought me to the quest of trying to upgrade my storage..there was a good time in this scene when many of these tablets had an internal sdcard baked onto the motherboard that could be changed to increase storage or recover from a brick... but apparently those days are past us unless we can make progress in the right to repair movement..which i recommend everyone here to support btw.

Now, We have 2 options 1- change onboard NAND which would be annoyingly difficult or 2- add another device

and here comes the questions.. we so far know that this thing runs on a i.mx single-what-not processor..
does anyone have documentation on this core or on any of its siblings??
does anyone have a schematic or a boardview of the PW4 logic board ? , seen them at least !?

I have already seen some of the 'teardowns' and pictures posted here and they do not provide much in the way of tangible information for this endeavor. My plan so far is to find out what interfaces we can speak to and work from there.. An SPI could pose a problem with the software stack side. But I'll take what I can get. A USB would be ideal especially if they already enumerate in the tablet as is. Last choice would be sacrificing the USB port if it can run in host mode or even OTG mode.

I'm lacking on free time these days but I'll see how to get to a terminal on this device and start looking around from there. being a linux person should come in handy.. anything I shouldn't do in /dev or /sys that you guys want to tell me about now before I start making posts in the unbrick section?

Thanks for reading this far , now tell me what you think

[knc1]

IIRC, the PW4 is a dual core device.


If you don't have 4G, then you do have a spare USB port on-board. You should be able to find those threads (on earlier models). At least one of them had added a hub using the 3G port.


The PW4 already supports OTG with both hardware and firmware.


geekmaster has posted threads and details of experimenting with the various remote file systems and remote file system hardwares. Again, older models, but Linux is still Linux.

[NiLuJe]

Only the Zelda platform (KOA2, KOA3) uses an i.MX7D, Rex (KT4, PW4) went back to an i.MX6SLL .

[Junket]

I missed where you said which PW4 model you are hoping to mod, or how much storage you were seeking? You do know that there is a 32GB PW4? If you are still inclined to proceed, then I would think that @knc1 's OTG suggestion would be an order of magnitude easier to implement than replacing the eMMC chip.

SMC BGA hot air rework is not out of reach of an advanced hobbyist, but it's not for the timid either. There are forum posts, blogs & at least one video on the net of people increasing capacity or replacing defective eMMC chips on at least one netbook, tablet & PW2 as well as nexus, samsung and iphone mobiles. The netbook upgrade was well documented, had an accompanying video and IIRC replaced a 32GB eMMC with a 64GB chip. You're not likely to get away with simply replacing the chip. You'll likely have to migrate firmware as well. This forum has an outline of what needed to be migrated in that case for a PW2.

I read somewhere that the PW4 processor is iMX6SL. But NiLuJe is a more reliable source. Have a look around NXP's site for a data sheet. OA2/3 documentation here.

[NiLuJe]

NXP's naming scheme is *extremely* confusing: there's an i.MX6SoloLite (i.MX6SL, which has been used on earlier devices), and the newer revision used on Rex (and Kobo Mk. 7): i.MX6SLL .

[Junket]

i.MX6SLL home page

[knc1]

Originally Posted by NiLuJe

Only the Zelda platform (KOA2, KOA3) uses an i.MX7D, Rex (KT4, PW4) went back to an i.MX6SLL .

Thanks.
I do have one of those, but I thought I had two.

[AbdulHamdy]

Originally Posted by knc1

IIRC, the PW4 is a dual core device.


If you don't have 4G, then you do have a spare USB port on-board. You should be able to find those threads (on earlier models). At least one of them had added a hub using the 3G port.


The PW4 already supports OTG with both hardware and firmware.


geekmaster has posted threads and details of experimenting with the various remote file systems and remote file system hardwares. Again, older models, but Linux is still Linux.

Indeed, I do not have 4G or any modem so that will be my choice. My PW4 is the 8GB version.

Only the Zelda platform (KOA2, KOA3) uses an i.MX7D, Rex (KT4, PW4) went back to an i.MX6SLL .

IIRC it does use the i.MX6SL solo lite that is somehow a dual core.. Extremely confusing indeed.

@Junket I don't feel like paying that extra money for 24 more gigabytes and nothing else.. Not to mention that they run so much telemetry that I don't even feel safe using the device. The book 1984 by George Orwell being wiped remotely from people's kindles should give you a sense of what I am talking about..ohh, the irony in that

It's been decided then.. I will locate that usb port and work on creating a space for the extra hardware. Then, I'm going to source a usb sdcard reader that is small and solder friendly with a decent, reliable controller and then solder that onto the logic board and try to figure out how the mounting procedure will work.. Then I'm going to make a cron script that will check for said device by id.. Then mount it to a folder inside the documents directory. That way everything firmware/JB related can be on the internal memory including caching space. However, in the documents dir, There will be a folder called MC_Clone, whichis the mountpoint and stand for master copy clone, meaning that it's a clone of the master copy of my library sans the video courses.. So I'll be able to fit the entire thing on a 256GB sdcard and roam the world with my whole collection in hand, rather than have to pick and choose the material I need at any given point then copy and organize. Also, the 8GB onboard could be used to cache the books in recent use as an alternative to the recently opened documents feature.. Many choices can be overwhelming at times.

Now, after that happens.. If only I could make a tutorial with pictures on how to do that so that everyone else can benefit from this and not be ripped off to buy more storage.

P. S I think if we just created the ultimate reader.. Then we should stock a battery or two for when planned obsolescence hits and these batteries become hard to find.. I'm sure 300ppi 6" screens with a power sipping processor will serve us for years to come and that stands directly against the interests of Amazon, B&N and many others.. So god knows what their plans will be to force us to buy a new device.. It is hard to make e-readers conform to the 24 months life-cycle like smartphones..

Sorry about the rant.. I was surprised at the speed and quality of the replies and couldn't help myself when I saw that I had an audience of "higher-level" people so I thought I should share my thoughts with you.

I'll update you with progress god-willing as soon as I can. Wish me luck on my dental board exam.
I love you all

[mergen3107]

Sounds like a plan
Good luck on your dental board exam (and Kindle surgery too)!

[NiLuJe]

@AbdulHamdy: Solo stands for, well, solo. It's *definitely* an UC SoC . Which is still the case of the following revision, the i.MX6SLL. (I actually have devices with both of those SoCs, if the NXP spec sheets weren't clear enough).

The i.MX7D, on the other hand, has a helpful 'D' for 'Dual' right in the name.

(I don't want to be annoying, but it's already confusing enough without spreading misinformation ).

[NiLuJe]

Okay, now I remember why it's confusing as hell.

PW4

Forma

They both use the exact same SoC, an i.MX6SLL.

NTX reports the Forma as an mx6sll despite the confusing human-readable bit of cpuinfo entry. That's accurate, IIRC, because earlier devices *were* using the original SoloLite, and were reported as mx6sl by NTX.

[NiLuJe]

The nail in the coffin being a PW2, which was actually using an i.MX6SL (i.e., SoloLite).

Processor       : ARMv7 Processor rev 10 (v7l)
BogoMIPS        : 790.16
Features        : swp half thumb fastmult vfp edsp neon vfpv3 
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x2
CPU part        : 0xc09
CPU revision    : 10

Hardware        : Freescale i.MX 6SoloLite based Wario Board
Revision        : 60000

[Junket]

Best of luck on both. It would be great to hear about your success when you get there.

[AbdulHamdy]

All information is good information.. Don't restrict yourselves to exactly on-topic.
If/When I am successful in pulling this off, Assuming I'm not consumed by the abyss of life, I will make another thread with an OP summarizing all what we gathered and pics to streamline the process for everyone.
As of now, I'm gathering the guides linked from all-over to assemble what will be on the monitor to guide me as I make my attempt.. (1) enameled wire for the connections to be as small as possible.. (2) 0.1mm soldering tip because the ones I have are in bad shape. (3) disassembly guides and USB connection points to know where to solder.. and (4) USB breakout setup to not butcher the reader I have before actually getting it to work.
After I have a female usb2 socket wired to the logic board... we'll then take a shot at picking the software apart.

Another question though.. I'm not feeling particularly confident that the reader will enumerate when it's connected.. So, Does anyone know what drivers are baked into the stock kernel that will work without issue (as-is) to test the success of my soldering job and concept ?
i.e. mouse/pointing device, keyboard, Ethernet, USB hubs, WWAN
in other words, if the source is released..can anyone take a look at it to get the VIDs and HIDs of stuff because I do NOT have the required skills to sift through the kernel tree and find locate what I need or understand it... I can barely read code and cannot follow it to understand what it is trying to do.

Thanks,
Abdul

[NiLuJe]

@AbdulHamdy: Re: moderation queue: Yep, perfectly normal for a new account. I approved the first and hid the second .