Mucked internal storage recovery

[fixerdave]

So, I'll start by saying that I went to make an Ubuntu USB startup disk... forgot the tablet was still connected... I suppose you can guess the rest. Now, I did actually make a copy of the internal storage when I first bought my tablet and I have made regular backups of the Oruxmaps directory (Orux being the primary app for this tablet) as I made changes. Thus, I'm not out data - so far. I'd just like to keep it that way. The tablet itself is still fine... all the installed apps are still there, etc.. I've just lost access to the internal storage data partition.

It's a CyberNav Android tablet running 2.2-103-gb456292. It's built as a GPS navigator and that's what I use it for. Mostly, I'm running Orux maps with highly customised OSM data built into tiles. Right now, it's stuck at the "Preparing Memory device, checking for errors" thing. I can see the drive on a computer when I connect a USB cable but the tablet won't use it. I have reformatted the internal storage back to fat32 via Windows (connected via USB) and can add/remove files from said storage. The tablet will expose the internal storage via USB but it won't use it in Android. I expect there's something mucked in the partition table, what with Ubuntu doing it's thing. When connected to Windows, diskpart shows 2 new volumes: the 3.5GB one in question and another 0B one. I'm not yet sure if that other partion is the OS part of the internal storage or some funky swap space that Ubuntu made (and thus the problem).

At this point, I'm proceeding very cautiously... now, anyway, as I don't want to brick it. Should have done that earlier, but, you know... I wouldn't have this wonderful learning opportunity would I? :'(

Specific questions:

* what is "developer mode?" Does it allow me access to the OS partition on the internal storage? If so, how?

* Is there a way to make a bit-for-bit backup of the entire internal storage? Something like ddrescue. Something that will allow me to recover even if I blow away the OS side of the internal storage. There must be something there as yet untouched as it still has the apps I installed. The exposed partition is showing as 3.5GB, so I'm assuming the OS side is 512MB. My biggest concern is getting a backup of that partition, and a way to restore it, just in case I muck it up further in my attempts at recovery.

* Is there a partition editing tool for Android that I can install? Well, I'll assume there is. What's the best free one?

* Is there a way to run up some kind of SSH server on the device such that I can use the terminal mode properly?

* Is there a list of Linux commands that actually work in Android 2.2?

* Any other tutorials or pointers I should be looking at as I figure this out?

I gues what I'm looking for now is to build up a toolkit, stuff I can use to move forward, and the knowledge to use those tools properly.

David...

 

[fixerdave]

Specific questions:

* what is "developer mode?" Does it allow me access to the OS partition on the internal storage? If so, how?

* Is there a way to make a bit-for-bit backup of the entire internal storage? Something like ddrescue. Something that will allow me to recover even if I blow away the OS side of the internal storage. There must be something there as yet untouched as it still has the apps I installed. The exposed partition is showing as 3.5GB, so I'm assuming the OS side is 512MB. My biggest concern is getting a backup of that partition, and a way to restore it, just in case I muck it up further in my attempts at recovery.

* Is there a partition editing tool for Android that I can install? Well, I'll assume there is. What's the best free one?

* Is there a way to run up some kind of SSH server on the device such that I can use the terminal mode properly?

* Is there a list of Linux commands that actually work in Android 2.2?

* Any other tutorials or pointers I should be looking at as I figure this out?

I gues what I'm looking for now is to build up a toolkit, stuff I can use to move forward, and the knowledge to use those tools properly.

David...

Well, answering my own questions here. No real solution yet but I'm getting there.

* Developer mode... well, I meant USB Debug Mode and, yes, it is very useful. Basically, enable this setting on the phone and then run up the Android SDK on the host computer. Said SDK includes Android Debug Bridge (ADB) and you're going to need that if you want to do anything technical with an Android phone.

* Still working on the bit-for-bit backup. DD is there, but if the device is bricked there's no way to use DD to put it back. I'm still exploring options. I may just use DD to copy what I can. Worst case, I can use that to reconstruct a usable ROM if I brick the device. There is an ADB backup system but it throws an error... not sure why yet.

* Partition editing is typically done via the BootLoader. However, as the CyberNav doesn't have any hardware buttons other than Power, bootloader options are very limited. It seems the installed bootloader simply looks for a particularly named file on the external SDcard (update.zip or something like that) and attempts to load it as the ROM if it finds it. All those fancy "engineering bootloaders" aren't going to be of much use with no way of navigating in them (assuming no touch-screen at that point). There is likely a way to edit partitions from within Android, but I'm not there yet.

* ADB provides a shell command with works much like SSH would - not perfect but way, way better than trying to do terminal stuff on a 5" touchscreen.

* installing BusyBox give a reasonable range of familiar Linux commands. Will pretty well need it for anything fancy.

I'm still sifting through all the available information but it's rather daunting what with the multiple learning curves hitting all at once. There are multiple versions of Android and each version has been custom-ported to many different devices. All are different in various ways. Most published hacking is done bottom-up rather than top-down... start with a particular phone and look through those forums for specific advice and phone-specific custom tools. For oddball stuff like the CyberNav, there's not much specific stuff so it's a matter of figuring out what the fancy tools are doing in general and working back down. Not easy, but I'm getting there.

I've managed to get root access, with a combination of superoneclick and manually loading and running psneuter via ADB. Thus, unless I brick the device, it's only a matter of time before beat it into submission.

The base problem is that fsck_msdos is coming up with a non-fixable error and thus Android is refusing to use the sdcard. However, it doesn't seem to worry about that check when hosting it as a mass storage device. TestDisk reports that mass storage device as having a mucked partition table (no surprise there) but I'm reluctant to let it try fixing it until I get that ROM backup. Getting the ROM backup might be a challenge, but that just makes it fun, right?

I'll add more when I know more. Someday, somebody might be doing a search on the CyberNav and this thread might be useful,

David...

 

[fixerdave]

Slow progress on this:

I've found a factory rom here: http://www.coscod.com/download/os/pw...H_20120428.rar

But, my tablet won't load it up. Still not sure why but seeing as how I can't mount the external sdcard I'm assuming, for now, that the partition muck I've done is preventing said mount via the bootloader.

A lot of tools aren't working properly and I'm actually becoming surprised that the thing isn't already bricked. So, now I'm off to learn about Android partition maps and, surprise-surprise, it's different for each device. Sigh... I've found partition editing tools here: [DEV][REF] El Grande Partition Table Reference - xda-developers and a wee bit of information. Hopefully, once I get fully immersed in this, the actual problem will be obvious as will the repair.

David...

 

[fixerdave]

Well, for anyone else searching for CyberNav Mini, it appears there are 2 versions (original and 2):

1) Cybernav Mini: CPU: IMAPX200 ARM11 800MHz
2) Cybernav Mini II: CPU: 1.2ghz Cortex A8 ARM Core

CyberNav Mini (original):

ROMs are here: http://dl.dropbox.com/u/18965091/YFPI08_yf.v2.2-104.zip via [Q] Help with Cybernav Mini tablet. Cant flash firmware - Page 2 - xda-developers
Flashing the CN:
Format ext sdcard as fat32
copy desired ROM image(s) to folder "YFPI08":
can include system, bootloader, background image, and ?lk.rom?.
insert sdcard in tablet
reboot the tablet - it will automatically update to the available images, showing text and status bar over the background boot image (pre Android logo).
remove sdcard

Getting a root command prompt:
enable USB debug mode on tablet
Applications - Development - Enable USB Debug bridge
While there, set tablet to never sleep while charging
use adb to install:
adb install busybox.apk
adb install Superuser.apk
use adb to push pneuter to a writeable folder
adb push psneuter /data/local/tmp
use adb shell to:
set x on psneuter (chmod via busybox)
busybox chmod +x /data/local/tmp/psneuter
run psneuter (will end shell)
/data/local/tmp/psneuter
restart adb shell - will have root (#) access until reboot

Note that my device is not happy and this may be why the various rooting tools don't work as advertised. The above does work.

CyberNav Mini 2:

ROMs are here: http://www.coscod.com/download/os/pw...H_20120428.rar via http://www.coscod.com/wi-fi-gps-5-in...gps-navigator/
Another is here: http://www.wayteq.eu/files/download/xtab50gps/xTAB-50.zip
Flashing requires the PheonixCard utility available here: http://www.wayteq.eu/files/download/xtab50gps/PhoenixCardV306.zip

No idea about root as I don't own this device.


I've flashed my device to the latest factory rom and it still won't mount the internal sdcard as storage. I get to play with partitions now. At least I've got the rom.

Credit for the above is spread around but a lot of it comes from craigsoup on [Q] Help with Cybernav Mini tablet. Cant flash firmware - Page 2 - xda-developers

David...

 

[fixerdave]

fixed... had to use adb to get parted to the tablet, identify the failed partition, then delete and recreate it. Reinstalled the apps and restore the data... all is now right in the universe.

Well, that was 2 weeks of fun.

David...