Partitions - how many, where are they, etc. - G Tablet Q&A, Help & Troubleshooting

Partitions are something we usually don't need to mess with - probably shouldn't mess with. That said - to understand how things work, it would be nice to peek around and look. I have enough experience with linux to be dangerous but not enough to answer my question on the gtab. I know there are multiple partititons - clockwork mod can wipe some. I see when I do nvflash that a bunch of partitions are restored. When we repartition with clockwork we set the size of only one partition to 2040 and the swap partition to 0 - what about all the others? Now, if I use terminal emulator or can get up to what I think is the root directory. In linux I could use fdisk -l and it would show me the various partitions. It doesn't produce any output here. I'm sure I just don't understand the structure so I'm not phrasing the command properly. There is also probably another place that would clue me in as to what partitions are mounted where but I don't know it. Anyone have any ideas for me?

Related

Root filesystem image.

Alright, so the root filesystem image is in /mnt/system/androidmerged.squashfs.secure
So do a temp root, copy to /mnt/storage, and then a adb pull gets it over.
The squashfs itself is offset by 256 bytes, so:
losetup -o 256 /dev/loop0 ./androidmerged.squashfs.secure
At this point, the FS can be mounted or unsquashfs can be used to extract it.
So, what's the first 256 bytes? The secure implies some type of signature, but what kind, and what else is in all those bytes?
I'm not feeling brave enough to try just grabbing the first 256 bytes and appending a modified squashfs image to it on my device just yet, but if others try please report back. (On both if it works, and if not what it takes to recover the unit.)
how big is it? can you upload it somewhere? (or would this be illegal?)
damm.. i need my 101!
chulri said:
how big is it? can you upload it somewhere? (or would this be illegal?)
damm.. i need my 101!
Click to expand...
Click to collapse
75 MB - uploading now
Edit: And up: http://hotfile.com/dl/88050103/f99f306/androidmerged.squashfs.secure.html
thx!
how would you replace the root fs image on the device?
chulri said:
how would you replace the root fs image on the device?
Click to expand...
Click to collapse
Connect via ADB, do a temproot, put the file in /mnt/storage, then copy it into /mnt/system overwriting the existing file. /mnt/storage is an ext3 filesystem mounted read/write, however I simply do not know if it will be possible to recover the unit if there is some kind of signature verification and we fail due to a modified image.
Again, someone braver then I should make this attempt and let us know how it goes.
The source did not give all that many hints, but I need to dig through in some more detail.
zelch said:
Connect via ADB, do a temproot, put the file in /mnt/storage, then copy it into /mnt/system overwriting the existing file. /mnt/storage is an ext3 filesystem mounted read/write, however I simply do not know if it will be possible to recover the unit if there is some kind of signature verification and we fail due to a modified image.
Again, someone braver then I should make this attempt and let us know how it goes.
The source did not give all that many hints, but I need to dig through in some more detail.
Click to expand...
Click to collapse
If the unit will still boot to recovery could a full wipe and reinstall of the base AOS over USB get it back up and running?
krohnjw said:
If the unit will still boot to recovery could a full wipe and reinstall of the base AOS over USB get it back up and running?
Click to expand...
Click to collapse
Recovery shouldn't be part of the FS so at worst, you'd have to do a format/firmware install.
You can do a full system wipe/format from recovery. it's not in any damageable storage by us without flashing a new recovery image.
Interesting about the front 256 bytes. It must be a signature. Not sure what good rebuilding the squashfs will do as it'll still be read only but it's a start. We could at least update the system properly and install the appropriate apps. Maybe in make some of the system dirs symlinks to writable locations possibly.
Permroot, giving us a filesystem mounted RW and not no-suid.
Ideally, I'd like to have decent support for the internal storage being ext3 without nosuid, but first we need to be able to replace the root filesystem image.
Other notes..
Looking at the hexdumps, the 256 byte chunk does not contain the start of the md5, sha1, sha224, sha256, sha384, or sha512 checksums.
The most troubling option which comes to mind is that it is the right size for a RSA 2048 bit block, hopefully not.
Anyone have ideas on how to find the initramfs image that the bootloader is feeding the kernel?
For that matter, has anyone tried taking apart the OS update images?
zelch said:
For that matter, has anyone tried taking apart the OS update images?
Click to expand...
Click to collapse
I think the aos file or the responsible installer/updater should give us a lot of information about how this stuff can be updated.
chulri said:
I think the aos file or the responsible installer/updater should give us a lot of information about how this stuff can be updated.
Click to expand...
Click to collapse
Agreed.
It looks like usr/bin/abcbox in the root filesystem has something to do with the update process.
zelch said:
Agreed.
It looks like usr/bin/abcbox in the root filesystem has something to do with the update process.
Click to expand...
Click to collapse
And it definitely is!
On a rooted device:
Code:
/usr/bin # PATH=$PATH:/tmp
/usr/bin # ln -s /usr/bin/abcbox /tmp/cramfschecker
/usr/bin # cramfschecker
USAGE: cramfschecker FILENAME
/usr/bin # cramfschecker /mnt/system/androidmerged.squashfs.secure
cramfschecker : check against 2.0.54
cramfschecker verification OK
Anyone with some ARM disassembly skills feeling up to taking abcbox apart to see how it's doing the signature check?
And so I've been digging into this, and it turns out that this is really quite similar to how the Gen 7 Archos 5 IT is locked.
The signature there is a RSA + MD5 signature, which is really the worst case as that means a 2048 bit RSA key, so we're kinda screwed there.
http://strazzere.com/blog/?p=320 has a good description of the situation on the 5IT. Getting a flash_unlock binary should be fairly trivial, so perhaps we can tamper with the key store to add additional keys.
ah zelch, this is good stuff.
i'm gonna diff the archos gpl kernel, looking for changes at mtd stuff. maybe we can build a kernel module which enables r/w access to stage1
edit: or do we already have r/w access?
This stuff is all pretty interesting to read, but if I'm reading this correctly (and it is entirely possible I'm not) it looks kind of like this device is going to be a total pain in the ass to root, and it may take a considerable amount of time for us to get there.
Can someone who is more knowledgeable on this sort of thing verify that? Thanks for all your hard work guys. It's appreciated.
its definitly not going to be that easy as other android devices were but would it be so interesting if it wouldn't be so hard to root?
While that's true, it will make it a bigger triumph when it is finally rooted, the tinkerer in me is dying to mess with roms on this device and see what it can really do once it's cracked open. Keep up the great work guys, I'm following with baited breath.
Write to stage1 appears to exist, and indeed looking at /proc/mounts /mnt/rawfs is mounted rw. Looking at the kernel source, write support should Just Work.
So, looking through /mnt/rawfs avboot is clearly the boot loader which verifies stuff, but we lack source for it.
I have absolutely no knowledge of ARM asm, and screwing this up will absolutely brick your device, quite possibly beyond repair. (And I wouldn't bet on ArchOS being willing to replace it either, I sure wouldn't.)
So, anyone with the right background willing to step in here?
I'll keep digging, perhaps we can still find the answers.
Note: avboot has some strings which reference a development kernel, this bears some additional hunting.
I still haven't got my A101, but its finally on its way to my home.
can you please upload these files and give me kind of a tree of the folder structure?

Clear Cache and Data from Stock Recovery

I've seen a number of requests for this functionality and recently it became necessary for one user who had a disabled Home Key to clear cache and data without the use of ClockworkMod. I have reserached two methods to address this issue. These instructions require some familiarity of android, computer and tablet terminology and usage. Feel free to ask for clarifications in comments. Here we go...
Method I - Stock Recovery Command File
Technical: Stock Recovery command file can be used to perform a few additional functions as well as to alter the path to update files. These commands will execute with all privileges available to recovery mode.
Advantages: Very easy to use. Very little technical knowledge required. No third party software is required for use.
Prerequisites: You will need a MicroSD card formatted FAT32 and a method for transferring files from your computer to the MicroSD.
Usage:
1) Prepare a text file named "command" (no file extension) with one of the following commands on a single line. The wipe data command will wipe both data and cache. Wipe cache will wipe cache only.
--wipe_data
--wipe_cache
2) Place the file in a folder named "recovery" in the root directory of your MicroSD card.
3) From a powered down state, insert the MicroSD card into your tablet and boot into recovery by powering it on while holding down the Volume Up key.
4) Allow the command to execute completely then the tablet should reboot (this may not occur automatically depending on firmware installed).
Method II - Updater Script
Technical: The attached "Updater Scripts" perform delete commands (recursively if necessary) on the named directory or file(s). The directories are mounted automatically by the system before the script executes but it could be easily revised to include that step if necessary. The partitioning, formatting and directory structure are left untouched. Only files are deleted.
Advantages: No third party software is necessary for execution. Relatively easy to modify for more surgical precision (i.e. leaving installed apps but clearing possibly corrupted system data). Included example: "Clear Battery Stats"
Prerequisites: You will need a MicroSD card formatted FAT32 and a method for transferring files from your computer to the MicroSD.
Usage:
1) Download the attached archive (ClearData.zip) to your computer.
2) Extract the files to your computer. You should then have a folder named "recovery" (which contains a file named "command") and an additional archive named "update.zip"
3) Place the recovery folder and the update.zip in the root directory of the MicroSD card.
4) From a powered down state, insert the MicroSD card into your tablet and boot into recovery by powering it on while holding down the Volume Up key.
5) Allow the script to execute completely then reboot the tablet (this may occur automatically depending on firmware installed).
This will become handy someday.
Thanks for sharing your knowledge.
You're welcome. One quick note... the new stock recovery adds a menu simiilar to ClockworkMod. These methods will still work since the recovery folder/command file are checked first but it really isn't as necessary any more.
Need Help
Tried both methods above but either way I get to the viewsonic splash with the message "Booting recovery kernel image" in the upper left and it just stays there, stuck there, I left it for a long time to see and it never leaves that screen.
Any ideas?
Me too
I can't get into clockworkmod either. My machine is running faster. I almost hate to mess it more.
lrgche said:
Tried both methods above but either way I get to the viewsonic splash with the message "Booting recovery kernel image" in the upper left and it just stays there, stuck there, I left it for a long time to see and it never leaves that screen.
Any ideas?
Click to expand...
Click to collapse
That's an indication that you may have more serious problems. nvflash will be required. http://forum.xda-developers.com/showthread.php?t=861950
Once done you will likely need to install ClockworkMod and repartition your internal storage.
Loukoebel said:
I can't get into clockworkmod either. My machine is running faster. I almost hate to mess it more.
Click to expand...
Click to collapse
If your tablet boots properly but you can't get into CWM then it probably isn't installed properly (or at all). http://forum.xda-developers.com/showthread.php?t=865245
Keep in mind that CWM is NOT compatible with all ROMs. Make sure the developer for your chosen ROM recommends it before installing it.
Does your method in opening post have to be run from external micro sdcard?
Both methods are performed with an external MicroSD card. They will work from internal also but it is a little more difficult to get the files in place if your tablet is not booting properly.
K J Rad said:
Both methods are performed with an external MicroSD card. They will work from internal also but it is a little more difficult to get the files in place if your tablet is not booting properly.
Click to expand...
Click to collapse
so your method is a simple way to replace one of the main uses of Clockword MOD?--Plus you stay stock more or less.
That is correct. Method II can also be modified to be less intrusive (leave user apps installed) or embedded into update scripts to perform a wipe during new ROM installs.
K J Rad said:
That is correct. Method II can also be modified to be less intrusive (leave user apps installed) or embedded into update scripts to perform a wipe during new ROM installs.
Click to expand...
Click to collapse
Wipe data does what--remove the apps installed?
And the partitions?
Your post is very interesting. It implies that you have a knowledge of the g-tabs partition structure. I have played with Linux off and on for the last 10+ years. When I began, I used Slackware and when you set it up you had to manually create partition tables using fdisk. You were only required to create two - the data partition and a swap partition but it was often recommended that you create several others - one to contain the home directory to prevent users from using all the disk space (in the days of small disks) for example. It appears that there are a lot of partition on the g-tab. Up to now, I have used various wiping tools like clockwork or calkulins wipe all on faith. I would really like to know what all the partitions are and what is in them. I have used terminal to get to the root folder and tried to do an fdisk to display the partitions but try as I might everything remains hidden. It would seem that a script like yours could be adapted to do many things but I would certainly want to understand the structure a little better before I did anything. I have searched and been unable to find that information. Can you point a way for the curious to learn more about the partition structure on the g-tab?
Wish I had a direction I could point you in. What I've found so far has mostly been stumbled upon while looking for something else. What I can tell you is this...
1) When using fdisk in Android you must specify the device to look at. Try something like: fdisk /dev/block/mccblk3 That should list the current partitions as defined by CWM or whatever was used originally.
2) Within one of those partitions in the list generated above are sub-partitions holding the bootloader, system, data, etc partitions. You can see how they're described in the .cfg files in the nvflash restores that are lying about.
lsu205 said:
Wipe data does what--remove the apps installed?
Click to expand...
Click to collapse
Removes user apps and their associated data as well as system related data and settings.
K J Rad - any idea if the partition size can be set with these methods (2048 & 0) in case I can't get clockwork installed?
CodeNamePapa said:
K J Rad - any idea if the partition size can be set with these methods (2048 & 0) in case I can't get clockwork installed?
Click to expand...
Click to collapse
I'm looking for a solution to that problem. Unfortunately these methods still require the ability to get into recovery mode which likely won't work if you're having trouble getting CWM installed.
If, however, you can get into recovery... then it is theoretically possible to create a script that would accomplish that. As soon as I have one I'll be adding it to the mix ;-)
Edit: I've found something I think will work. Will do some testing tonight. It will still require access to recovery.
I wasn't sure if you saw my other post but I am seeing no partition 0 when I NVFlash with a verifypartition.
http://forum.xda-developers.com/showpost.php?p=13059520&postcount=57
I haven't yet but I will. Let's try to keep this thread on topic. Thanks.
More thoughts:
because I went w/ cyan7 is it possible i have a "bad" kernel and that the stock bekit-1105 or the roebeet-3588 files are crashing w/ the kernel in place already?
I know custom ROMs can have a custom kernel applied separately, but I have no idea whether cyan7 loads it's own kernel...
I have yet to try the nvflash_gtablet_46 version, as I see the img files w/in are different from the original 1105 .zip
Also:
read on another thread that part 2 and part 3 aren't loading for other users when doing nvflash - I did notice that it pauses, runs some stuff, then starts loading part 4 through to the last part, then success. - do part 2 and 3 run for you?
edit: I see a 4349 downgrade.zip in another thread for those who got the OTA update but want to go back to stock 3588 prior to jumping off somewhere else - I can't expect that would help me as I can't do squat w/ recovery yet, but could that possibly "reset" any bad kernel problems? - again, I'm just thinking out loud.
This is well outside the scope of this thread but I find some of what you mention interesting so I'll address it and then end any further off topic discussions.
I did not build nor have I ever used Cyan7 so I have no basis for an opinion on the matter other than this... Each ROM comes with a kernel installed so if properly done an nvflash should overwrite any "bad" kernel.
Part2 and Part3 do indeed load, they are just displayed differently than the other Parts. Just minutes ago I flashed down from Mountain Laurel (4349 based with the new bootloader and recovery) with absolutely no trouble. I can, and have, read back those partitions after an nvflash to prove that point.
The 4349 downgrade will only work for you if recovery is working. Having never used it I don't know that it would "reset" the kernel but any subsequent flashing of a new ROM image would.
I am working on a stock recovery solution for partitioning but it isn't likely to help anyone who is stuck in an APX loop. I do have some ideas on what might help for that condition but I haven't been able to get my hands on one for testing and trying to help people here is like being a consulting mechanic for a car repair that's in someone else's shop having work done on it that you're not being told about.
I'll be happy to address any further comments or questions regarding your specific issue in an appropriate thread or via PM. Thanks.

[Q] Read raw block range with dd/cat?

Hi,
I used to know a way to dump a raw range of data (i.e. specifying start/end in hex address) from a block device which I used to do from data recovery days, but I can't remember what it is. I have been googling for about an hour and it's driving me nuts! Can anybody help?
FYI, I am trying to grab data from an unknown range of data on the nand layout for the Xperia Play but this is a general linux/busybox question. For details on what I'm doing check here.
Thanks so much in advance.
EDIT: Nevermind, I've discovered that the range I'm trying to read is a protected area. Mods please close if possible.
cat is more like a parser, dd is capable of dealing with raw data.
http://www.linuxquestions.org/questions/linux-newbie-8/learn-the-dd-command-362506/
http://linux.die.net/man/1/dd
Yeah I figured it would be done with dd, though I can't find any device that represents the "entire" mtd/nand - only mtd# for existing partitions exposed by the kernel. If i could find a "root mtd" device I could use skip and count parameters of dd to read what I want.
Regardless, I don't really need help with this specifically anymore - my problem seems to be specific to the Xperia Play. I am basically trying to resize the partitions (which I did previously on the X10) and I have exposed an unknown ~100MB+ that goes between userdata and cache, but I can't read or write to it at all no matter what I do.
I think what I'm trying to get is a protected area for DRM or something which I want to shift (so I can give space from cache to userdata). I/we need to make kernel or bootloader changes for the device.
Thanks for the help anyway.
I have a Samsung and Samsung is the probably the only one brand that adopt a different partition system for mtd; but remember that dd just copies everything, free space included, if with dd you are copying a filesystem with a total of 100MB and only 40MB are in use, you end up having a 100MB image file with dd.
Yeah I know it's a raw by-sector mirror/dump tool. Well what I did was edit the kernel to only create one entire partition taking the complete nand storage and then tried to dd from that, it works for a long time then once it hits this special "protected" area around ~800MB offset it spams a lot of "I/O Error" messages but doesn't fill these with zero's or anything (using conv=noerror), then once it passes the protected area it successfully dumps the rest (which is where the cache partition for the zeus would go).
OK, I have another question now. I found that this unknown 133MB has about 53MB of data in there, somewhere in the middle, which grabs fine. But the resulting file is not 133MB so I don't know the offset. Can I use dd or another tool to grab this partition while filling I/O errors with zero's? I have googled a lot and couldn't find anything.
Nevermind *facepalm* I use conv=noerror,sync. http://www.mkssoftware.com/docs/man1/dd.1.asp

[Q] Best way to backup and restore on a number of devices

Hi
I've done a bit of searching but can't find anything too specific to what I'm trying to do. Basically we have 10 Android tablets, and I want to make them all standardised e.g. have the same Apps on, configured in the same way (e.g. enterprise wireless network added).
Now the thing is if anyone messes around with them I want a really easy way to restore them to the original config which I've done.
One way I thought was to configure one fully, install Titanium Backup on it, do a full backup of apps/system data etc, and put the backup onto an SD card. Then I already have the base ROM on an SD card so if theres any problems, I can just flash the ROM over it again, install TB, and restore all the data. Would this be suitable to do to duplicate the data onto 10 tablets, and also restore the data if required?
The other thing I looked into was customising a ROM myself, don't want to do anything too tricky it'll just be a case of removing all the preinstalled crap I don't want, preloading the Apps we do want, and if possible preloading the wireless key and getting rid of the first boot initial set up wizard.
PS I've looked at installing CWM and doing whole image backups, but supposedly the tablet isnt supported (its an Ainol Novo 7 Elf 2)
Any advice would be great, hopefully theres some fairly straight forward way of managing this
Thanks
One of the reasons I integrated a full blown GNU/Linux on my devices, was the need to run full and automated backups. If you are looking into the possibility making a custom ROM, this might be a solution for you as well. I'm using BackuPC to run backups nightly, backing them up as any other GNU/Linux machine (using tar over ssh).
See the link in my signature for more information about this.
kuisma said:
One of the reasons I integrated a full blown GNU/Linux on my devices, was the need to run full and automated backups. If you are looking into the possibility making a custom ROM, this might be a solution for you as well. I'm using BackuPC to run backups nightly, backing them up as any other GNU/Linux machine (using tar over ssh).
See the link in my signature for more information about this.
Click to expand...
Click to collapse
Hi
Thanks for the reply, not too sure this would be the right option for us. I don't really need to take nightly backups, I just need to make a backup of a preconfigured image, and then put that image onto 10 other devices. Then I want to keep the original backup and have an easy way to restore it onto any devices which have been messed up. Sort of like image cloning for PCs, I want to prepare a base image, and then flash it over all the devices.
fro5tie said:
Hi
Thanks for the reply, not too sure this would be the right option for us. I don't really need to take nightly backups, I just need to make a backup of a preconfigured image, and then put that image onto 10 other devices. Then I want to keep the original backup and have an easy way to restore it onto any devices which have been messed up. Sort of like image cloning for PCs, I want to prepare a base image, and then flash it over all the devices.
Click to expand...
Click to collapse
Ok, I see. Compile the image to you likings (boot image and system partition), and then flash it using fastboot onto you devices.
Hi
Does anyone have any more thoughts on this?
I have experimented with Titanium Backup and this seems to work quite well. I have installed a ROM, and customised it e.g. installed the apps I need and configured the apps, wireless settings and home screens etc. Then I do a full apps + system backup in TB to my SD card.
Then the plan is, I can reflash the ROM onto the other device, install TB and then restore this backup. This saves my user state and wireless settings etc.
Only problems is when I flash the ROM, I have to go through all the initial set up again and also remove some preinstalled apps which I dont want. Any ways around this?
There must be something I'm missing. Why don't you install the device, walk through the setup, remove the bloatware you don't want and then dumps the disk partitions into images you flash the other devices with using fastboot? This way you'll get'em cloned, isn't it this you want..?
Of course there's still some tinkering needed once restored/cloned, such as giving them individual Google accounts etc, but you can easily fix this without re-running the setup wizard.
kuisma said:
There must be something I'm missing. Why don't you install the device, walk through the setup, remove the bloatware you don't want and then dumps the disk partitions into images you flash the other devices with using fastboot? This way you'll get'em cloned, isn't it this you want..?
Of course there's still some tinkering needed once restored/cloned, such as giving them individual Google accounts etc, but you can easily fix this without re-running the setup wizard.
Click to expand...
Click to collapse
Hi
Yes that's what I want to do! How would I go about dumping the disk into an image and then flashing?
fro5tie said:
Hi
Yes that's what I want to do! How would I go about dumping the disk into an image and then flashing?
Click to expand...
Click to collapse
There are several methods. Some boot loaders (such as nvflash for tegra based devices) can actually read back the disk partitions to a computer via the USB port. You can also on the tablet read the raw mtd device with busybox/dd. I assume you've unlocked the bootloader and gain root access to the device, since this is a requirement for flashing them as well. A third alternative is using busybox/tar, and then recreate the filesystem image using mkyaffs (or if ext3/ext4 even easier, just loopback mount an image on you linux maching to unpack the tar archive to). Once you got the images (system and userdata partitions), you flash the devices with "fastboot flash system system.img" and "fastboot flash userdata data.img". I don't believe you'll need to tamper with the other partitions.
kuisma said:
There are several methods. Some boot loaders (such as nvflash for tegra based devices) can actually read back the disk partitions to a computer via the USB port. You can also on the tablet read the raw mtd device with busybox/dd. I assume you've unlocked the bootloader and gain root access to the device, since this is a requirement for flashing them as well. A third alternative is using busybox/tar, and then recreate the filesystem image using mkyaffs (or if ext3/ext4 even easier, just loopback mount an image on you linux maching to unpack the tar archive to). Once you got the images (system and userdata partitions), you flash the devices with "fastboot flash system system.img" and "fastboot flash userdata data.img". I don't believe you'll need to tamper with the other partitions.
Click to expand...
Click to collapse
Hi
Thanks for the quick reply, much appreciated.
Unfortunately you've lost me a bit here!
Yes the device is rooted, I dont have a linux machine though.
Any chance you'd be able to provide some more specific instructions? The device is a chinese tablet from manufacturer Ainol, the model is a Novo 7 Elf 2. Unfortunately there isn't much discussion on these online so specific help is hard to find!
fro5tie said:
Any chance you'd be able to provide some more specific instructions? The device is a chinese tablet from manufacturer Ainol, the model is a Novo 7 Elf 2. Unfortunately there isn't much discussion on these online so specific help is hard to find!
Click to expand...
Click to collapse
I can provide you specific answers to specific questions, but I have no experience of the tablet in question, so you'll have to do some digging yourself first. Make sure it supports fastboot, investigate what the proprietary bootloader is capable of, see how/if you can obtain an original image etc.
One maybe easier solution, especially if you plan to restore the tablets on a regular basis, is to only make a new boot image to reflash the devices with. The only modification done is that you change the /init.rc script to mount /data and /system from the SDcard instead of from the internal nand disk device.
Once this is done, you'll power up and run the installation wizard and everything on your master tablet. Then power it down, and clone the SDcard. This SDcard now contains everything, so you'll simply restore a device by replacing its SDcard with a copy of this master card. I guess it's easier to clone a SDcard than reflashing several internal partitions. Easier to make the master as well - you don't need to dd or tar them, they are already in "image" format. If you can get hold of the original firmware, this should be quite easy without the need to preserving data from the device itself.
fro5tie said:
Any chance you'd be able to provide some more specific instructions?
Click to expand...
Click to collapse
Issue the commands "cat /proc/mtd" and "mount" on your device at command prompt (e.g. via "adb shell" or the "ConnectBot" terminal app). This shows you if the device allows you to copy the boot image from it. Paste in the output into this thread. If you believe the "clone the tablet via the SDcard" is a good solution for you, the process is in short terms something as below;
Copy the boot image to the sdcard:
# dd if=/dev/mtd/mtd2ro of=/mnt/sdcard/boot.img bs=2048 (device dependent of contents of /proc/mtd)
Remove the sdcard, insert into a computer, split the boot image info kernel + initramfs. Read http://android-dls.com/wiki/index.php?title=HOWTO:_Unpack%2C_Edit%2C_and_Re-Pack_Boot_Images for instructions about how to work with the boot.img file. I really recommend a GNU/Linux environment for this.
Then edit /init.rc replacing the "mount yaffs2 [email protected] /system" with "mount ext3 /dev/block/mmcblk0p2 /system" for system and data (use p3 for data partition, the device name may be different on your tablet, see mount output).
Create an SDcard with three partitions: #1 vfat (standard), #2 and #3 ext3. Insert into you device and boot it up again.
# mount -t ext3 /dev/block/mmcblk0p2 /root
# cd /system
# tar cf - . | (cd /root ; tar xf - )
# umount /root
# mount -t ext3 /dev/block/mmcblk0p3 /root
# cd /data
# tar cf - . | (cd /root ; tar xf - )
# umount /root
This copies your partitions to the SDcard. Shutdown the tablet again.
Make a new boot.img using the instructions in the link above, using the edited init.rc script.
Now you can non-destrutive give this a try.
Place you tablet in fastboot mode (often vol-up (or vol-down) during power on).
$ fastboot devices
This vill verify the tablet is in fastboot mode. It should be listed. Then:
$ fastboot boot boot.img
Note here, only BOOT the tablet, do NOT use the "flash" keyword. This in case of the image isn't working, you'll just have to restart you tablet, and no harm's done.
Look around. Do a "mount" command. Everything works? Mount shows /data and /system from sdcard? Perfect. Now you can reflash it. Shutdown and flash:
$ fastboot flash boot boot.img
Now the device will use /data and /system from the SDcard every time. Customize your device, and then clone your SDcard and try it in tablet #2 you'll booting with your new boot.img and the cloned SDcard. Verify that #tablet #2 is a perfect clone of tablet #1. It is? Now you can flash the boot,img into all your tablets.
--------------------
But don't forget, there may be other solutions as well, maybe more suitable. This you'll have to investigate yourself.
And the usual disclaimer - you can probably not follow above by the letter. There sure is some obstacle you'll have to overcome, something non-standard, etc.
Also keep the original boot.img file for safekeeping in the case you want to restore the device's boot image some day.
Wow! Thanks for the info! This is really helpful, I need to set aside a bit of time to work through this and have a look. Thanks again its really appreciated, I'll be back with info once I've had chance to give it a go!
I certainly can't offer more detailed info than the fellow from Sweden who seems to really know his stuff...but what about making a nandroid backup of your fully configured reference tablet (I'm assuming all tablets are rooted). Ensure all your tabs have CWM recovery and copy your nandroid file to each one.
If any of your fleet get 'corrupted' you can simply restore the original, fully configured ROM.
In fact that sounds too obvious..likely I missed something about your scenario which precludes this option from consideration!
Good luck mate.
tweeny80 said:
I certainly can't offer more detailed info than the fellow from Sweden who seems to really know his stuff...but what about making a nandroid backup of your fully configured reference tablet (I'm assuming all tablets are rooted). Ensure all your tabs have CWM recovery and copy your nandroid file to each one.
If any of your fleet get 'corrupted' you can simply restore the original, fully configured ROM.
In fact that sounds too obvious..likely I missed something about your scenario which precludes this option from consideration!
Good luck mate.
Click to expand...
Click to collapse
Hi
Yes that was my first thought as well, tablets are rooted yes but there is no CWM for the tablet. Its an obscure Chinese branded tablet.
Unless there is another way to do nandroid backups?
hmm tricky situation. Catch 22 ! From what I know, your best bet is to backup all possible things through Titanium Backup given that you don't have the use of Nandroid backups. You can include wifi settings, messages etc but it's modular & not systemic.
I did a quick google search with no luck - time to upgrade your fleet dude :-0
Best of luck.

[Q] Mounting ext2 partition

I've created a single primary Ext2 partition in my phone's external SD card but Android refuses to mount it automatically. Whenever I attempted to mount it manually it kept throwing the error "mount operation not supported on transport endpoint".
How can I mount it?
Using (SlimKat) Android 4.4.2.
EDIT: I'm now able to mount it only manually but have to specify ext4 as its filesystem -- why and will it make a difference since ext2 is non-journalled? Also, I tried adding a mount entry in /fstab.smdk4x12 but it was deleted upon reboot; does this mean no manual entries are allowed in that file and I will instead have to hack my own /init-xx.rc file to manually mount the partition at boot time?
miguelg_ said:
I've created a single primary Ext2 partition in my phone's external SD card but Android refuses to mount it automatically. Whenever I attempted to mount it manually it kept throwing the error "mount operation not supported on transport endpoint".
How can I mount it?
Using (SlimKat) Android 4.4.2.
EDIT: I'm now able to mount it only manually but have to specify ext4 as its filesystem -- why and will it make a difference since ext2 is non-journalled? Also, I tried adding a mount entry in /fstab.smdk4x12 but it was deleted upon reboot; does this mean no manual entries are allowed in that file and I will instead have to hack my own /init-xx.rc file to manually mount the partition at boot time?
Click to expand...
Click to collapse
Why not just reformat to ext4?
es0tericcha0s said:
Why not just reformat to ext4?
Click to expand...
Click to collapse
Ultimately that's what I'll need to do but was hoping to use the non-journalled ext2. Is it not supported by Android or it the case that only some versions support it (in which case, what idiocy!)?
Have to say I'm beginning to truly hate Android. They might as well build their own kernel such that Linux (and by implication UNIX) is removed from the mix for they have completely butchered this OS. I suppose this is what happens when egos larger than the world are responsible for designing software; NIH syndrome.
Answering myself: if anyone is wondering how to automount a partition at boot time, you'll have to create your own init script and place in /system/etc/init.d/.
Well, realistically, the amount of people that have any use for mounting ext2/3/4 etc partitions is a very small % of users. Most people with android phones don't even know what Linux is, much less know about different kinds of partitions and what they are used for - or have a need for it. 99% of things you would NEED to do on a phone would be covered by the fat32 and exFat types. Of course, here on XDA, you'll find plenty of posts, guides, complaints about it, etc but there's obviously a certain type of user that seeks out or finds XDA and are more inclined to know of or have use for more technical things like this.
As far as auto-mounting the script on boot, you have to be rooted with init.d enabled and not all phones have full /system RW capabilities to even add stuff like that even when rooted. This is rare, but there's some HTCs and others like that. Often times there are ways around, but just saying, it's not a universal thing.
es0tericcha0s said:
Well, realistically, the amount of people that have any use for mounting ext2/3/4 etc partitions is a very small % of users. Most people with android phones don't even know what Linux is, much less know about different kinds of partitions and what they are used for - or have a need for it. 99% of things you would NEED to do on a phone would be covered by the fat32 and exFat types. Of course, here on XDA, you'll find plenty of posts, guides, complaints about it, etc but there's obviously a certain type of user that seeks out or finds XDA and are more inclined to know of or have use for more technical things like this.
Click to expand...
Click to collapse
That doesn't excuse the fact that they've deliberately crippled the OS. As an example, the FAT filesystems don't support symbolic links, which means that if you want to move any data outside of internal storage for whatever reason, you pretty much need an extX partition. Besides, those people (the vast majority) who don't know and don't care about the internals of their devices aren't the ones creating software for said devices in the first place. We are. And so these technical aspects matter and are relevant to us, not the masses.
es0tericcha0s said:
As far as auto-mounting the script on boot, you have to be rooted with init.d enabled and not all phones have full /system RW capabilities to even add stuff like that even when rooted. This is rare, but there's some HTCs and others like that. Often times there are ways around, but just saying, it's not a universal thing.
Click to expand...
Click to collapse
Didn't know about that limitation. Can you not remount the rootfs with RW privileges? And do you mean to say that some devices don't even support init.d; if so, what mechanism do they have in place?
miguelg_ said:
That doesn't excuse the fact that they've deliberately crippled the OS. As an example, the FAT filesystems don't support symbolic links, which means that if you want to move any data outside of internal storage for whatever reason, you pretty much need an extX partition. Besides, those people (the vast majority) who don't know and don't care about the internals of their devices aren't the ones creating software for said devices in the first place. We are. And so these technical aspects matter and are relevant to us, not the masses.
Didn't know about that limitation. Can you not remount the rootfs with RW privileges? And do you mean to say that some devices don't even support init.d; if so, what mechanism do they have in place?
Click to expand...
Click to collapse
Well, cripple might be a bit of hyperbole considering it's not something most people would need. I get your point though, it is weird that it's not native since it works with Linux generally. You can link symbolically to FAT systems while rooted with something like this:
https://play.google.com/store/apps/details?id=com.devasque.fmount
And yes, the tech people are creating software for these devices, but they are made for the general public, because that's who buy 90% of these things.
Could you please clarify what you said earlier on the read-only init.d and even some devices not supporting it? Again, thanks for your input, es0tericcha0s.
miguelg_ said:
Could you please clarify what you said earlier on the read-only init.d and even some devices not supporting it? Again, thanks for your input, es0tericcha0s.
Click to expand...
Click to collapse
Sure. Most android devices, actually I can't think of any of the top of my head, don't come with native init.d support or even have init.d that is not accessible. It's just not there. It's enabled in almost all custom roms, or you can add it yourself to many stock roms via a couple different ways like this:
https://play.google.com/store/apps/details?id=com.androguide.universal.init.d
As far as the system RW issue, some phones, like many newer HTCs, have the system protected so that you can make changes to the /system while booted, no problem, but once you reboot, all the changes will get undone. Very annoying. Example:
https://www.youtube.com/watch?v=KV3YaMBnEYI

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