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?
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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.
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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.
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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?
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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.
Here are some questions about Android 4.3 and upper.
A pair of questions about unrooting/locking/unlocking/booting.
1) What are the benefits of rooting other than being able to a) set custom cpufrequency policies, b) being able to update your phone (to custom new ROMs like cyanogenmod) when your OEM has decided to stop supporting it, c) full filesystem access, d) tuning sysctl parameters?
I don't like the fact the rooting totally breaks Android's security model.
2) Do I understand correctly that a locked phone is the phone in which you cannot overwrite/replace/customize vmlinuz? or there are even stricter limitations?
3) Do I understand correctly that in order to change e.g. /etc files you don't really need a custom ROM, you can boot into TWRP and replace/edit/remove the needed files?
4) Why does unlock wipe all your data?
5) If the phone is locked, how bootloader/firmware understands that our bootloader is untempered? Does the bootloader have a digital signature? I have this question because let's imagine that I 1) unlock 2) change vmlinuz (allow superuser) 3) lock?
6) How does "oem lock" verifies that system data is genuine? Or it simply wipes everything clean? Does Android has some (RO) partition which always contains a genuine virgin ROM you cannot meddle with?
7) If I do "unlock" on my Nexus device, without changing anything or installing any 3d party bootloader (like TWRP), will I be able to update to new official ROMs via OTA updates?
8) Why every "lock" manual says that I need to upload a genuine official ROM - what if I've changed it and made it "rooted"?
Storage.
Why does Android has so many partitions?
What method is used to break the internal storage into partitions? Is it some kind of partition table (MS-DOS, GPT) or it's hardware based?
Thank you for answers.
Lovely. 4 years and zero answers.
Hello. I'm wondering if its possible to make a phone copy files from the sd card to a destination on the phone while its booting so it has root permissions with some sort of custom code pushed to the phone via adb update for this to happen. I know something of the sort is possible but i may have the wrong idea about it?
My goal is to access a phone with a pattern lock on it by removing the gesture.key file in order to access the data. The phone does belong to me but i don't know the pattern to it. Any help would be appreciated.
The phone is un-rooted but does have usb debugging enabled.
Hello,
I am new to xda, but with what I would say a good understanding of computers in general, and good knowledge of c programming (if that matters)
I am structuring a guide for myself to be as foolproof as possible when attempting flashing my new phone. Please fill in any voids, comment, or answer questions if you can. This should prove useful to other users as well as it's not so model-specific.
1) It appears that the custom recovery of choice in most situations and for the time being is TWRP (correct?).
2) If I can get a backup of EVERY partition on my stock phone (as it came from the factory) using TWRP, could I conceivably restore ALL of them and be in a factory default setting? Excluding stuff like eFuse and similar mechanisms.
3) If the phone supports fastboot, unlocked bootloader and there is a compatible TWRP for it, would it be possible to boot the TWRP recovery through fastboot (without flashing that particular partition to phone), open a shell and take backups of all partitions on the phone? That should give us a file for each partition.
4) If one accomplishes step 3 successfully, in what scenarios would he/she NOT be able to bring the phone back to life after software bricking?
Minor questions:
a) "To have root" on a phone, is basically the same as having a root account on a BOOTED OS partition (like the admin accoun on a booted windows machine, or a root account on a linux machine)? If that's the case, booting a different partition (for example the recovery partition) could also give you root priviledges without affecting the booted partition, correct?
b) Why do some custom ROMs require a certain version of the stock/OEM rom to be installed PRIOR to flashing, since they are going to replace those partitions anyway?
c) How is Xiaomi's Anti Roll Back (ARB) feature implemented, if one restores all partitions to stock from step (3) ? There must be some other places of storing of information on the phone, besides internal memory, correct?
Storage shows 97% in use always. Cannot find files in category "Other"
47G+. Have tried several file managers. No change. 6.87G in System files. No medià, backups, or apks. New phone.
Is this that dreaded modem dump thing that happens on certain OnePlus devices?
This happens when the modem firmware is mis-flashed or defective.
You'll need to return that phone for repair or exchange.
In this condition you cannot root the phone as the unlock bootloader is greyed out and cannot be changed in dev. options to delete the dump files.
steveaudioaka said:
Storage shows 97% in use always. Cannot find files in category "Other"
47G+. Have tried several file managers. No change. 6.87G in System files. No medià, backups, or apks. New phone.
Click to expand...
Click to collapse
This solution will factory reset your device in a way that you likely have not.
Ensure you have USB debugging enabled and permissions granted for the connected device (PC,Linux, another android device) and reboot to bootloader.
While in the bootloader run the command "fastboot -w"
This will completely reformat the data and metadata partitions.
After this you can reboot system, go through the setup and check available storage.
I hope this resolves your issue.