I've been learning to edit and make ROMs for couple of months, some of the early works had been uploaded to a Chinese Milestone developers' BBS.
But there is a simple question which still confused me a lot. (- =)
Some senior developers in that Chinese BBS reminded their supporters in their threads to wipe before and AFTER applying the Rom in Open Recovery. But, why should we wipe AFTER applying the Rom? I've viewed some threads here, but none of them require to wipe after applying.
So I wonder if it is really necessary to wipe AFTER applying a new ROM. I'm very appreciate if you guys can answer my question and tell me why. Thx~~~
BTW, Xda is an excellent website. And it's much more professional than the BBS I used to visit. May you have a nice day~
It's a common myth. I'm not sure why it gets repeated over and over again.
One wipe is enough. Dalvik-cache is not populated again until the system is booting for the first time. While you are in recovery, it also doesn't matter if you wipe before or after you apply the update (unless the updater script in some particular update.zip also installs something to /data or /cache partition, which is not very common).
You can read cvpcs's thoughts on this matter here: http://cvpcs.org/blog/2011-06-05/time_to_wipe_data/cache
kabaldan said:
It's a common myth. I'm not sure why it gets repeated over and over again.
One wipe is enough. Dalvik-cache is not populated again until the system is booting for the first time. While you are in recovery, it also doesn't matter if you wipe before or after you apply the update (unless the updater script in some particular update.zip also installs something to /data or /cache partition, which is not very common).
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Thanks a lot~ (I'm looking for some threads which can explain how "wipe" works. Actually I still got some problem about that, like " Why system app still maintain after wipe? Is it because those system app has a backup in Flash Memory, and it will restore after wipe the EEPROM?")
(This message is only for testing whether it is reply to the original poster or the people who answer it....)
[E]Xtreme said:
Thanks a lot~ (I'm looking for some threads which can explain how "wipe" works. Actually I still got some problem about that, like " Why system app still maintain after wipe? Is it because those system app has a backup in Flash Memory, and it will restore after wipe the EEPROM?")
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System apps are installed into a different partition (/system), which also holds the OS files. Wiping data and cache only wipes the /data and /cache partitions and leaves /system alone. Otherwise the phone wouldn't work at all.
Dave Lister said:
System apps are installed into a different partition (/system), which also holds the OS files. Wiping data and cache only wipes the /data and /cache partitions and leaves /system alone. Otherwise the phone wouldn't work at all.
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Got it~ That's very kind of you.
Hello
I'm pretty sure that my /data partition was corrupted. Not sure how, maybe using a custom recovery with the ICS kernel, maybe some other way, but it can't be formatted, copied to etc.
I've been reading on some other devices about editing the .pit file after finding out where the corruption is. I'm having trouble using LInux tools since using adb, I don't get the root command prompt, just a $.
Anyone have experience on a P7300 about how to work around the corruption, identify, perhaps run a fsck on the partition?
I'd also be willing to pay a $50 reward for anyone who can get it running again, even with a reduced size data partition, but ideally I'd like to try repairing the damaged partition first.
Thanks
Harry
check "Guide & ToolKit" thread
http://forum.xda-developers.com/showthread.php?t=1406137
SOLVED
Discovered after reading the Toolkit and guide that it wasn't an EMMC bug hard brick, thank goodness. I was directed in post #250 to one specific stock ROM to install with ODIN, that supposedly, was the only stock ROM that when you did a wipe data/factory reset, actually recreated the partitions and reformatted them. It is P7310XARLA3_P7310UELA3_HOME.tar.md5
But I had nothing to lose, so I installed the stock ROM with ODIN, booted the stock recovery, did the wipe, and for the first time in about 10 hours of trying this, it was able to format the /data partition, and installed the bootable ROM. After that, I installed a CWM recover in the tar format, and now about to put my old ICS ROM back on, the one in the development section that came from an OTA leak.
Thanks, I hope this helps someone who has problems accessing their /data or /sdcard directories..
I have flashed a bunch of different ROMs lately. I always wipe cache, dalvik and do a factory reset but maybe it may no longer be enough. Currently, my phone is rooted with Cocore and CWM. I am thinking about going to CM11. Last time I tried that, I noticed some stuff during setup was overlooked because it already seemed to be there. So I think some bits and pieces are left in the phone. Therefore, I want to "scrub" it before trying another ROM (thinking CM11 this time). I know the CM kernel comes with it.
questions:
1) Can I just mount and reformat system, data, cache and preload to clear everything out before flashing a new ROM?
2) Will the kernel be protected (in this case is CoCore) after reformating or should I worry about it?
3) When I flash the original stock 4.1.2 from Odin, does it completely reformat everything when it loads onto the system?
corvus.corax said:
I have flashed a bunch of different ROMs lately. I always wipe cache, dalvik and do a factory reset but maybe it may no longer be enough. Currently, my phone is rooted with Cocore and CWM. I am thinking about going to CM11. Last time I tried that, I noticed some stuff during setup was overlooked because it already seemed to be there. So I think some bits and pieces are left in the phone. Therefore, I want to "scrub" it before trying another ROM (thinking CM11 this time). I know the CM kernel comes with it.
questions:
1) Can I just mount and reformat system, data, cache and preload to clear everything out before flashing a new ROM?
2) Will the kernel be protected (in this case is CoCore) after reformating or should I worry about it?
3) When I flash the original stock 4.1.2 from Odin, does it completely reformat everything when it loads onto the system?
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Click to collapse
Some information are stored on internal SD memory. Maybe it was there. Try to delete it. Backup SD to PC, format it - do factory reset and see if it is happening again.
shut_down said:
Some information are stored on internal SD memory. Maybe it was there. Try to delete it. Backup SD to PC, format it - do factory reset and see if it is happening again.
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If I backup the internal SD card to the PC and then restore after a reformat, won't the offending bits come back again?
corvus.corax said:
If I backup the internal SD card to the PC and then restore after a reformat, won't the offending bits come back again?
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Click to collapse
I did not tell you to restore it. Keep it on PC, in case you need some of data from there. Maybe you erase some picture that you need or something like that. And not to blame me later. :fingers-crossed:
I'm getting ready to update my old ParanoidAndroid (with CWM v5.5.0.4) with the CarbonRom.
I've backed up all kinds of logs, settings, and data that I think I may want to restore with the new rom.
I've also made a CWM backup (although of course I hope not to use it).
My question is - should I format the system partition (from CWM, Mounts & Storage option) before flashing the new rom?
I've seen people say emphatically that to get a clean install you need to do this.
Yet I've seen other's write just as insistently that you should NOT format the system partition. Do they say this because it is too dangerous? If I format the system partition and then for some reason the new rom won't load, does that mean my CWM is wiped out, making it difficult to recover?
I think I do want the system format because I don't want a bunch of old files hanging around ... but I want to make sure this is not too dangerous.
I've also seen others who recommended also formating the boot partition. Is there any value in that? Sounds even more dangerous ... no?
~Paul
pmennen said:
I'm getting ready to update my old ParanoidAndroid (with CWM v5.5.0.4) with the CarbonRom.
I've backed up all kinds of logs, settings, and data that I think I may want to restore with the new rom.
I've also made a CWM backup (although of course I hope not to use it).
My question is - should I format the system partition (from CWM, Mounts & Storage option) before flashing the new rom?
I've seen people say emphatically that to get a clean install you need to do this.
Yet I've seen other's write just as insistently that you should NOT format the system partition. Do they say this because it is too dangerous? If I format the system partition and then for some reason the new rom won't load, does that mean my CWM is wiped out, making it difficult to recover?
I think I do want the system format because I don't want a bunch of old files hanging around ... but I want to make sure this is not too dangerous.
I've also seen others who recommended also formating the boot partition. Is there any value in that? Sounds even more dangerous ... no?
~Paul
Click to expand...
Click to collapse
You can format system,data, internal storage and cache without any worries if you are on PA rom read install instructions in carbon rom thread after or before.
Sent from my GT-N7000 using Tapatalk
Question: I want to wipe everything from my HD+ and start completely fresh. What is safe to wipe and how do I do it in TWPR or CWM? A "factory reset" isn't good enough. It leaves old data around. But I've read too many stories about bricking a device by formatting /data using CWM.
Background: I've been running CM 10.2.1 for a few weeks now. Given what Jon Lee posted about Google and security, I thought I'd try a clean install of CM 10.2.1 without installing gapps, just to see what that's like. (And what services don't run.)
So I did the usual "factory reset" from TWRP and reinstalled CM 10.2.1. To my surprise, when I booted, the latest version of Google Play was still showing on the launcher!
I had used Link2SD to integrate the latest version of Google Play with the OEM system app. So apparently, that this was not wiped. And of course, internal media data is not wiped (not by TWRP, anyway) in a factory reset. But I thought /system was.
The TWRP FAQ has a page about wiping. It says
Depending on your device and its configuration, you may have options for wiping internal storage, external storage, sd-ext, android_secure, and/or an option for formatting data. There's almost no reason that you would ever need to use these items. These options are there for convenience. For instance, if you're getting ready to sell your device, then it's a good idea to wipe everything on the device so that the new owner doesn't get your private data.
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But they don't tell you which to select.
TWRP makes it confusing by offering to 1) wipe data, 2) internal storage, 3) SDcard or 4) SDcard data in Advanced Wipe. Which is it for wiping your media stuff?
From what I've read, "internal storage" should be the same as "SDcard." So why both? And how is "SDcard data" distinct from those two?
To make matters worse, in the Nook I thought there was an additional element of confusion because the Nook doesn't call the internal SDcard memory what everyone else calls it.
So let's say I am selling my HD+. Would I select all of the above and still be able to install a ROM clean?
Or would I brick?
I know that on a desk top computer if you want to start bare metal, you format the hard drive, wiping everything, and install onto that. But judging from what Succulent wrote in his blog about recovering from an EMMC crash, you can't start totally clean with Android. Apparently, Android needs some preexisting files on the "drive" in order to install. (Like the devconf folder, which contains your MAC and your serial number.)
[Am I understanding him correctly? He was talking about recovering from a tablet wrecked by the EMMC brick bug. Perhaps no /data partition at all, as he offers a script to rebuild/expand that partition?]
I have read stories of people bricking their tablets by formatting /data from CWM. I don't understand why that should brick it. Why couldn't you boot into recovery? How can the /data partition affect the /recovery partition?
So - has anybody done a complete wipe on their Nook HD+? Please explain, for those of us who are obsessive compulsive, exactly how you do it.
To wipe your device with CWM go to mounts and storage and format /system, /cache and 'data and datamedia'. A normal factory reset only wipes /cache and the portion of /data that does not hold your media files. It does not wipe /system. Usually the ROM install does that, but the install script has a feature that saves gapps if you are installing the same version of the ROM (eg, CM11 over CM11). So to get rid of everything, including media files and gapps, do what I said in the first sentence. Of course after formatting /system you must put a ROM back on it for it to boot.
And it is not /data formatting that is the brick problem, it is formatting the /bootdata partition. They are different things. Don't format that.
And succulent was talking about /rom partition which is different yet that needs to be left alone. That is where the devconf folder is. It contains things you need to keep.
If you want to understand the partition structure of the HD/HD+ go to my HD/HD+ Tips thread linked in my signature and read item 16.
And please read my PM to you about removing those assert removal instructions from my dummies thread.
Sent from my BN NookHD+ using XDA Premium HD app
Best Answer
leapinlar said:
To wipe your device with CWM go to mounts and storage and format /system, /cache and 'data and datamedia'. A normal factory reset only wipes /cache and the portion of /data that does not hold your media files. It does not wipe /system. Usually the ROM install does that, but the install script has a feature that saves gapps if you are installing the same version of the ROM (eg, CM11 over CM11). So to get rid of everything, including media files and gapps, do what I said in the first sentence. Of course after formatting /system you must put a ROM back on it for it to boot.
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Thanks for the thorough answer. And explanations. I always find it easier to remember something when I understand the reason for it. So I didn't know before that the install scripts keep gapps.(But that's what I was deducing.)
I know to stay away from /rom and /boot. Hopefully, TWRP would not let one format those in their numerous choices for Advanced Wipe.
From what you've written before in one of your other threads, I know that you're not a fan of TWRP. So I still don't know what the similar commands are in TWRP for a total clean. But for now I can delete /system in TWRP and do the reinstall without gapps. When I'm ready for a total wipe, I'll revert to CWM.
Can we trade /factory for /swap?
leapinlar said:
If you want to understand the partition structure of the HD/HD+ go to my HD/HD+ Tips thread linked in my signature and read item 16.
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Click to collapse
Read it. (And made an image of my factory partition. And then moved it to my extSDcard for safer keeping.)
So, the Nook HD+ partition structure is a bit different from the stock Android partition stuff I had found on the web.
So, for those of us running a custom ROM, I presume the factory image doesn't do us much good anymore. Will the HD+ automagically restore after 8 failed boots?
If not (or even if it will), is there a way to take that 448MB in the /factory image partition and use them for, say, a /swap partition instead? I think an xda developer is doing something like this for the Galaxy Tab 2, where he's using some memory that Samsung uses for animations and uses them for ZRam instead. Since I've backed up the factory image, and since I already have your factory 2.0.2 ROM, I really don't need the image any more. Seems like wasted space.
PMikeP said:
Read it. (And made an image of my factory partition. And then moved it to my extSDcard for safer keeping.)
So, the Nook HD+ partition structure is a bit different from the stock Android partition stuff I had found on the web.
So, for those of us running a custom ROM, I presume the factory image doesn't do us much good anymore. Will the HD+ automagically restore after 8 failed boots?
If not (or even if it will), is there a way to take that 448MB in the /factory image partition and use them for, say, a /swap partition instead? I think an xda developer is doing something like this for the Galaxy Tab 2, where he's using some memory that Samsung uses for animations and uses them for ZRam instead. Since I've backed up the factory image, and since I already have your factory 2.0.2 ROM, I really don't need the image any more. Seems like wasted space.
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Click to collapse
You can play with the partitions all you want. Just don't ask me to help you fix it. You don't seem to heed my warnings anyway.
But other users be warned that factory partition has vital backup information there (it has more than just the factory zip there) and if you lose it, your device is as good as a paperweight. That is why I recommended all users back that partition up. Not for the factory zip, but for the backup files there. The device has other safety backup routines other than just restoring the stock ROM. An example is, I told you and succulent told you that devconf has vital files all ROMs need in /rom. Well, /factory has a backup of /rom there and if the device discovers /rom is messed up, it tries to repair itself. No /factory and no repair. Paperweight!
Sent from my BN NookHD+ using XDA Premium HD app
leapinlar said:
You can play with the partitions all you want. Just don't ask me to help you fix it. You don't seem to heed my warnings anyway.
But other users be warned that factory partition has vital backup information there (it has more than just the factory zip there) and if you lose it, your device is as good as a paperweight. That is why I recommended all users back that partition up. Not for the factory zip, but for the backup files there. The device has other safety backup routines other than just restoring the stock ROM. An example is, I told you and succulent told you that devconf has vital files all ROMs need in /rom. Well, /factory has a backup of /rom there and if the device discovers /rom is messed up, it tries to repair itself. No /factory and no repair. Paperweight!
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Click to collapse
Thanks for the quick response.
I am sorry that I seem to have gotten on your bad side. I did what you asked and moved my previous comment out of your thread. And I warned everyone that you don't think it's a good procedure.
And I did heed your warning. I made a backup of the factory partition and even moved the copy to my ext SD card for safer keeping. Especially since we were talking about wiping the sdcard. (Unless you're trying to say that storing the /factory img on the ext SD card is a bad idea because I won't be able to get it back to the internal SDcard if/when I need it.)
As for the devconf files, they're in the /rom partition. I don't understand how using the /factory partition for a /swap is going to ruin the /rom partition.
From what you're saying, the HD+ still has a "safety routine" built in, even when running custom recovery and a custom ROM? Does that mean that its safety routine is hard coded somewhere? Or part of the /rom code itself? How does the HD+ know to look in /factory when its running a non-factory OS? Does CM tell it to do that?
You're the expert. I'm just guessing here. If the /factory partition were used as a /swap, and if the system turned into a paperweight because it needed the /factory image later someday, then couldn't one go into recovery and copy the /factory partition back over, per your instructions? As a minimum, couldn't one use succulent's emmc recovery procedure to get back to factory status?
I'd be willing to trade that off for more performance.
How does one know when the HD+ goes into this safety routine? Does it tell you? Or is it transparent to the user? It would be interesting to know how often that happens. Does the safety routine then repair the /rom partition once booted if it detects a problem in /rom?
PMikeP said:
Thanks for the quick response.
I am sorry that I seem to have gotten on your bad side. I did what you asked and moved my previous comment out of your thread. And I warned everyone that you don't think it's a good procedure.
And I did heed your warning. I made a backup of the factory partition and even moved the copy to my ext SD card for safer keeping. Especially since we were talking about wiping the sdcard. (Unless you're trying to say that storing the /factory img on the ext SD card is a bad idea because I won't be able to get it back to the internal SDcard if/when I need it.)
As for the devconf files, they're in the /rom partition. I don't understand how using the /factory partition for a /swap is going to ruin the /rom partition.
From what you're saying, the HD+ still has a "safety routine" built in, even when running custom recovery and a custom ROM? Does that mean that its safety routine is hard coded somewhere? Or part of the /rom code itself? How does the HD+ know to look in /factory when its running a non-factory OS? Does CM tell it to do that?
You're the expert. I'm just guessing here. If the /factory partition were used as a /swap, and if the system turned into a paperweight because it needed the /factory image later someday, then couldn't one go into recovery and copy the /factory partition back over, per your instructions? As a minimum, couldn't one use succulent's emmc recovery procedure to get back to factory status?
I'd be willing to trade that off for more performance.
How does one know when the HD+ goes into this safety routine? Does it tell you? Or is it transparent to the user? It would be interesting to know how often that happens. Does the safety routine then repair the /rom partition once booted if it detects a problem in /rom?
Click to expand...
Click to collapse
If you want to know more how the automatic repairs work, go to my Nook Color Tips thread linked in my signature and read item A12. The partition numbers are different but the repair process works exactly the same way on the HD/HD+, including the need for stock recovery to be installed. There are two ways to get your device automatically repaired if you have CM and CWM/TWRP recovery installed on internal memory. One is to flash stock recovery back per my item 5 in my HD/HD+ CWM thread, and the second is to flash the plain stock zip from item 6 there. That puts stock recovery back. Then it can repair /rom if need be.
And there is no real drawback of removing the factory.zip file from /factory partition since it is basically the same as a plain stock zip I have published. But the other files there are vital and should not be touched.
You got on my bad side by publishing that assert removal procedure on the help forum after I asked you to remove it from my thread. I don't want to make it easy for any user to do that as I consider it dangerous for noobs to do. See my response to your posting of that procedure.
Sent from my BN NookHD+ using XDA Premium HD app
leapinlar said:
You got on my bad side by publishing that assert removal procedure on the help forum after I asked you to remove it from my thread. I don't want to make it easy for any user to do that as I consider it dangerous for noobs to do.
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Thanks for letting me know. Later last night, I saw a post of yours on the Nook Color (I think it was) where you thought that anyone who would remove the updater-script safety check was an "idiot."
Okay, so I'm an idiot. But I am free to be an idiot and start my own thread in the Help forum, right? Just as you are free to respond there as you did. That's what makes the forum go 'round.
PMikeP said:
Thanks for letting me know. Later last night, I saw a post of yours on the Nook Color (I think it was) where you thought that anyone who would remove the updater-script safety check was an "idiot."
Okay, so I'm an idiot. But it's my right to be an idiot and my right to start my own thread in the Help forum, right? Just as it's your right to respond there as you did. That's what makes the forum go 'round.
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As I recall, I did not say the person that removed the assert was an idiot, it was the person who recommended it that I said was an idiot. The user was a noob and knew no better. He was trying to flash a Nook Tablet ROM to his Nook Color and the assert kept failing (doing what it was designed to do). The idiot was the one that told him just to remove the assert. He did that and bricked his Nook Color.
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