Develop Bugs

[Q] Nandroid backup and boot image restore

Hey,
If you do a nandroid backup, then wipe, flash a new rom and a new boot.img, will the boot.img from the previous rom be restored if you do restore it? Or do you have to fastboot flash it again? If so, is the boot.img which is found in the backup folder the one to use?
Thanks

yeah i am wondering the same question. Actually I have a nandroid backup of the stock rom, and i flashed other roms before too. I tried nandroid restore and everything did go back to stock, but I am concerned whether I need to flash any boot.img? if the stock kernel is untouched while flashing other roms, does that mean i dont need to reflash the boot.img?

When flashing other roms the stock kernel is not changed. Unless you have an s-off device. If you did not fastboot flash boot boot.img then when you restore your back up you will be fine. If you did flash a new kernel then you will need to flash the boot.img for your backup as the backup will only restore the kernel on s-off devices.
Sent from my HTC One X using Tapatalk 2

[Q] Do I ALWAYS have to flash a new boot image when installing a rom?

Hello,
I'm coming from a HTC Desire, and when reading the guides how to install roms on the HOX, the neccesity to flash a separate boot.img for every rom via fastboot was new to me.
Is this always the case? And lets say I have a stable 4.0.4 installation and want to mess around with CM10 - I get that have to flash the CM10 boot.img before installing the ROM, but would I then also have to re-flash my old boot.img before rstoring my old nandroid backup, or is the boot image included in the backup?
Thanks aheasd for an answer,
saxelfur

i guess yes.. you have to re-flash the boot.img of the rom that you are restoring...

faiz02 said:
i guess yes.. you have to re-flash the boot.img of the rom that you are restoring...
Click to expand...
Click to collapse
Okay, thanks - so I suppose right now there is now way to restore a backup from a different rom on the go. Oh well, I should be able to live without that

saxelfur said:
Okay, thanks - so I suppose right now there is now way to restore a backup from a different rom on the go. Oh well, I should be able to live without that
Click to expand...
Click to collapse
You do not have to flash the boot.img before restoring a nandroid backup...Y
ou restore everything, boot.img included.

panooos said:
You do not have to flash the boot.img before restoring a nandroid backup...Y
ou restore everything, boot.img included.
Click to expand...
Click to collapse
Great, even better!

panooos said:
You do not have to flash the boot.img before restoring a nandroid backup...Y
ou restore everything, boot.img included.
Click to expand...
Click to collapse
Not true; if you're restoring a backup which used a different boot.img than the one you already have installed, you need to manually flash the boot.img from your nandroid backup in fastboot.
The reason we have to use fastboot to flash the boot.img is that, thanks to HTC's security policies, it is not possible to write to the boot partition from recovery. Hence when you flash a ROM the boot.img isnt written, and has to be manually flashed. This also means that when you restore a backup in recovery it is still unable to write to the boot partition, so the boot.img from your backup is not written and must also be flashed manually.

hopscotchjunkie said:
Not true; if you're restoring a backup which used a different boot.img than the one you already have installed, you need to manually flash the boot.img from your nandroid backup in fastboot.
The reason we have to use fastboot to flash the boot.img is that, thanks to HTC's security policies, it is not possible to write to the boot partition from recovery. Hence when you flash a ROM the boot.img isnt written, and has to be manually flashed. This also means that when you restore a backup in recovery it is still unable to write to the boot partition, so the boot.img from your backup is not written and must also be flashed manually.
Click to expand...
Click to collapse
Really? I once flashed a kernel and could not pass the loading screen...everything got fixed as soon as i restored my backup...

Lucky for you. But these guys are correct. The only way to flash boot is through fastboot.
Recovery restore cannot restore a boot.img
Sent from my HTC One X using xda app-developers app

panooos said:
Really? I once flashed a kernel and could not pass the loading screen...everything got fixed as soon as i restored my backup...
Click to expand...
Click to collapse
Yep. Boot partition simply isn't writable from recovery (without s-off). There's no difference between recovery trying to write a boot.img from a zip on /sdcard and recovery trying to write a boot.img from a folder on /sdcard (if there was we would just need to modify recovery to treat new flashes as restores to get around the problem).
I'm not saying it won't work if you don't; if you're switching between Sense ROMs or restoring an earlier version of the ROM you're using then there's a good chance that the ROM will still boot and run fine, but you'll be running with the kernel & ramdisk you had before the restore.

Always learning sth new... Ty
Sent from my HTC One X using xda app-developers app

Well shoot. How do I get the boot.img from the stock rom that came with it. It wasn't exactly in standard .zip format for me to extract the .img......

If you did a nandroid backup it's there in plain sight.

[Q] Bit of a noob question regarding backups and switching ROMs

I just want to confirm this and it might be a foolish question... But if I'm using AOKP and I have a CM10.1 backup, can I do a restore to that backup and it will restore to that ROM as well? Or do I need to re-flash CM10.1 before restoring the backup?
Thanks, still figuring all this out!

The backup contains everything of the rom. Apps/contacts...you name it. Make sure when you are coming from another rom back to the backup to flash the boot.img from the backup !

Mr Hofs said:
The backup contains everything of the rom. Apps/contacts...you name it. Make sure when you are coming from another rom back to the backup to flash the boot.img from the backup !
Click to expand...
Click to collapse
Thanks for the quick answer! It actually looks like CWM automatically does the boot.img as well! At least for AOKP back to CM10.1...
Thanks again!

A nandroid backup contains all ! ,the recovery at the time of backing up. Even the boot.img. restoring a nandroid backup wont restore the boot img. It needs to be flashed manually

[Q] Quick Question on boot.img from Nandroid recovery...

Hey guys, just a quick question about restoring from a nandroid backup. Let's assuming I'm using custom rom A and made a nandroid backup of it. Then later on, I change to custom rom B and made another nandroid backup of that.
Well, assuming the boot.img from both custom rom A and B are different, then say if I were to restore back to custom rom A, I would have to re-flash the boot.img for that rom correct? OR, will restoring custom rom A from the nandroid backup also flash the boot.img for me automatically?
I came from other phones where flashing a new rom or from a nandroid backup is simply a one-step process. HTC One X is the first phone I've used where I have to deal with flashing the boot.img as an additional step as well, so just wanna confirm if this is the case for a nandroid restore as well.

chaoscreater said:
Hey guys, just a quick question about restoring from a nandroid backup. Let's assuming I'm using custom rom A and made a nandroid backup of it. Then later on, I change to custom rom B and made another nandroid backup of that.
Well, assuming the boot.img from both custom rom A and B are different, then say if I were to restore back to custom rom A, I would have to re-flash the boot.img for that rom correct? OR, will restoring custom rom A from the nandroid backup also flash the boot.img for me automatically?
I came from other phones where flashing a new rom or from a nandroid backup is simply a one-step process. HTC One X is the first phone I've used where I have to deal with flashing the boot.img as an additional step as well, so just wanna confirm if this is the case for a nandroid restore as well.
Click to expand...
Click to collapse
You have to flash the boot.img for the ROM you're restoring through fastboot. Recovery cannot flash boot.img for you since you need S-OFF, which impossible to achieve (let's not go there).

tomascus said:
You have to flash the boot.img for the ROM you're restoring through fastboot. Recovery cannot flash boot.img for you since you need S-OFF, which impossible to achieve (let's not go there).
Click to expand...
Click to collapse
yup got it. Thanks!

OTA update to N

Hello everybody, it is time to update to Nougat and I'm ready to do it.
According to this thread https://forum.xda-developers.com/showpost.php?p=59745198&postcount=3
I need a system_image and stock recovery backup for being able to do an OTA.
I did it and I must restore the system_image and the stock recovery as written in point 8.
But according to this other thread https://forum.xda-developers.com/showpost.php?p=64299835&postcount=4
in Hidden Content point 13, I must backup the system_image, the stock recovery and the boot image.
I have only backupped system_image and recovery and I can download boot.emmc.win from the second thead, but I wish to ask:
Is it really necessary to restore boot.emmc.win? Now I'm on ViperOneM9 4.3.0
Why @Captain_Throwback didn't mention it in his official TWRP thread?
I thank you in advance anyone may help me to get the OTA in the right way

Balteck said:
Hello everybody, it is time to update to Nougat and I'm ready to do it.
According to this thread https://forum.xda-developers.com/showpost.php?p=59745198&postcount=3
I need a system_image and stock recovery backup for being able to do an OTA.
I did it and I must restore the system_image and the stock recovery as written in point 8.
But according to this other thread https://forum.xda-developers.com/showpost.php?p=64299835&postcount=4
in Hidden Content point 13, I must backup the system_image, the stock recovery and the boot image.
I have only backupped system_image and recovery and I can download boot.emmc.win from the second thead, but I wish to ask:
Is it really necessary to restore boot.emmc.win? Now I'm on ViperOneM9 4.3.0
Why @Captain_Throwback didn't mention it in his official TWRP thread?
I thank you in advance anyone may help me to get the OTA in the right way
Click to expand...
Click to collapse
If I didn't mention it, then you don't have to do it .

@Captain_Throwback can you maybe explain that a little further? I made the experience that people are facing problems if they return from a custom rom to a stock rom and don't wipe their phone. That's why I added the wiping step to my instructions. After that several users reported that their phones didn't boot after they restored the first version of my backups (which lacked the boot.img). Therefore, I thought the boot.img is needed as well and all backups got replaced over a year ago with the current version which includes the boot.img.
However, all this is based on the reports of users who had problems with returning back to stock. I've never faced these issues myself. So if there is anything wrong with my instructions I'll correct them, of course.
Sent from my HTC One M9 using XDA Labs

I thought it's impossible to backup the stock recovery seeing as twrp is needed to be flashed to make the backup..
Beamed in by telepathy.

shivadow said:
I thought it's impossible to backup the stock recovery seeing as twrp is needed to be flashed to make the backup..
Beamed in by telepathy.
Click to expand...
Click to collapse
Since firmware 3.x you can boot TWRP via fastboot from the bootloader without overwriting the currently installed stock recovery.

Flippy498 said:
@Captain_Throwback can you maybe explain that a little further? I made the experience that people are facing problems if they return from a custom rom to a stock rom and don't wipe their phone. That's why I added the wiping step to my instructions. After that several users reported that their phones didn't boot after they restored the first version of my backups (which lacked the boot.img). Therefore, I thought the boot.img is needed as well and all backups got replaced over a year ago with the current version which includes the boot.img.
However, all this is based on the reports of users who had problems with returning back to stock. I've never faced these issues myself. So if there is anything wrong with my instructions I'll correct them, of course.
Click to expand...
Click to collapse
Not sure what to explain - OTA does no verification on boot.img. So it doesn't have to be stock for an OTA to install. It's that simple.

Captain_Throwback said:
Not sure what to explain - OTA does no verification on boot.img. So it doesn't have to be stock for an OTA to install. It's that simple.
Click to expand...
Click to collapse
OK. I guess there was a little misunderstanding.
The current version of my instructions is meant to be used if you want to return to a clean stock system. (In other words the ability to install OTAs, again, is only a side effect.) I never was talking about the boot.img being necessary for being able to install the OTA. I thought you were saying that the boot.img wouldn't be needed inside a backup if you do a full wipe before the restoration and that the phone would still boot.
Sent from my HTC One M9 using XDA Labs

I'm little confused now.
For installing an OTA update I MUST have an untouched system partition and stock recovery.
But the steps I need to do are:
1) backup apps and settings
2) restore untouched system partiton and stock recovery partition from TWRP, doing a factory reset (wipe data, dalvik and cache)
3) boot the original stock OS, configure wifi and go to Software Update
4) download OTA(s)
5) apply update and reboot phone
6) with ADB start TWRP recovery and backup the new stock recovery and the new stock system_image
7) flash TWRP and new custom ROM
8) restore apps and settings from point 1)
So, is it possible that at step 3 my HTC cannot boot because I didn't restore the boot partition (I'm coming from ViperOneM9 4.3.0)?
Or is there a simpler method, without backuping, wiping, restoring?

Flippy498 said:
Since firmware 3.x you can boot TWRP via fastboot from the bootloader without overwriting the currently installed stock firmware.
Click to expand...
Click to collapse
Looks liks i used an out of date tutorial then.. What a bugger..
Beamed in by telepathy.

Anyone can confirm me that my previous steps are right?
So I may uodate to Android n without doubt
Thank you very much