nandroid restore kernel? - Samsung Galaxy Nexus

Took the plunge and flashed custom ROM and kernel. Battery is being sucked dry at a rate about 10x faster than my stock config. If I restore my nandroid backup from before flashing anything, will the Kernel be restored too?
On the Epic4G three kernel was ina separate partition that had to be flashed on its own. Nor sure if the new memory architecture works the same way.
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yes, nandroid restore from CWM will restore your kernel too... and you always have a fastboot option to flash your boot.img again if you want run a custom rom with stock kernel

Ahhh... thanks! Wasn't sure if the boot.img listed in the status messages from CWM was the kernel, or something else (like the bootloader, the recovery image, or something else). I'll submit a request to koosh to maybe add parenthetically to the status messages something like this:
backing up boot.img (kernel)
restoring boot.img (kernel)

Related

How to backup and flash kernel

Hi,
I just flashed the new rmk gingerbread sense ROM to my Desire Z, and I'm thinking of trying the unity v3 kernel since it seems to have better battery life and performance from what I'm reading.
I've never flashed a kernel before. It seems like the flash process is identical to flashing a ROM? i.e. place the zip file in my sdcard, go to ROM manager and flash it there?
How do I backup the previous kernel though? Do I just do a backup via the ROM manager, which backs up everything, or do I backup just the existing kernel? Also, if I have the rmk ROM zip in my sdcard, if anything goes wrong with the kernel flash, can I just flash that zip in recovery boot? That way I don't have to backup anything.
Also, do I still need SetCPU to manage governors and clockspeeds? Not sure if anything has changed...
Thanks!
Do a full nandroid backup before flashing a new kernel. Nandroid backup will back-up the kernel and the entire ROM.
Flashing a kernel.zip is the same as flashing a ROM. Enter recovery, select "install .zip from SDcard" and proceed from there.
If the kernel causes problems or isn't working properly, revert to your previous nandroid backup.
Depending on the ROM and kernel combination, SetCPU may be required or advised, such as with a high OC kernel. Everyone has their own method to setting profiles, however.
Thanks.
I'm using rmk vision gingerbread sense 2.42. If I already have this downloaded ROM zip file in my sdcard, can I just flash back to this, rather than do a nandroid backup and restore to that? Does the nandroid backup keep my user settings?
Thanks.
goister said:
Thanks.
I'm using rmk vision gingerbread sense 2.42. If I already have this downloaded ROM zip file in my sdcard, can I just flash back to this, rather than do a nandroid backup and restore to that? Does the nandroid backup keep my user settings?
Thanks.
Click to expand...
Click to collapse
No, don't just flash over it. You're best off simply using CWM to backup and restore. The nandroid backup makes a complete perfect copy of the state of your phone at that time, restoring to it makes it seem as though nothing has happened after that point.

[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

Do I need to reflash boot.img when restoring ROMs?

Hello,
This is probably a silly question but I was just wondering if I had to reflash the correct kernel when I restore a ROM. Let me give a scenario as I don't think I can find a decent way to word it.
Lets say I flashed PACman last week and that runs on Hellboy CM10 kernel but then I fancied a change so I did a Nandroid backup in CWM, flashed a Sense kernel (Like Titanium Kiss) then flashed a Sense ROM such as SuPrimo. If I decided to switch back to PACman would I have to flash the boot.img (Hellboy CM10 in this case) before hand or is the boot.img stored in the Nandroid backup?
I'm just curious.
Thank you,
Curtis.
Hello Curtis,
The boot.img is backed up in the nandroid backup.if you open the backup using winrar,you will be able to see it.
you will need to flash the Hellboy kernel again or Pacman will not boot.
If our device was s-off,there would be no need to flash the kernel as it would automatically flash it.
It(boot.img) is stored in the backup,but you must flash it.
U must flash boot.IMG while restoring pacman... that's what while restoring ROM first u should flash boot.IMG
Sent from my One V using Tapatalk 2

[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!

[Q] How to flash a boot.img without fastboot?

Samsung apparently does not allow you to boot into the bootloader on their phones. I am trying to return to a different kernel I was using previously, which was contained in a nandroid backup. However, to my understanding, restoring a nandroid backup does not restore the kernel, and you have to extract the boot.img and flash that by itself.
What is the best way to go about doing this without fastboot?
Also, I don't suppose "restore boot" in nandroid advanced restore does this now, does it? Can't find anything on it online.
From what I recall, restoring the nandroid backup would restore the kernel. What recovery was used to create the nandroid?
audit13 said:
From what I recall, restoring the nandroid backup would restore the kernel. What recovery was used to create the nandroid?
Click to expand...
Click to collapse
I used CWM. I read in several places (forums) that it didn't....Hm. I mean I have the boot.img from the backup, so I have the kernel right there. I suppose I could find some way to make it into a flashable zip, but I was just wanting to see if anyone knew a way around that.
But if you are confident that the backup would restore the kernel, do you know if I could restore just the kernel from advanced restore? It'd be fab if I could keep /data the same, but not a must I suppose.
I use TWRP on an HTC and just restored a nandroid backup. After restoring the backup, the previous kernel was restored too.
I don't have any devices at the moment that use CWM.
Not sure about just restoring the kernel. Any particular reason you just want to restore the kernel?
audit13 said:
I use TWRP on an HTC and just restored a nandroid backup. After restoring the backup, the previous kernel was restored too.
I don't have any devices at the moment that use CWM.
Not sure about just restoring the kernel. Any particular reason you just want to restore the kernel?
Click to expand...
Click to collapse
I started getting some problems after flashing a custom kernel and I want to revert to the previous one, the default CM one, to test if my problems are related to that kernel or not. I suppose I'll look into making the .img a flashable zip then, unless anyone else knows of a better way. I'm not familiar enough with Odin to know if you can flash a .img in it.
There's that "restore boot" option in the advanced restore menu on CWM. Do you have any idea what that restores? I want to naturally say that it probably restores the boot.img, but I have searched and searched and just cannot find anything online about what that actually restores.
Nandroid backups created with CWM need to be restored using CWM.
Sorry, not sure what the advanced options will do but you could try different ones.
Restoring boot in advanced nandroid restore restores the zimage and initrd.gz. The kernel. Thus, I suppose a full restore will restore the kernel. Perhaps there are exceptions for certain devices. Restoring boot got me where I needed.
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