Are there any negatives to flashing a custom kernel? I want to put the knock feature on my N5 and from what I understand it requires a custom kernel. Can I just flash it or do I have to wipe my data? Thanks.
Just flash it in recovery. Wipe is not needed. If you are worried you could make back up first. Stock kernel is also available aroud the forum.
However if you are talking about the knock which wakes up tje screen, it is very power consuming in my exp...
Sent from my Nexus 5 using Tapatalk
Not really any downside. I mean technically the custom kernels on here are experimental and they're always being updated, so you might run into bugs here and there, but if you can always reflash the stock kernel if you're unsatisfied with a custom kernel.
Related
Well, I'm a complete noob and I'm a bit confused. Consider this:
I flash the phone with CM7(say). Here I'm assuming that CyanogenMod comes with its own kernel. My question is: Can I flash a custom kernel on top of this setup? and what difference does it make?
One can also think the other way round. I have flashed my phone with a custom kernel. Successively I flash CM7 on to my phone. What happens then? Is the original custom kernel wiped out to be over-written by CM7 kernel? What can be done to keep it intact? Please people solve this dilemma...
saurabh.khare1000 said:
Well, I'm a complete noob and I'm a bit confused. Consider this:
I flash the phone with CM7(say). Here I'm assuming that CyanogenMod comes with its own kernel. My question is: Can I flash a custom kernel on top of this setup? and what difference does it make?
One can also think the other way round. I have flashed my phone with a custom kernel. Successively I flash CM7 on to my phone. What happens then? Is the original custom kernel wiped out to be over-written by CM7 kernel? What can be done to keep it intact? Please people solve this dilemma...
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If you wipe your data and system partitions on your phone and then flash a ROM you'll end up having that ROM's kernel.
Anytime you can flash another kernel over the default one. You might get some
advantages, but that depends on kernel's specifications. It might get you able to
increase more the frequency of your phone's CPU. There isn't necessarily an
advantage in flashing another kernel. ROM developers usually use to provide
the most stable kernel for their rom.
So coming from dx we had no kernels to worry about. Now, my questions are.
Say I flash to a rom that now has a kernel that's flashed with the rom. And I make a backup before I flash. After being on that rom with a kernel, can I restore the backup and it restores the stock kernel that the backup was running on?
It seems I've read some people coming from cm10 trying to restore to a tw rom and it not booting, thoughts have been because of the cm10 kernel it was
the on?
If I need to flash kernels before restoring backups where do I get stock kernel and what's the proper way to get to a working backup once kernels are involved?
I hope I'm not to confusing here.
Sent from my Synergized vzw S3!
silver04v said:
So coming from dx we had no kernels to worry about. Now, my questions are.
Say I flash to a rom that now has a kernel that's flashed with the rom. And I make a backup before I flash. After being on that rom with a kernel, can I restore the backup and it restores the stock kernel that the backup was running on?
It seems I've read some people coming from cm10 trying to restore to a tw rom and it not booting, thoughts have been because of the cm10 kernel it was
the on?
If I need to flash kernels before restoring backups where do I get stock kernel and what's the proper way to get to a working backup once kernels are involved?
I hope I'm not to confusing here.
Sent from my Synergized vzw S3!
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im not sure but I think things are a bit different now with the unlocked bootloader. there was a lot of problems between kexec and switching between TW and CM10.
I think that any restore will get you back just fine as it flashes everything back including kernel. just be REALLY careful what CWM you are on. its just safer overall to stick with 6.0.1.0 as it works with every rom.
i have no idea if its on XDA but you can find imoseyon and stock kernel on rootzwiki.com
xicewallx said:
im not sure but I think things are a bit different now with the unlocked bootloader. there was a lot of problems between kexec and switching between TW and CM10.
I think that any restore will get you back just fine as it flashes everything back including kernel. just be REALLY careful what CWM you are on. its just safer overall to stick with 6.0.1.0 as it works with every rom.
i have no idea if its on XDA but you can find imoseyon and stock kernel on rootzwiki.com
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That helps a little. I know with being unlocked any recovery should work. Twrp has been good to me so far, I'm going to try and stick with it.
Sent from my Synergized vzw S3!
Nobody else is used to flashing with kernels and can give a little input?
Sent from my Synergized vzw S3!
Yes there were issues going from kexec to no kexec...I have tried almost all the ROMs out since the unlocked bootloader and not had any issues with this I have also been using a Sprint kernel and not having any issues...just make sure that you flash aosp kernels if you're using aosp and tw kernels if using a tw ROM...and personally I use TWRP and have never had any issues at all...if using TWRP just pay attention to what you're wiping because you have lots of options there
Delete
1. Unlock your bootloader first. Skip anything that says for k-exec.
2. Use latest CWM.
3. Make sure that any Kernel you use is designed for your type of ROM. JB-AOSP Kernels for JB-AOSP ROMs, ICS-TW for ICS-TW ROMs, etc. Again, make sure it is non-kexec.
4. Always wipe cache and dalvik cache when switching kernels to be sure your dalvik is rebuilt by the new kernel.
If these steps are followed you should be golden. Happy flashing!
Sent from my SCH-I535 using Tapatalk 2
Sorry if this has already been asked before. If you already have a custom ROM with stock kernel, and now you want to install a custom kernel, would you just boot into custom recovery then flash it on top of the existing ROM just like flashing Gapps? or do you have to wipe the ROM first, flash the kernel then ROM after that? Here's another question. Custom ROMs come with their own kernels, would my custom kernel get overwritten when I upgrade my ROM to a newer version (for example from cm10.1-20130226 to cm10.1-20130309?
k20- said:
Sorry if this has already been asked before. If you already have a custom ROM with stock kernel, and now you want to install a custom kernel, would you just boot into custom recovery then flash it on top of the existing ROM just like flashing Gapps? or do you have to wipe the ROM first, flash the kernel then ROM after that? Here's another question. Custom ROMs come with their own kernels, would my custom kernel get overwritten when I upgrade my ROM to a newer version (for example from cm10.1-20130226 to cm10.1-20130309?
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Click to collapse
Correct just copy the kernel to your sdcard clear cache in recovery and flash away.
I tried your ROM and rebooted twice and still looking good. Hope it'll still survive after the 3rd reboot. However, I notice some delay before the first ring back, probably due to weak signal in my area. I'll try more at different locations in the next few days to see how it goes. I really appreciate your contribution and all coders with TeamChopsticks who have nailed down the root cause of audio loss in the cm10.1 nightlies for skyrocket.
I'm having problem with Carbon ROM. My video doesn't playback I only see purple screen. However taking pictures is fine but both the qualities are low. I already set to HD. I flashed AOKP from toyes and REVOLT they had no problems with the video.
sent from Skyrocket
My apologies if this has been answered before -
1.) Should I flash a new kernel for my HOX? I am s-off, bootloader unlocked and running Viper XL 3.2.6.
2.) I know it is not absolutely necessary (flashing the kernel that is), but what are the advantages? what are the pitfalls should I be aware of?
3.) I am a relative noob so I don't think I'll be UV, OC or any of that cool stuff. So is stock better?
4.) Is there a thread out here where I can read about flashing kernels?
Thanks.
1:NO
2:None [edit] unless you flash aosp to sense kernel, visa versa.
3:matters of opinion
4:how did you achieve s-off and not know how to flash stuff?
Sent from my HOX w/CM10.1 4.2.2 s-off
Haha.. i know how to flash stuff.. it is just about the kernels.. and i wanted to read about kernels and such. not how to flash them..
thanks for the answers though
Flashing kernels is just like flashing anything else: Have a backup, clear cache/dalvik, and flash away.
The only thing to be aware of is that Sense roms need a Sense kernel, and AOSP roms need an AOSP kernel, and never the twain shall meet.
S-off removed the need to flash in fastboot that exists with 2.20 and later bases. The only reason to flash one now is because you want features in a custom kernel.
Custom kernels are "better" in the sense that you can do more with your phone, but they usually not as stable as stock, depending on how hard you push them.
Since I am not going to UV, OC etc, I guess it is better to stick with stock.
Thanks Elvis
sriramll said:
Since I am not going to UV, OC etc, I guess it is better to stick with stock.
Thanks Elvis
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Keep in mind stability has as much to do with your phone as what kernel you pick. Some phones can't take overclocking or undervolting at all without losing stability; others (like mine) can run flat out without any problems. Only way to find out is to try it.
I'd definitely recommend looking into the ElementalX kernel. For me, it's increased my battery tremendously and it's also been a good bit smoother.
is there a way to go back to stock kernel? I guess flashing the rom again?
sriramll said:
is there a way to go back to stock kernel? I guess flashing the rom again?
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Click to collapse
You can extract the boot.img from the rom you flashed and flash that. This will be the stock kernel from that particular rom.
If you're using Viper, there's an option for flashing stock kernel within the viper installer so no need to worry about extracting or reflashing the whole rom.
I am about to flash my nexus 5 device.
I was wondering.. if i unlock the bootloader and install a custom recovery plus create a backup.. that means ill have basicly a backup on my phone of a factory ROM and kernel right ?
So If i play around with custom roms and Kernels does that mean if I want to go back to stock kernel or/and ROM I can just recover my backup files from ,for example, CWM ?
And also if anyone here knows... how big difference can a kernel for battery life extension make ?
Then..
If I want to flash both.. Custom ROM and Kernel.. Rom comes first ? And if after that .. lets say I have flashed Cyanogenmod , and I have decided to change ROMs , Do I have to flash factory ROM ? Or I can just factory reset and Flash ir over the Cyanogenmod ?
For example.. for elementalX kernel I read this line... "You should only flash ElementalX over the kernel that came with your ROM!!!" I assume that means I do flash the ROM first... and what if I want to change Kernels later on? I re-flash the factory kernel ? And how do I do that?
For now that would be it
Thanks
Yes, installing a custom recovery (I recommend TWRP) allows you to create a backup of the existing ROM for restoration at a later point in time if you don't like the phone's existing ROM. Restoring TWRP backups have always worked except for me except in a couple of situations where I could not boot the restored ROM without first doing a factory wipe of the data and cache partitions.
I can't comment on custom kernels except to say that everyone uses their phone in different ways and getting the best battery life and performance may require a lot of tweaking. You could just try different kernels to see which one suits your needs.
You can restore the ROM's original kernel by extracting the kernel from the original ROM and flashing it. Alternatively, you could dirty flash the over the existing ROM. For example, if you are running CM12.1 2015-12-30 with a custom kernel and you want to go back to CM12.1 2015-12-30 without the custom kernel, you could just re-flash the entire CM12.1 2015-12-30 ROM again.
audit13 said:
Yes, installing a custom recovery (I recommend TWRP) allows you to create a backup of the existing ROM for restoration at a later point in time if you don't like the phone's existing ROM. Restoring TWRP backups have always worked except for me except in a couple of situations where I could not boot the restored ROM without first doing a factory wipe of the data and cache partitions.
I can't comment on custom kernels except to say that everyone uses their phone in different ways and getting the best battery life and performance may require a lot of tweaking. You could just try different kernels to see which one suits your needs.
You can restore the ROM's original kernel by extracting the kernel from the original ROM and flashing it. Alternatively, you could dirty flash the over the existing ROM. For example, if you are running CM12.1 2015-12-30 with a custom kernel and you want to go back to CM12.1 2015-12-30 without the custom kernel, you could just re-flash the entire CM12.1 2015-12-30 ROM again.
Click to expand...
Click to collapse
Thanks!
What advantages does TWRP has over CWM ? And also does it recover other files as well or just the system ones ?
And I guess its safer to just extract the original ROMs kernel.. Just how do i do that ?
TWRP is well supported and features a simple touch interface. TWRP will recover the system and data files.
Not necessarily safer to flash just the kernel rather than the entire ROM. It also saves time and effort because, if the kernel is not extracted and compiled for flashing in recovery, it could cause the phone to bootloop.
I've never extracted the kernel myself but this may help: https://www.youtube.com/watch?v=rLhprnOF6-U
audit13 said:
TWRP is well supported and features a simple touch interface. TWRP will recover the system and data files.
Not necessarily safer to flash just the kernel rather than the entire ROM. It also saves time and effort because, if the kernel is not extracted and compiled for flashing in recovery, it could cause the phone to bootloop.
I've never extracted the kernel myself but this may help:
Click to expand...
Click to collapse
Thanks!
So.. If, lets say, I flash cyanogenmod. Then Flash custom kernel. In order to change other kernel which is also custom , I should first flash the factory ROM which will have kernel on it ? And then reflash the ROM and then flash the new kernel ?
Im sorry , I also read a lot about this and somewhere on the way got really confused , haha.
Let's assume you flash CM version 1 and then you flash custom kernel "Kernel A". If you want to try another custom kernel named "Kernel B", you could just flash "Kernel B" over "Kernel A". If the developer of "Kernel B" cays it must be flashed over CM's original kernal, you could still flash "Kernel B" over "Kernel A" and hope it works. If it doesn't work, you could dirty flash CM version 1 over the existing ROM, then flash "Kernel B".
audit13 said:
Let's assume you flash CM version 1 and then you flash custom kernel "Kernel A". If you want to try another custom kernel named "Kernel B", you could just flash "Kernel B" over "Kernel A". If the developer of "Kernel B" cays it must be flashed over CM's original kernal, you could still flash "Kernel B" over "Kernel A" and hope it works. If it doesn't work, you could dirty flash CM version 1 over the existing ROM, then flash "Kernel B".
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Click to collapse
Thank you. Made things much clearer. Dirty flash means just flashing over the existing custom ROM and Kernel right?
And also.. What about if i have CM and Kernel B ... But i want to go change to ParanoidAndroid and still keep the Kernel B? This ROM would remove the Kernel and I would have to re flash ir right?
And also if I am just switching around ROMs only.. I can just flash them one over another? Perhaps a factory reset is healthy in between though.
Dirty flash means flashing over the existing ROM without wiping the system in recovery.
Flashing any ROM over an existing ROM will replace the system and kernel. If you want to change ROMs altogether, you'd flash PA and then flash Kernel B.
When changing ROMs, I always recommend a full wipe (i.e. system, data, cache).
audit13 said:
Dirty flash means flashing over the existing ROM without wiping the system in recovery.
Flashing any ROM over an existing ROM will replace the system and kernel. If you want to change ROMs altogether, you'd flash PA and then flash Kernel B.
When changing ROMs, I always recommend a full wipe (i.e. system, data, cache).
Click to expand...
Click to collapse
Alright. And just one last thing that I got a bit confused of..
When I root and install a custom ROM, I am not going to receive OTAs. If I just flash the newest custom ROM does that work as an update? Or the newest ROM can ble flashed over the newest android? If so... How do I exactly get the newest updates manually? I have to flash to factory ROM and then somehow flash the update? By far thats how I understood it.
rihz said:
Alright. And just one last thing that I got a bit confused of..
When I root and install a custom ROM, I am not going to receive OTAs. If I just flash the newest custom ROM does that work as an update? Or the newest ROM can ble flashed over the newest android? If so... How do I exactly get the newest updates manually? I have to flash to factory ROM and then somehow flash the update? By far thats how I understood it.
Click to expand...
Click to collapse
Depends on which rom, but updates to custom roms generally can just be flashed over. Not sure of the MM jump, but from KK to LP, it worked fine so far. Whatever you do read the instructions of the rom and kernel builders. You get lucky sometimes and can dirty flash things that should not be dirty flashed, but if there are issues, there are instructions on the rom or kernel page how to start again.
If you are factory modified and want a factory image you need to flash in fastboot. If on a custom rom, well, like I said follow their advice. Make sure to backup with recovery and save on computer before doing anything.
wangdaning said:
Depends on which rom, but updates to custom roms generally can just be flashed over. Not sure of the MM jump, but from KK to LP, it worked fine so far. Whatever you do read the instructions of the rom and kernel builders. You get lucky sometimes and can dirty flash things that should not be dirty flashed, but if there are issues, there are instructions on the rom or kernel page how to start again.
If you are factory modified and want a factory image you need to flash in fastboot. If on a custom rom, well, like I said follow their advice. Make sure to backup with recovery and save on computer before doing anything.
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Okay, thanks!
And Happy New year to you all!