After reading the forum for a few few hours and finding some great info and reading more.
My noob question(please dont bite my head of for asking)
can you flash a kernal without installing a rom? Just got my N7 unlocked it, rooted no probs. and want to take things one thing at a time.
Thanks
ajg007 said:
After reading the forum for a few few hours and finding some great info and reading more.
My noob question(please dont bite my head of for asking)
can you flash a kernal without installing a rom? Just got my N7 unlocked it, rooted no probs. and want to take things one thing at a time.
Thanks
Click to expand...
Click to collapse
yes. you can flash a custom kernel without flashing a rom. pretty much all of the custom kernels can run on stock roms. youll need a custom recovery to flash it though(or flash franco kermel through fastboot).
Absolutely. Kernel is usually contained in a boot.img while ROMs by definition are modifications to a system.img. Most ROMs either use a modified stock boot image, a custom built boot image or the CyanogenMod boot image .
The boot.img usually contains a kernel and a ramdisk. This ramdisk tells the kernel how to interface with system.img which us why I said earlier "modified" since not all boot image use stock ramdisk and need to be modified.
As for you question. There are always ways to make a 3rd party kernel integrate with a ROM or repackage a internal boot image of a ROM to contain a stock kernel. My suggestion would be find a rom you like and then flash the old boot image. This will not work on all devices so i suggest looking it up in you developers section. If worst comes to worse i would recommend googling or searching the forums for unpacking and repacking boot.img and then trying your luck at that.
Please do this at your own risk. I am not to be held responsible for your actions.
Sent from my Galaxy Nexus using xda app-developers app
Loglud said:
Absolutely. Kernel is usually contained in a boot.img while ROMs by definition are modifications to a system.img. Most ROMs either use a modified stock boot image, a custom built boot image or the CyanogenMod boot image .
The boot.img usually contains a kernel and a ramdisk. This ramdisk tells the kernel how to interface with system.img which us why I said earlier "modified" since not all boot image use stock ramdisk and need to be modified.
As for you question. There are always ways to make a 3rd party kernel integrate with a ROM or repackage a internal boot image of a ROM to contain a stock kernel. My suggestion would be find a rom you like and then flash the old boot image. This will not work on all devices so i suggest looking it up in you developers section. If worst comes to worse i would recommend googling or searching the forums for unpacking and repacking boot.img and then trying your luck at that.
Please do this at your own risk. I am not to be held responsible for your actions.
Sent from my Galaxy Nexus using xda app-developers app
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Click to collapse
most custom kernels are using koushs' anykernel nowadays, so theres no ramdisk involved, besides the ramdisk that comes with the roms kernel. this way theres a better chance of compatibility. except for franco kernel and cm kernel, which use there own ramdisk. anykernel grabs the available ramdisk(the roms default kernels ramsisk).
Related
I've searched around in the forums, and have found nothing. So here goes.
Is FFF for ALL roms, regardless of whether it is stock or not? In other words, are all the kindle fire roms out there compatible with FFF?
Also, in the threads for most roms they do not mention a specific custom kernel the rom must be used with. Does that mean that any custom kernel can be used?
oh, and all the roms, are they compatible with all the custom recoveries, or just some specific ones?
Just a little mixed up and confused xD
Thanks!
Sent from my E10i using XDA
1:I know you can for stock and cm7 but im not sure as for CM9 and MIUI
2:Most roms already have the kernals integrated in so most of the time you can just flash worry free but if you want to get technical for CM9 they have their own kernal that they're working on thats especially for the Android 4.0 of the device which in the future will probably give the KF HWA for CM9 , But for MIUI , CM7, and others they either use intersectravens kernal which is universal for all or most roms and the stock which is good for some roms not all.
3: yes most roms that people make are tested to work with either CWM or twrp . Yes CWM and TWRP have different ways of flashing their roms but i found that if you toggle signature verification on CWM you can Flash roms that you normally can only flash on twrp
aloy99 said:
Is FFF for ALL roms, regardless of whether it is stock or not? In other words, are all the kindle fire roms out there compatible with FFF?
Click to expand...
Click to collapse
yes - fff is a custom bootloader which loads before any rom - it basically allows you to switch to recovery (twrp or cwm) and activates fastboot mode for some seconds at startup (great in case of some failures)
I see, thanks!
Sent from my Kindle Fire using xda premium
Basically I've never flashed a custom kernel before so I'm trying to do some research so if someone could give me some incite or point me in the right direction I'd really appreciate it.
The only thing I'm not sure of is if I flash a custom kernel will it prevent me from receiving any future ota updates? If so, any ideas where to find a flashable stock kernel? I couldn't find one. I really want to stay with the stock rom. Had my fill of custom roms on my phone.
Sent from my Nexus 7
Y u not like roms?!
nick2418 said:
Basically I've never flashed a custom kernel before so I'm trying to do some research so if someone could give me some incite or point me in the right direction I'd really appreciate it.
The only thing I'm not sure of is if I flash a custom kernel will it prevent me from receiving any future ota updates? If so, any ideas where to find a flashable stock kernel? I couldn't find one. I really want to stay with the stock rom. Had my fill of custom roms on my phone.
Sent from my Nexus 7
Click to expand...
Click to collapse
Let's see. AFAIK yes, non-stock kernels will prevent you from getting those long-awaited OTAs (not sure though as the first thing I did after getting my N7 was to flash PA ).
If you really like the stock experience but still want a custom kernel, you must flash a custom recovery to flash kernels. The latest TWRP touch is what you need.
After you've flashed the recovery, just download the kernel zip, reboot to recovery, flash, profit.
As for a kernel, you can go with M-Kernel, DerKernel, franco.Kernel, Faux and so on and so forth. I love M-Kernel personally. You can tweak it with TricksterMOD for a smokin' good overclock as well as purty good battery life
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Also, just asking, what do you mean by a "a flashable stock kernel"? If you already have the stock kernel, why flash the same over it?
AFAIK updates to stock kernel are provided by OTAs.
I guess I was looking for a way to return to the stock kernel if need be. I have my recovery and understand that part. Just trying to make sure I understand kernels better before I brick my n7. Thanks for the help!
Sent from my Nexus 7
i also need a stock flashable kernel..just in cased i wan to revert back...
Sent from both my sexy galaxy nexus and nexus 7 X)
nick2418 said:
I guess I was looking for a way to return to the stock kernel if need be. I have my recovery and understand that part. Just trying to make sure I understand kernels better before I brick my n7. Thanks for the help!
Sent from my Nexus 7
Click to expand...
Click to collapse
Oh, ok. If you flash the stock ROM, it flashes the kernel as well (but it's a lot of work reflashing a ROM just for the kernel )
What you can do is this: extract the stock ROM zip and flash the boot.img you get.
Here's a link to the stock ROM: https://dl.google.com/dl/android/aosp/nakasig-jop40d-factory-efcec044.tgz
Edit: I figured I'd explain the rest as well...
After you download that file, untar it: nakasig-jop40d-factory-efcec044.tgz will untar to a folder probably named:nakasig-jop40d-factory-efcec044
Open that folder. You will find a zip (probably image-nakasig-jop40d.zip or something like that), unzip it.
You'll find four files. boot.img is the one you need. Flash it to your device with fastboot.
If you wan a flashable zip, unzip any custom kernel, replace the awesome custom boot.img with the boring stock one and rezip. You should be able to flash it from TWRP or CWM.
Note that the stock kernel nukes CWM on first boot. I assume you don't have root. Do this:
1. Connect the N7 to your PC. [you should have debugging enabled in dev options]
2. Open an adb shell and type this: mv /system/recovery-from-boot.p /system/recovery-from/boot.p.bak
3. ???
4. Profit
[If you do have root, open a file manager, remount /system as read/write and rename /system/recovery-from-boot.p to something.]
Click thanks if I helped!
That's why I was hoping to find the JOP40D stock kernel as a flashable zip. But I'll give the boot. I'm a shot. Thanks again!
Sent from my Nexus 7
nick2418 said:
That's why I was hoping to find the JOP40D stock kernel as a flashable zip. But I'll give the boot. I'm a shot. Thanks again!
Sent from my Nexus 7
Click to expand...
Click to collapse
I added some stuff, see if it helps.
It would be nice if you clicked "thanks" below my post
stock flashable 4.1.2 kernel for grouper(put up by faux as a "reset" kernel) http://faux.androidro.ms/grouper-faux123-reset-kernel-4.1.2.zip (should be fine on 4.2.1)
flashable in twrp or cwm recovery. no hoops to jump through flashing or after flashing this. it doesnt nuke your recovery.
simms22 said:
stock flashable 4.1.2 kernel for grouper(put up by faux as a "reset" kernel) http://faux.androidro.ms/grouper-faux123-reset-kernel-4.1.2.zip
flashable in twrp or cwm recovery. no hoops to jump through flashing or after flashing this. it doesnt nuke your recovery.
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Click to collapse
Will that work with OP's 4.2.1?
Awesoham said:
Will that work with OP's 4.2.1?
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Click to collapse
yea. i occasionally run a 4.1.2 trinity kernel on my 4.2.1 rasbean jelly rom
Why is it that I have to reflash a custom kernel every time I flash the newest build of a rom?
Any time you flash a custom ROM, it will always include some kernel along with it. Hence, when you flash the newest build of a rom, you're also re-flashing the original kernel that it came with.
btse said:
Any time you flash a custom ROM, it will always include some kernel along with it. Hence, when you flash the newest build of a rom, you're also re-flashing the original kernel that it came with.
Click to expand...
Click to collapse
I see. Thanks! So I pretty much gotta flash my own custom kernel every time then?
As far as I know yes. There could possible be some way of flashing without the kernel, but I think it's much safer to just flash the whole custom ROM and then re-flashing your own custom kernel.
Yeah the easiest thing to do is just install the ROM with its kernel then just flash your kernel of choice.
Sent from my Nexus 4 using Tapatalk 2
I'm just coming from the S2 EG4T where, from what I understand, the kernel and recovery were all contained in one file. Is this different for the S4...are they separate?
If they are separate files, I am rooted, and want to get a custom recovery so I can flash some mods. Do I also need a custom kernel or do I only need a custom kernel to over/underclock/get additional governors and schedulers?
Thanks for helping me understand this new phone of mine.
Foulwx
yes recovery is separate thankfully. you are free to flash kernels all you want and your recovery will be untouched.
see the kernel threads for info on what they features they offer.
Foulwx said:
I'm just coming from the S2 EG4T where, from what I understand, the kernel and recovery were all contained in one file. Is this different for the S4...are they separate?
If they are separate files, I am rooted, and want to get a custom recovery so I can flash some mods. Do I also need a custom kernel or do I only need a custom kernel to over/underclock/get additional governors and schedulers?
Thanks for helping me understand this new phone of mine.
Foulwx
Click to expand...
Click to collapse
Yups, what lafester said is corrrect. For the recovery, I recommend TWRP v2.5.0.2. You can download and install via Goomanager from the app store. It's a touch-based recovery and it also supports up to 64GB exFat microSDs.
As for custom kernels, my current favorite is agat's v0.2.0 kernel.
Is it possible to take a custom ROM that uses a custom kernel and modify it, either by flashing or manually editing the zip file, to use a stock kernel instead?
Just a thought I had to help those with locked bootloaders.
Apoplectic1 said:
Is it possible to take a custom ROM that uses a custom kernel and modify it, either by flashing or manually editing the zip file, to use a stock kernel instead?
Just a thought I had to help those with locked bootloaders.
Click to expand...
Click to collapse
If it uses a TW based kernel, no changes are needed of course. AOSP is different enough that booting it on a locked bootloader stuck on a different kernel is generally accepted as not something to spend time on. Just putting a stock kernel in the ROM zip doesn't help since Safestrap doesn't flash them anyway. In order to make it work, you'd have to make sure everything was set up the way the kernel wants it and calls for things.
Sent from my SGH-I337 running GPE
DeadlySin9 said:
If it uses a TW based kernel, no changes are needed of course. AOSP is different enough that booting it on a locked bootloader stuck on a different kernel is generally accepted as not something to spend time on. Just putting a stock kernel in the ROM zip doesn't help since Safestrap doesn't flash them anyway. In order to make it work, you'd have to make sure everything was set up the way the kernel wants it and calls for things.
Sent from my SGH-I337 running GPE
Click to expand...
Click to collapse
Well damn, thought I was onto something .
I may give writing my own TW based kernel+ROM package a go then.