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Difference between ROM and Kernel?

Hello,
Sorry for this very basic question, I am just wondering what is the difference between a Kernel and a ROM? I see in the development forum there are lots of new Kernels, what are these actually optimizing except underclocking or undervolting (understand that terminology). I am also wondering if the Kernels are specific for the original Nexus One 2.1 Android or can you install for example Modaco or Cyan ROM and then a different random Kernel?
Thanks!

To my understanding, a kernel is what directly interacts with the hardware. Every OS has this, but it's more customizable on our phones since it's based on Linux. The Rom contains the OS itself, and the software and file structure therein. The kernel even can tell the OS how fast the processor goes and how much juice to use from the battery.
Hope that makes sense, as I'm no expert. You can mix and match the two as far as I know. I've mixed them, anyway.

Halorin,
Based on what you said, with my stock vibrant ROM 2.1 JI6 update, it is possible to change the kernel or install another kernel (like the CM kernel)?

tomasitoc said:
Halorin,
Based on what you said, with my stock vibrant ROM 2.1 JI6 update, it is possible to change the kernel or install another kernel (like the CM kernel)?
Click to expand...
Click to collapse
That is really a question better suited to the rom 's development thread, but in general yes you can flash a different kernel. Some kernel/rom combinations work better than others, but you really wont know until you try. Get comfortable with nandroid backups and start trying out different kernel combinations until you find one you like.

Usually most custom roms will include a kernel but they usually have tweaks like coding for 720p, oc, and audio tweaks and what not. Alsways do a nandroid back up and start exploring. When flashing kernels always wipe, I think their are exceptions but its best to wipe just in case. Browse XDA, download a kernel from your phone browser, rom manager install from SD, should be in your downloads folder, backup and wipe, repeat until your phone does what you want.
Sent from my Nexus One using XDA App

which is the better to install???
Thank you your post..
but i can't understand clearly.
so.,
which one is better to install NewRom / Kernal. for android phones.

Neither one is better it just depends on what you want to do.
If you want to totally change over your phone to look and function differently then you need to flash a ROM if you just want to keep the same look but want to enable lets say overclocking then flash an overclocked kernel. If it has to do with the hardware mostly then it's probably something that the kernel can change. Although like mentioned above if you flash a ROM most of the time it will come with a custom kernel.

Dude Random21 said:
Neither one is better it just depends on what you want to do.
If you want to totally change over your phone to look and function differently then you need to flash a ROM if you just want to keep the same look but want to enable lets say overclocking then flash an overclocked kernel. If it has to do with the hardware mostly then it's probably something that the kernel can change. Although like mentioned above if you flash a ROM most of the time it will come with a custom kernel.
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Click to collapse
What he said.
ROMs and kernels are two separate things that have two separate functions. Neither is better than the other, but they do complement each other.

Seshu9899 said:
Thank you your post..
but i can't understand clearly.
so.,
which one is better to install NewRom / Kernal. for android phones.
Click to expand...
Click to collapse
I know both Dude Random21 and codesplice have gone into this, but to try and give a bit more info...
The kernel is kinda like the nervous system of the body. It directly interacts with the hardware (which is how it is able to adjust CPU speed) and it is what allows the ROM to function.
The ROM is the rest of the body. Every other aspect of the phone. In fact, most ROMs include custom kernels. Various ROMs give you various features/enhancements/bugfixes. You will probably notice the biggest change in your phone if you load a custom ROM. Most people load the custom kernels to help with battery life as a lot of them allow you to lower the phones minimum processing speed from 245Mhz to 128MHz.
The ROM can change so many different aspects of how the phone works. There is CyanogenMod which is based off of stock Android with a lot of tweaks, bugfixes, and new features added. There is also MIUI, which is similar to the iOS style (not the same, but much closer than stock Android), and then there are a ton others out there.

Then which Rom is best for my samsung galaxy s???
so i am using froyo.jpjpg on my galaxys.
i want to flash new Rom with upgaraded to gingerbread.
can i flash only rom../ kernal also.
which is best Rom for samsung galaxys.
cynogenmod, miui, .?????
battery drain is very fast now ian running rom/kernal.

Start by going to the forum for your phone.
Sent from my Nexus One using XDA App

thank you...
i Start the post from samsung galaxy s..

Seshu9899 said:
thank you...
i Start the post from samsung galaxy s..
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Click to collapse
your welcomed

Nandbackup + Rom & Kernel
One question: when I do a backup with CWM, it is the Nandroid backup you talk about, correct...? Same thing? So, if I do a backup with CWM, it's a backup only of the ROM, or also the stock Kernel...? Imagine that I do a Rom (GingerDX for example), and flash with a custom Kernel.... If things go bad and I do a restore from my backup (stock) CWM, what do I restore? Rom, or Rom + (stock) Kernel...?

Yes, a backup that is done in ClockworkMod (or Amon_RA) is considered a nandroid backup. And this takes a complete snapshot of your system. Your ROM, your kernel, your apps and your data are all inlcuded. The only thing that isn't included is the fat partition on your sdcard. So if things go bad and you restore your nandroid backup, it will go back to however it was when you made the backup.

thanks a lot. reading this thread clear up a lot of things

Hi!
I am currently running Lite'ning ROM 6.1. XXKH3 Kernel version 2.6.35.11-ninphetamine-2.0.5+ [email protected] #20 on SGSII. Phew.
I've tried a lot of ROMS including MIUI, villain, galmetMIUI ICS version . I like Lite'ning ROM because it gave me the least (virtually Nil) problems (FCs/ reboots) and has almost all the features I need (TV-out that's missing from MIUI, good camera with panorama mode, Recording mode in phone). However I miss the CIFS feature. Is it because the kernel does not support it? Can I get CIFS support if I flash another kernel? Any suggesstions on which Kernel should I flash? I realise that this ROM is pretty old now so Can I get additional features with a newer Kernel.

codesplice said:
What he said.
ROMs and kernels are two separate things that have two separate functions. Neither is better than the other, but they do complement each other.
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Click to collapse
That made everything clear. Thanks man. I'm new to the xda but already flashed a new rom that overclocked my CPU to 1.5 and my HTC Sensation 4G Is running so much better right now. However I wish i knew how to thank people... because i see the thanks meter but cannot find where to thank from.

radoslav.trahanov said:
That made everything clear. Thanks man. I'm new to the xda but already flashed a new rom that overclocked my CPU to 1.5 and my HTC Sensation 4G Is running so much better right now. However I wish i knew how to thank people... because i see the thanks meter but cannot find where to thank from.
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Click to collapse
The rom didn't overclock your phone. The kernel did. READ. You came to the MT4GS forum starting up a storm for people not giving you a direct link to the regular MT4G. How is it you cant find the freakin' "thanks" button? THERE'S A FREAKIN' THANKS BUTTON IN EVERY FREAKIN' POST. OPEN YOUR FREAKIN' EYES.

Sori m jst new here..jst b0ught my f0ne 2 m0nths ago. Flashed r0m: gingercrime ITA, flashed kernel: ver 2.6.35.14 v6. And iv overclock my fone 245-710Mhz, smartass. fone: lg optimus one, running on gingerbread 2.3.3
Many thanx xda developers..!!

Overclocking the Stock Rom on Heroc

I like the stock ROM because it works. I think all I really need is root access and overclocking to have a good fast phone. What would be the best kernel to use with it if all I want is overclocking? Is not having a custom ROM a stupid idea?

Here's your ROM:
http://forum.xda-developers.com/showthread.php?t=703267
It's basically the stock Sprint 2.1 ROM that's been de-odexed. I use it and am plenty happy. If you like the stock Hero look and feel, then you'll be plenty happy with this ROM.
I'm also using an overclock kernel. You can use the SetCPU app (available for free elsewhere on this site) to fine-tune your max and min CPU clock speeds.
Here's a link to a whole family of overclock kernels, some of which were cooked up specifically to work well with the above-mentioned ROM:
http://forum.xda-developers.com/showthread.php?t=705074
I've been using the regular 710mhz version of kernel listed for that ROM, but yesterday I loaded the 710mhz undervolt version just to see if my battery life would benefit any. Not that my battery life is a problem at all, though...in fact I've been getting GREAT battery life with the regular 710 mhz kernel I was running before.

I am using the same Rom but I seem to have issues with the OC kernels specifically for the Rom. I use the DarchHoneyOCV3 kernel and do not seem to have any issue with that one.

Tibedabeeto said:
I am using the same Rom but I seem to have issues with the OC kernels specifically for the Rom. I use the DarchHoneyOCV3 kernel and do not seem to have any issue with that one.
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That's the same kernel I was using before I went to the UV 710mhz for nfinitefx45...DarchHoneyOCV3 is a good kernel for sure, can't find fault with it.
Forgot to mention in my previous post, the reason I recommend the nfinitefx45 ROM is because it includes apps2sd, which lets you put your apps on the sd card and frees up active RAM (hope I stated that correctly). I never worry about running out of memory any more. And for all intents and purposes, it looks, feels and acts just like the factory Sprint 2.1 release. When you're done with the install, just use your phone like it was completely factory stock (only faster and smoother) if that's what makes you happy. On the other hand, if you want you can install the SetCPU app and tweak it however you want.
Don't be afraid to take the plunge, parrothead. You'll be in good company. And you almost can't go wrong going with the same combination Tibedabeeto did, as long as you can follow simple directions (I know I should put a disclaimer in there somewhere, LOL).

[Q] Samsung Galaxy S Overclock PLEASE READ

This thread is somewhat different from others. I am fully aware that overclocking requires a custom kernel however with the Application "Galaxy Tuner" my CPU on my SGS i9000 can go 1.2GHZ with a custom Voodo Kernel not supporting Overclock. I am not sure what method the guy uses and he only allows it to be used 2 minutes at a time, so I was wondering if this would be just as risky / safe to do as going into a new kernel and doing such.
If the first is not possible and I would have to use a custom kernel as it is safer, please PM me some kind of contact information as I am afraid I will break my Phone as I use a custom Voodo kernel + DArkys EXTREME ROM 9.X

Still need to know wheter or not it is safe to overclock the way the application "Galaxy Tuner" does or if its SAFER to do it with a custom OC'ing kernel.
If last, I need some help over Skype / msn

I expect an answer when so many viewed this thread....

cocopara said:
I expect an answer when so many viewed this thread....
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I wouldn't expect anything, just because people like me view it doesn't mean we know anything about it.....why don't you email the author of the app.

spectre85 said:
I wouldn't expect anything, just because people like me view it doesn't mean we know anything about it.....why don't you email the author of the app.
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Click to collapse
Exactly, views don't mean answers! It can be frustrating seeing a lot of views and no answer, but you must acknowledge that viewers may be looking for the answer themselves or just plain don't know. Be patient.

Well. Still, I am wondering about the overclocking that The application uses (Galaxy Tuner) because it manages to overclock a phone WITHOUT a custom OC'ing kernel. Hence i am wondering if it is just as SAFE to do as using a custom kernel.
If not, I need some guidance as I dont know how I can switch my kernel and update my ROM

The code to overclock existed on stock kernel sources apparently, it was just commented out.
When OC in this app is enabled, the CPU governor is changed to performance, and the clocks were changed. So I'd wager it's equivalent in terms of safety to a custom kernel.
Why only do the above for 5 minutes at a time when a custom kernel allows you to always have an overlclock? Just use a custom kernel..

I'm using a custom kernel to overclock to 1.2ghz and my battery is exactly the same as it's always been. I'm also underclocking to 100mhz with setCPU when the phone is idle so that's a big help. It's perfectly stable on mine but CPUs can differ so I suggest that if you do flash a custom kernel with overclock that you start lower and stress test just to make sure there are no issues. Also, don't save any voltage control settings as default until you have applied and stress tested.
Also, make sure to keep a spare kernel in zip form and always have backups.

I use super optimized kernel. Though I am looking for a 500-1000 HZ OC kernel. Any suggestion?

I don't know what method this app is using, but just due to my own paranoia I would say using a kernel with OC is safer. Too many horror stories of apps bricking phones due to small errors or badly written instructions.
Beyond that, it just takes experimenting. I am currently using DamienGTO's Ultimate Kernel OCed to 1200 and have had no problems with it, but there are a lot of high quality kernels available down in the Android Development forum. I suggest you install SGS Kernel Flasher from the market (a great app, makes kernel flashing painless and dead simple), download the newest versions of each kernel that says it supports OC, and spend a day flashing and testing. Just remember to disable any OC/UV, lagfixes or tweaks between flashings.

[Q] ROMs and KERNELs

I have a question about kernels and roms regarding the competability. I believed I'm still considered new in the android sector though I have used 2.1, 2.2 and now 2.3.
Over the years, I have been using stock ROMs because and putting in my own kernel to get a good balance of performance and battery life. Recently I've have tried getting into custom ROMs as I felt that some stability issues I have read might be some user experience instead of a real stability issue. So I decided to give a go. I looked at certain ROMs but decided to go with more popular ROMs like DarkyRom, they until then I somehow bricked my phone (not ROM issue) and manage to save it back, I decided to go for a newer ROM, which might be as popular as my previous ROM. I decided to go for Doctorz Rom, since all these custom ROMs usually come with another kernel already, is it perfectly Okay to flash any other kernel (Kernel are competitable with the version of the firmware, of course) on the ROM, irregardless of whether the ROM is customized by a developer or not. Example, DarkyRom comes with darkcore kernel (I flashed it to speedmod because I saw that you can do it), Doctorz Rom come with semaphore kernel.
My question in simpler terms, is whether can I flash Doctorz Rom with say, darkcore or speedmod kernel?

simple question for which I am afraid there is no one, simple answer. Some roms play nice with most, if not all kernels, some don't. Similarly, some kernels seem to work with just about every rom, many do not. Hardcore's kernel is one of the more robust ones and usually works with most roms.
Part of the issue is the scripts used in many roms and kernels and what is left behind when you copy a new program to conflict with the new stuff.
(1) Always read the directions on any new kernel or rom.
(2) A clean phone will decrease the chances of having issues with any newly flashed kernel or rom. If your phone is cleansed correctly, any issues are solely a problem of the newly flashed firmware. Bits of legacy program can and do cause issues, which is why a system clean is important.

Thank you, that was the answer I needed

If you were happy with stock ROMs, you should be looking at slightly tweaked stock ROM. I was using Darky with all its bells and whistles for quite a long time. But recently I started to look for something more closer to stock versions and found Simplicity which does pretty good job for me so far.
The choice of ROMs and kernels is so wide that it's hard to decide and it depends if we want to achieve speed or stability. But you can mix ROMs and kernels definitely. I was using Darky ROM JVR with Semaphore kernel completely fine.

stiwipl said:
If you were happy with stock ROMs, you should be looking at slightly tweaked stock ROM. I was using Darky with all its bells and whistles for quite a long time. But recently I started to look for something more closer to stock versions and found Simplicity which does pretty good job for me so far.
The choice of ROMs and kernels is so wide that it's hard to decide and it depends if we want to achieve speed or stability. But you can mix ROMs and kernels definitely. I was using Darky ROM JVR with Semaphore kernel completely fine.
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Click to collapse
I decided to use custom rom because of the features, since i had nv used one before. I cant deny that stock ROM gives a very neat and clean rom which sometimes leads to more speed/battery life, but lets give these developers some.chance as well
Sent from my GT-I9000 using XDA App

Custom Kernel and LKT module Magisk?

Hello everyone, I have a strong doubt. If you installed in a custom ROM (complete with a custom kernel), the magisk LKT module (with various kernel kits for the battery or performance); somehow the kernel would be compromised? Ie it's better with a custom kernel, do not install this module or install it anyway? Thanks to those who will answer

You asked like this, no one answered you. The developer made up the module to increase everyone's performance. The right one for you to choose is just that.

I have seen that the Developer has had mention, that it will work on "Any" Kernel !
With that said, I have and do use this, although, it has not been long. Trying to see, "IF" it helps or hurts the custom kernel .
I will say, that, if there is anything bad, I will test again without a modded kernel...
Guess is short, give it a try, it may help.. may not, can always uninstall and reboot...

I am using oxygen kernel on j7 2016 and lkt is working fine.

Tested LKT onGoogle Pixel with Franco Kernel and King Kernel, so far so good on balanced profile.
One time started lagging as hell on a version of King Kernel even with performance profile, I think because of some kernel features related to battery saving or boot tweaks, as far as I know they can conflict.

seems become slow or laggy. i dont know if this is the cause. i played mobile legend in the previous version my ping is 20-40ms after i installed the update in became 120ms-180ms.. So i try to uninstall the latest version.. Reboot then install previous version reboot played mobile legend and it goes back to 20-40ms ping.