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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.
Click to expand...
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..
Click to expand...
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.
Click to expand...
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.
Click to expand...
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.
Click to expand...
Click to collapse
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] Best Kernel for my HTC Hero?

I've done some researching and found out that some kernels are better than the ones the ROMS bring... not sure whether this is true but would like to know if this IS true which kernel is the best you guys have come across that makes games run faster, smoother?
Tips appreciated!

Slash837 said:
I've done some researching and found out that some kernels are better than the ones the ROMS bring... not sure whether this is true but would like to know if this IS true which kernel is the best you guys have come across that makes games run faster, smoother?
Tips appreciated!
Click to expand...
Click to collapse
Well s0be just somewhat recently came out with a new kernel that he states is a release canidate. there is also decafuct. Those are the two i use mainly

Slash837 said:
I've done some researching and found out that some kernels are better than the ones the ROMS bring... not sure whether this is true but would like to know if this IS true which kernel is the best you guys have come across that makes games run faster, smoother?
Tips appreciated!
Click to expand...
Click to collapse
Ideally you should stick with the kernel that comes with your ROM. There are slight differences between the kernels that can cause issues.
For instance, CyanogenMod 7 and its derivatives already contain an up-to-date version of Decad3nce's kernel. So there's no need to flash his (now outdated) kernel over these ROMs. Doing so will break CM7's built-in CPU controls and may cause instability.
On the other hand, some of the older, Sense-based ROMs have software that hasn't been updated to reflect changes in the kernel. These ROMs need kernels designed especially for them.
The best idea in regard to stability is to stay with what you have. If you're feeling adventurous, you should look for an explicit statement of compatibility either in a ROM or kernel developer's thread.

Thanks ill read more about s0be and stick with aosp's default kernel.
Sent from my GingerHERO200 using XDA App

Interesting......I was under the impression that all of the Cyanogen kernels were capped at 691 MHz though? My phone is stable to 748 MHz with virtually every rom I've tried crashes at 768 MHz. I have been using the Decafuct uncapped #589 kernel with RC4, however it doesn't work at all with 7.0.0 stable and the pre-packed kernel seems very sluggish to me compared with how RC4 runs.

Slash837 said:
Thanks ill read more about s0be and stick with aosp's default kernel.
Sent from my GingerHERO200 using XDA App
Click to expand...
Click to collapse
s0be's latest (Ap 5) FTW!!!! Smokin'!

[Q] Overclock Nexus One Gingerbread?

Hi, I've tried searching but what with the 30 second search delay and all the outdated threads, I'll ask afresh.
I have a rooted N1 with Set CPU running. Is there a simple way to overclock it, and to what speed?
What settings are recommended?

you need a custom kernel, than you can put your clock speed up to the speed, the **** allows you ( 1113, 1150 or 1190 Mhz)
my nexus can handle 1190 mhz, but there are not many kernels for this speed
have fun with your N1

BikerBoy030 said:
you need a custom kernel, than you can put your clock speed up to the speed, the **** allows you ( 1113, 1150 or 1190 Mhz)
my nexus can handle 1190 mhz, but there are not many kernels for this speed
have fun with your N1
Click to expand...
Click to collapse
Sometimes misspellings are both funny and disasterous!
Most people say 1150 is the most you should run at for 24/7 use. I use 1113 on CM7 and the phone seems perfectly happy with this. Whether there is any noticable gain though is another matter

Thanks guys. Is there an easy guide to the recommended new kernel?
Will replacing the kernel lose me any data or SD card stuff or is it safe?
And will new updates like 2.3.4 come in from Google OTA?

Take this rom and you are happy:
http://forum.xda-developers.com/showthread.php?t=653598
2.6.38.4_AVS-CM7_CFS_20110429_1856.ZIP <<< with this,you would be happy
2.3.4? i can't see in the future but why shouldn't it come for our Nexus One
and sorry for my **** :s...i meaned cook of course
edit:
http://www.xda-developers.com/android/android-2-3-4-about-to-roll-out-to-nexus-s-available-for-download-now/
read it

Will this overwrite my data?
I'm confused about the difference between your suggested new "ROM" and the new "kernel" which is actually all I need for overclocking.
Do I have to get a new ROM to get a new kernel, or can I just get the new kernel on its own.
I like to keep things as close to stock as I can.

CJSnet said:
Will this overwrite my data?
I'm confused about the difference between your suggested new "ROM" and the new "kernel" which is actually all I need for overclocking.
Do I have to get a new ROM to get a new kernel, or can I just get the new kernel on its own.
I like to keep things as close to stock as I can.
Click to expand...
Click to collapse
I believe all is required is that you are rooted. Then you can flash a new kernel. Think as a ROM as a new browser you would use to use your phone.
And no flashing kernels do not erase any data. HOWEVER always, always make a backup before flashing anything. Better to be safe than sorry.

Thanks, so the best new "kernel" (rather than ROM) to give me overclocking is?...

Most of the kernels floating around out there are compatible with and made for CM7 or one of its Kang's / and or variants. If you are running a stock ROM, a custom kernel may not be compatible with all of its features, ie the camera may force close etc...
Do a NANDROID, flash a custom kernel and then test. If certain functionalities are gone, restore your NANDROID and either live with stock or try a custom ROM.

Try Kernel Manager from the market

So I flashed CM7 but as predicted the camera doesn't load.
I wasn't able to take a nadroid backup. What else can I do to revert the kernel?
Please help.
Sent from my Nexus One using Tapatalk

CJSnet said:
So I flashed CM7 but as predicted the camera doesn't load.
I wasn't able to take a nadroid backup. What else can I do to revert the kernel?
Please help.
Sent from my Nexus One using Tapatalk
Click to expand...
Click to collapse
Try this kernel: http://forum.xda-developers.com/showthread.php?t=820172

efrant said:
Try this kernel: http://forum.xda-developers.com/showthread.php?t=820172
Click to expand...
Click to collapse
I love you.

[Q] Rom with best battery performance?

Hey guys, i m new to your forum, so pls be nice to me :-D i just bought the i9001 for my girlfriend and i wanna flash a custom rom right away. My question now is, which rom is the most stable and offers the best battery performance? I dont wanna overclock it, since it seems to be fast enough, but as i already know from my lg device, is that battery is much better on cust roms. So i hope you can help me out and guide me the right direction. If you already have got a discussion thread about roms, pls guide me there, since i couldnt find it till now. Flashing and so on, seems far more complicated with samsung devices but i ll keep on reading, in order not to screw this beautiful device
Sent from my LG-P970 using Tapatalk

Hi, try this UCM GingerBread Rom 2.1 (http://forum.xda-developers.com/showthread.php?t=1457437). I have installed it in my SGS+ yesterday.For now this ROM seems to be the best battery and performance combination.

best battery for me was stock rom 2.3.5

I think you will have as many answers as there's customs ROM fo GS2... I have my GS2 since few weeks only and I already tested 5 ROMS to assess which one is the best for my own usage (performance / quality / stability / battery life, etc).
So I think the ROM which has the best match for someone's usage will not be the same than for you.
So far if I could give you a reco it would be for Gingermod, CheckROM v6 or just Stock ROM + Siyha Kernel. But again take it only as my own view which can be different for someone else
Links:
Gingermod: http://forum.xda-developers.com/showthread.php?t=1220283
CheckROM: http://forum.xda-developers.com/showthread.php?t=1312240
Siyha: http://forum.xda-developers.com/showthread.php?t=1263838

lelex79 said:
I think you will have as many answers as there's customs ROM fo GS2... I have my GS2 since few weeks only and I already tested 5 ROMS to assess which one is the best for my own usage (performance / quality / stability / battery life, etc).
So I think the ROM which has the best match for someone's usage will not be the same than for you.
So far if I could give you a reco it would be for Gingermod, CheckROM v6 or just Stock ROM + Siyha Kernel. But again take it only as my own view which can be different for someone else
Links:
Gingermod: http://forum.xda-developers.com/showthread.php?t=1220283
CheckROM: http://forum.xda-developers.com/showthread.php?t=1312240
Siyha: http://forum.xda-developers.com/showthread.php?t=1263838
Click to expand...
Click to collapse
He asks for a rom for the sgs+ not the sgs2.
I think it doesn't really matter which rom you take. It does matter what governor and which I/O scheduler you take! change them with no frills cpu controll for the market.

Oh thanks your right, thank all of you guys, I think i ll read some more and try to flash first, when i have enough knowledge about the phone. As far as i got, i first of all need to flash the cust recovery, then pick a rom and either flash it via recovery, or client on pc. Depending on the rom. But i guess i ll take the one from first post, since i only want it to improve battery life and not the overall performance, or even oc, since it is a good phone already ;-) again, thank all of you so far :-D
One more thing, whats the best governor and iosched for you? I prefere interactivex and simple, for battery
Sent from my LG-P970 using Tapatalk