Database Develop

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..!!

[Q] Browser on odex\deodex Roms

Is it for everyone, or i'm the only one who have noticed that the browser (the stock one, or any other) works far way smoother on the stock JVQ which is ofcourse odex rom than any other deodexed rom (even those who are based on jvq or jvp...) Just flashed the new Darky 10.2 final and also over there... the browser feel very very lagy after i've experienced it on the stock rom.
I know that it was a known issue with the deodexed JVQ roms but some devs published that it was fixed. Neither way i couldn't find ANY deodexed rom that the browsers works like they work over the stock rom.
Any other thoughts?

please respond
well i can see u guys viewing this thread but not responding...
I just want your opinion about the web browsing experience over your deodexed roms (I assume that 90% of you use custom roms which all of them are deodexed).
Please respond.

Nobody is responding because it's a known, and highly documented and talked about issue since JVQ was leaked. Do a quick search of the forums and you'll see for yourself. I suggest next time doing that first as people on XDA don't like wasting their time re-iterating the same information that is already freely available.
So to answer your question, yes it is the same for everyone else. There may be a fix but there are conflicting results. Run a quick search for more info on that.

you might not understood my question
First of all thanks for the answer.
Second thing - i did searched for this kind of topic, and as i mentioned - i know people have discussed about this issue but on the specific JVQ firmware and i didn't asked if everyone gets better browsing results on the odex jvq comparing to the deodexed jvq.
WHAT I DID ASKED - (and i couldn't find any answer for that - even though there are several pages which explains the cons and pros of odex and the deodex roms)
IS THAT TRUE TO SAY THAT THE BROWSERS ON ODEXED ROMS ALWAYS WORKS BETTER THAN ANY DEODEXED ROM???

Truths and myths about deodexed/odexed roms?

I just read in some other forum that the lag in deodexed stock browser, is/was caused by an error in the deodexing tools that are used. Is that true?
Also there was discussed how deodexed actually uses less space than odexed because there is only one file instead of two, and that the odex file just gets converted into a classes.dex and put right into the apk file - which means that it also will get compressed since the apk's are nothing else but zip files in the end.
So that would mean that deodexed still is better right? If done with bugless deodexing tools that is.
Another question I'd love to have clarified:
What can and what can't be modded on odexed? General consensus is that you can't really theme/modify framework of odexed rosms, but for the simplicity rom for example (its odexed) there is a theme available. That theme makes the pulldown menu transparent, changes the icons, and also makes the extended power menu monochrome (plus icon changes there as well). So that kinda stuff definitely must be modable even on odexed - so what is it that can't be modded?
And couldn't you just re-odex the framework after modding to fix it?
I'm sorry, I'm an enthusiastic end-user and also studied computer science, but I still have no clue about the technical details about all this stuff - which I would like to change in this thread (not only for myself but also for other people who are interested about this stuff) so that I can eventually start to mod and develop stuff myself.
Please explain the stuff or point me to the right threads to learn about it all.
Thanks ahead.

Interesting thread indeed! I heard many rumors but most of them are just that: rumors, not facts. The hype is that odex roms are faster, and my personal experience confirms they feel smoother in launching apps and the like, but again this is just a feeling and could well be placebo or caused by other variables...
Sent from my GT-I9000 using XDA App

I'm currently using simplicity (which is odexed) - and it also feels more smooth and with less "bugs" than all the other roms I used before, which all had been deodexed.
Plus quadrant score I get without any overclocking goes up to 2.9k which is highest I ever had on any rom also. With OC enabled it even goes up to 3.2k. But I know that a benchmark not necessarily means much.

+1
Would really like to learn the difference and benefits = odexed vs deodexed
Anyone ?

Hopefully this thread will spark an intelligent discussion. I'm interested as well.

Hi all,
I'm not actually a dev or so but i found this interesting.....
http://www.addictivetips.com/mobile/what-is-odex-and-deodex-in-android-complete-guide/
I think this would break the jargon about ODEX , DE-ODEX 'ed ROM's !

Ashtrix said:
Hi all,
I'm not actually a dev or so but i found this interesting.....
http://www.addictivetips.com/mobile/what-is-odex-and-deodex-in-android-complete-guide/
I think this would break the jargon about ODEX , DE-ODEX 'ed ROM's !
Click to expand...
Click to collapse
Uhm... interesting link, thanks. So, according to the author of that article, odexed is faster than deodex only on the first boot...
On the other hand, since the .odex files were supposed to quickly build the dalvik cache, removing them would mean longer initial boot times. However, this is true only for the first ever boot after deodexing, since the cache would still get built over time as applications are used. Longer boot times may only be seen again if the dalvik cache is wiped for some reason.
Click to expand...
Click to collapse
My experience with odex/deodex versions of the same ROM (be it stock or custom) tells me this is not telling the whole story. Application startup time is definitely longer with deodex, and not only for the first launch...

when developing Tornado for JVR both odexed and deodexed versions were Beta tested: the odex version was significantly better in stability, speed and battery life, so much so that the decision was made to develop Tornado solely as an odexed rom. These differences were tested using the same firmware source, same kernel and configuration and across phones from 10+ testers.
Themes can be developed for odexed roms but it does require some development and greater care and attention than for deodexed roms (an existing theme can be ported into odex but not by simple cutting and pasting of files by the user).
A number of excellent themes now exist in both deodexed and odexed forms: but the range and variety of themes remains the sole advantage of a deodexed rom. But it is a questionable advantage, as most rom threads will confirm that a significant number of rom issues arise from the addition and application of themes and incompatabilites that arise.

ZioGTS said:
Uhm... interesting link, thanks. So, according to the author of that article, odexed is faster than deodex only on the first boot...
My experience with odex/deodex versions of the same ROM (be it stock or custom) tells me this is not telling the whole story. Application startup time is definitely longer with deodex, and not only for the first launch...
Click to expand...
Click to collapse
Hmm, actually you got it wrong the first boot takes time on DE-ODEXED not ODEXED!
I'm on Jetpack Deodexed ROM it's super fast and only the first boot took a long time and after that im smooth no FC's and all without OC {Semaphore}..!!

Official ICS ROM(s) ok, or better stick with GB ROM(s)?

Hi, fellow Noters!
I have the N7000 Note, with stock GB ROM installed and only rooted, flashed with abyss kernel.
I am in the UK, so I am considering updating/upgrading to ICS... Now, from most of the posts here I gather that most of custom ICS ROMs aren't yet the most stable and people who installed the official ICS have mixed reactions...
Don't get me wrong- I am completely satisfied with my Note and the functionality of the apps as it is, but was just wondering how much improvement would I see, if I installed ICS...
Also, if I want to install official ICS ROM, do I need to unroot first and then flash it with ICS, or just straight on?
Thanks and enjoy the weekend!

Ics is suffing from the brickbug for now, that is not to mention other issues such as baterry drain. So if you are still satiafied with gb then should hold on unrik tge brixk bug is cleared. Cheers.
Sent from my GT-N7000 using XDA

If you want to do an update ics stock , you have to flash with odin 1.85 the rom that you prefere..... it is not necessary performing unroot...

I'm still running GB as it's running great. Nothing really worth upgrading to ICS.
Sent from my GT-N7000 using Tapatalk 2

Stay with GB. If you desperately wants ICS then flash CM9 or PA.

If you want to stay on a Touchwiz rom, then it may be better to stick with Gingerbread as it has less bugs that the TW ICS counterparts. However I would thoroughly recommend AOKP or CyanogenMod 9 if you truly want ICS; it has almost all features fully working (including camera, tethering and full access to all storage) and are both extremely light and quick. Plus both support themeing and have a wealth of customization options.
As for the brick bug, that has been almost eradicated IF you use a safe kernel such as Speed mod 3.3. Of course the worry is non existent on AOSP roms.
Sent via carrier pigeon

Right... Thanks guys for your input!
I am in no rush to get to ICS, as pretty much all the visual stuff can be achieved through some extra launchers and themes while still staying with stock GB ROM.
I am pretty much happy with TouchWizz, but find the Go launcher a bit more faster and easier to use. I go to TW only when I need S Memo and that stuff from the suite...
so, until the bug in the official ICS ROM is fixed, or a very stable custom ICS ROM made, I will stick with GB...

Atomix86 said:
If you want to stay on a Touchwiz rom, then it may be better to stick with Gingerbread as it has less bugs that the TW ICS counterparts. However I would thoroughly recommend AOKP or CyanogenMod 9 if you truly want ICS; it has almost all features fully working (including camera, tethering and full access to all storage) and are both extremely light and quick. Plus both support themeing and have a wealth of customization options.
As for the brick bug, that has been almost eradicated IF you use a safe kernel such as Speed mod 3.3. Of course the worry is non existent on AOSP roms.
Sent via carrier pigeon
Click to expand...
Click to collapse
so you say that flashing Cyanogmod9 rom and Speedmod 33 is a good bet?
can you give instructions on just how to do just that.I've never flashed anything before, but I do have lies and Odin on my PC already and both can see my note.
thanks

jimmbomb said:
...but I do have lies and Odin on my PC...
thanks
Click to expand...
Click to collapse
He, he, he... you mean Kies?
I also sometimes mistype words and it is annoying when the result is actually a proper word, so it completely can confuse the recipient of the SMS, for instance...
I wonder if there are alternatives to the current ordering of letters on keyboards, you know-instead of ASDF-JKLsomething...

yeah.. typing on the note.
using GB keyboard with autospell ..
messes me up alot,cause I rarely proofread.
I Still would like to install the safe Cynamiod 9 and speed mod 33 if someone could walk me thru it.
thanks

[Q] Most reliable, yet visually fun TW based custom ROM (preferably JB, or ICS)?

First off-hold your guns!
I know JB as such isn't out yet, and can't be expected to be as stable as ICS... But, still- after watching video reviews of some custom ROMs, one asks themselves, if they should give it a go...
Ok, so I am running stock (LAME!!!, I know ) GB, rooted and couple of launchers make it more interesting, sure... However, after browsing through this lovely and extremely helpful forum, I noticed that there are people who are already enjoying the benefits of running JB ROMs, or very good and matured TW based ICS custom ROMs...
1. So, I know ICS stock kernel has been a bit of a problem, what that just 4.03, or did 4.04 fix that?
2.Kill be for being so easily pleased, but I do find my Note and its current ROM already pretty smooth... I know all the bits that ICS makes it better and even more so JB, but considering all the things ICS brought, is there a point of trying JB, except for experimenting?
3. One thing I am so after, is that bit where from the lock screen you have like 3, or 4 options, one of them being going straight into the camera mode. I don't know if that is only JB, but I could really use it, as the old way (press the menu button, swipe to unlock, then press the camera icon) so many times made me miss the scene I wanted to take a photo of. So, any info on that would be much appreciated.
4.So much hype around GN II, but seeing that so many features are being ported to GN I custom ROMs, I am only after a ROM which will have those new and useful S III and GN II bits sawn onto the old(er) jacket.
5. I am in no rush, so do you think that in 3-4 weeks something more stable JB based will be available(official JB update should be rolling out soon, no)?
Big thanks to all you guys here, not just for answering the questions, but also all the tutorials and topics we noobs can find here... Keep up the good work.

See custom jb roms are stable like cm10 aosp liquidsmooth etc.you will feel smooth quality on it and butter project.
Ics 4.0.4 is very stable and has many mods and a good battery life too.
So lastly its your choice which one to flash.
Hit thanks button pleass
Sent from my GT-N7000 using xda app-developers app

Answering the title of your thread, there are no TW-based JB roms yet. All the TW-based ROMs are ICS. So if you are looking for smooth and reliable TW-based ROMs I would go for Kingdroid (ICS). If you want Jelly Bean you have ParanoidAndroid, Liquidsmooth, but these are not TW-based.
And answering the 5 questions in the contents of your post:
1. The problem is not with the kernel, the problem is with the chip itself, the *workaround* is using a modified kernel that does not use the MMC_CAP_ERASE command, so to answer your question, no the problem isn't solved and it won't be solved unless Samsung recalls all the units and gives out new ones without the bug. You will have to be careful when upgrading to ICS/JB because you will need to use safe kernels.
2. Jelly bean is definitely smoother than ICS, it is worth upgrading IMO.
3. That is the ICS/JB unlock screen that comes in stock android, and it is also available in most AOSP/AOKP ROMs. It is not available by default in Touchwiz but you can download that lockscreen from the Play Store as a standalone app and replace it.
4. Not all the Note2 features have been ported to the Note1, for instance the multi-window view is not available on any ROM yet as far as I know.
5. I have made the switch because I can't stand the look of Touchwiz, the complete disregard of Google's Holo design is for me a reason enough to switch to AOSP/AOKP, that said even when official JB ROMs start rolling out I probably won't come back to Touchwiz.

I think that you need a stock ICS TW rom, maybe RocketRom or Alliance v2.1 rom. I have tried a couple JB roms, but it feels like you have giant nexus insted of a great note.
If you want stock, pick up a last 4.0.4 xxlrt or ddlr9 or something similar, depends where you live but it's not too important. After that, just flash PhilZ kernel and you are safe, disable all aplications that you dont need, and thats it.
Or if you want a custom rom which is great like stock and cool like custom, choose rocketrom v12 or alliance v2.1
Hope that helps!

Ooooohhh-dann so...
Well, that clears so many things...
I mean, am no Samsung fan boy. It is just that I edit many pdf docs on the go, and other TW apps are very useful as they bring the functionality and the precision of the S Pen... As I said. I even find stock GB smooth, so I believe ICS should feel like heaven for me.
BIG QUESTION = so, since the problem was the chip, not the stock kernel itself, and the only solution is a modification of kernel, surely Google will include the workaround in a new JB update, no?
I haven't updated OTA to ICS, because I was scared of bricking the phone, or something.... Are the updates incremental, or so I need to update to official ICS and then to JB, or will I be able to go straight to JB (official one)?
I think I might go for Kingdroid (ICS), or Sweet ROM... Though, I from reading their respective threads, I get the idea that less people have issues with Sweet ROM....
Thanks again...

Ota update from GB ROM is safe because GB kernel is safe. Or can download stock ICS from Dr Ketan and flash with pc odin. Then flash appropriate Philz kernel (can do it from stock recovery). You will then be on safe stock kernel (only brick bug is disabled) with advanced CWM recovery. Once on Phils u can backups/restores and flash any ROM u like. Just have to do full wipe before flashing new ROMs.
Sent from my GT-N7000 using xda app-developers app

cmick30 said:
Ooooohhh-dann so...
Well, that clears so many things...
I mean, am no Samsung fan boy. It is just that I edit many pdf docs on the go, and other TW apps are very useful as they bring the functionality and the precision of the S Pen... As I said. I even find stock GB smooth, so I believe ICS should feel like heaven for me.
BIG QUESTION = so, since the problem was the chip, not the stock kernel itself, and the only solution is a modification of kernel, surely Google will include the workaround in a new JB update, no?
I haven't updated OTA to ICS, because I was scared of bricking the phone, or something.... Are the updates incremental, or so I need to update to official ICS and then to JB, or will I be able to go straight to JB (official one)?
I think I might go for Kingdroid (ICS), or Sweet ROM... Though, I from reading their respective threads, I get the idea that less people have issues with Sweet ROM....
Thanks again...
Click to expand...
Click to collapse
You could try ics stock rom with non stock kernel, i my self use notecore and hydracore kernel while i am using ics rom.
This will give you another experience..
Sent from my GT-N7000 using Tapatalk 2