[Q] Kernel, Rom, Firmware. Some noob questions

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Hi there! I'm new to the forum and to android as well.
As you can guess I'm a proud owner of SGS

Since my SGS sucks a bit (random crashes, reboot, RFS) I'm interested in taking the maximum out of it, and I have some questions.

What is the difference between kernel and a rom? As far as I know from Linux and OS theory, kernel is the layer between the user (applications) and the hardware. I also know that most of the ROMs have kernel in them. Then what else the ROM contains?

What is firmware? Is it used a synonym for kernel/rom?

Is it worth installing custom kernel/rom on SGS? I'm a bit paranoid in those things and have some fears about the issue.

Is there a way to install some good kernel (like speedmod) and naked ROM (not someones mod, i.e. a stock android ROM without any additions from third party developers)? Is it hard to make my own ROM based on stock ROM (without touching the kernel, even tough I looked at the code and read books about the linux kernel, I dont yet consider my self a guru to be able to make my own kernel for android), just the modification and custom applications?

Thanks a lot guys!

Everyone has a kernel - even if you don't mod your phone at all. It wouldn't work without one!

Now, if you flash a ROM, you change the whole system including the kernel. If you flash a kernel, you're only changing the core piece of your system.

Sent from my GT-I9000 using XDA App

A rom is a full firmware .
A kernel is the bit at the base level between processors and OS .Or just as you said .
Is it worth installing custom kernel/rom on SGS? I'm a bit paranoid in those things and have some fears about the issue.
YES but its at your risk though SGS is relatively un brick able .

Simplest upgrade would be via Rom Kitchen and build your own rom .
Choose base rom kernel modem and CSC to suit plus themes and apps .

http://forum.xda-developers.com/showthread.php?t=817703

jje

The kernel in android is essentially just a customized Linux kernel. The ROM is basically the application layer and the framework. Usually ROMs include kernels, but you can flash a different compatible kernel.

Firmware usually refers to either all the basic software on your phone (minus the apps) or the ROM, csc and modem.

You can definetly flash a custom kernel onto a stock ROM, which will improve performance a great deal even without a custom ROM. Find instructions aplenty here on XDA.

Sent from my GT-I9000 using XDA Premium App

Thanks for the replies guys!

YES but its at your risk though SGS is relatively un brick able .

By un brick able you mean that its hard to brick it, or if I brick it its hard to un brick (fix) it then?

Also I'm having a hard understanding, if kernel is the thing that manages the hardware and also responsible for lagfix then kernel is really what matters for the performance of the phone. How a ROM could improve phones performance?

Also one more questions:
As I understand CSC and modem are connectivity related files (3G internet, APNS etc) right? So its better not to touch them when flashing custom ROM/kernel?

Thanks a lot again!

JJEgan means it's really hard to get to brick your SGS.
The kernel is responsible for the proper functionality and cooperation between hardware parts. As for SGS, it is a common belief that Samsung's RFS is not as robust or "agile" as ext4 FS. Thus, converting RFS to ext4 should increase device's performance (the time needed for the read/write operations to take place is decreased). BUT, in order for the device to function properly, the kernel MUST support ext4 as a file system format otherwise it won't work anymore (This could happen after installing a stock kernel on a device that uses some filesystem apart from rfs). Samsung's stock kernel does not, so you have to replace it, if that's the case.

(E.g. If you format a USB drive under Windows 7 with "exFAT" as its filesystem, you won't be able to access it through Windows XP for example, because XP does not support "exFAT" - Different kernels & Different OS version ).

Yes, CSC and modem.bin are what makes your device a TELEPHONE, too Connectivity issues between your operator and your handset depend on those files. If you can find the latest COMPATIBLE modem file, then go for it.

Thanks for the explanation!

As for CSC and modem, by compatible you mean the same version (XXJPY for example)? How do I know they are compatible with my phone?

Thanks a lot again!

the CSC doesnt have to match the baseband. for exapmle, you can have XXJPY baseband and XXJQ1 modem. (thats what i used to run)

its all about finding the right modem for your region, you want to make sure you get good connections dont ya ? modems affect SMS, Calls, Data, WIFI, so on.....

so you want the right one. If you go to rom kitchen, you can see all the modems and what region they cover

Thanks!

But is there a way not to touch the CSC/modem when flashing custom kernel/ROM? I'm really afraid to mess with those.

Also could someone refer to this question:

Also I'm having a hard understanding, if kernel is the thing that manages the hardware and also responsible for lagfix then kernel is really what matters for the performance of the phone. How a ROM could improve phones performance?

Thanks a lot again, and sorry for a bunch of questions!

So is the pda is the kernel then if you are flasing pda/modem/csc?