Database Users

developing for the DSTL1 / N21

I want to try developing for the DSTL1 / N21
There are quite a few interesting things we can do...
Success has been been seen by xda-devs such as JesusFreke, Amon_RA, Haykuro, and Cyanogen (yes there others) in the field of Android ROMs. The ground work is there, porting and developing can commence.
Why do this?
Current ROM 1.5 - has many problems...
Unofficial ROM 1.6 - is a GREAT improvement, but makes one hungry for something better...
It would be awesome to have some success in this field. I know this device is capable of so much more, but I believe the implementation of the system is the issue. This is not the phone developers fault, as they have their own company agenda, but we could improve our own performance and satisfaction .
For example, my device (1.6 rooted) lags with having only ~50% CPU utilization and ~50MB RAM free...
Overclocking (i mean forcing full CPU capacity - 624Mhz) the CPU has barely helped and only aided battery drain...
Relevant comparison of G1 vs DSTL1 (N21) are
RAM - G1: 192MB vs DSTL1: 128MB
CPU - G1: 528Mhz vs DSTL1: 624Mhz
These specification comparisons say that G1 can run a better ROM than DSTL1? I don't think so. DSTL1 only loses in RAM, which can be made up for using swap!
Devs had success with techniques using: App2SD, swap, ext3, and BFS (faster file system). I believe we could do something impressive here! There are pros and cons to this.
Developers and Testers would be needed. A team of 5 developers and a few testers should be able to get us on the right track. We would definitely need Linux experience, or the desire and ability to soak up all the info on Google
A Linux kernel is a must for this phone, we would have to compile our own... It would be nice to preserve DUAL SIM, but in reality we might have to give up this luxury, as it is proprietary code, unless a new ROM is made backwards compatible (which is possible).
Cyanogen's Github is available for knowledge osmosis http://github.com/cyanogen
A DSTL1 Recovery by Amon_RA (based on Cyanogen's Recovery) is already in Beta...
Cool things are possible. Could I find some developers willing to donate their free time?
Please limit responses to dev talk.

reserved for later

crzyruski,
Believe it or not the very luxury you talk about giving up(dual sim) is the reason why may of us bother to buy these phones(DSTL1\N21) in the first place. Other wise we might as well go with a mainstream phone such as hero etc.

chrismotto said:
crzyruski,
Believe it or not the very luxury you talk about giving up(dual sim) is the reason why may of us bother to buy these phones(DSTL1\N21) in the first place. Other wise we might as well go with a mainstream phone such as hero etc.
Click to expand...
Click to collapse
Its a possibility that I'm not going to ignore, so I stated it.
The point is that the current OS is lacking. Initially we would want to port and learn from porting of the quality ROMs available now. Those obviously don't support dual-SIM.
Progress needs to start from somewhere. When someone releases a new port or ROM not all pieces work... look at the Eclair (2.0) port, half the features don't work!
If enough heads came together we could probably retain dual-SIM, common this is linux and I've seen the most amazing development come to realization. I just need the teamwork because it might take me a whole year in my spare time...

Having a kernel working
Hi,
the most important IMHO is having a kernel working, built from sources.
Obviously, some closed source drivers must be rewritten, notably the NXP5209 (the GSM modem), if we want the device to be useful (i.e. if we want to make phone call).
My first attempt of booting with a custom kernel was unsucessfull (black screen), which brings to the second point: the lack of some sort of console for kernel debuging.
Any idea regarding the NXP? Anyone is aware of some opensource driver or specs?
Any idea also regarding kernel debugging in the N21/DSTL1?
sfabris

@sfabris
I will try to find info for the questions you have.
My initial work will be to make an emulator so we can test on PC and not our devices (because we need them functional for every day life )
Have you checked out how other modders have done kernel modifications?
Namely JF and Cyanogen?
I can't begin to comprehend so I'm glad you took the initiative with this.
Lets make some progress

sfabris said:
Obviously, some closed source drivers must be rewritten, notably the NXP5209 (the GSM modem), if we want the device to be useful (i.e. if we want to make phone call).
Any idea regarding the NXP? Anyone is aware of some opensource driver or specs?
Click to expand...
Click to collapse
Maybe we have it all wrong???? Maybe its PNX?
PDA DB reports DSTL1 as having Nexperia PNX5209 (ARM946) Phone Controller.
http://pdadb.net/index.php?m=specs&id=1714&view=1&c=general_mobile_dstl1
A similar Android with this phone controller is WayteQ X-Phone (TechFaith Lancer)
http://pdadb.net/index.php?m=specs&id=1801&view=1&c=wayteq_x-phone_android_techfaith_lancer

crzyruski said:
@sfabris
Have you checked out how other modders have done kernel modifications?
Namely JF and Cyanogen?
I can't begin to comprehend so I'm glad you took the initiative with this.
Lets make some progress
Click to expand...
Click to collapse
As I'm forced to HTC G1 until I'll wait the replacement for my N21 I'll go in detail on the kernel boot process on other hardware.
A fast way to test kernel in our every day device is kexec which should work also on ARM.

sfabris said:
A fast way to test kernel in our every day device is kexec which should work also on ARM.
Click to expand...
Click to collapse
As far as I understand, kexec is a program that can run a new kernel on the fly...
So I could try a new kernel right from my device without reflashing?
have you tried this? Or is this still theory?

crzyruski said:
As far as I understand, kexec is a program that can run a new kernel on the fly...
So I could try a new kernel right from my device without reflashing?
have you tried this? Or is this still theory?
Click to expand...
Click to collapse
I've tried it on x86, never on arm.
Support is there also for arm, but this not imply that also the Marvell PXA is supported.
It's basically the same way of booting Android from WM via haret.
Fastest way to boot your new kernel or to crash your machine

I have created an emulator.
FYI, LCD density should be 120.
Edit: Technically the density is 133...

files prevent recovery-RA-DSTL1-v1.2.3 from loading
I have been wrestling with the beta recovery-RA-DSTL1-v1.2.3
Amon_RA retrofitted his own recovery image to work for the DSTL1 (N21)...
IT HAS AWESOME POTENTIAL.
Currently ADB RECOVERY SHELL + ROOT is the only thing that is functional.
But I haven't been able to get in touch with him to continue work on it.
The following files prevent me from booting into RA's Recovery, so I remove them:
- e2fsck
- mke2fs
- parted
- tune2fs
Once I am in ADB RECOVERY SHELL I can push them back on and do what I need to do.
Unfortunately the changes are persistent so if I were to reboot and try Recovery Mode again, it won't load
What is so special about those four programs that prevent my recovery from loading?????

is there any ways to update the firmware of N21
hi,
i'm just buy a sciphone n21 (actually is already in our office for 2 weeks but find it now:-( )
and i've to face myself in a situation that i can't use this phone:-( since i buy this phone because:
- i assume that google apps auto sync contact and calendars. unfortunately this phone has not google apps by default.
- and has dual sim support.
so my question: is there any way to upgrade it to a firmware which support is?
can i do anything to use my phone?
thanks in advance.
regards.

crzyruski said:
I have been wrestling with the beta recovery-RA-DSTL1-v1.2.3
Amon_RA retrofitted his own recovery image to work for the DSTL1 (N21)...
IT HAS AWESOME POTENTIAL.
Currently ADB RECOVERY SHELL + ROOT is the only thing that is functional.
But I haven't been able to get in touch with him to continue work on it.
The following files prevent me from booting into RA's Recovery, so I remove them:
- e2fsck
- mke2fs
- parted
- tune2fs
Once I am in ADB RECOVERY SHELL I can push them back on and do what I need to do.
Unfortunately the changes are persistent so if I were to reboot and try Recovery Mode again, it won't load
What is so special about those four programs that prevent my recovery from loading?????
Click to expand...
Click to collapse
e2fsck is a filesystem check utility for ext2
mke2fs is for ext2 filesystem creation
parted is a partitioning tool
tune2fs is for change some filesystem parameters (usually checking interval)
I've read that recovery from Amon-Ra creates automatically 3 partitions (ext2, swap and FAT32). So those commands whould probably mean ext2 filesystem creation. I'm sure Amon-Ra could give us more information on this subject because he added them to the image.
Have you checked your SD card?.
PD: I'm waiting for my N21 . So I can't test yet.

andferno said:
e2fsck is a filesystem check utility for ext2
mke2fs is for ext2 filesystem creation
parted is a partitioning tool
tune2fs is for change some filesystem parameters (usually checking interval)
I've read that recovery from Amon-Ra creates automatically 3 partitions (ext2, swap and FAT32). So those commands whould probably mean ext2 filesystem creation. I'm sure Amon-Ra could give us more information on this subject because he added them to the image.
Have you checked your SD card?.
PD: I'm waiting for my N21 . So I can't test yet.
Click to expand...
Click to collapse
Thank you for that insight.
I am not sure what RA's recovery would have done on its own...
but I have initiated and completed successfully a partition of my SDCard that includes FAT32, swap, and ext2.
Now that I have done this, for experimentation really, I don't know how to use it and what it gives me.
Obviously the swap is useless because I would need a cooked Android ROM that would actually utilize swap.
ext2 is probably for apps2sd... which I tried unsuccessfully - probably because of my own mistake.
I will continue trying and report again later.
As far as Amon_RA, he mentioned he was working on upgrading all the recovery images he has put out to the next version - thus we will be in queue until this comes to pass. Maybe we can just skip this version and go to the next

N21 vs DSTL1: stock comparisons
I have completed the comparison of recovery images of the DSTL1 and N21.
For this test I used an original mtd2.img from my DSTL1 and an original mtd2.img from Slemmen's N21.
The recovery images are identical:
Both mt2.img are 4,194,304 bytes
Both mtd2.img-kernel are 2,141,616 bytes
Both mtd2.img-ramdisk.gz are 386,645 bytes
What is also interesting to note is that the two boot images i inspected were also identical.
The DSTL1 boot image is one that came with the 1502 update from General Mobile (which may or may not be identical to the original).
The original N21 boot image, thanks to ikarishinjisan, is identical to the DSTL1 boot image:
Both mt1.img are 4,194,304 bytes
Both mtd1.img-kernel are 2,141,816 bytes
Both mtd1.img-ramdisk.gz are 148,671 bytes
*Notice how both recovery and boot are the same size... must be padded?
*Notice how boot kernel is 200 bytes more than recovery kernel.... interesting...
On a side note:
Bootloader is identical as expected: both ikarishinjisan's and my mtd0.img are 1,048,576 bytes.

If things are going to go custom, it might make some sense to put ext3 filesystems on these things.. ext3 is just ext2 with journalling, which could be helpful since phones can just die/get dropped/lose connection with battery/whatever.

Also, this can be done with the tools already there..
mkfs.ext2
tune2fs -j

dnfm said:
Also, this can be done with the tools already there..
mkfs.ext2
tune2fs -j
Click to expand...
Click to collapse
Are you referring to the Amon_RA's custom recovery?
I can't get tune2fs onto the recovery without trickery, definitely not noob friendly... until we figure out why.
But great suggestion
I'm guessing the ROM must be coded to make use of ext3, otherwise its worthless?

The kernel would need to be configured to support ext3.

Archos gen8 bootloader crack (disable signature check)

" PWNED " :-D
As you know, Archos bootloaders check digital signatures of init and recovery kernels, so you need to install SDE to use custom kernels, and it somehow "watermarks" the device.
Good news everyone! I've disassembled both bootloaders, found the code which checks signature, and replaced it (first instructions of verify_hash function) with "return 0" which is "mov r0, #0; bx lr" in ARM assembly. It's much the same hack as on Archos 5, thanks EiNSTeiN from archos.g3nius.org for reverse engineering previous generation.
Archos gen8 boots using OMAP boot ROM from internal eMMC card. Primary bootloader ("boot0") is in 0x20000 bytes after the first sector of internal flash (i.e. at 0x200) and secondary bootloader is written into rawfs, /mnt/rawfs/avboot. boot0 contains image size and loading address in first 8 bytes.
So, here is the patch:
1) boot0: replace 8 bytes at 0x7520 from the beginning of mmcblk0 from 7F402DE9003091E5 to 0000A0E31EFF2FE1.
2) avboot: replace 8 bytes at 0x14424 in avboot from 7F402DE9003091E5 to 0000A0E31EFF2FE1 (same patch). 0x14424 from avboot beginning is usually 0x14824 from the beginning of mmcblk0p1 (avboot comes first in rawfs, just after 2 blocks of header).
Of course you need root to do it. I've done it on my Archos 101, then changed 1 byte in recovery image - it boots into recovery without problem (before the hack it didn't boot into this 1-byte changed recovery).
And of course do it with caution and at your own risk DO NOT replace the bytes if you find other original data at these offsets! Bad boot0 or avboot means bricked Archos. There must be some sort of test point (something connected to OMAP SYS_BOOT5 pin) to boot from USB, or a boot UART interface, so debricking the device must be possible, but it would require some effort to find it, find a proper bootloader and use it.
If someone wants to see IDA database, I'll send my.
P.S: I do not have enough messages to post inside Development subforum, so I'm posting here.

Great work! With this base, can yout get something like CW to run?

I'm so waiting for him to come back and say April fools.

I'm gonna screw him up if this was an april fool

First, if this is an April fools, I will find you and hurt you.
Second, what does all that mean anyway? Does that mean Cyanogen on Gen8 is near? Does it have anything to do with roms?

vitalif said:
P.S: I do not have enough messages to post inside Development subforum, so I'm posting here.
Click to expand...
Click to collapse
Maybe you should increase that number of post by explaining how you did this.

)))) No it isn't an April fool, my device now really has a modified recovery. Ridiculously modified (1 byte changed), but that's the proof!
Check the patch by yourself )) all you need to write to mmcblk0 is a standard linux dd tool... which is included into standard Archos busybox...
wdl1908 said:
Maybe you should increase that number of post by explaining how you did this.
Click to expand...
Click to collapse
In fact, it was not hard, and if I knew ARM assembly language before, it would be even easier... All I had to do is to find bootloader on the flash (boot0 is obviously in its beginning, and avboot is on /mnt/rawfs), copy it to computer, download IDA, feed bootloader to it and find functions similar to ones described on archos.g3nius.org (BigInteger_ModulusEnter, RSADecipher, etc). It also could be simpler, as BigInteger_ModulusEnter is mentioned inside an ASCII string inside data section... But I've found them by text search also there is a magic "ZMfX" in first 4 bytes of avboot and some other magic inside init and recovery... One also could use them to find interesting points in bootloader.
At first I've started disassembling with the wrong base address, but bootloader has code which copies itself to the correct one in the very beginning, so I've changed it and started over. In fact, it has size and address in first 8 bytes, so this also could be simpler...
So the hack is done, what needs to be done by now - utilize it and create some custom ROM or simply flash urukdroid without SDE...
chulri said:
Great work! With this base, can you get something like CW to run?
Click to expand...
Click to collapse
CW == ClockWorkMod recovery? I don't have any experience with CWM porting yet, but in theory yes, the hack gives us the ability to run custom recovery images.

Don't know alot about the bootloader, but what advantage does this have?

SWFlyerUK said:
Don't know alot about the bootloader, but what advantage does this have?
Click to expand...
Click to collapse
Hm. I'll explain... Bootloader is the program which starts up the device, similar to bootloader on your PC signature check in bootloader prevents us installing modified Linux kernel, initial ramdisk and recovery images. So, for example, we can't have netfilter in kernel without installing SDE, we can't have ClockWorkMod recovery on Archos at all, and we can't, for example, change MMC card splitting into 512M mmcblk0 for system + remaining for "internal SD" with data.
With signature check removed, all this is possible.
The underlying idea of all this signature checking is probably protecting f**king DRM... I HATE IT !!!!!! And hate companies promoting it =) When you install SDE on previous generation archos (5it), it removes drm keys from device memory (this is the "watermarking" mentioned on Archos site). It makes device unable to play the content buyed for it anymore... Not a big deal, but unpleasant. I don't know if this is the same on gen8.
In detail: Archos 101 has OMAP3630 processor. The "0-stage" (very-very first stage) bootloader, i.e. program which gains control after processor power-up, is hard-coded into one-time programmable area on the processor itself and is named "OMAP boot ROM" (similar to PC BIOS). The boot ROM can continue device booting process from different devices including SD/MMC card, NAND flash, UART (serial port) or USB interfaces. The boot sequence is determined from physical pin connection configuration. Our Archos boots from internal eMMC card.
So, OMAP boot ROM loads primary Archos bootloader, without checking any signatures or checksums, and simply transmits control to it. Primary bootloader sets up some processor configuration and then reads secondary bootloader (avboot) from flash. Then, it checks its MD5-RSA digital signature using Archos public key. If signature is incorrect, it hangs the device (goes to infinite loop). So if we modify avboot without removing signature check from boot0, device would be bricked. If signature is correct, control is transmitted to avboot. Avboot determines what system we want to start by pressing different keys, loads it, checks signature if system is init (normal system) or recovery, sets up configuration for Linux kernel and transmit control to Linux.
Interesting facts:
* According to the code, boot0 can use rawfs or FAT filesystems for boot partition.
* During boot process, various messages are printed to serial console. avboot even has some code for receiving commands over serial connections.
* OMAP processor boot sequence can be configured via special memory area which remains unchanged after soft reset, and this configuration will override one determined by physical pin configuration. This does not give us much profit, but is also interesting...

Thanks for the explanation, so is it worth doing for a noticable difference in performance etc?

SWFlyerUK said:
Thanks for the explanation, so is it worth doing for a noticable difference in performance etc?
Click to expand...
Click to collapse
Whats being done will have no affect on performance of the device. It will however, allow a lot of work that can contribute to better performance on the device. That is assuming that we can put on a modified clockworkmod recovery on these devices without bricking them.

He says the only way to do this is with root but in order to have root with r/w access at this point is SDE....right? Don't get me wrong custom recovery with the ability to make backups would be awesome but it seems SDE will still be necessary unless a new rooting option comes along.
*on a side note about root has anyone tried using psneuter to gain temp root through ADB? I really am not super knowledgeable about this stuff but this was used on the thunderbolt to aid in getting full root and s-off.
Sent from my ADR6400L using XDA App

JBO1018 said:
He says the only way to do this is with root but in order to have root with r/w access at this point is SDE....right? Don't get me wrong custom recovery with the ability to make backups would be awesome but it seems SDE will still be necessary unless a new rooting option comes along.
*on a side note about root has anyone tried using psneuter to gain temp root through ADB? I really am not super knowledgeable about this stuff but this was used on the thunderbolt to aid in getting full root and s-off.
Sent from my ADR6400L using XDA App
Click to expand...
Click to collapse
Archangel will give you temp root without using SDE.

He said root with r/w access. Archangel won't do that, the file system is still protected.

pbarrett said:
He said root with r/w access. Archangel won't do that, the file system is still protected.
Click to expand...
Click to collapse
Nope r/w access is not needed the only changes to be made are on /dev/mmcblk0p1 which is mounted on /mnt/rawfs the read-only is on the root file system so they are seperate. Archangel will do just fine for this.

wdl1908 said:
Nope r/w access is not needed the only changes to be made are on /dev/mmcblk0p1 which is mounted on /mnt/rawfs the read-only is on the root file system so they are seperate. Archangel will do just fine for this.
Click to expand...
Click to collapse
To be correct, there is no write protection on internal MMC at all, there is readonly rootfs which is mounted from a squashfs archive (squashfs is compressed readonly filesystem commonly used on Linux Live CDs), so you can't modify _files_ on it while it is mounted. But, nothing stops you from updating it as a whole.

Urukdroid
Someone should give a shout out ro $auron, creator of the Urukdroid project about this, he might find it useful.

So, if your hack is confirmed, that would give us the possibility to port CW recovery and Cyanogen to Gen8 devices... am I right ?

shrewdlove said:
Someone should give a shout out ro $auron, creator of the Urukdroid project about this, he might find it useful.
Click to expand...
Click to collapse
I think he has already seen this thread but you can ask him
lechuckthepirate said:
So, if your hack is confirmed, that would give us the possibility to port CW recovery and Cyanogen to Gen8 devices... am I right ?
Click to expand...
Click to collapse
Yes you are^^ but the thing is you have to port cyanogen to our gen8^^ and this must be done by a or more devs
i heard the biggest problem is that our touchscreen is connected by an usb controller inside the archos thats why the honeycomb port by luisivan is not recognize our touchscreen ( but when the source code is released, finally, we will get a hc port )

Lennb said:
i heard the biggest problem is that our touchscreen is connected by an usb controller inside the archos thats why the honeycomb port by luisivan is not recognize our touchscreen ( but when the source code is released, finally, we will get a hc port )
Click to expand...
Click to collapse
this isn't a problem for cyanogen (v7 = Android 2.3.3) because we have the source.

Dual Boot,Splitting Partitions

Can you dual boot or any other way to have 2 different roms installed at the same time,so i can switch back and forth?Like windows either at boot or logging in and out of 2 different desktops.
Maybe find a way to split the partitions.Any suggestions would be great.

Duel= 2 roms fighting. Make it dual. Thought it was funny, no malice intended.

lol - duel - dual...
It would be interesting if that was possible. There would have to be another program in there to act as the buffer between both OS's though - that would take control of the start-up, hold on a page that has both options and then would boot the option you want.
Not sure if that's possible since some files are right on the root and in order to have an OS work it can't have files in the same directory - they would just overwrite each other.
But, I too, have wondered if it would ever happen. Be a great way to test new ROM's if you didn't always have to overwrite the existing ROM but rather, you could place a new ROM in a special directory and then run it from that - or partition the internal memory with the new partition available to boot from and store.

partition the internal memory with the new partition available to boot from and store.
Click to expand...
Click to collapse
Thats exactly what i was thinking,partition the system os,i rebuild computers and a little system modding in windows,but this is a linux based os,so it would be a little odd for me.I'm gonna look into this a little more.

You may try to contact the guys who developed boot manager. www.init2winitapps.com they have a listing of supported devices and a request form. Works on the thunderbolt 5 slots for 5 roms, I'm unsure how difficult it would be to add support for the iconia.
Sent from my A500 using XDA Premium App

ibsk8 said:
You may try to contact the guys who developed boot manager. www.init2winitapps.com they have a listing of supported devices and a request form. Works on the thunderbolt 5 slots for 5 roms, I'm unsure how difficult it would be to add support for the iconia.
Sent from my A500 using XDA Premium App
Click to expand...
Click to collapse
Thanks,i submitted the idea,lets see if they will run with it,hopefully they will find interest.

Hello Diabblo,
Any update on that?
I think the idea of dual boot (or 5al boot) is just fantastic!
I have beside my iconia a501 a poor old zt180s and it can triple boot on android, ubuntu and WinCE!
Best,
Inji.

inji75 said:
Hello Diabblo,
Any update on that?
I think the idea of dual boot (or 5al boot) is just fantastic!
I have beside my iconia a501 a poor old zt180s and it can triple boot on android, ubuntu and WinCE!
Best,
Inji.
Click to expand...
Click to collapse
Im guessing that device has a open non encrypted boot loader. The Iconia was encrypted at birth with the 3.2 push they tightened security even more from whqt I have read.So this is likely never happening unless acer changes ttjere boot loader policy.not likely to happen.
hope this helps you understand more of this issue.

I'm dual-booting my A500 right now with ICS and Ubuntu. The method for dual-booting is a replacement recovery.img which contains a Linux kernel and acts as a bootloader for Linux. Ubuntu itself runs from a rootfs.img on the internal storage (there's also recovery.img's available to run from external SD too). If I want to run Android, I just boot my tab normally. When I wanna run Ubuntu, I hold vol+ as I'm turning it on to force the modded recovery to load. It's a pretty cool setup more info in this thread: http://forum.xda-developers.com/showthread.php?t=1158260

Dear Erica Renee and Bloodflame,
Thanks a lot for your answers. Ok, I got it with the encrypted bootloader.
Will try the method described by Bloodflame.
Actually, since I got these tablets my main use of them is flashing new ROMs... I don't really have the use of new ROMs but I think it's so exciting!
Cheers,
Inji.

I don't believe the encryption is the problem.
The current boot loader is available unencrypted in update packages if anyone want to have a look at it.
Replacing the boot loader on the device is done as part of a down grade procedure described elsewhere on this forum.
So unless I'm missing something, the problem is more likely time and interest. Someone need to care enough about it and have the time to make some other boot loader work. Or patch Acer's. Either way it is likely to require quite a bit of time and patience.

So let me see if I have this correct. Acer's hardware bios code is 'locked down' enough to keep the average code manipulator out? A custom boot loader needs to be dev'd that can communicate correctly to be able to handle Android recovery and a linux/android boot screen etc. ? Could someone elaborate more blatantly if I am incorrect...

★★★★[INFO]ANDROID ROM & How they Work★★★★

★★★★[INFO]ANDROID ROM & How they Work★★★★
Parts of a ROM
i. The kernel.
Android (like many other Smartphone operating systems) runs on the Linux kernel. The Linux kernel was created in the early 1990’s by a gentleman named Linus Torvalds in Helsinki, Finland. It’s incredibly stable, incredibly friendly, and incredibly difficult for the layman to understand and modify. Thankfully it’s also very popular so it has been ported on to a multitude of hardware, including our Android devices.
Think of the kernel as an interface layer between the hardware and software on your device. The kernel decides when things happen, such as the LED indicator gets lit or when the soft button's LED gets lit. An application sends a request to the operating system to blink the LED. The operating system then sends the request to the kernel, which makes the light flash for the amount of time requested by the OS.
What sounds like a round-about way to get things done is also what makes the system so scalable and robust. Application developers only have to code in a way the operating system understands and the kernel makes it work on the hardware. This also keeps the application running in it’s own user-space and separate from the kernel. That means when you run the latest uber-cool app that wasn’t designed for your particular OS version, or is still very beta and it crashes, the kernel gives you the option to Force Close the application and the kernel can run untouched.
In a standard Android ROM (we will leave developer images and the like for another discussion) the kernel is bundled along with a set of instructions that tell the device how to load the kernel and the OS during boot. This is the boot.img that you see inside a zipped ROM that your not able to easily open. The device knows to extract this image to internal memory (the ramdisk) and follow a series of scripts (init scripts) to load the kernel and then the other portions of the OS. That’s what’s happening while you’re watching the boot animation. Interestingly enough this is done the same way for a PC, your smartphone, an Android tablet, or even a smart Linux powered toaster. If you’re feeling exceptionally geeky, plug your Android phone into the USB port on your PC and let the PC boot from the USB device. No, it doesn’t actually load, but you can watch the animation while it tries to match up the hardware support with what’s inside your PC. As I said, Linux is amazingly scalable and as a result so is Android.
What is a kernel? If you spend any time reading Android forums, blogs, how-to posts or online discussion you'll soon hear people talking about the kernel. A kernel isn't something unique to Android -- iOS and MacOS have one, Windows has one, BlackBerry's QNX has one, in fact all high level operating systems have one. The one we're interested in is Linux, as it's the one Android uses. Let's try to break down what it is and what it does.
Android devices use the Linux kernel, but it's not the exact same kernel other Linux-based operating systems use. There's a lot of Android specific code built in, and Google's Android kernel maintainers have their work cut out for them. OEMs have to contribute as well, because they need to develop hardware drivers for the parts they're using for the kernel version they're using. This is why it takes a while for independent Android developers and hackers to port new versions to older devices and get everything working. Drivers written to work with the Gingerbread kernel on a phone won't necessarily work with the Ice Cream Sandwich kernel. And that's important, because one of the kernel's main functions is to control the hardware. It's a whole lot of source code, with more options while building it than you can imagine, but in the end it's just the intermediary between the hardware and the software.
When software needs the hardware to do anything, it sends a request to the kernel. And when we say anything, we mean anything. From the brightness of the screen, to the volume level, to initiating a call through the radio, even what's drawn on the display is ultimately controlled by the kernel. For example -- when you tap the search button on your phone, you tell the software to open the search application. What happens is that you touched a certain point on the digitizer, which tells the software that you've touched the screen at those coordinates. The software knows that when that particular spot is touched, the search dialog is supposed to open. The kernel is what tells the digitizer to look (or listen, events are "listened" for) for touches, helps figure out where you touched, and tells the system you touched it. In turn, when the system receives a touch event at a specific point from the kernel (through the driver) it knows what to draw on your screen. Both the hardware and the software communicate both ways with the kernel, and that's how your phone knows when to do something. Input from one side is sent as output to the other, whether it's you playing Angry Birds, or connecting to your car's Bluetooth.
It sounds complicated, and it is. But it's also pretty standard computer logic -- there's an action of some sort generated for every event. Without the kernel to accept and send information, developers would have to write code for every single event for every single piece of hardware in your device. With the kernel, all they have to do is communicate with it through the Android system API's, and hardware developers only have to make the device hardware communicate with the kernel. The good thing is that you don't need to know exactly how or why the kernel does what it does, just understanding that it's the go-between from software to hardware gives you a pretty good grasp of what's happening under the glass. Sort of gives a whole new outlook towards those fellows who stay up all night to work on kernels for your phone, doesn't it?
Click to expand...
Click to collapse
ii. The operating system.
Once the kernel is loaded, the init scripts tell the Operating System to load. Android is the user interface for a custom built Java virtual machine called Dalvik. Dalvik was written by Dan Bornstein, who named it after the fishing village of Dalvik in Iceland, where his family originated from. The debate of which Java VM is superior is best left for another discussion, so I’ll simply say that DalvikVM is a register-based machine versus true JavaVMs which are stack based.
The Dalvik machine creates executable files (.dex files) which can be interpreted by the OS and run by the end user. These .dex files are OS version dependant. That simply means that applications and core functions built to work with one version of Android may or may not work well with other versions. Google provides the tools through it’s Software Development Kit (SDK) for applications to communicate with the OS.
Click to expand...
Click to collapse
iii. Core functions.
No smartphone would be complete without a set of functions that allow the device to be used as intended. Things like the phone and dialer interface, the calendar, the messaging system are core functions of the Operating System. In Android, these are run on top of the kernel as separate applications. The merits (or lack of) of providing these needed functions as separate applications is once again best left for another discussion, but this is what allows developers like HTC or Motorola to replace the standard functions with alternatives that provide a different look and feel from stock. HTC’s onscreen keyboard or Motorola’s MotoBlur contact list are great examples of this. The “little guy” isn’t left out of the mix either. Handcent SMS or Chomp SMS can integrate into the OS very well, as most of us already know.
An additional set of Core Functions are provided by Google. Popularly called GoogleBits, things like Gmail, sync, Gtalk and the Android Market are applications written by Google that give an extra set of useful functions to the OS. You’ll find these on all smartphones, as well as many other Android devices.
Click to expand...
Click to collapse
iv. Optional applications.
These are applications provided by the manufacturer to give the device even more usability. Things like the Amazon MP3 store, PDF readers, Corporate Calendar etc. allow you to do even more with your device. Remember - Droid Does
Click to expand...
Click to collapse
B. How is a ROM packaged?
In most cases a ROM will come packaged in a .zip file. The recovery image’s kernel (yes, it has one too!) has the ability to unzip and copy the contents into the correct place. Inside this zip file is a folder (META-INF\com\google\android\) that contains a script prepared by the ROM “cooker” (another of those techie terms - it means the person(s) who developed the ROM) that tells the system what to format, what to copy and where, and any file operations that need to be done. Each device does things a bit differently, but this script is where it all gets done. More on this folder later.
You’ll also see a /system folder. This is the meat of the ROM. It has the necessary OS files, the Core functions, and any optional applications the cooker decided to include. The folder is structured the same way it is on your device - /system/app, /system/framework, etc. The whole tree is usually copied over and the existing /system folder is overwritten. The cooker uses the script to tell the kernel to erase the existing system folder, copy the new folder over, and set the file permissions.
Sometimes you will also see a data folder. This usually is space set up for optional applications, including optional system tools like busybox or SuperUser white list. These applications could be placed in the /system folder, but placing them in the data folder makes it easier for the end user (you and I) to remove or update them as needed.
You’ll also notice a META-INF folder. This contains the update script we talked about earlier, as well as secure keys that need to be provided so the device knows the update can be trusted. A special note needs made here. Trusted means that the update is trusted to be in the correct form to load the device. It in no way means the ROM is safe from malicious code. Anyone is able to use a set of test keys and create a ROM that will flash and run your device - even those people with bad intentions. Flashing and running a custom 3rd party ROM is putting faith in the cooker that he or she not only knows what they are doing, but are honest as well. Also, some Motorola custom ROMs will have a small update.zip stored inside this folder to be run on first boot of the device.
Finally we are left with the boot.img file. This is the kernel and ramdisk image we discussed earlier. Your phone copies this over to be decompressed and run when the device boots.
Click to expand...
Click to collapse
2. How do I install a ROM?
In this section we’re discussing how to install a custom 3rd party ROM. ROMs from the manufacturer usually have a utility that runs on your PC to flash and load the new image.
A. Got Root???
Yes ?:good:!!!
Custom ROM’s simply will not load on devices that aren’t rooted. In theory, it may be possible to sign a 3rd party ROM with the keys that the stock recovery image will flash, but for the most part you need to have flashed a custom recovery image before you can change your device’s ROM. Instructions and tutorials on how to root your device are all over the internet. Some are good, some are bad. The hacking forum is a great place to go and learn more about rooting and how to successfully get it done on your device.
Click to expand...
Click to collapse
B. Recovery
Most Android devices have had a custom recovery image written for them. This will overwrite the stock recovery image, allowing you to flash 3rd party ROMs as well as giving extra functionality. Help with finding and flashing the custom recovery image for your device can also be found in the hacking forum. The installation of a custom recovery image also allows for a very important function. Backup and restore.
Click to expand...
Click to collapse
.C. Nandroid
Nandroid is a set of bash scripts and code written by that copies the state of your system and stores it in a folder on your SD card. You can then use the restore function of Nandroid to restore to this point at any time. This is a priceless feature and reason enough to root your phone. It’s included by default in most custom recovery images, and the code is freely available to use if you’re inclined to write your own recovery image.
Click to expand...
Click to collapse
In most situations, using Nandroid to back everything up is easy:
1. Verify you have a memory card with enough free space (~300MB to backup, ~500MB to restore).
2. Reboot your device into recovery. It’s slightly different for each device, once again hacking forum FTW!
3. Navigate through the menu and select the Nandroid Backup function.
4. Apply your choice and wait for the device to tell you it’s finished.
It’s always good practice to copy the entire nandroid folder from your SD card to a safe place. You can then copy it back to the SD card if the card is ever damaged, lost or erased.
D. Copy and Flash
You’re rooted, have downloaded a custom ROM, have your system backed up and are now ready to flash your device. This is not nearly as scary as it sounds.
1. Mount your SD card to your PC, and copy the .zip file to the root folder of the card. Don’t unzip the file, and don’t look for a folder called root. The root folder in this case means the base folder, what you will see when you mount your card to a PC or the device.
2. Reboot your phone into recovery.
3. Navigate through the recovery menu and select the flash update option. Depending on your recovery image, the file may need to be named update.zip, or you may be able to select any zip file on your card as long as it’s the correct format. The cooker knows this as well and if the ROM needs to be named update.zip it will be.
4. Apply your choice and wait for your device to tell you it’s finished.
5. Reboot.
Click to expand...
Click to collapse
It’s worth noting that many times a new ROM will require that you wipe and factory reset your devices data. While inconvenient, it’s often necessary to get rid of the old data as it may be incompatible. As long as you’re using the cloud for calendar and contacts, they will be re- downloaded and stored back on your device automatically.
Dirty flash and Clean flash
A dirty flash is only wiping cache and davlik then flashing your ROM....
a Clean flash is at LEAST factory reset/data wipe + wiping davlik(factory wipe takes care of /cache also)... Maybe doing a format /system also.
***Odin***
Odin is the ROM Flashing Tool for SAMSUNG smartphones. ROM files flashable with Odin come with .tar extension.
Most of the ROMs you are going to flash with Odin are the official stock Samsung ROMs (or leaked stock ROMs). Custom ROMs are rerely flashable by Odin because they come with .zip extension that Odin does not recognize (it recognizes .tar files).
Custom kernels, however, are sometimes provided in .tar format by their developers (e.g. CF-Root kernels), so that they can be flashed by Odin. When your phone is new and running official firmware you most often cannot flash a custom ROM to it because a Samsung phone often requires a custom recovery and root rights that are included in a custom kernel to be able to flash custom ROMs. That's why Odin often comes in handy in rooting and flashing a custom firmware to your phone because you (often) can flash a custom kernel with it that already includes root and custom recovery and enables you to flash custom firmware (custom ROMs). I use the word "often" very frequently in the previous sentence because every Samsung smartphone is different and requires various procedures for rooting it and flashing custom ROMs (see the section about using Odin below).
If it comes to stock ROMs, the best source of stock (official) Samsung ROM files is located at this excellent website: SamMobile.com/firmwares (link). It requires registration (it's free) and I encourage you to set up an account there because you will most likely use this site several times during your stay at XDA. You will most likely come across 1 .tar or 3 .tar file ROMs there, flashable by Odin. Refer to the Odin flashing guide below for more info.
Click to expand...
Click to collapse
****Heimdall****
What is Heimdall?
Heimdall is a cross-platform open-source tool suite used to flash ROMs onto Samsung Galaxy S devices.
How does it work?
Heimdall uses the same protocol as Odin to interact with a device in download mode. USB communication in Heimdall is handled by the popular open-source USB library, libusb-1.0.
Why “Heimdall”?
The flashing software Odin is named after the king of gods in Norse mythology. Loke, the software component on the Galaxy S that provides functionality to flash, may also to be named after an important character in Norse mythology, often translated as Loki. As such I have named my flashing software Heimdall, after the Norse god, and guardian of the Bifrost Bridge.
What platforms does Heimdall run on?
Linux, OS X and Windows (XP, Vista, 7 etc.)
Why use Heimdall when we can use Odin?
Odin is generally unreliable and only runs on Windows systems. Furthermore, Odin is leaked Samsung software that is not freely available or well understood by the community.
Is Heimdall safe?
No matter what method you chose, flashing firmware onto your phone has a lot of potential for disaster. We have tested Heimdall with a variety of phones flashing several different firmware versions resulting in a 100% success rate. As such we believe that Heimdall is generally reliable. However keep in mind, just like any flashing software, Heimdall has the potential to brick your phone if not used correctly.
How do Galaxy S phones get bricked when flashing?
Besides the inherent risks like power outs, accidental removal of the USB cable etc. The Galaxy S appears to be running extremely unreliable USB control software.
A failure to flash does not automatically equate to a bricked phone. However if you're extremely unlucky and the flash fails whilst transferring the primary boot-loader, secondary boot-loader or params.lfs (all quite small) than you've got yourself a paper weight that you're hoping Samsung will replace.
Please be extremely careful mixing files from different firmware releases. Don't do so unless you're certain it will work!
What Galaxy S variants has Heimdall been tested with?
We’ve tested Heimdall with a Galaxy S GT-I9000 (8 GB) from the United Kingdom and Galaxy S GT-I9000 (16 GB) from Australia. We don’t personally have access to any other devices to test with, however users have confirmed Heimdall functions correctly with the AT&T Captivate, Bell Vibrant, Telstra GT-I9000T, Epic 4G and the Galaxy Tab.
Click to expand...
Click to collapse
^

CWM Errors and Solutions
ERRORS encountered in CWM Recovery
.
What is CWM Recovery ?
ClockworkMod Recovery is a custom recovery for many Android devices. It is considered to be the most popular recovery for Android due to its easily-ported nature, and integration with ClockworkMod ROM Manager by Koush(Koushik Dutta). The easiest way to recognize it is by the printed name when it first starts, and the background logo of a gear and hat.
Click to expand...
Click to collapse
ERROR STATUS 6
This is usually caused by CR/LF EOL(Windows style End Of Line) in updater-script. Change it to LF EOL(Unix Style EOL) using Linux command: dos2unix updater-script, then re-signing the ZIP, will usually fix this error.
Click to expand...
Click to collapse
ERROR STATUS 7
This is usually caused by a corrupt download, or bad file signature. Re-downloading (or re-signing) the ZIP will usually fix this.
Click to expand...
Click to collapse
We have been consistently seen and heard people facing error “Status 7″ error while trying to flash or install
custom ROMs or firmware packages on their Android smart phones or tablets with ClockworkMod Recovery. Many
of the users are nowadays facing this problem with CWM Recovery while flashing .zip files of modded or custom
Ice Cream Sandwich (ICS) or Jelly Bean (JB) ROMs on their devices. So, you have also downloaded a custom ROM,
placed its .zip file in your phone’s or tablet’s SD card, booted into ClockworkMod Recovery, selected – “install zip
from sdcard” and then chosen the .zip file of the ROM to get it installed on your device. But instead of getting
flashed successfully, if you are facing the issue mentioned below, then just keep reading this article to find out
what’s wrong and fix up the problem :
Finding update package…
Opening update package…
Installing update…
Error in /sdcard/custom-jelly-bean-rom.zip (Status 7)
Installation aborted
Click to expand...
Click to collapse
or the following error right after CWM recovery shows –
Installing update…
assert failed: getprop(“ro.product.device”) == “I9103″ || getprop(“ro.build.product”) == “I9103″ || getprop
(“ro.product.board”) == “I9103″
Error in /sdcard/android-4-1-1-ics-rom-latest.zip (status 7)
Click to expand...
Click to collapse
So, if you are facing any of these errors while trying to install the desired custom ROM package on your Android
phone or tab, then you may try a various things or steps which may turn out to be the workaround of this
problem. Here are a few tips to get this “Status 7” error fixed in ClockworkMod Recovery and flash the ROM
successfully on your device :
(1) First of all, make sure your device’s bootloader is unlocked. If it is already unlocked but you are still
not able to flash the ROM, then just extract the .zip file of the ROM into a new folder, find the boot.img file from
that directory and flash it up on your phone or tablet via fastboot on your PC.
(2) Make sure that you are having the appropriate Radio or Baseband version installed on your device which is
supported by the custom ROM you are trying to flash. Most of the ROMs requires the latest version of Baseband, so
just update or upgrade your device to the latest Baseband version and then try to install the ROM once again.
(3) Update your device to the supported / latest build of official firmware before trying to install the ROM. You can
do it from – Settings > About Phone / Device > Software Update.
(4) Make sure you are having the supported or required kernel installed on your phone or tab. If it’s not, then flash
a new kernel right away and try to install your custom ROM once again.
(5) Is the ROM which you are trying to flash really works ? Find out whether it is working for other users or not.
Click to expand...
Click to collapse
Error Status 0
Well sometimes while flashing some ROMs especially the cooked ones we get Error status 0 in the CWM Recovery
this error is an indicator of Wrong Update Binary.This is usually caused by an incompatible update-binary in edify ZIPs. Replacing it with a compatible one, then re-signing the ZIP, will usually fix this error.
Click to expand...
Click to collapse

Partitions
Now it's time for the partitions :good:
Let’s start with a list of standard internal memory partitions on Android phones and tablets. These are:
/boot
/system
/recovery
/data
/cache
/misc
In addition, there are the SD card partitions.
/sdcard
/sd-ext
Note that only /sdcard is found in all Android devices and the rest are present only in select devices. Let’s now take a look at the purpose and contents of each of these partitions.
/boot
This is the partition that enables the phone to boot, as the name suggests. It includes the kernel and the ramdisk. Without this partition, the device will simply not be able to boot. Wiping this partition from recovery should only be done if absolutely required and once done, the device must NOT be rebooted before installing a new one, which can be done by installing a ROM that includes a /boot partition.
/system
This partition basically contains the entire operating system, other than the kernel and the ramdisk. This includes the Android user interface as well as all the system applications that come pre-installed on the device. Wiping this partition will remove Android from the device without rendering it unbootable, and you will still be able to put the phone into recovery or bootloader mode to install a new ROM.
/recovery
The recovery partition can be considered as an alternative boot partition that lets you boot the device into a recovery console for performing advanced recovery and maintenance operations on it. To learn more about this partition and its contents, see the ‘About Android Recovery’ section of our guide to ClockworkMod recovery.
/data
Also called userdata, the data partition contains the user’s data – this is where your contacts, messages, settings and apps that you have installed go. Wiping this partition essentially performs a factory reset on your device, restoring it to the way it was when you first booted it, or the way it was after the last official or custom ROM installation. When you perform a wipe data/factory reset from recovery, it is this partition that you are wiping.
/cache
This is the partition where Android stores frequently accessed data and app components. Wiping the cache doesn’t effect your personal data but simply gets rid of the existing data there, which gets automatically rebuilt as you continue using the device.
/misc
This partition contains miscellaneous system settings in form of on/off switches. These settings may include CID (Carrier or Region ID), USB configuration and certain hardware settings etc. This is an important partition and if it is corrupt or missing, several of the device’s features will will not function normally.
/sdcard
This is not a partition on the internal memory of the device but rather the SD card. In terms of usage, this is your storage space to use as you see fit, to store your media, documents, ROMs etc. on it. Wiping it is perfectly safe as long as you backup all the data you require from it, to your computer first. Though several user-installed apps save their data and settings on the SD card and wiping this partition will make you lose all that data.
On devices with both an internal and an external SD card – devices like the Samsung Galaxy S and several tablets – the /sdcard partition is always used to refer to the internal SD card. For the external SD card – if present – an alternative partition is used, which differs from device to device. In case of Samsung Galaxy S series devices, it is /sdcard/sd while in many other devices, it is /sdcard2. Unlike /sdcard, no system or app data whatsoever is stored automatically on this external SD card and everything present on it has been added there by the user. You can safely wipe it after backing up any data from it that you need to save.
/sd-ext
This is not a standard Android partition, but has become popular in the custom ROM scene. It is basically an additional partition on your SD card that acts as the /data partition when used with certain ROMs that have special features called APP2SD+ or data2ext enabled. It is especially useful on devices with little internal memory allotted to the /data partition. Thus, users who want to install more programs than the internal memory allows can make this partition and use it with a custom ROM that supports this feature, to get additional storage for installing their apps. Wiping this partition is essentially the same as wiping the /data partition – you lose your contacts, SMS, market apps and settings.
With this, we conclude our tour of Android partitions. Now whenever you install a ROM or mod that requires you to wipe certain partitions before the installation, you should be in a better position to know what you’re losing and what not and thus, you’ll know what to backup and what not.

You should at least post the source of such a large copy paste post.
Sent from my GT-N7100 using Tapatalk 2

Source? How do you post a source for an article which is compiled from 10+ sites? Plus my own addition?
Started from the bottom

Good job man, this saves me the time to do all this researches.
Keep it up
Best regards
Sifou
Using a Samsung N7100

sos_sifou said:
Good job man, this saves me the time to do all this researches.
Keep it up
Best regards
Sifou
Using a Samsung N7100
Click to expand...
Click to collapse
DO tell me if you have some suggestions for the thread.
"Thanks button is just to avoid "THANKS" posts in threads. Nothing more than that. Don't ask in signature or post for it and defeat the purpose why it was introduced"

I think that this is a pretty good summary of the basics. I even converted it to epub and stocked it on my e-reader for reference
You can get to the details if you want? Adding some info about flashing softwares like odin and the Linux based one (i don't remember it name)
The different recoveries available and their advantages vs désavantages
How to protect yourself from malicious applications, starting from knowing what are permissions...
Keep it up mate
Best regards
Sifou
Using a Samsung N7100

sos_sifou said:
I think that this is a pretty good summary of the basics. I even converted it to epub and stocked it on my e-reader for reference
You can get to the details if you want? Adding some info about flashing softwares like odin and the Linux based one (i don't remember it name)
The different recoveries available and their advantages vs désavantages
How to protect yourself from malicious applications, starting from knowing what are permissions...
Keep it up mate
Best regards
Sifou
Using a Samsung N7100
Click to expand...
Click to collapse
Heimdall?
"Thanks button is just to avoid "THANKS" posts in threads. Nothing more than that. Don't ask in signature or post for it and defeat the purpose why it was introduced"

Tha TechnoCrat said:
Source? How do you post a source for an article which is compiled from 10+ sites? Plus my own addition?
Started from the bottom
Click to expand...
Click to collapse
I guess you have a point, it's just the scientist in me with source-referral-ocd.
Sent from my GT-N7100 using Tapatalk 2

adytum said:
I guess you have a point, it's just the scientist in me with source-referral-ocd.
Sent from my GT-N7100 using Tapatalk 2
Click to expand...
Click to collapse
DO tell me if you have any problems or if you want something to be added.
"Thanks button is just to avoid "THANKS" posts in threads. Nothing more than that. Don't ask in signature or post for it and defeat the purpose why it was introduced"

Thread updated with Odin and Heimdall information.
"Thanks button is just to avoid "THANKS" posts in threads. Nothing more than that. Don't ask in signature or post for it and defeat the purpose why it was introduced"

Tha TechnoCrat said:
Source? How do you post a source for an article which is compiled from 10+ sites? Plus my own addition?
Started from the bottom
Click to expand...
Click to collapse
By listing ALL the different sources? And obviously crediting yourself with bits you've added.
Sent from my GT-N7100 using xda premium

You should make the title of the thread more presentable though.

Simone said:
You should make the title of the thread more presentable though.
Click to expand...
Click to collapse
Would like some suggestions.
"Thanks button is just to avoid "THANKS" posts in threads. Nothing more than that. Don't ask in signature or post for it and defeat the purpose why it was introduced"

Tha TechnoCrat said:
Would like some suggestions.
"Thanks button is just to avoid "THANKS" posts in threads. Nothing more than that. Don't ask in signature or post for it and defeat the purpose why it was introduced"
Click to expand...
Click to collapse
You should think of your own. That would be the best
Make it more professional looking, though.
Everything else is good.

Guys I have got my Note 2 finally. Will compile some guides for it too.
Sent from my GT-N7100 using xda app-developers app

You bought a note 2? Congrats mate !
Best regards
Sifou
Using a Samsung N7100

sos_sifou said:
You bought a note 2? Congrats mate !
Best regards
Sifou
Using a Samsung N7100
Click to expand...
Click to collapse
Thanks buddy. Get ready for more guides
Sent from my GT-N7100 using xda app-developers app

[REF] Understanding the basics before rooting your S3 (GT-i9300/i9305)

Note from the Author -
I am moving on to the N5 now and ditching my S3. I will continue to maintain this thread, however - please do PM me if you think that something needs to be changed or updated in this thread as I doubt I will be answering questions within the thread as much. Please don't PM support questions to me. Only PM updates that need to be made in the thread.
It's been a blast!
Regards
Dan
efs | backup your efs | backup your efs | backup your efs | backup your efs | backup your
Understanding the basics before rooting your S3 (GT-i9300/i9305)
This thread is intended to give you (as someone considering rooting your device) an overview of some of what I deem to be, really important information. Many people blindly follow guides and end up in trouble because they break their phones and don't really know what they were even doing at the time.
This may seem a bit overwhelming at first, there is a lot of text, but please do take the time to read it. It may save you further down the line.
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
Before we get started...
Here are a couple of threads you should get familiar with before posting on XDA.
Forum Rules - use Search before posting
Post Questions or Support queries in Q&A, NOT General
What is root access?
"root" is (but not exclusively) a Linux term. As you may or may not know, Android is based on a Linux Kernel.
The term "root" refers to the root of the device. All devices with an operating system use a series of directories (or folders) nested within one another. If you think of windows, your documents folder would be C:\users\username\documents.. Well, "documents" is a directory. It is within another directory (username).
Imagine "documents" being the top of a tree (A folder tree). You climb down the tree to username, past there to "users" and down to the root, in this example "c:". You cannot go beyond this level, because nothing exists beyond the root. To save a file directly on C: (not within any folders) would be to save a file to the root of your c: drive.
In Linux (unlike Windows), these root locations are completely locked down. A user of normal priviledges cannot edit any file or create files in these locations. They can only do this in their "home" location, which is the equivelant of username on windows. To gain access to these locations, you would need to be an administrator of the machine. Linux calls this Super User (su), and this user is said to have "root access".
This applies to Android in the same way. To root your Android device, is to have superuser access to the root locations of your phone, that you normally could not have access to.
Is it Risky?
There is always a risk having access to locations on your phone that are supposed to be locked down. You can easily delete things that your phone needs to boot up, which could lead to you losing all your data or even breaking your phone. This is why it is good have an understanding of your device and root access BEFORE you root.
It is worth noting that although many say rooting shouldn't void your warranty (it does in many places) even where that is supposed to be true, in practice, it isn't really. Even in the EU, I've seen many warranty claims rejected due to root so do think of your phone as out of warranty when you root.
The advantages of rooting
Why root?
More control over how the CPU acts. This can increase performance or battery life
More control over power consumption (undervolting)
More control over how apps start up. Prevent apps from starting up when they don't need to
Baseband. Try different basebands with the possibility of reducing drain or imporving signal strength
De-bloat. Remove or freeze system apps that you don't use
Access to community driven bug fixes that Samsung haven't released
Custom ROMs. Add additional functionality and controls over and above the stock experience
Increase redundancy. The ability to backup apps and entire phone
Theme. Don't be stuck with Samsung driving aesthetics.
Innovations. Use community driven features that improve your day to day experience
Better RAM management. Change the values of "Out of memory". Decide yourself when android should kill unused apps. Increase mutlitasking capabilities
Custom kernels. With kernels you can bring support for better audio features, better graphics performance and support for stock unsupported files systems
Google Android. Use android as it was intended before Samsung got their hands on it.
The Disadvantages of rooting
Why not root?
For all intents and purposes, rooting voids warranty.
Dangerous. You can break your phone and need the warranty you probably just voided
You open the doors for more mistakes. These mistakes may cause you to panic and further damage your phone
Lack of understanding. Blindly following guides and not understanding what you're doing.
No more official updates. Updating is a more manual process
Basic layout of /root on the GT-i9300
I'm not going to go into too much detail here. I just need you to know the basics. The GT-i9300 has an embedded Multi Media Card. This is the internal memory that everything on your phone you need to run it, is insalled on. It is the "internal memory" of the device.
Like windows and linux, there is a root to this memory, which has a few basic partitions that you need to know.
/efs - This is REALLY important. This is where your IMEI is stored, which you need to connect to your provider's network. Unfortunately it is the easiest partition to corrupt and impossible to restore without a backup so ensure you have a recovery or application to backup your efs cause if it goes (likely) you'll be sending your S3 to Samsung for repair.
Please read THIS THREAD for more info on EFS and IMEI issues.
/system - This is where the ROM is installed. Within /system are many important folders that you normally cannot get to.
For example, you have /system/app where all the important ROM apps are located. Things like the phone app and the messaging app. /system/bin, where all the important binaries are located that allow android to execute commands that it needs to, so it can function as an OS and /system/framework, where the crucial policies that control how things the user and processes interact with - act.
/data - This is where apps you install are kept. This is also where your data is kept, eg your SMS and e-mails. It also stores settings. If you change the wallpaper, it is stored here. What ringtone you have chosen... etc. The important directories here are /data/app and /data/data. These are what get wiped when you choose to wipe data\factory reset
/data/media is an important directory in /data. This is what is known as your "internal storage" or your "internal sdcard". /sdcard maps to here.
When you have root access to android, you can browse these partitions with a root explorer / file manager with root functionality.
There are also some hidden partitions you cannot browse like this. These are the partitions that contain recovery, bootloader and kernel
What are those things?
Kernel - This is always supplied with a ROM. It is the beating heart of Android. The ROM cannot function without the kernel. Since all ROMs include a kernel, if you're using a custom Kernel then flash a ROM, you will need to reflash the kernel again.
Please note, unlike the Galaxy S2 (and like almost every other modern android device) the kernel and recovery are independent. There is no link between recovery and kernel. Kernels are boot.img files.
Bootloader - this is what handles what you boot into. When you see the black Galaxy s III text, thats the bootloader. Its job is to handle the boot. It is responsible for booting into android, or if you manipulate the buttons in a certain way, it will boot into recovery or download mode. PLEASE NOTE, i9300/5 Bootloader is NOT LOCKED. DO NOT TRY TO UNLOCK IT. Only some US variants have a locked bootloader...
When you see this screen, you're looking at the bootloader:
Download mode is part of the bootloader itself. Again, it is a mini OS. It is designed for flashing stock (official) ROMs onto the phone (Which you can do using Odin). It is also used by Samsung to detect the status of your phone (if you have modified it or not).
If you have (or had before rooting) an official ROM above 4.1.1, Your bootloader flash counter in download mode will change to "1" at every boot, if you have a custom kernel or recovery - even if you reset it with Triangle Away. See the return for warranty link later in this post to get around this.
To access download mode, turn off your phone. Home volume down + home then press power. You will get to the screen below:
Press volume up to continue into Download mode:
Recovery - a secondary, min operating system designed to offer a few "drastic" options to recover when you cannot boot into android. For example, factory reset. Recovery isn't part of android. It is a seperate operting system. You can either boot into android or boot into reocvery.
To access recovery (custom or stock), turn of you phone. Hold volume up + home then press power.
The intial use of Stock recovery was to allow a user whose phone does not boot, to wipe their device to "recover" it to a booting state. It could also flash official updates from the sdcard. Custom recoveries do so much more, such as allowing you to flash custom rom.zip or kernel.zips from sdcard or backing up your device with a nandroid recovery.
Here is an example of a custom recovery (Philx Touch 5):
Please note, unlike the Galaxy S2 (and like almost every other modern android device) the kernel and recovery are independent. There is no link between recovery and kernel.
Some other stuff you may have heard about
Baseband / Modem / Radio - This is the software that manages your connection to wireless networks, be that voice or data. Unlike unrooted users, you can download and flash any number of i9300 (Versions for other models WILL BRICK YOUR PHONE) or i9305 radios pulled from official ROMs. I wouldn't waste too much time on them. Usually what your official ROM comes with in your country / for your carrier, is the most optimised for you. Try a few by all means but don't waste time testing every last one.
Be aware that Samsung official ROMs come with a baseband. Often this means Samsung based custom ROMs may also do so. Some ROMs which install using the Aroma installer (A kind of set-up wizard) may give the option to not flash the baseband. AOSP ROMs almost never come with a baseband. When you flash a ROM withotu a baseband, the previous baseband remains. You can by all means, mix and match ROMs and basebands. You are not tied to the baseband with the same build number as the ROM. For example, if you are on XXEMB1 ROM, you definitely do NOT have to stay on the XXEMB1 baseband.
RIL - RIL is Radio Interface layer. It's what sits between the radio (above) and the android telephony services. Each Radio is supposed to have a specific RIL. Every ROM comes with RIL as it's a requirement to function. Again, although the best pair is a matched RIL and Radio version, if you do change your Radio, it's not the end of the world. You may notice a little difference flashing the right one, but it's not something to get bogged down with. Personally, I very rarely try a new Radio. I almost never change my RIL.
It's worth mentioning that the above is only really valid for Touchwiz ROMs. AOSP ROMs use OpenRIL and are not compatible with Samsung RILs. Do not use apps like GetRIL or flash Modem+RIL packages on AOSP ROMs. You would have to reflash the ROM if you do this because using a Samsung RIL on your AOSP ROM will likely break your signal.
Also note, Nandroid backups generally don't backup the Radio. Some recoveries may give you a separate option to do so however. The RIL (as part of the ROM itself) is backed up in a Nandroid.
ROM - ROM really stands for "Read Only Memory" which refers to memory that cannot be overwritten. When we talk about an Android ROM, we are really talking about the Android OS which is installed ON the Read Only Memory, of course since rooting, the /system partition where the ROM is installed is no longer read only. It is read / write. Flashing a ROM will over write the entire /system partition with whatever is in the ROM.zip or ROM.tar. Any mods, scripts, themes or apps will be replaced. You can only have one ROM at a time, unless you use one of those funky dual boot kernels.
More advanced layout of the GT-i9300
Here we have a lovely MS paint diagram of the eMMC layout of the GT-i9300/5. Some of this you don't need to know, some of it you do.
1 BOTA0 - mmcblk0p1 - 4 MB
2 BOTA1 - mmcblk0p2 - 4 MB
3 EFS - mmcblk0p3 - 19.7M
4 PARAM - mmcblk0p4 - 8 MB
5 BOOT - mmcblk0p5 - 8 MB
6 RECOVERY - mmcblk0p6 - 8 MB
7 RADIO - mmcblk0p7 - 33 MB
8 CACHE - mmcblk0p8 - 1 GB
9 SYSTEM - mmcblk0p9 - 1.48 GB
10 HIDDEN - mmcblk0p10 - 587 MB
11 OTA - mmcblk0p11 - 8 MB
12 USERDATA - mmcblk0p12 - 11.4 GB
The above sizes are approximate and the diagram is not to scale.
Rooting the phone
When you go through the process of rooting the phone, you have to alter the ROM. Although the risks of this are very minimal, we couldn't technically say it was risk free. The process of rooting puts a binary (called "su") in /system/bin (remember we talked about that earlier?). This binary is what allows the user (you) to run things at an elevated privilidge (super user). That in itself would be quite risky, so rooting also gives you one of the superuser apps (there are 2 - SuperSU and SuperUser, both very good). These apps install to /system/app and act as a gateway. Essentially, these apps prompt you when another application wants "root access" so you can allow it or deny it. It's a form of protection against malicious intent.
Root is often enough for most people who simply want to run a few root apps, but many people will need to replace their stock recovery with a custom recovery. This is because you cannot flash custom roms from the stock recovery. Some methods of rooting give you root AND recovery. Some just give you root, but you can flash a recovery yourself using Odin and download mode. Technically you do not need root to flash a recovery and then flash a custom ROM as the rom will include /system/bin/su and /system/app/SuperSU anyway.
Odin is a useful Windows tool. You'll be using this to return your phone back to stock too by flashing a stock "firmware"
Please read Samsung Galaxy S3 General Sticky Roll-Up Thread ***Stickies found here!** to find all the rooting and flashing guides you need for the GT-i9300
If I were asked my opinion on how to root, I would recommend one of the 2 scenarios.
1) You want root only. No custom ROMs, kernels etc. Just root, just to use root apps.
CF Auto Root Via Odin
Why? Tried and tested method, simple to use. No need to choose what exploit you want to use as it's tailored for your device.
What does it do? It gives you a stock recovery (so can't flash things) and roots the Android OS
The Steps:
1) Download the Latest Odin
2) Download CF-Auto-Root for your model
3) Follow These steps to root
2) You want to flash custom ROMs / Kernels
If you want root on your existing Android ROM, you can do 1) first. Then flash a recovery of your choice (CWM, Philz, TWRP) via Odin
However, if you immediately plan on flashing a ROM, there's no need to root your existing ROM. Simply skip straight to installing a recovery. Backup then flash what you like.
The Steps:
1) Download the Latest Odin
2) Download recovery of your choice CWM, Philz, TWRP
3) Follow The steps to Flash Philz recovery (But for the recovery of your choice)
These steps can also be followed to update recovery to newer versions

Official Updates
Once you have rooted your phone, the phone is classed as "modified" and no longer qualifies for Official Samsung OTA updates.
It is possible to receive official updates (whilst rooted) via Kies, however this will remove root (just like flashing a full stock rom) and if you have any custom themes, kernels or /system modifications, this could really cause some problems to the ROM so it is best to avoid. Of course if you have flashed a custom ROM (even TouchWiz based ones) Official updates are a big, fat No-No.
If you do run custom ROMs, it's best to use their OTA method if they have one, or download from the threads on XDA and flash via recovery.
Flashing - Good practice
Recovery - Custom recoveries are very handy tools. Unlike the stock recovery, they have lots of options. Not only do they allow you to flash custom ROMs, but you can backup your current ROM too. This is called a Nandroid backup. Its a snapshot in time. It backs up your entire device, from the ROM to the Kernel and all your data too. If you restore a nandroid backup, your device will be extactly the same as it was when you took the backup. This means if you took a backup 2 weeks ago and restored it today, you could have lost 2 weeks worth of SMS.. but it is very handy. As soon as you have a custom recovery, a Nandroid backup should be the FIRST thing you do. You should take one before you flash any Mod, kernel, ROM or theme. It really is important, incase you manage to break your device.,
The RIGHT files - Always be careful that you know what you're flashing is for your device and you know what it is. Flashing files (ROMs, kernels etc) for other devices could BRICK your phone. Bricking means that it is beyond normal levels of repair, often meaning it needs the internal memory (which equates to the motherboard) being replaced. very expensive.
NEVER remove power - When flashing something, be it from your computer or from recovery (or mobile Odin), do NOT remove the power. It can corrupt not only what you're flashing but also what you're flashing to. If you corrupt any of your eMMC partitions, you could have Bricked the device.
Read, read and read - Read the development threads before you flash anything. Ensure you understand what you are flashing. Ensure you know the specific procedure layed out by the developer and you follow it closely. Do not ad lib. If you are unsure, ask.
DON'T PANIC - Think you've bricked your device? Dont panic. Stay calm. Dont google "unbrick S3" and flash lots of files you dont understand. There are many types of S3 "brick" (they're not bricks if you can easily recover) and many varients of the S3. Flashign these files could further break your phone and actually brick a not already bricked phone. Nothing for any other variant than the GT-i9300 should be flashed on it. The same goes for the i9305. Never flash for another model number.
Search and Ask - Unsure of something, read the stickies Samsung Galaxy S3 General Sticky Roll-Up Thread ***Stickies found here!** and do a search. Can't find your answer? Ask. It is easier for us to help you understand something before you do it than to fix something after you've broken it.
Provide details - ALWAYS tell us exactly what happened if you are requesting help. Always describe in detail what is happening.
"Flashed my phone now it doesn't work" is useless information.
"I rooted my phone 3 months ago and flashed a custom ROM. I decided today to flash ROM X from recovery Y. I booted into recovery and flashed from my internal SD card. I rebooted the phone and it is not starting up. It is looping at the boot animation" is GOOD information. We need to know What, when, how. We need to know if you followed a guide and which one (links where possible)
Backups
Backups are really important. This is how you can mitigate the risk of losing all your important data. Without these you could have to start again from scratch or worse, need to send your device for repair.
Your entire phone - Nandroid - Recovery
[*]efs - Recovery - EFS backup aapplications
[*]Your apps and data - Titanium backup
[*]SMS - SMS backup+
[*]Photos - Dropbox
[*]sdcards - FolderSync
The reason we backup is multifaceted.
A Nandroid will backup your entire phone. This is usually taken immediately before you flash a mod or a new ROM. Nandroid restores /system and /data. Usually when you flash a mod (kernel, theme, some system app or libs etc) and it causes a bootloop, a simple restore of Nandroid will return your phone as it was and booting again. In fact, you can use an advanced restore in recovery and choose ONLY to restore /system if appropriate
Titanium backup would often be done on a schedule. Every 2nd night or something, maybe once a week if you're daring. These are important for a number of reasons but the most important is if you are flashing a new ROM.
Remember earlier, we talked about all your data and apps being in /data/data and /data/app? Well, Titanium backs that up. When you flash a ROM, you have to perform a full wipe / factory reset before it will boot up properly. This is because you have settings stored in data/data for apps in /system/app that may have changed or no longer exist, or settings different to the settings in the new ROM. These are incompatibilities and these incompatibilities often will prevent a new ROM booting. Of course, a factory reset doesn't fully restore it to it's factory condition. It cannot restore the bootloader, rom, baseband etc because you overwrote these by flashing a new one.
We wipe, we install titanium and we restore all the data/apps and the /data/data related to /data/apps, but none of the data/data related to /system/apps (because that would restore the incompatibilities)
Here is how I restore using titanium backup after a wipe and flash....
Remember if your backup is on external sd, you need to point titanium to the location using preferences > backup folder location...
Go to backup / restore tab and press "click to edit filters" and deselect "system" and press the done tick icon to apply. Then from the previous backup / restore screen, go into the batch screen (another tick icon top right).
From this batch screen, select "restore missing apps with data" by pressing "run". Manually go through every app (yes, even if you have 300 apps) ensuring there's nothing samsung or rom specific there, unticking anything that is...
This should ensure a clean, user only app and settings. You will then need to manually set your system settings (ring tones, email etc)
Warranty
So, as we have discussed, warranty should be considered void once rooted. Technically in the EU, the OEM must prove root damaged your phone to reject warranty, however this is almost never the case.
When the S3 was released, it came with android 4.0.4 (ICS). The bootloader with ICS was normal. If you used Triangle Away once rooted, it would reset your binary counter forever. You may have kept status: Modified until you factory reset but that is not so much a problem.
When the S3 was upgraded to 4.1.1 Jelly Bean, a new bootloader was introduced. You could still reset with Triangle away, however on the next boot, if you had a custom recovery or kernel, the binary counter went back up to 1 again, which can present a problem.
Please see the following scenarios.
1) You just want root. No custom Kernels, no custom ROMs, no custom recoveries.
This is fine. If you root with CF-Auto Root it gives you a stock recovery. Once you reset the flash counter with triangle away, you should be fine.
2) You want root and recovery on a 4.1.1+ S3.
If you have a custom recovery or kernel, you can set triangle away to reset at every boot. The problem is if your phone breaks in such a way that you can never boot into android, but download and recovery mode still work, you're screwed, It goes back up to 1 on boot, fails to boot then you can only reset it with triangle away, which you can't use because it needs you to boot into Android. You see the risk?
3) You want root and recovery on a 4.1.1+ S3.
The alternative to the above is to flash This 4.0.4 bootloader via cwm. It can be reset by Triangle Away, and stays reset forever. Well why aren't we all using this? Because it is NOT SDS safe. This means if you ahev the unsafe internal memory, if you use download mode to flash anything, you risk bricking your device. Read [Important] Sudden Death Fix - Are you covered? for more information.
So it's a choice between:
I risk that under certain conditions, I may not be able to reset the binary counter for a warranty return
or
I have my binary counter at 0 always, but I cannot use download mode.
Please note, you need to run a TouchWiz ROM to use triangle away
Popular misconceptions
USB Debugging is always required for flashing.
Incorrect. USB debugging is an Android setting. It is only applicable within android. This setting does not work in recovery or download mode, so obviously anything done in those modes does not require USB debugging.
When rooting, all your data is lost.
Incorrect. Rooting adds a binary and application to your phone. It does not wipe it.
I need to root to fix my battery by wiping battery stats.
Incorrect. No one needs to wipe battery stats. Please read the wiping battery stats thread linked below:
Battery stats
What's good for you is good for me!
Incorrect. Everyone's usage is different. Everyone's set-up is different. Everyone's environment is different. There is no "Best" ROM. There is no "Best kernel for..." There is no "Most battery efficient baseband". All these things may acti differently for you than they will for me. What I like isn't what you like. Please do not create any "Best" threads.
If I ask the question "Blah blah blah for custom ROMS?", everyone will know what I am talking about
Incorrect. "Custom ROM" and "AOSP ROM" are NOT synonymous. People imagine when they ask about "Custom ROMS" that we know they really mean "AOSP ROMS". We don't. There are TouchwIz based custom ROMs too. We assume nothing.
B]I need yo be on a certain ROM to flash certain other ROMs[/b]
Incorrect. You're overwriting the ROM so why would ot matter what ROM you're overwriting?!
Important threads and resources
A list of important threads and resources...Please read ALL of these threads before rooting.
Mskip's unified toolbox(Root, drivers etc)
Index of Roms, recoveries and kernels
Guide for flashing roms, backups etc
Returning to stock for warranty
Odin flashing guide
Sammobile.com - stock firmwares
Be prepared ahead of time to fix a Brick
rootSU recommends
A few recommendations from me...
RootExplorer
Titanium Backup
Philz Recovery (CWM advanced)
Odin
Heimdall (Linux / Mac odin equivelant
That's it for now. I know this is a lot of information, but I believe this info to be the very least you should know before deciding to go ahead with rooting your S3. Please read it and read it again. Anything doesn't make sense, please ask in this thread and I will gladly help.
If any other seasoned rooters / flashers think there is something salient missing, please post her too. happy to add to it.

Glossary of terms
adb - Android Debug Bridge. This is a Windows or Linux command line tool that can be used to push files to a device, pull them, create directories. Very handy with a custom Kernel if you can't boot and need to get data from the device. This can be downloaded as part of the Android SDK or mskip's unified toolbox mentioned earlier.
AOSP - Android Open Source Project. This is google's code base. This is Android in it's pureset form. Anyone can download this code and build a ROM. It will take some work to build for a specific device however. Even Samsung start with this code at some point.
AOKP - Unofficial development team building ROMs based on AOSP accross a range of devices. AOKP stands for Android Open Kang Project. A play of the AOSP it is based on. Kang means to find / use (or even steal, although not in this case) source code.
baseband - The software responsible for controlling the radio hardware. Essential for network connectivity. Also referred to as "modem" or "radio"
bash - bash is a shell script language. Natively used in unix and linux, it can also be used within terminal emulators on android and scripts. Most mods that are scripts, use bash.
binary - a binary file is the opposite of a text file. It may contain data to be read by the OS rather than a human. It usually contains instructions on how a particular function should be handled.
binary counter - also referred to as flash counter. This is in part of the bootloader, viewed in download mode. The Binary counter increases as you flash non-stock (custom) recoveries and roms and kernels not "signed" by Samsung. The app, triangle away can help a little
boot.img - the kernel is contained within an .img file named boot.img. Not to be confised with sboot.img (bootloader)
bootloader - Bootloaders exist on almost any multi-OS bootable system. Windows has one, linux has one and android has one. It is how the device "decides" which OS to boot into. the user can manipulate hardware buttons during boot to alter which OS the bootloader boots into. It boots into Android by default but it can also boot into recovery or download mode. The bootloader is within an .img called sboot.img
brick - brick refers to a device that has been "bricked". A bricked device is beyond repair. In other words, your phone may as well be a brick, because it cant be a phone any more. A bricked device must be sent to the manufacturer / carrier / service centre for repair. You cannot repair a brick yourself. If you have something that can be repaired, it is not a true brick.
There are 2 types of brick referred to..
Soft brick, where the phone bootloops. These can sometimes be repaired, so for that reason it is not a true brick and I prefer to never use the term "Soft Brick".
Hard Brick. This is what I call a true brick. The phone cannot be repaired by a user. This of course does not extend to replacing parts. Sure, a brick can be replaced by replacing parts. It can't be fixed with external hardware or software however.
busybox - A set of tools to be added to android. Many root apps require busybox to run. It can be installed using an installer from the market. Similarly, most custom ROMs will contain busybox by default
clockwork mod - clockwork mod is a custom recovery
cfq - this is a scheduler (see scheduler). There is some info that can be read here: http://www.alliance-rom.com/community/wiki/i-o-schedulers/
checksum - see md5 checksum
cm - abbreviation for cyanogen mod. See Cyanogen
CPU - central processing unit. This is the brains of the operation. the CPU is what translates all the instructions and processes them. This is the main "power" behind any device. The better the CPU, the faster these instructions can be processed
custom ROM - A Custom ROM can be based on Touchwiz (Samsung stock), or it can be built from AOSP code. It really just means "unofficial" and will usually contain tweaks, fixes and imporvements for your device. A Custom ROM is a complete android replacement.
cwm - abbreviation for (see) Clockwork Mod.
cyanogen - a team of developers spanning multiple devices. Probably the most famous of development teams releasing heavily modified AOSP based ROMs. If there's any AOSP ROM thread for any Android device forum, there will be credits to cyanogen in there.
dalvik-cache - Dalvik-cache is a way of optimising applications. Its a way of ensuring all the dependencies an app requires are "at hand" to speed up use. It is rebuilt at start up when wiped. A de-odexed system will have more dalvik-cache than an odexed one.
de-odex - The act of removing odex from a stock ROM. On Stock ROMs, instead of using a dalvik-cache for system apps, we use .odex files instead. Generally custom ROMs prefer de-odexed configurations as it's easier to wipe and maintain when you make changes to your system.
deadline - this is a scheduler (see scheduler). There is some info that can be read here: http://www.alliance-rom.com/community/wiki/i-o-schedulers/
download mode - Samsung's own mode accessible via the bootloader. Hold Vul down, Home and power (from off) to boot here. Also referred to as "Odin Mode". This replaces the "fastboot mode" that most other devices have.
efs - Important partition / directory on the root of your phone. Ensures the IMEI number is present in the software. Back this up, because if it breaks, it's gone for ever. You need Samsung to repair.
eMMC - Embedded MultiMedia Card. This is like an SD card, but it's embedded in a device. the eMMC is a NAND flash memory chip which acts as internal memory (storage) on the S3.
exFAT - exFAT is a Microsoft proprietary (closed source) file system, used for media (sdcards, USB flash memory, HDD's etc). ExFAT is not natively supported in Linux and AOSP ROMs
ext - ext2, ext3 and ext4 are file systems created specifically for Linux. Our internal memory is ext (or "extended" as it is known). This can sometimes be used to refer to an ext partition, an old school method of partitioning your sdcard to link the internal ext partitions to to increase app space on low memory devices. Ext file systems cannot be read on Windows machines without special applications / drivers installed.
extSdCard - This is referring to the removable Micro SD card. Samsung ROMs mount the rremovable sd card in Android as /extSdCard. Recoveries such as CWM will mount it as external_sd. Both of these terms are valid, but it depends if the phone is booted to Android or Recovery. In AOSP ROMs, the removable SD card is often mounted as /sdcard1
FAT32 - another file system which is quite old now but still a good one. This is the only file system that is compatible with all devices unconditionally. The downfall is a maximum file size limit of 4 GB. Windows disk management GUI can only format up to 32 GB. Windows command lien tool "diskpart" can format up to the max volume size of 2 TB, as can many 3rd party tools such as easeus.
flash - Flash means a few things. It can refer to the fact that our internal memory is NAND Flash (Solid state) memory. It can also be the act of "flashing", or "to flash", meaning to install to flash memory. This doesn't really refer to installing an .apk. Rather, it refers to bigger, OS, System or device wide altering modifications (Kernels, recoveries, ROMs etc). Always back up before flashing.
Custom ROMS are usually flashed from your SDcard via recovery, as are kernels and basebands however, kernels and basebands usually can come in .tar format which means odin/mobile odin can flash them too from your computer/sdcard respectively. Rule of thumb, .zip from sdcard via recovery. .tar from sdcard via mobile odin or from computer using odin
flash counter - See binary counter
framework - The android frameworks are a standard structure within android that the OS is built around. It determines things like policy (how the OS should manage an event). It controls everything from notification behaviours to the theme. Anything visual within Android with exception to the notification area is controlled by framework-res-apk. AOSP and most manufactured ROMs only have 1 frsamework-res, however Samsugn Touchwiz ROMs alsu have a twframework-res.apk for Samsung only visuals.
gapps - Google Apps (gapps). AOSP ROMs like Cyanogen, have been asked by google to not include the google apps packages, which are proprietary to google (meaning not open source). This means that when you download these roms, you need to flash a gapps package separately. They are usually available as link in the ROM thread
governor - governors are included with kernels. I will not go into too much detail but essentially, the governor is a set of instructions which tell the kernel how to manage the CPU. It can control when the CPU ramps up or down, or how long it stays at a certain frequency. Most custom kernels come with a selection of governors to choose from using things like Set CPU. The governor settings for each can also be fine tuned or tweaked to y7our liking.
hotplug - this is a governor (see governor). Governors are explained in great detail here: http://www.alliance-rom.com/community/wiki/governors-explained/ - not all these governors are valid for our device, but it's a good technical read.
jig - a small usb device that plugs into the USB port of the S3. Designed to provoke "bricked" S3's to boot to download mode in an attempt to help recovery the device.
kernel - The kernel, it is said - is the "beating heart" of Android (or any OS for that matter). It sit's between the application layer (Android, applications etc) and the Hardware (CPU, Memory) and handles all transactions between the physical and the virtual. It passes information and instructions inbetween and translates. Very important stuff!
lulzactive - this is a governor (see governor). Governors are explained in great detail here: http://www.alliance-rom.com/community/wiki/governors-explained/ - not all these governors are valid for our device, but it's a good technical read.
md5 checksum - md5 checksum is a way to verify that a zip (or file) is not corrupt. A developer or uploader may provide a hexidecimal string called an md5 checksum. This checksum is a test done on the files that gives it a unique string based on it's contents. If you download the file and check the checksum and it does not match, it means the contents of the file have altered, usually meaning it is corrupt and shouldn't be flashed.
An md5 checksum is easy to check on android. My preferred method is using an android terminal emulator. Lets imaging I have a file on my external sd card called "rom.zip"...
In terminal emulator, type "md5 /mnt/extSdCard/rom.zip" and the terminal will give you an md5 string, If this matches the uploader's string, you're good to go.
If you're downloading something on Windows and then transferring it to your phone, it's a good idea to check md5 on both.
Linux is pretty much the same except the command is "md5sum"
For windows: http://www.winmd5.com/
modem - see baseband
NAND - NAND is a type of Flash memory. If anyone say's "NAND" to you, they are talking about the internal memory (Storage) of your device.
nandroid - nandroid refers to a backup taken or restored via custom recoveries. This is a universal term, although nowadays most recoveries simply say "backup" or "restore", but it is a nandroid backup they will be taking or restoring, which got it's name from the NAND flash memory that Android devices use internally. Nandroids are often only compatible with the variant of recovery you have. For example, a backup taken with CWM may not be compatible with TWRP, unless they introduce a compatibility setting in the future, which Philz recovery has done.
noop - this is a scheduler (see scheduler). There is some info that can be read here: http://www.alliance-rom.com/community/wiki/i-o-schedulers/
oem - Original Equipment Manufacturer. The OEM ROM for us is teh one the Manufacturer (Samsung) shipped with the phone.
overclock - overclocking is to set the CPU clock speed (frequency) higher than intended by the manufacturer. For example, the S3 has a 1.4 GHz (1400 MHz) maximum clock speed. With the use of a custom kernel and an application such as Set CPU, you can set this higher, to 1.6GHz or maybe even higher.
The risk is that the higher clock speed uses more voltage and voltage = heat. A higher clock with higher heat can permanently damage the CPU. Overclocking is usually paired with undervolting for these reasons. Another risk is instability. Each individual CPU has different tolerances due to imperfections in the manufacturing process. My CPU may be stable at 1.6 GHz, yet yours may be stable at a higher or lower clock. The side effects you will see here will be random reboots when the phone is under load.
pegasusq - this is a governor (see governor). Governors are explained in great detail here: http://www.alliance-rom.com/community/wiki/governors-explained/ - not all these governors are valid for our device, but it's a good technical read.
radio - see baseband
RAM - Random Access Memory. Great explanation here: http://www.androidcentral.com/ram-what-it-how-its-used-and-why-you-shouldnt-care
scheduler - built into kernels, there are schedulers to determine how CPU load is spread across different tasks. There are also read / write schedulers that spread out read and write operation priorities across the internal memory. Like Governors, there are different types of scheduler available.
sio - this is a scheduler (see scheduler). There is some info that can be read here: http://www.alliance-rom.com/community/wiki/i-o-schedulers/
stock - Imagine your phone is on a shelf in a shop. The phone is "stock" of that shop. If anything is referred to as "stock", this means standard for the device / as it was when shipped / as per factory set up. It is the opposite of custom. Some people refer to AOSP ROMs as "Stock Android". This may be the case for some phones, like the Nexus devices, but generally this is incorrect. Stock is whatever the phone came with as standard.
triangle away - an application designed to reset the binary counter. Warning, newer bootloaders (4.1.1+) now re-increment the binary counter at boot, so some trickery is required to get the counter to remain 0. This can be troublesome if you need to return for warranty.
undervolt - to undervolt is to lower the voltage used, either by the CPU or the GPU. Kernels assign a static voltage to each clock speed. For example, 200 MHz = 900 mV, 300MHz = 925 mV. Undervolting is the process of lowering this voltage staticaly for each clock speed, which potentially will save battery, although many people think it wont have much affect. Beware, undervolting too much can cause instability. When a clock frequency hasn't got enough power to sustain, the device will likely reboot or power off.
vanilla - meaning plain. Often used to refer to the "pure" android. AOSP without OEM skins, UI's and Launchers etc. The people who incorrectly use "Stock" to describe AOSP, really mean vanilla.
zzmove - this is a governor (see governor). Governors are explained in great detail here: http://www.alliance-rom.com/community/wiki/governors-explained/ - not all these governors are valid for our device, but it's a good technical read.

Every phone specific section needs something like this.
Very well done!:beer:

abaaaabbbb63 said:
Every phone specific section that can be rooted needs something like this.
Very well done!:beer:
Click to expand...
Click to collapse
Now you need the difficult part, people to actually read it.

Nice work @rootSU
Needs to be stickied and a humongous "READ ME" sticker attached! :thumbup::thumbup:
Edit........Reported©®™ so it gets stickied!

Its getting noobs to actually bother to read is the problem .
jje

True but i'll start with the "read my sig" method. At least if it's here, thats a small part of the battle. Anyone anything to add to post 1? Slappy? jje?
Sent from my GT-I9300 using Tapatalk 4 Beta

Add backup EFS first ??
jje

Some of the stickies in the roll up thread are badly out of date, you also might want to link to Mike Skip's toolbox, which reduces the chances of bricking considerably.

rootSU said:
True but i'll start with the "read my sig" method. At least if it's here, thats a small part of the battle. Anyone anything to add to post 1? Slappy? jje?
Sent from my GT-I9300 using Tapatalk 4 Beta
Click to expand...
Click to collapse
Seeing as this may well attract lots of attention, possibly add a reminder about reading the rules and link? I know it's not relevant particularly, but any chance to ram the message home is good :thumbup:

rootSU said:
True but i'll start with the "read my sig" method. At least if it's here, thats a small part of the battle. Anyone anything to add to post 1? Slappy? jje?
Sent from my GT-I9300 using Tapatalk 4 Beta
Click to expand...
Click to collapse
Instead of [REF] you should write [BOOBS]. That would attract attention.

Added:
Link to forum rules and "post in Q&A" threads
Important links and resources
efs (in partitions)
backups

I'm sure there's still loads missing, I just can't think of much so all suggestions welcome.

Added "The advantages of rooting". Miss anything?
EDIT > added disadvantages too.

OP, I have moved your thread to the q&a section and stuck it. It is a great FAQ type thread and will serve a good purpose being stuck where people go to ask these types of questions. :good:
Towle
XDA Moderator

Towle said:
OP, I have moved your thread to the q&a section and stuck it. It is a great FAQ type thread and will serve a good purpose being stuck where people go to ask these types of questions. :good:
Towle
XDA Moderator
Click to expand...
Click to collapse
Thanks @Towle
Sent from my GT-I9300 using Tapatalk 4 Beta

I've updated the following to sections to read as below:
Bootloader - this is what handles what you boot into. When you see the black Galaxy s III text, thats the bootloader. Its job is to handle the boot. It is responsible for booting into android, or if you manipulate the buttons in a certain way, it will boot into recovery or download mode. PLEASE NOTE, i9300 Bootloader is NOT LOCKED. DO NOT TRY TO UNLOCK IT.
Download mode is part of the bootloader itself. Again, it is a mini OS. It is designed for flashing stock (official) ROMs onto the phone. It is also used by Samsung to detect the status of your phone (if you have modified it or not).
If you have an official ROM above 4.1.1, Your bootloader flash counter in download mode will change to "1" at every boot, if you have a custom kernel or recovery - even if you reset it with Triangle Away. See the return for warranty link later in this post to get around this.

oops
first i thought it was typo but after i check out dictionary i just learn a new and rare word ... teh ....:fingers-crossed:

qtwrk said:
oops
first i thought it was typo but after i check out dictionary i just learn a new and rare word ... teh ....:fingers-crossed:
Click to expand...
Click to collapse
Not new, not rare:
http://en.wikipedia.org/wiki/Teh