[Galaxy S III General] mirroalex:
Hello all,

This is my first GUIDE thread, hope it will help you.

I will update interface of this thread regularly and try to answer your questions.

Story:

As i flashed many devices (mine,friends,relatives,...) i understand that SOMETIMES bootloaders makes difference. I know they don't have functions of KERNEL or MODEM but some random reboots can be caused by bootloaders, so by updating bootloader, you probably(or maybe) overcome to them. I was searching a lot and found THIS thread although it is very nice thread/REFERENCE but not updated... so i posted a request there for new bootloader and didn't get any response for days and that makes me to learn how to this task by myself.

so here we are the Required Tools:

1- STOCK Firmware: you can download it from anywhere you want, however i prefer sammobile, just note that you have to register(which is free) in sammobile in order to download firmwares.

NOTE!!!: don't download operator firmwares like(orange,Tmobile,...) i am not sure whether their bootloader is safe(locked/unlocked) or not.

2- WinRAR: to extract ZIP, RAR, TAR, TAR.MD5, it is paid application but it is functioning even after trial period and it only gives you a notification, I know there are many alternatives but I tested with this software and recommend it to anyone.

3- [Script][Tool] how to create a tar.md5 file from img For Odin go to this thread download tar-Tool_Odin3-v3.07_by_mkh.mourad.zip and extract it to some folder lets call it Flashing(can be anything) on your desktop.

!!!!!!!!Credits of this tool goes to user mkh.mourad thanks to him for this great handy tool, otherwise you had to do many other steps...

4- Odin for PC: I tested Odin v3.09 i don't know whether lower version would work or not. (do not use Mobile Odin look at the warning section point 3)

UPDATE: Odin v3.10 tested and it worked too, moreover odin v3.10 is fastest, use this version please.

Now INSTRUCTION:

1- Download your desired firmware (NOTE: see "Required tools" section)

2- Extract it anywhere you want and you will see *.tar.md5 file extract it again (* name of the firmware is not important)

3- After extracting *.tar.md5 you will see several files with extensions *.img and *.bin, we need >>sboot.bin>>

4- Extract content of tar-Tool_Odin3-v3.07_by_mkh.mourad.zip to any folder that you want, copy sboot.bin from previous step to this folder(the folder that you have extracted tar-Tool_Odin3-v3.07_by_mkh.mourad.zip)

5- Now you can see bunch of batch files and of course sboot.bin that you have copied there, run ImgToTar.MD5.bat, the command window will open and after a few seconds will disappear. now in that same folder you can see sboot.tar.md5 which is the odin flashable bootloader.

After creating final sboot.tar.md5 do not rename it because MD5 value get changed by renaming so odin will refuse to flash file (invalid MD5 error)

Note that if you use windows OS you would see sboot.tar NOT sboot.tar.md5 which is ok. (you can see it if you look in file's properties or turn on "show file extension" option in folder options)

6- Very very very very important, you must go into download mode by hardware buttons (turn off device or pull out and in battery just to be safe, press Volume down + home button and power it on) please do notgo to bootloader from reboot menu i warned you.

7- Open odin, unthick Auto reboot, click on BL, and add sboot.tar.md5, plug your phone in download mode and flash, IMPORTANT: wait till it write all threads completed and port color became GREEN with PASS written in it, it will take about 2-3 minutes be patient.

UPDATE: if you use odin v3.10 you wont have to wait this much because after a few seconds unlike odin v3.09 the port color became green. So i recommend you to use v3.10

8- After above step finished, unplug your phone, hold power button till phone get rebooted

9- DONE, enjoy your new bootloader, if you use Boeffla kernel you can go into stweaks and check your bootloader version or use "phone info" application from market.

WARNING!!!

1- I am not responsible for any hard bricks, bootloader flashing is risky and it can make your phone unusable, do it on your RISK

2- Method above is tested by me on my I9300, i don't know whether it will work for other S3 varients or other phones... UPDATE: Working on Note 3 N900 too, seems this method could work on most of the Samsung phones...

3- Do not use Mobile Odin to flash this bootloader(or any!?), it may give you md5 error or may be WORST, brick the phone Thanks to [MENTION=4447186]nainaabd[/MENTION]

Downloads

XXUGNG3 bootloader you can get in attachment, made by the above method and tested by me on i9300 just extract zip and flash XXUGNG3.tar by odin

XXUGNH4 Thanks [MENTION=4214105]katolink[/MENTION]

UBUGNI1 Thanks [MENTION=4214105]katolink[/MENTION]

XXUGNJ2 Thanks [MENTION=1469100]k-semler[/MENTION]

UBUGNK1 Thanks [MENTION=1469100]k-semler[/MENTION]

EDIT: Attached bootloader fixed, i updated step 5 of instruction, please read there to find out why you would get md5 error...