[15/12][NEW DUAL BOOT PROCEDURE][Secondary OS][Dual Boot AOSP and Sammy] - Galaxy S II Android Development

Hey guys!!
I'm here to introduce you the first Dual ROM for this device!!
Haven't you ever wanted to have the speed and awesomeness of AOSP ROM but without missing the special features of Stocks ROM (Tv OUT and so on.)?!?
This prebuild flashable zips I made allows you to install and boot into 2 different OSes according to the way you start the phone.
I wanted to start telling you that nothing would have been possible without the inventor of the special kernel inside the ROMs HellcatDroid and this is the kernel's thread if you need more info about it!
How this works?
There's a special kernel inside the ROM which is the same both for Sammy and for AOSP ROM which boot into a os (primary) just booting up the phone as we normally do. The secondary OS boots when you press the Recovery Combo. The recovery starts if you power off the phone and attach the charger.
here's a video explaining how it works :
VIDEO
Downloads and new procedure
I completely changed the procedure and the way you should dualboot...so this is the NEW procedure :
1)Go to recovery, make a nandroid backup and then wipe all your data (strongly suggested)
2)Install the ROM you want for PRIMARY OS (you can choose the one you mostly like here on xda!)
3)Then and only then choose between these beautiful ROMs for your SECONDARY OS :
CheckROM v4
MIUI 9.12
CM7
4)Enjoy!
IF YOU WANT TO RESTORE EVERYTHING BACK :
Install via CWM this package : RESTORE OS
This will delete your secondary OS permanently and leave just your primary with Siyah kernel
Changelog
-Brand NEW procedure!
-Restore Primary OS option
-CheckROM v4
OLD Downloads
Here's the most sweet part...
each ROM has a primary OS (more space and boots as you normally do) and a secondary OS (less space and boots with recovery combo)...
It depends on your preferences...however here it is :
http://www.multiupload.com/Y357LP81T9 > Clean Sammy (primary) MIUI (secondary)
http://www.multiupload.com/ZWGKORKUC4 > Clean Sammy (primary) CM7 (secondary)
http://www.multiupload.com/OCAVFNEL0N > MIUI (primary) Clean Sammy (secondary)
http://www.multiupload.com/RO00M8UC7P > CM7 (primary) Clean Sammy (secondary)
Final notes and instruction
Please just boot into ROMs and Recovery as it's shown in the video!!
DONT USE REBOOT TO RECOVERY or similar command because it can make you to be stucked in a single ROM!!!
The most stable ROMs are the one with Sammy ROM as primary just because it requires more space than AOSP but the others runs good as well.
THE SECONDARY OS HAS NOT SO MUCH SPACE!!! So you can't install many apps on it.
This thread is for development only. so if you have a suggestion send me a PM.
If you want me to create other ROMs just ask me and if you have technical problems write here in the thread and I'll try to answer to most of you.
I'll make further development just if I see that it is interesting for you as I am a very busy person!
If you want to edit your preference you can use lolboot app on the market here :
https://market.android.com/details?id=net.hellcat.droiddev.lolboot
Credits
-HellcatDroid for his kernel and his precious instructions
-Siyah for the base of this kernel which is able to run on every ROM!!
-CM7 team and MIUI for their beautiful ROMs
-Samsung for his good stock ROM
-LeoMar75 and GadgetCheck (visit CheckROM's thread here)
Enjoy and IF you want to contribute look at my signature and DONATE

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Gonna try this!!!:d

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To get the TV Out feature, can I use CM7 as primary and Sammy as secondary?

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This would be just great for testing out beta/experimental ROMs on one partition without hampering your primary driver.
Good work mate!

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Willl try awesome dude

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Jibreil said:
This would be just great for testing out beta/experimental ROMs on one partition without hampering your primary driver.
Good work mate!
Click to expand...
Click to collapse
Or you can just do a nandroid...

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pcboyy said:
To get the TV Out feature, can I use CM7 as primary and Sammy as secondary?
Click to expand...
Click to collapse
Thank you for the interest guys!!
However sure you can!!
It's uploading...that's what I do...I leave Stock ROM as secondary just for TV out and enjoy the awesomeness of AOSP as primary...
PS More has to come...slighter Stock ROM and better optimized AOSP...if you have any questions or suggestions please let me know!!

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EDIT : New ROM Added!!

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This seems to be one of the best things happened to SGS II in recent times, awesome!
Sent from my GT-I9000 using XDA App

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what if battery complitly dies ? then can we charge it or it would go to recovery without charge???
and can we change the files inside preload folder with new MIUI (For example change it with the latest update for next week) ( if it's already MIUI ) or not ???
or can we change the main file(Primary files) with new weekly MIUI ( IF it's already miui as primary ) ?

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Can this samsung one change to checkrom v4??
Sent from my GT-I9100 using XDA Premium App

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Henrywcy81 said:
Can this samsung one change to checkrom v4??
Sent from my GT-I9100 using XDA Premium App
Click to expand...
Click to collapse
Yes...it could...but you should ask the permission to the ROM's dev first...and only then I'll start to make a double ROM with it...
If the battery dies you can attach the charger and it will charge your battery even if it's in recovery...wait some minutes and then reboot...and it's done...
If MIUI or CM7 is PRIMARY you can directly update it with the weekly package provided by the ROM team...it's fair...
if you have MIUI or CM7 as SECONDARY you should change the updater script of the secondary or change the preload dir as you said...
however if there'll be a great interest I'm gonna update it very very frequently...so there'll be no need to do this...
I'm going to make the Samsung ROM much lighter...MIUI or CM7 ROM as PRIMARY is however the best choise if you want to stay up to date with these ROMs...
Cheers dude!
And thank you for the interest shown...

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thank you alot...
yes
miui would be a great idea as a primary and sammy as second ...
now...
i'm going to flash this amazing ROM/KERNEL/ ( don't know what should we call it ... but it's great ... )
but one last question ....
if we update through rom updater in the miui what would happend to kernel ???
---------- Post added at 03:47 PM ---------- Previous post was at 03:22 PM ----------
WOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOW...
it's VERY CLEAN... FAST... Without ANY Problem ...
just i should test the Battery/wifi/Bluetooth and ... just because of new kernel ...
thank you so much
keep UP the GOOD and Amazing work...

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Quick question: the Japanese SGS2 (the sc-02c) is a bit kernel needy, and thus really only responds to siyah kernel and stock. If I install this rom, but then reflash siyah's kernel, am I just wasting time?

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I cant get it work. I am stuck at boot screen.

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1 Problem :
for the first time i flashe sammy+miui and every thing goes well
but then i flashed miui+sammy and it's not going to recover as you mentioned at OP
please help...
i don't know what to do...
i want Flash RTL Patch on my miui ( Which is the primary rom for me )

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What version of Siyah is being used to power this? Thx.
Also why not link to hellcat's app?

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Doesn't work for me either. Installed Sammy as primary as miui as secondary. Phone now only boots into miui whether I hold recovery buttons or not. Also phone does not boot into recovery so I now need to flash back via ODIN.

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Lolboot
If anybody has it working could you install lolboot from market and check if it works with it?

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nilsido said:
I cant get it work. I am stuck at boot screen.
Click to expand...
Click to collapse
jimhaddon said:
Doesn't work for me either. Installed Sammy as primary as miui as secondary. Phone now only boots into miui whether I hold recovery buttons or not. Also phone does not boot into recovery so I now need to flash back via ODIN.
Click to expand...
Click to collapse
Please keep in mind that it's still under development and I need some time to make it work properly...I'm going to put fast link to boot into a OS using a simple command in the other ROM...
Probably you used command like "boot in recovery" or something similar...the kernel made by HellcatDroid is still under dev and need some fixes...
You could just install another normal kernel and go back to recovery with the classic combo...
bclark said:
What version of Siyah is being used to power this? Thx.
Also why not link to hellcat's app?
Click to expand...
Click to collapse
It's 2.0 however the first thing I made is to link everybody to HellcatDroid thread in which there's a section for his app...
NO OTHER KERNEL ARE SUPPORTED FOR THE MOMENT!
I'm sorry...
I'll continue my development to make it much stabler...for the time being it do need some fixes...I totally agree with you...