[Tutorial] How to MULTIBOOT CM7 alpha 6 & 7 (thread updated)

Hello people...

I opened this thread to help users of our Galaxy 3 to understand and learn how to use CyanogenMod 7.1 RC 1 with multiboot option. I did this because I've noticed many users is asking various questions regarding CM 7 in diferent threads that are not related to CM 7. So I decided to make this Tutorial&how to do it. Let's get started now .

What do we need?

1 - Galaxy 3 I5800/I5801
2 - Latest G3mod kernel (2.4.1 OC/NON OC) recommended (no other way than this kernel)
3 - System.img of CyanogenMod 7
4 - Titanium backup ( this is optional, if you want to have all your apps & data backuped, and restored when in CM 7 ).

Instructions :

- backup all your data and apps with titanium backup when you are on froyo....
- download system.img of CyanogenMod 7.1 RC 1...extract it out of .rar
- put system.img to sdcard/data/g3mod/roms/CyanogenMod7_rom
- boot your phone in (cwm) recovery mode
- (in cwm) go in multiboot--> backup your current rom (make backup) when complete do next:

- go in multiboot and select backup data->froyo based rom....make a backup...that might take a while...it depends on how many apps you've installed...this option makes two .img files on sdcard-> data.img & sd-ext.img....
- now you are ready to switch to CM 7
- (in cwm) multiboot-->switch rom-->CyanogenMod7-->activate-->yes...wait...done..
NOTE: PLEASE DO NOT wipe data/factory reset !!!!!! (it will corupt your backup img's )

- from now on there are two options avaliable...:

1. reboot phone with existing data & sd-ext installed....or
2. (in cwm) go to mounts & storage and format data...and then format sd-ext...

Explanation of options 1&2 :

Option -1-

If you reboot phone now to CM7..this will happen:

- YOU WILL LOSE; your system settings, background, widgets...and there is great possibility that some of apps you've installed when being on froyo will force close...(that's why titanium backup comes in handy )
this happens because when we install an app on froyo, a part of app goes to internal data partition (widgets or some other data) and because data from froyo isn't compatible with CM7 it doesn't get restored hence force closes occure...you can restore app&data from titanium backup though...

Option -2-

If you'll choose this option, this is what will happen:

- you will have a fresh clean CM7 system installed...
just like when you flashed new clean rom...
Here's what you can do:

- use magic of titanium backup, restore/install whatever you want to have on CM7....
Next....:
- this step is usable if you want to switch betwen CM7&FROYO and FROYO&CM7 later if you feel so and keep all data&apps fully functional :

When you've finished restoring everything in CM7 and made all your favourite settings and stuff, do this:

- boot in (cwm) recovery mode
- (in cwm) multiboot-->backup data-->CM7data...(make backup)...
- again like you did backup before for froyo, you do it now for CM7...and you have two .img's on your sdcard stored in sdcard/Android/data/g3mod/data/CyanogenMod7_data....
--------------------------------------------------------
Procedure to switch back to FROYO from CM7 and have froyo data back as before:

- boot phone in (cwm) recovery mode
- (in cwm) multiboot-->switch rom--> "select any froyo rom that you have made backup of it before"-->activate...wait...done
- now this is important:
- (still in cwm) go to mounts&storage-->format data...wait....done...and again..still in same menu...format sd-ext...wait...done...
now still in cwm go:
multiboot-->restore data-->FROYO_DATA...then wait a while....restoring takes some time....done
-now you are ready to reboot phone and have all your data&apps fully functional again
NOTE: PLEASE DO NOT wipe data/factory reset !!!!!!!!!!

DISCLAIMER:
When you'll multiboot from froyo to cm7a7 with g3mod 2.4.1 kernel...you'll found out that:
-Wifi is not working(Arakmar posted some solution in g3mod thread....find it)
-Bluetooth is not working(it doesn't find devices...and can not be found)
This are kernel issues...otherwise runs great


System.img's download:

CM7.1 ALPHA6

CM7.1 ALPHA 7 (153.6Mb)
and yes....it's uncompressed system.img


NOTE: I've added hd2sd script & sdcardspeedfix script
NOTE 2 : System.img has installed latest update for CM7, and i did not install Gapps for CM7...so...you know where to find them
TIP: If you want to see your a2sd partition in Titanium backup navigate with root explorer to system/and mount system r/w...and just create empty folder called. - sd - and reboot your phone
..
G3mod kernel thread:

http://xdaforums.com/showthread.php?t=1252698

Original CM7 thread:

http://xdaforums.com/showthread.php?t=1101218

Credits goes to:

Marcellusbe - for CM7 working on our phone
Hillbeast for hybridata2sd script
Kyrillos13 for sdcardspeedfix script
and to this Galaxy 3 forum where I learned a lot of new stuff

UPDATE OF GUIDE:

I'm really sorry that I didn't test this before, but anyway:
Enable multiosdata in your system as hillbeast & i_rnb said in below post...(thanks)...as i made a mistake with this one ..so
when you'll enable multiosdata before you'll boot CM7...then when you'll activate CM7 in cwm...froyo data backup will get automatically created......
and the same will happen when you'll make your settings in CM7 and then switch to froyo back.......and therefore there's no need to make aditional backups..(but it's good idea to have it)
For enabling multiOSdata i recommend KMapp v 1.3..

KMapp thread:

http://xdaforums.com/showthread.php?t=1301697

Sent from Galaxy
Kyrillos' 9.3 powered by
G3mod 2.2.2 OC

i see sum misunderstanding in ur process..

u dint mentioned about multiosdata(brain child of hillbest)..

if multiosdata is off & u dnt wipe sdext & data, cm7 will try to boot with froyo data & dat is not possible.. phone will go into bootloop..

if multiosdata is enabled, then ur froyo data & dalvik cache will backed up to sdext & then wiped.. & phone will boot into cm7 then with all apps , but with no data !! it wld b like all apps r just installed..

now take TB & restore only data ..
hopefully some apps will force close due to using lib files from system partition.. just restore app+data for them..

now reboot ..

voila !! now u r done..

now u can use cwm data backup&restore feature for more convenience from the next uses..

remember, no need to restore apk files, just backup modified data via TB from current rom & restore only data in the nultibooted rom..

cheers!!

ps: wiping sdext&data wld wipe backedup multiosdata in sdext , but not the backedup imgs by cwm in sd..
##here u got it wrong!!

-tapatalked by RnB

i_rnb said:

i see sum misunderstanding in ur process..

u dint mentioned about multiosdata(brain child of hillbest)..

if multiosdata is off & u dnt wipe sdext & data, cm7 will try to boot with froyo data & dat is not possible.. phone will go into bootloop..

if multiosdata is enabled, then ur froyo data & dalvik cache will backed up to sdext & then wiped.. & phone will boot into cm7 then with all apps , but with no data !! it wld b like all apps r just installed..

now take TB & restore only data ..
hopefully some apps will force close due to using lib files from system partition.. just restore app+data for them..

now reboot ..

voila !! now u r done..

now u can use cwm data backup&restore feature for more convenience from the next uses..

remember, no need to restore apk files, just backup modified data via TB from current rom & restore only data in the nultibooted rom..

cheers!!

ps: wiping sdext&data wld wipe backedup multiosdata in sdext , but not the backedup imgs by cwm in sd..
##here u got it wrong!!

-tapatalked by RnB

Click to expand...

Click to collapse

Great guide rkkoby, but I agree, you should also mention Multi OS Data as it makes the switching process much easier. No need to do manual backups or anything. Just good old fashioned multi-boot.

Great guide now people will stop asking where to find system img of cm7 now that you provided it and how to switch.

Sent from my GT-i5801 using XDA App

Nice. Quite clearly explained. :-D

Sent from my GT-I5800 using xda premium