Dual-Boot FAQ thread | devil2-kernel by DerTeufel1980 [Note 2]

[myaslioglu]

Play store works fine for me on second rom

Is yours cm or touchwiz?

Sent from my GT-N7100 using xda premium

 

[n4553]

Yes, for now I haven't installed the second rom, however this is what I want to achieve, dual-boot. But firstly I wanted to make sure the kernel is working. I am using Devil recovery, when I flash other things with it, there are no problems...

I got it working! Also dual-boot!

Initially I played only with Devil kernel and kernels from nandroids of Cyanogenmod / stock. And for all I used and I'm using Devil recovery. Every time when I flashed DB kernel, the strange behaviour was present (4-5 minutes at boot, no touchscreen, reboot at waking from sleep). And I tried this several times (also restoring nandroids, flashing again kernel... ).

At RichMD recommendation I tried Perseus kernel. This worked from the first time.
After that I flashed again DB kernel and now the previous problem was no longer present! Maybe the Perseus kernel made a change to my system? I don't know.
Thank you very much!

 

[n4553]

Switch between ROMs

I wanted to automate a bit the switching between the 2 ROMs, without going through recovery, so this is what I've done:

- Install "GScript Lite" , free from Google Play, on primary ROM.

- On first ROM, open this app, press Menu button -> Add script
Script name, eg.: Reboot second ROM
Check the "Need SU"
In the script text, write:

echo 1 > /data/.secondaryboot
reboot

- Save script

- You can add a shortcut to the script to homescreen, by going to All apps -> Widgets, drag "GScript Lite" and then select the name of your script
- Tap the script shortcut, to make sure it's working. Grant the root access, and the phone should quickly reboot in the second ROM

- On the second ROM, install this app, create a new script named eg.: Reboot first ROM
- On the text script, write:

echo 0 > /.secondrom/.secondaryboot
reboot

- Also make sure "Need SU" is checked, save and make a shortcut if you want, and test it.

Hope this helps, until a key combination is added to the kernel.
I would post this to DerTeufel's thread, but I'm a "noob", I don't have rights to post on dev threads.

 

[JoyMoro]

I am getting error at step 6.


How did u get it working since i got the same issue here?

You need to mount Secondary System in due boot menu

duel boot menu -enable mounting of sec File.


regards
Joy

---------- Post added at 01:14 PM ---------- Previous post was at 12:49 PM ----------

I wanted to automate a bit the switching between the 2 ROMs, without going through recovery, so this is what I've done:

- Install "GScript Lite" , free from Google Play, on primary ROM.

- On first ROM, open this app, press Menu button -> Add script
Script name, eg.: Reboot second ROM
Check the "Need SU"
In the script text, write:

echo 1 > /data/.secondaryboot
reboot

- Save script

- You can add a shortcut to the script to homescreen, by going to All apps -> Widgets, drag "GScript Lite" and then select the name of your script
- Tap the script shortcut, to make sure it's working. Grant the root access, and the phone should quickly reboot in the second ROM

- .

Hi
Tried this on Primary Rom, Its not working. Checking again.n will also test for secondary Rom n let yoiu know

JoyMoro

 

[JoyMoro]

You need to mount Secondary System in due boot menu

duel boot menu -enable mounting of sec File.


regards
Joy

---------- Post added at 01:14 PM ---------- Previous post was at 12:49 PM ----------





Hi
Tried this on Primary Rom, Its not working. Checking again.n will also test for secondary Rom n let yoiu know

JoyMoro

it is working alright on both rom
thanks

 

[MajorTom_]

No word yet on how to remove dual boot?

Sent from my SGH-T889 using xda premium

 

[RichMD]

No word yet on how to remove dual boot?

Sent from my SGH-T889 using xda premium

I will post in the FAQ later today but basically just flash a different recovery such as TWRP or standard CWM and full wipe (format /system and /data) and that should cove it. Obviously, you would need to reinstall or restore a nandroid - I assume only a backup of the primary would work. I will have to check for the special folders on the SD card and list them in the FAQ.

 

[bdd786]

App2SD script not working

I have successfully made dual boot working on my Tmobile. ROM1 (Primary): Xenon HD and ROM2 (secondary) Jedi Master 13. I have tried to acitvate App2SD script. Not working in either of the ROMs.Please reply.

 

[RichMD]

I have successfully made dual boot working on my Tmobile. ROM1 (Primary): Xenon HD and ROM2 (secondary) Jedi Master 13. I have tried to acitvate App2SD script. Not working in either of the ROMs.Please reply.

Sorry, but I have no idea if App2SD would be compatible. DerTeufel1980 would have to answer that.

 

[paulove]

I will post in the FAQ later today but basically just flash a different recovery such as TWRP or standard CWM and full wipe (format /system and /data) and that should cove it. Obviously, you would need to reinstall or restore a nandroid - I assume only a backup of the primary would work. I will have to check for the special folders on the SD card and list them in the FAQ.

I did a nandroid of a Sammy rom from second FS and restored to primary, that is the rom I am using now.

Just remember to choose right FS and mount all partitions needed.

Sent from my GT-N7100 using Tapatalk 2

 

[frenkie9999999]

I would just make a small clarification:

The first time you flash the kernel and recovery,
Going to dual boot options, select File System, primary, and then only now you can create the secondary partition.

the first time I've done the procedure, without selecting a FS, the secondary partition doesn't will create.

:good:

 

[ravijani]

just 2 questions...

so which works???
both Sammy or CM/AOSP - Sammy ???

and how to revert ??

 

[RichMD]

just 2 questions...

so which works???
both Sammy or CM/AOSP - Sammy ???

and how to revert ??

In theory, any combination of AOSP and Samsung (Sammy) based.
There does seem to be some ROMs that don't work as well with the dual-boot kernel but I don't have a good list yet.
I have been trying to find time to update this thread with the FAQs such as how to revert. Possibly tonight. ..

Sent from my SGH-I317 using Tapatalk 2

 

[Dingchow]

I will try to update this thread to clarify the methods you can use to enable dual-boot functionality along with common problems and solutions. This is an initial draft that I will update after it is verified (by DerTeufel and others). Additionally, I will try to re-word as necessary to avoid confusion. Hopefully, the list of questions should help you to complete what you are trying to do.

1) Have you flashed the dual-boot (aka DB) kernel yet? If yes, go to step 3

2) Flash the DB kernel: Go to the DB OP here and flash the version for your model type - http://forum.xda-developers.com/showpost.php?p=40410021&postcount=1 N7100 is for non-LTE models and t0lte is LTE enabled (AT&T, Verizon, etc). The zip will NOT list recovery in the name...

3) Have you flashed the DB recovery? If yes, go to step 5

4) Flash the DB Recovery: Navigate to DB OP listed above and flash the version for your model type (as in step 2 above)

5) Have you created the secondary system partition? If yes, go to step 7

6) Create the secondary partition image: Boot into the DB recovery and select Dual Boot Menu > create secondary system image. This will take a couple of minutes. This only has to be done once.

7) Ready to flash primary or secondary ROMs: Note: It is probably a good idea to get in the habit of always selecting the FS (primary or secondary) that you want to affect just to ensure you don't wipe the wrong one, etc. Select Dual boot menu > enable mounting of (pri or sec.)... It stays selected until you boot into recovery and change it. You will see recovery flash (reload) with the appropriate FS selected. Obviously, don't select it again - logic loop...

8) You at least need to follow standard ROM installation instructions at this point such as wipe data, etc (as appropriate). Wipe Data/Factory Reset will leave the ROM (typical) and the 2nd option (wipe data-cache-system-preload) will wipe out the ROM completely so you can start "clean". Only the selected FS is modified so the other ROM is not affected. All apps and data are separate for each ROM. SD card storage is common so keep that in mind for an app that exists in both ROMs.

9) Installing to the primary partition does not need any special instructions. You should have already selected "enable primary". Select "Install zip" > Choose zip from sdcard or external > ROM to Primary FS. The difference between the "ROM" and "Zip" selections is that zips do not typically explicitly access the file systems - they use references in recovery.fstab which DerTeufel modified to point to the appropriate locations depending on your selection (primary or secondary). Yes, choosing install zip might work for installing a ROM to primary but NOT to secondary. Also, the intention is to avoid confusion.

10) Installing to the secondary partition MIGHT be more problematic since the zip has to be modified first to replace FS references with the secondary locations. When you select this option, it can take a couple of minutes since it is changing the references and then re-zipping to a modified file on the SD card. Note: The original will be gone (at least if it was originally on the SD rather than the external SD) so make a copy, etc before proceeding if you want it to be available for standard/primary flashing in the future. The modified file will always install to the secondary partition after being modified. Note: Complicated install scripts (such as AROMA) will likely fail. If you want an AROMA based installation then the safest way is to install it to the primary partition, ensure it is working, make a backup and then restore the backup to the secondary partition (using the DB recovery of course). Backup/restore will be detailed below.

11) Recovery does not automatically mount /system, and /data so ensure /cache and these are already mounted before running a zip that will need to modify them

12) Avoiding MTP issues: After flashing a ROM, recovery prompts you to install the DB kernel again. Otherwise, the kernel installed with your ROM will not be able to boot the secondary ROM. However, if you do flash the DB kernel right away (for now at least) you may have a problem with MTP (access from a PC over USB). If you boot the new ROM (with the ROM's kernel which will work for PRIMARY) then MTP should be working. You can then flash the DB kernel after rebooting to recovery and MTP will still work (afaik). Similar to the AROMA note above, you might want to install a ROM to primary first even if you want it in the secondary partition. The install script will not need to be modified and a normal kernel will boot the ROM so MTP will work. Then you can flash the DB kernel, make a backup and restore to the secondary. Hopefully, this is only temporary but at least this workaround exists.

13) Ready to flash zips to primary or secondary ROMs Flashing gapps, etc. simply requires that the correct FS is enabled, /system and /data (as necessary) are mounted and select your target under "Install zip" > "Choose zip from..." > Zip to (primary or secondary).

I will update this tomorrow with more info on backup/restore, common problems, etc. If the format above is not clear, please suggest an alternative.

RichMD
sorry to hijack your thread, delete if you need.. here's what works for me, several times ( I used your and Der Teufel guide as reference) just put it in a step by step guide

After a lot of reading and some tinkering, I've got PACMAN 4.2.2 PA /AOKP /CM10 1on ROM1 and 4.1.2 Mike1986 ARHD17 Sammy on ROM2.

Adb, MTP, Trickster works fine on both.
Working great. Even managed to get Simplistic Framework and Xposed working on rom 2 (Sammy)

simply
(a) first put the rom you want as PRIMARY on your ext sd card, either a flashable zip or a CWM nandroid backup (NOT TWRP).. you will need this later in step 32
1 on your existing rom and kernel combination , flash DT recovery,
2 reboot to recovery
3 go to dual boot options in recovery
4 create second partition
5 reboot to first rom
6 check MTP
7 reboot recovery
8 dual boot menu
9 enable mount primary ( second on list of 3 options )
10 go back, Mounts and storage
11 mount efs, system, data, ext sdcard
12 go Back, wipe data (2nd option for FULL wipe)
13 check mounts again and remount as above
14 flash the rom you want to be as SECOND rom
15 do all your fancy mods now (Xposed etc)
16 check mounts, remount if necessary
17 flash DT dual boot kernel with "flash kernel" option
18 reboot
19 check MTP
20 go to step 7 and repeat 7-11 inclusive
21 do a backup to ext sd

to move the rom to second rom position..
22 dual boot menu
23 enable mount secondary ( third/last on list of 3 options )
24 go back, Mounts and storage
25 mount efs, system, data, ext sdcard
26 go Back, wipe data (2nd option for FULL wipe)
27 go to Backup and Restore
28 restore the rom you made in step 21 from the ext sd
29 reboot to second rom (allow full boot)
30 check MTP, should work
31 do steps 7-13
32 flash, or restore the rom you placed on your ext sd card in the very beginning step (a) ie the one that you want to be as FIRST/PRIMARY rom
33 Reboot

Done

DO NOT FLASH ANY KERNEL AFTER STEP 33 ( the kernel will show in primary rom settings as unavailable but check with Trickster Mod or CPU spy, it will show you that it is DT dual boot kernel)

The above has worked for me several times now, and some steps are overkill..
The 0 folder from 4.2.2 is visible from the Sammy rom but the Sammy files are not visible from 4.2.2 that's why I recommend using the ext sd for the above procedures as a failsafe

Sent from my dual boot GT-N7100 using Tapatalk 2

I wanted to automate a bit the switching between the 2 ROMs, without going through recovery, so this is what I've done:

- Install "GScript Lite" , free from Google Play, on primary ROM.

- On first ROM, open this app, press Menu button -> Add script
Script name, eg.: Reboot second ROM
Check the "Need SU"
In the script text, write:

echo 1 > /data/.secondaryboot
reboot

- Save script

- You can add a shortcut to the script to homescreen, by going to All apps -> Widgets, drag "GScript Lite" and then select the name of your script
- Tap the script shortcut, to make sure it's working. Grant the root access, and the phone should quickly reboot in the second ROM

- On the second ROM, install this app, create a new script named eg.: Reboot first ROM
- On the text script, write:

echo 0 > /.secondrom/.secondaryboot
reboot

- Also make sure "Need SU" is checked, save and make a shortcut if you want, and test it.

Hope this helps, until a key combination is added to the kernel.
I would post this to DerTeufel's thread, but I'm a "noob", I don't have rights to post on dev threads.

GENIUS

All work like a charm. I have PACman Rom on primary and Jedi XP on secondary. Everything working.
The one problem was PACman Rom would not boot on Secondary. Was trying to have Jedi XP as primary to start but had to moved to secondary.

 

[AsfaltSame]

I got it working! Also dual-boot!

Initially I played only with Devil kernel and kernels from nandroids of Cyanogenmod / stock. And for all I used and I'm using Devil recovery. Every time when I flashed DB kernel, the strange behaviour was present (4-5 minutes at boot, no touchscreen, reboot at waking from sleep). And I tried this several times (also restoring nandroids, flashing again kernel... ).

At RichMD recommendation I tried Perseus kernel. This worked from the first time.
After that I flashed again DB kernel and now the previous problem was no longer present! Maybe the Perseus kernel made a change to my system? I don't know.
Thank you very much!

I have the same problem, and I'm running CM 10.1. Isn't Persius a TW kernel? Did you revert back to stock before flashing Persius?

Sent from my GT-N7105 using xda app-developers app

 

[n4553]

I have the same problem, and I'm running CM 10.1. Isn't Persius a TW kernel? Did you revert back to stock before flashing Persius?

Sent from my GT-N7105 using xda app-developers app

For all my playing with dual-boot I had 2 nandroids of Stock Samsung 4.1.1 rooted and CM10.1 stored on external SDcard. As recovery, only Dual-Boot Recovery and never changed it.
Initially, the Devil kernel always gave me this strange behaviour, and I tried maybe all possibilities.

Then I flashed Perseus kernel having as the ROM the Samsung nandroid. It worked from first time, after that I reflashed Devil kernel and it also worked now! After, I restored CM10.1 on primary and Samsung on secondary and it's working this way (only MTP on Samsung Rom isn't, but I haven't bothered any more).

Perseus-alpha36.3-i9300-CWM.zip from http://forum.xda-developers.com/showthread.php?t=1691401, first post.

 

[tkasob]

At first, I would like thank you for great guide and sorry for my bad English. I hope, that you understand me. I've done everything according to the instruction (I hope . At the beginng I had small problems with the second partition ROM (bootloop). Now I have on the primary partition Sammy Rom (Moon Rom v. 6.5). There is no problem with MTP. On the secondary partition I tried succesfully install three different 4.2.2 roms (PAC MAN, Asylum CM 10.1 and currently Helly Bean ROM). And there is the same problem. Play Store app doesn't work (crash), also there is a message, "no external memory" (for exaple, when I open Camera app, Gallery app). File manager shows error message: "Doesn't found any file or folder."
What i've done wrong?
Tom

Wysyłane z mojego Transformer TF101 za pomocą Tapatalk 2

 

[RichMD]

At first, I would like thank you for great guide and sorry for my bad English. I hope, that you understand me. I've done everything according to the instruction (I hope . At the beginng I had small problems with the second partition ROM (bootloop). Now I have on the primary partition Sammy Rom (Moon Rom v. 6.5). There is no problem with MTP. On the secondary partition I tried succesfully install three different 4.2.2 roms (PAC MAN, Asylum CM 10.1 and currently Helly Bean ROM). And there is the same problem. Play Store app doesn't work (crash), also there is a message, "no external memory" (for exaple, when I open Camera app, Gallery app). File manager shows error message: "Doesn't found any file or folder."
What i've done wrong?
Tom

Wysyłane z mojego Transformer TF101 za pomocą Tapatalk 2

I just updated the OP with the answer to this very frequently asked question: http://forum.xda-developers.com/showpost.php?p=41953794&postcount=1
I have not included detailed instructions on backup/restore from primary to secondary so post if you have problems.

 

[angieri918]

Ok guys so i want this bad!! it looks like theres a lot to setup tho and it feels like it may be a little too far over my head to do on my own.. I havent been able to find any youtube videos on how to install on ATT GNote 2. Can someone help me out with this?? Ill donate to whoever helps me get this on my phone!!!!!

 

[RichMD]

Ok guys so i want this bad!! it looks like theres a lot to setup tho and it feels like it may be a little too far over my head to do on my own.. I havent been able to find any youtube videos on how to install on ATT GNote 2. Can someone help me out with this?? Ill donate to whoever helps me get this on my phone!!!!!

You can send me questions or messages via PM. You can donate to DerTeufel

Sent from my SGH-I317 using Tapatalk 2