Cyanogenmod 10.1 (CM 10.1) aka Android 4.2.1 Jelly Bean on Samsung Galaxy S2 GT I9100


Known Issues – CM 10.1 for Galaxy S2 Intl GT I9100 (Source)

  • Audio: not all features implemented yet
  • USB: slow ums transfer speed
  • Camera: recording effects broken
  • FM Radio: unsupported, will probably never be
  • TV Out: unsupported, will never work (proprietary, undocumented)
  • NFC: no support on GT-I9100P is missing

CM 10.1 Official Nightlies – XDA Thread

Cherrypicked CM variant by MCM (which I am using) – XDA Thread


After weeks of hesitation deliberation, I finally decided that it’s time to move to Android 4.2 (CM 10.1) and not look back. Usually I would always be among the first to try every time a new ROM is ready for flashing; I guess my flashaholism is fading, which is perhaps a good news for my OCD. Regardless, I couldn’t resist after reading many raving reviews that confirm CM 10.1 to be a daily driver material on Galaxy S2.

Android 4.2 is still called Jelly Bean and is in fact an incremental update to Android 4.1 Jelly Bean. The changes are rather subtle and definitely not many, but overall the under-the-hood improvements make my old Galaxy S2 much less “dated”.

What’s New in Android 4.2

Lockscreen Widgets

This is perhaps my least favorite feature in Android 4.2. I understand the convenience of being able to scan through emails, texts, to-do lists, or basically any “available” information you would like on the lockscreen itself, but it’s just not for me partly because I don’t like information to be all over my lockscreen and also because I believe in the minimal usage of widgets even on my homescreens, so I am not a fan of this. Still it’s a very nifty feature if you’ve been expecting something like that from Android.

Lockscreen cameraSwiping right to access camera right from the lockscreen

Lockscreen widgetsSwiping left to add as many pages of widgets as you wish

LS widget optionsWidget options | I am sure more will be added soon

remove ls widget

Removing a widget/page is just like you would a normal widget

Quick Settings Panel 

If you are a long-time CM user, this feature would probably not appeal to you too. Maybe for people who first got their hands on a Nexus device, this would be a very handy feature but we CM users have this in the form of “Widget Buttons” for ages and really couldn’t ask for more. At first I thought Google did it again with awkward gesture (remember 2-finger gesture to expand notifications in 4.1?) but it turns out that you can access this quick settings panel either by pulling down the notification with 2 fingers or pulling down the notification bar from near the right edge; the latter is definitely much less awkward to use. I forgot to mention that you can access the quick settings also by tapping the icon at the top right corner of the notification area; the icon will flip between your notifications and quick settings.

Quick Settings Panel

Quick Settings Panel 

widget buttons

CM’s Widget Buttons

Native “swype” feature in the stock keyboard

Swype had it for a really long time, however, because of the on again off again support and availability from Swype, many competitors have started to implement it into their apps, such as SwiftKey Flow and Kii. Of course, Google’s stock Android keyboard finally features it natively too. The swiping gesture is very smooth and easy to use, but it’s virtually impossible for me to leave SwiftKey 3 because of its incredible word prediction system, so if you aren’t a fan of any third party keyboard, Android 4.2 stock keyboard could be an awesome alternative in this tight keyboard battle on Android.

Native Swipe

Android 4.2 Keyboard with native gesture typing

New Stock Camera App

Since we’re on the camera topic, I have to make something very clear – Photosphere would NOT work in this ROM or in fact in any other device that is not a Nexus (well there are workarounds but things are broken, so I wouldn’t even try). You would have heard from a lot of people’s raving about “Photosphere” feature when Nexus 4 was introduced. It’s kind of like an advanced panorama feature which takes err “spherical” photos (check them out on Google+, really awesome stuff).

Anyway back to the camera topic, the stock camera app receives a UI overhaul and now it also comes with built-in filters (just like those on Instagram). A lot of things still work the same as the camera on Android 4.1 (swiping right to view pic, swiping up to delete, etc)

Camera circle buttonNew Camera UI on 4.2

Camera Options

Camera, Video and good ol Panorama is still available

Filmstrip viewFilmstrip View

Native FiltersLooks familiar? Yep, Instagram-inspired native filters 

Google Now

Finally, you can’t talk about Jelly Bean without mentioning Google Now. Arguably deemed as the future of mobile technology, Google Now has become even more intelligent, making use of the ever-expanding Google’s Knowledge Graph to provide contextual recommendations tailored to each user. In other words, your phone is learning every movement/behavior of yours each day to serve you better. Newly included in this version (that I have noticed) are pedometer and research topics. Pedometer uses your location history and motion sensor of your phone to determine how many kilometers you’ve walked in a month and show you a card with that data at the end of each month. Research topics show cards related to what you’ve just searched on Google and recommend you articles to read. It now also shows Google+ birthdays. A lot of things aren’t working in where I live as of now, such as flight information, package tracking and others. Or maybe I haven’t fed Google enough data just yet. Regardless, Google Now’s contextual awareness makes it among the best mobile technologies introduced in recent years. Oh and if you’re a privacy freak, please don’t ever use Google Now. Save yourself and people around you some lame, pointless complaints!

Google now

Google now settings


– Multi-user support is only available on tablets.

– Battery life is incredible with Siyah kernel. Unless placebo is in place, it’s the most power-efficient CM ROM I’ve used.

– There isn’t any major difference between official CM nightlies and MCM’s builds I am flashing now. In the near future, all the open-source HAL that the CM team has been working on will be completely implemented and of course all variants of CM would also be synced with the sources. So it’s just a matter of personal preference.h

– I use Siyah kernel version 4. Somehow it gives me a better battery life than Siyah 5, although I use BLN in both kernels and Siyah 5 has BLNWW (Back Light Notification Without Wakelock). If you decide to flash MCM’s ROM, the Siyah kernel is available in the MCM’s thread itself. Don’t take it from the original blog – it will get you into a bootloop.

– Media scanner continues to create wakelocks in my experience. I use this app, Rescan Media ROOT to manually run the media scanner only after I add new pictures, songs, etc.

That’s it for Android 4.2 on Galaxy S2. I’ve to say this – these little changes are huge for this platform. Read through the known issues and if you’re fine with them, flash ahead! Or if you believe in the official updates (being better) and want to wait for them, be my guest (Hint: you might never get them).

UPDATE on the Photosphere (January 8, 2013) – Thanks Alfred for the heads up that a flashable zip for Android 4.2 camera allows S2 to enjoy Photosphere feature. To save you the trouble of searching, download the zip here. Just flash it in CWM and if there’s any FC issue, wipe dalvik cache & fix permissions. I’ve already tried and it works fine; no FC or whatsoever. Note that after flashing this, you’ll have 2 stock camera and 2 identical gallery apps respectively in your drawer; one with photosphere, one not.

2013-01-08 15.49.25


  1. Photosphere is not broken. It is working, well sort of. It can take normal and spherical photos, but no videos from the main camera. So I keep both apps handy. Personally I use the original camera app with the Photosphere gallery most of the time.

    The elevation and depression photos are not rendered. Even if take them, they won’t come out. I have tried taking in the sky to the ground at my feet, only the horizon level shots came out. Oh well better than nothing. It is a great way to document large expanse of scenery.

    Lastly, I don’t like putting so much personal data on my lock screen, but I recommend everyone to put a flashlight widget on the lock screen. Tiny fine.

    • Hey Alfred, thanks so much for pointing out. Do you have the working Android 4.2 camera zip or can you please link me the site you downloaded from?! I will try it out and update the post accordingly.

  2. Can I used Siyah with CM10.1? If so, which version would you recommend? Thanks!

  3. @Davi, Yes you can use MCM’s version of the Siyah 4. If you use the original Siyah 4 kernel, you will end up in a boot loop. If after flashing or stuck in a boot loop, reboot into recovery and reflash MCM stock again.

    BTDT, went screaming for help in XDA before.

  4. Thank you for this post, it made my day! I’m now running latest 10.1 with MCM version of Siyah and latest modem firmware. This is like completely new phone!

  5. you said you’re usind BLN, does it work for stock sms app or do you have to use something like Handsent or gosms?

    • It works just fine for Stock sms app. So far, BLN works well for all my apps. Except very occasionally it would miss if let’s say I receive a stream of Whatsapp messages in a row. But it rarely happens, like 1 in 10 times.

  6. how to remove the second camera?? also video recording is not working and photosphere nothing works (s2 rooted)… 🙁 let me know how to remove the second camera..)plz

    • If you flash the zip for Camera 4.2 I posted at the end of the post under “Update”, photosphere works in that camera. If you want to get rid of the second camera, re-flash the ROM itself and there will only be one camera left (stock) with no photosphere.

  7. Hi there I have just installed JellyBean 4.1.2 JoelDroid’s on my S2, I wanted to switch to Cyanogenmod 10.1 (CM 10.1) Android 4.2.1 Jelly Bean, unfortunately everytime flash the rom it was aborted…I am not good at this since I am a newbie but enjoying doing it..
    fyi I have siyah kernel on my s2, is there any suggestion to resolve this problem.
    thank you so much.

  8. I will immediately snatch your rss as I can’t in finding your email subscription link or newsletter service. Do you’ve any? Kindly allow me realize in order that I may subscribe. Thanks.

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