Though samsung didnot provide lollipop update for samsung galaxy s2 Gt-I9100 you can still update it to android lollipop by flashing blisspop custom rom.This rom is quite stable for stable for daily usage.It is based on cyangenmod custom rom with lot of added features on top of it.Since samsung has stopped official updates for galaxy s2 Gt-I9100 and stock one has very less features as this mobile is some what old you will experience a lot of difference between this and stock one.
About Blisspop custom rom for galaxy s2:Blisspop custom rom is based on cyanogenmod 12.1 rom with lot of added features with improved performance and customisation.This rom offers all the features that cyanogenmod 12 has to offer and also there are lot of added features from other popular roms too.This rom offer wide range of features from status bar to lock screen.This is an unofficial port of blisspop original rom and you can expect all features of official one.
- Statusbar tweaks: Status bar tweaks include notification count,network speed indicator,double tap to sleep ,brightness control and weather in status bar header.
- Recents panel tweaks:The recent panel has a button to clear all the tasks and omni switch is present is present as an alternative to traditional recent menu.
- Gesture anywhere:Gesture any where is also available which makes it easy for you to launch apps with gestures instead of returning to home screen and app drawer to launch apps.
- App circle:In addition to this app circle bar is also present which makes it too easy to launch apps with just a swipe from the edge of the screen.
- Soft Navigation controls:You can enable soft keys too if you like them and also set the dimension of the navigation keys and also you can define custom actions.
- Capacitive buttons: hardware keys have an option to adjust back light duration of the button and now you you can do various things with the just home key like accessing a call with just a tap on home key , wake the device and also you can set custom action for double tapping on home key.
- Power button: Press and hold power button you will have various options including soft boot ,reboot recovery ,screen reorder,air plane mode,screen shot,user switch and lot more,
- Animation control: You can set custom animation for app opening and closing,scrolling up and down.There are lot of animations available to choose from.
- Display and light:This includes live display,adaptive display,rotation mods,wake device on plugiing in charger or usb cable,Custom DPI and change font size according to your needs.
- Cyanogenmod Camera app is built in.
- Dark Bliss: This completely greys out system ui which makes it easy to use during night times.As samsung galaxy s2 has a amoled display it should save battery life a lot.
- Other mods include audio Fx equaliser,security options,bliss pop ota updates, and all standard android features.
Install blisspop custom rom samsung galaxy s2 GT-i9100:
- Backup:Backup all your data which includes apps,contacts,photos videos etc everything to computer or any cloud storage as flashing this blisspop on samsung galaxy s2 GT-I9100 will erase all your data.
- Battery: Charge your galaxy s2 I9100 to at least 90% so that you wont encounter any battery related issues while flashing this.
- Backup Efs partitions: Backup all your efs partition of your samsung galaxy s2 on current ROM.If you loose signal you can just restore it back.
- Lock Gps:Lock your gps position on your current rom.If you use this a lot then you have to lock it so that it could work even after flashing other roms.Its easy to lock gps .Turn on gps in settings and find your current location in google maps and now now have locked on to gps.
- Custom recovery: You need a custom recovery installed on your s2 .Without it you can not flash roms at all.
- Downloads: Download Blisspop I9100 rom and google apps if needed.Transfer them to internal storage.
Flash Blisspop rom using Twrp recovery:
- Download blisspop rom for ha3g and Gapps transfer it to sdcard or internal storage of device.
- Power of the device completely.
- Press volume up,power button and home key simultaneously and once you see boot loader screen release buttons.
- Using volume down as a navigation button move to recovery and click on power button to confirm action.
- Once you are in twrp backup existing rom first.It might about 5 minutes for backup to complete.
- Wipe data,cache and dalvik cache.You may not need to wipe system.
- Flash ROM and then gapps.
- Reboot to system.Wait at least 15 minutes for initial boot to complete and once done you can explore ROM features.
- If rom fails to boot Remove battery and put it back.Reboot it to recovery and this wipe system too and flash rom again.
After flashing ROM if you don't find super user in app drawer or non of your root apps don't work then go to setting and then to about device.You will find build number.Tap on it continuously until you see a message you are now a developer.Go back and you will find developer options.Click on it and and scroll down ,you will find option to set root permissions.
If you are facing lot of force closes after booting ,reboot to recovery and do a factory reset.If this doesn't help then flash ROM again with another google apps package.
This is a simple tutorial guiding you to install blisspop custom rom on samung galaxy s2 Gt-I9100..As this ROM is meant only for this variant of don't try to flash it on other variants like on carrier variants as it might cause lot of errors or even brick it.