Installing Ice Cream Sandwich on your Samsung Galaxy S2

SOUTH AFRICAN READERS: The official firmwares are all out. So if you want them, you should be able to upgrade via Kies if you’re still on an official Gingerbread ROM. If you want to use the Odin method described here, go sign up for an account at SamFirmware, search for the i9100 (Galaxy S2), and download the appropriate firmware for your device. You’ll see three ICS ROM’s there – one labelled Vodafone (for Vodacom), one labelled XFM (for MTN) and one just called “South Africa” (for anyone else). The password to unzip all these should be “”. Or, go download CheckFus and get the firmware using that (no password on those downloads). If you want the rooted kernel, here’s a download link. If that link stops working, search for the LP7 kernel on this thread.

Also see a more recent post on installing CyanogenMod9.

For South African S2 owners sick of waiting for MTN/CellC/Vodacom to release ICS, here’s a dummies guide to installing it on your S2 (and optionally, rooting). If you don’t understand the dummies guide, please don’t even consider attempting this. And if you do decide to install ICS, the risks are all your own – if you end up with a R7000 paperweight, tough luck. Having said that, hundreds of people have followed this procedure without complication, and I’ve been running ICS for months now, thanks to the folks at XDA-Developers (a forum Android geeks would benefit from immersing themselves in). The guide below is really just a simplified version of Intratech’s thread at XDA, so the credit is all his.

File download recommendations and links are current as of today, but new ROM’s get released all the time and I probably won’t be updating this post. If you get to this late, rummage around in Intratech’s thread for new firmware. I also don’t use official ICS ROM’s, so it’s no use asking me how to do stuff with them, what works and what doesn’t, etc.

The instructions here assume that you already have Samsung’s Kies installed. You won’t need that to install ICS, but Kies does come with the drivers you need to follow the steps below. So install Kies if you haven’t already. I’m using a Windows PC, and have no idea how different things might be on other OS’es.

Files to download:

  1. Odin
  2. 7Zip
  3. Ice Cream Sandwich (see top of post for official SA firmwares)
  4. If you intend to root, the rooted kernel (likewise)

The ICS version you’ll be installing does not wipe the phone, and if you don’t root, your warranty is intact. This is an official (UK) ICS release.

Install 7Zip, then use it to extract the ICS Rom. If there are errors extracting, the download is most likely corrupt, and you certainly shouldn’t proceed. Try downloading it again. Odin and the kernel should obviously also extract without error. Extract these files into a folder somewhere on your PC, where all that matters is that you are able to find them. This guide assumes that you’re coming from a stock Gingerbread ROM – if you’re not, weird things might happen (see this comment, for example).

  1. install Kies (if you don’t already have it). While you’re in Kies, de-activate the “Run Samsung KIES automatically when device is connected” option, seeing as you don’t want it to interfere with Odin flashes (the procedure outlined here).
  2. connect your phone with the USB cable, let the PC recognise it and install drivers (if necessary – if you’ve used Kies before, it won’t be).
  3. disconnect the phone, and close Kies (important – check the system tray etc. to make sure it’s closed, because it interferes with Odin).
  4. Put the disconnected phone into ‘Download’ mode, which you do by a) powering down, then restarting by b) holding both volume down and the main button on front of phone in when pressing power. Hold all 3 until you see the screen pictured above. You’ll be asked whether you’re sure you want to go to download mode. You are.
  5. Launch Odin. Connect the phone with USB cable.
  6. A block of the Odin screen (ID:COM) should go yellow if everything is in order. If not, something is wrong, probably driver related – but you must not proceed with flashing anything.
  7. Click on the PDA button and browse to the ICS ROM .tar or .tar.md5 (the large extracted file, something over 500Mb) file that you extracted earlier
  8. Do not select any other options in Odin. And make sure you’ve used the PDA block, not one of the others.
  9. Click start to flash
  10. Don’t disconnect the cable or turn off the phone – it will reboot when it finishes.

You’re done, and running ICS. What you’ll have now is stock firmware. But your phone is not rooted yet. If you want to root, repeat steps 4-10 above, but this time using the kernel file instead of the ICS file (also in the PDA section of Odin).

Note: If you do root, you’ll now see a scary-looking yellow triangle on boot (similar to the picture above), which is Samsung’s way of saying you’ve been naughty. To get rid of that, install an app called TriangleAway, which is free for XDA forum members, or R15 in the Play Store. Or use a jig that you’ve bought from e-Bay.

If you do root, it’s now easy to go into Recovery mode (volume up+home+power) and make a full system backup. Once you’ve done that, you can install any ROM you like, and be able to flash your backup back in 5 minutes if you don’t like the result. Rooted users should certainly check out CyanogenMod, which is what I’ve been running for the past few months. Once you go ‘pure’ Android and dump Touchwiz, your life will be immeasurably improved…

By Jacques Rousseau

Jacques Rousseau teaches critical thinking and ethics at the University of Cape Town, South Africa, and is the founder and director of the Free Society Institute, a non-profit organisation promoting secular humanism and scientific reasoning.