The ICS update has just started rolling out for Samsung Galaxy SII, and still have to reach many regions. You can get the ICS kernel source code for your Galaxy SII phone by going to Samsung’s Open Source Release Center website.
Now search for GT-I9100 you will be getting few zip file for your SII, you can download the update 4 for ICS source code. Samsung released the Source code too quick, but probably a good news for SII users as there is lot more to come for there phones so keep waiting for more great news.
According to report, the official ICS update for Samsung Galaxy S2 has rolled out for South Korea, Hungary, Poland, UK, Sweden, Denmark, Finland, Nepal, Philippine, Canada, Brazil, Estonia, Cyprus, Turkey, and few other regions.