So you want to root your phone?

One thing I really enjoy in life is learning how things work – I might not be the world’s most gifted programmer and not everything I do is groundbreaking, but I do know that if I get the sense that I don’t fully grasp some aspect of technology, I’m probably going to tackle it at some point. While often this involves some relatively short-lived pain, the end reward of knowledge is always worth it. So this is a tale of upgrading the Android operating system on my T-Mobile Samsung Galaxy S II, and the (many) mistakes I made along the way.

So there are a couple of reasons I wanted to upgrade my phone to Ice Cream Sandwich, which is Google’s cutesy codename for the 4.0 version of the Android operating system. Encryption is now built-in, Face Unlock is now enabled as a security option, and some improvements in the NFC capabilities (which I admit, my first thought was that it could be a potentially powerful pentesting weapon) were enough to convince me that upgrading to ICS was the right thing to do.

At this point, I was unaware that Samsung/T-Mobile was supporting an ICS distribution for the Galaxy S II. They were not pushing this update OTA, but rather through Samsung’s Kies software, which is a basic smartphone management utility. I had received previous incremental Gingerbread updates OTA, so had no reason to think they would not do the same for ICS. So if you want ICS without the hassle of rooting and installing a 3rd-party Android distro, download Kies and take that route.

So the first thing I needed to do was to gain root on the phone (I’m not totally sure if this is necessary, but the instructions I followed over at Cyanogenmod implied this). I actually got some information from a somewhat unlikely source (in general, I don’t trust domains that are so narrowly focused, probably a remnant from my SEO days), but the information given was good and it introduced me to ODIN, one of many tools whose name I would curse before the day was done.

Using ODIN I was able to replace the factory “recovery” mode with a custom one called ClockWorkMod Recovery – this method seemed like the first one to emerge (as opposed to using ClockWorkMod’s ROM Manager), so I used this, figuring there would be more documentation available should I run into problems.

So far, so good – got ClockWorkMod Recovery installed, and I’m ready to flash a new ROM onto my phone, hopefully from CyanogenMod. But here’s where I was thrown for a multi-hour, head-slamming-into-wall tailspin. Apparently there are several distinct models of phone which are all known colloquially as a Samsung Galaxy S II. Looking at the list of phones on the left side of the CyanogenMod Downloads page, I think I want the “galaxys2”, seeing as the other obvious possibility is the “galaxys2att” (the AT&T model).

Unfortunately, I notice that the only stable CyanogenMod ROMs for the Galaxy S2 are for version 7 of CyanogenMod, which equates to the Gingerbread build, not ICS. So I grab a copy of one of those, and a copy of the nightly build (not stable) for CM9, hoping that the build can actually run on my phone and that I’ll be an Alpha tester. I follow the instructions for flashing, and…my phone ends up in a reboot loop. Worse, I can no longer enter ClockWorkMod Recovery on my phone, and my phone displays a screen which says to recover using the Samsung Kies recovery mode.

So I run Kies, plug in my phone to the computer and…nothing. Kies doesn’t even recognize that I have a phone plugged in, so basically the phone is either constantly rebooting and I can’t enter any kind of recovery mode. Now I’m maybe starting to panic just a little. I try a few other things that I learn from Googling, but most of the message boards are dead ends, so I take a step back and fire up ODIN again.

During my search, I was also able to find a slightly more up-to-date version of ClockWorkMod Recovery, so I instruct ODIN to load that onto my phone and am relieved that this works and I’m able to get back to the CWM Recovery screen. So I follow the wiki instructions again and load the CM7 ROM – again, I’m faced with an endless reboot, an indication that things did not go so well.

Now I’m actually starting to panic, as I can’t even load the STABLE version of this software onto my phone, and I’m definitely following the wiki to the letter. So I have effectively transformed my phone into an expensive paperweight and am already starting to think about how I’m going to broach this subject at my local T-Mobile store.

So after trying a couple other ROMs, I decide to stop digging and backtrack a little bit. I go back to that first article on rooting the phone on my specific device (SGH-T989). Hmmm…what was that tarball called again – “recovery-cmw-hercules.tar”? Hercules, eh? So I head back to the CyanogenMod download page and sure enough, I hover over the word “hercules” and it says “Samsung Galaxy S2”! Hooray! My hopes are dashed seconds later, when I realize there are NO stable builds for my phone. I try installing the nightly, but without any luck – another endless reboot loop.

After some additional frantic googling, I finally stumble across AOKP, a group who has been working on implementing hardware support for the Hercules model of Samsung Galaxy S2. Apparently, they have developed a working ROM, but there were a few other hoops to jump through first, including using an additional wiping utility and flashing an update to the “modem” (I hate that term because it’s not an modulator-demodulator but I digress). You can take a look at some of their supported devices here and check out their open-source code as well.

Now, a few pros and cons about this install, compared to the stock Android 2.3.6 rev that T-Mobile pushed out. First, swype (or the swype equivalent used by T-Mobile) is not present, so I went ahead and installed the beta, and it seems to work well. It’s a little too permission-hungry for my tastes, so I am going to search out one of the apps that lets you restrict an application’s permissions and see how it holds up.

One thing I really like about the new install is that the bottom buttons light up if you get a text message. Maybe there is a way to set this up somewhere in my previous Android install, but it’s very handy to glance at your phone and see if you have a message rather than lighting up the entire phone’s screen. The UI is easier to customize now – a setting called ROM Control allows changes to the UI on a very granular scale. As I mentioned previously, the disk encryption seems to work as well.

Overall, I’m glad I went through the process, though at the time I questioned my sanity. I learned quite a bit about the Android development scene and the very talented people that help create this wonderful software.

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