This is going to be a very long how-to post, so I'll ditch my usual long intro.

To install the Cyanogenmod custom ROM on the Samsung Galaxy S2, you'll go through three easy steps. Unfortunately, most blogs have managed to make it extremely hard to do - it's either they didn't put up any step-wise screenshot supported post or they write it out like an help/documentation file. So, I have decided to make the ultimate how-to guide and you can be sure you won't brick your phone.

Last year I made a post on making your newly rooted phone speedier. Well, I have just discovered an equally novel way of getting the best out of a new ROM, be it you are upgrading or installing the ROM for the first time.

Since this post will have loads of images, I will go straight to the crust. The whole idea behind this post is hinged on the fact that preserving data and system settings across ROMs makes the phone oftentimes perform less speedy than on the former ROM, even though you just did an upgrade. And that is what I discovered when I upgraded from CyanogenMod 6.0 to CyanogenMod 6.1, when I preserved the system settings the phone was annoyingly sluggish, but when I wiped the system settings (a factory reset) the phone was amazingly speedy. In (near) fact, the homescreen scrolls before I actually swipe! But in this post I will teach you how to factory reset your phone to get the best out of the new ROM and yet not lose a single system/user data, not even a last call record!

As is my usual (self-inconvenienting) habit, I will start from the basics.

STEP 1
You are going to install two free softwares from the android market, they are Titanium Backup root and MyBackup Root.

STEP 2

Run the MyBackup Root, follow the screenshots below. Don't bother backing up Applications and Media. Titanium will do the applications backup and as for your media, they are as safe as your SD card. Note that your phone must be rooted (if you don't know, then it isn't)

(Tick as many as all)

STEP 3

Run the Titanium Backup Root, again follow the screen shots below to backup all system and user apps including their data/settings.

(Press the Menu button to see the options above)

STEP 4

I'll assume that you already have the new ROM copied unto your SD card. So reboot into recovery (if you don't know how, just shutdown and when the phone is off, press the power button + home button). 

Do a Nandroid backup! (You will see the option on the first screen)

Follow the following screen shots to wipe the system and data settings, wipe cache and wipe dalvik cache. Wiping the  caches do not have any possible adverse effect on the phone, in fact it is recommended to wipe them often as it releases more system memory for better phone performance (removes junk data from system memory).

(Scroll to Wipe, which is the sixth option)

(Wipe data/system, reset)

(Wipe Cache)

(Wipe Dalvik cache)

(Flash the new ROM onto the phone)

STEP 5
Again, you will go through the android market to install Titanium Backup root. Then run it to install all your user apps that you had on the previous ROM (which are already backed up unto your SD card). As soon as you run the Titanium Backup Root, it automatically detects all the apps you backed up in the previous ROM. Just select those you want to install on the new ROM and restore the app + data (though one at a time). If you want to restore all, just go through the batch tool and Restore all apps with data.
Below are the screenshots, scroll down to see that for complete apps restore.

(Scroll to the app you wish to restore and touch it)

STEP 6
You must have (re)installed My Backup Root app, so run it and restore your phone data (contacts, call records, SMS, MMS etc).

STEP 7

Voila! Get yourself your favorite drink and explore your New ROM without carrying over any legacy settings. Enjoy what those developers spent hundreds of hours tweaking to tickle your fantasy!

Cliche: If you have any trouble getting by any of the steps, just hit me with a comment.

Remember that post I made on modding your G1 and how I mentioned that I just recently modded mine. Well after flashing cyanogenmod 6.0.0-DS on my G1 and was stunned by the exquisite (Windows 7 – like) graphics, I was greatly disappointed to find my G1 so slow that navigating to the homescreen became a touch and travel activity. The camera app was greatly frustrating, after taking seconds to open it is only good for snapping still scenes because the pictures are taken seconds after the shutter button has been pressed. Not forgetting the gallery, that one became so useless I started searching the android market for any alternative app. When I try to view the pictures I took with the phone's camera, it takes forever to scroll to the next picture. The phone app wasn't left out, typing phone number has never been this hard, and after all the frustration and the tendency of you forgetting why you wanted to make the call, it takes about 5 seconds for the call to be terminated after you end it.

Though I must confess that I still preferred my modded G1 state to the unmodded (running android 1.6) state because I now run the latest android version, I can install apps on SD, I can install root (requiring) apps, and I can install apps meant for android 2.1 and above. So I convinced myself that all I have been reading about cyanogenmod, that it is way faster than the stock OS, is true and I am going to make that true fact a reality on my G1. Armed with google, I searched the internet using various words combination to locate any article that might address a similar issue. But I was disappointed to discover that as far as the internet is concerned I am the only one with such issue. After giving up on finding any online assistance, I decided to fiddle with the settings on my modded G1 and one day I struck luck, after changing a couple of things mostly disabling a lot of cpu sucking tweaks, and now my modded G1 is working really fast. So in the following paragraphs I am going to share with you the changes I made on my G1 that made it work real fast.

From the homescreen, press the menu button, tap on Settings, tap on CyanogenMod settings and tap on Performance settings. You will receive a “WARNING: Dragons Ahead!” prompt, don't worry (you won't do anything that will change the performance of your system, potentially for the worse), tap on OK. Now make sure Use Compcache is enabled, Use JIT is enabled and Surface Dithering is disabled. You can also change the VM heap size to 24m.

Now go back to Settings, tap on ADWLauncher, tap on Drawer Settings, disable Animated Drawer and disable Fade app labels. Go back to ADWLauncher settings, tap on Preview settings, disable Sense previews and Clean Screen Mode. Go back to ADWLauncher, tap on System Preferences, set Scrolling cache to Low quality.

With these settings on your G1 it should work really fast.

Remember that post I made on changing the google account of HTC Dream? Then you will remember me saying “I bought a fairly new G1...”

Well, there was this day I posted a tweet on twitter saying I had issues with data usage of my G1, and a friend (@kenniy) responded and told me to mod my G1 for optimum performance and recommended Cyanogen Mod. Since that day (which should be 6 months ago), after reading about the benefits, I decided in my mind that I was definitely gonna mod my G1. Then after reading about doing it on several websites and discovered that most of them had very different ways of doing it with a common recurrent warning that my phone might get bricked, I finally gave it a trial 5 months ago. I choose a website that explained very well with detailed snapshots of the process, then I discovered that I couldn't go past the first stage because my G1 has android 1.6 (donut) and the steps will only work for 1.5 (cupcake). I searched for ways of modding my G1 running donut, and the only site I found that seems to explain it well didn't have a single snapshot and had too much warnings. So I suspended my desire to mod the G1 till when I have used the phone for a considerable time, when I won't be too bothered if the phone bricks.

Well that time came yesterday, I just couldn't put up any longer with the restrictions of the small internal memory and the fact that some applications are now being built for OS 2.1 (eclair) and above. So I braced up and faced my fear, and believe me I'm glad I did. I now have the latest android OS (froyo) running on my G1,can now send files via bluetooth and even operate a swap partition on my phone.

So in case someone might need a more recent post by a more current user, I decided to share my experience, step by step and with snapshots. So let's go!

STEP 1

NOTE: I'll assume you are also using the android 1.6 on a G1.

First you will need to boot into the bootloader of the G1 to record the radio type and ROM type of your G1. 

There are two ROM types,

PVT, and

DVT.

There are two radio types also,

2.22.23.02

2.22.19.26I

To boot into this mode you will need to switch off the phone first. Then press the camera button and almost immediately, without leaving the camera button, press the power button. Below is a snapshot of how I did it with my phone. Now note the multicolor screen that comes up and record the ROM type and the radio type of your phone (it will show at the upper part of the phone screen).

STEP 2

Now you are going to download all the necessary files you will need for the whole modding process.

First, you will download the DREAMING.nbh RC29(US) or DREAIMG.nbh RC7(Europe) file that will downgrade the android 1.6 to 1.0 which is necessary for the whole modding process (actually you won't be able to root the phone without this downgrade, that is why it is necessary).

Secondly, you will download Amon_Ra's Recovery which is the actual rooting image file. 

Thirdly, you will download the appropriate radio for your G1, 2.22.23.02 or 2.22.19.26I

Fourthly, you will download the appropriate SPL file, depending on the ROM type of your G1. If your ROM is PVT, Haytou's SPL is recommended. But if your ROM is DVT, you have to make do with HardSPL to avoid bricking your G1.

Finally, you will now download the Cyanogen Mod 6.0.0-DS and the tiny gapps files (you need this google apps zip file to pre-install the market app during the installation the Cyanogen Mod, this will be very useful)

STEP 3

Get a MicroSD card (the small external memory card the phone uses), format it with FAT32. Copy only the DREAMING.nbh file into it.

Power off the G1 and like you did earlier on in step 1, boot into the bootloader. Follow the instructions to apply the DREAMING.ngh which will downgrade the phone to android 1.0. Now press MENU, HOME and POWER buttons all at once to power off.

STEP 4

Put a SIM that has active data plan or GPRS/EDGE/3G enabled (with enough money in it to access the internet). Power on the G1, it will show you a screen with the Emergency call dial button. Press the MENU button to reveal APNs, touchclick it and create a new APN entering the correct APN setting for your SIM Network provider. If your Provider is already listed in the APN list, do not bother creating a new APN. Now return back to the initial screen, touch the middle of the screen and configure your google account to gain access to other functionalities.

Press the home button and slide the phone to reveal the keyboard. Press ENTER twice, type telnetd and press ENTER (do not bother about the contact screen that comes up and the apparent nothing that happens after pressing ENTER). Go to the market app and install telnet by clockworld, launch the telnet app you just installed and make sure localhost is in the first textbox and 23 in the small textbox to the right. Press ENTER.

STEP 5

Remember the Amon_Ra's Recovery file you downloaded? Rename it to recovery.img and copy it to the MicroSD card and disconnect the phone from the computer. Now open the telnet application you installed earlier on and type the following  flash_image recovery /sdcard/recovery.img  and once this is successful you will notice # # on the screen showing below the command you typed. If you got a "permission denied" prompt, type su flash_image recovery /sdcard/recovery.img 

STEP 6

Power off the phone and remove the MicroSD card, copy the radio file you downloaded (2.22.23.02 or 2.22.1.26I), the SPL file (a .zip file), the Cyanogen Mod 6.0.0-DS (mostly likely named as update-cm-6.0.0-DS-signed.zip)and the gapps file into the card. Replace the memory card.

STEP 7

You will now boot into the recovery mode by pressing the home and power buttons at the same time.

Once the phone has boot into the recovery mode, scroll to "apply zip from sdcard" and select the radio file, press the home button to confirm. The phone will reboot during the installation, once the installation is complete select the reboot option (first on the list).
Now boot into the recovery mode again by pressing the home and power buttons at the same time, scroll to "apply zip from sdcard" and select the SPL zip file, press the home button to confirm. Again you will be requested to reboot, select the reboot option to complete the installation. 

Again boot the phone into the recovery mode, select the "apply zip from sdcard" and select the Cyanogen Mod 6.0.0-DS zip file, press the home button to confirm and the phone will say update successful. Now scroll again to the "apply zip from sdcard" and select the gapps zip file, press the home button to confirm. Then reboot the phone and power off, if it boots back to the recovery mode (power off is the last option on the recovery mode list).

Now you are through installing the Cyanogen Mod 6.0.0-DS which is built on the android 2.2 (code named froyo). Just power on your phone and it will now boot into the new OS that makes your phone operate like a linux computer with the much needed root permission (or superuser capability).

TROUBLESHOOTING

Just like it happened to me, if you notice that the phone after booting to the new OS only shows the lock screen and a black screen with notification bar, and does not detect network or show home screen. Just reboot into the recovery mode and select wipe, apply all the wipe options (wipe data/factory rest, wipe cache and wipe Dalvik-cache) and reboot. That should solve the problem, I don't know why it happened to me but I suspect it's that my cache is full and the /system is also full. But whatever the reason is, wiping did resolve it.

If you need any further clarification or help, feel free to use the comment. I will try to monitor this post's comment as often as possible.